WorldWideScience

Sample records for cost multi-layer fabrication

  1. LOW COST MULTI-LAYER FABRICATION METHOD FOR SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Christopher Milliken; Robert Ruhl; Jennifer Hillman

    2002-06-01

    Technology Management, Inc has evaluated the practical fabrication advantages and potential economic impact of a multi-pass screen printing process on the costs of fabricating planar solid oxide fuel cell stacks. During this program, multiple catalyzed binder systems were considered. Preliminary screening experiments resulted in four systems being selected for further evaluation. Inks were formulated using these binders in combination with at least three fuel cell materials (anode, cathode, and seal material). Reactivity of the binder with catalyst and fuel cell materials was evaluated. Cell tests indicated that the catalyzed binders did not negatively impact cell performance. Tests were conducted demonstrating single cell performance comparable with standard cell fabrication technology. Tailored patterns were also demonstrated. Economic evaluation indicated that a significant reduction in cost could be achieved, primarily through reduced capital equipment needs.

  2. Weaving multi-layer fabrics for reinforcement of engineering components

    Science.gov (United States)

    Hill, B. J.; Mcilhagger, R.; Mclaughlin, P.

    1993-01-01

    The performance of interlinked, multi-layer fabrics and near net shape preforms for engineering applications, woven on a 48 shaft dobby loom using glass, aramid, and carbon continuous filament yarns is assessed. The interlinking was formed using the warp yarns. Two basic types of structure were used. The first used a single warp beam and hence each of the warp yarns followed a similar path to form four layer interlinked reinforcements and preforms. In the second two warp beams were used, one for the interlinking yarns which pass from the top to the bottom layer through-the-thickness of the fabric and vice versa, and the other to provide 'straight' yarns in the body of the structure to carry the axial loading. Fabrics up to 15mm in thickness were constructed with varying amounts of through-the-thickness reinforcement. Tapered T and I sections were also woven, with the shaping produced by progressive removal of ends during construction. These fabrics and preforms were impregnated with resin and cured to form composite samples for testing. Using these two basic types of construction, the influence of reinforcement construction and the proportion and type of interlinking yarn on the performance of the composite was assessed.

  3. A simple method for fabricating multi-layer PDMS structures for 3D microfluidic chips

    KAUST Repository

    Zhang, Mengying

    2010-01-01

    We report a simple methodology to fabricate PDMS multi-layer microfluidic chips. A PDMS slab was surface-treated by trichloro (1H,1H,2H,2H-perfluorooctyl) silane, and acts as a reusable transferring layer. Uniformity of the thickness of the patterned PDMS layer and the well-alignment could be achieved due to the transparency and proper flexibility of this transferring layer. Surface treatment results are confirmed by XPS and contact angle testing, while bonding forces between different layers were measured for better understanding of the transferring process. We have also designed and fabricated a few simple types of 3D PDMS chip, especially one consisting of 6 thin layers (each with thickness of 50 μm), to demonstrate the potential utilization of this technique. 3D fluorescence images were taken by a confocal microscope to illustrate the spatial characters of essential parts. This fabrication method is confirmed to be fast, simple, repeatable, low cost and possible to be mechanized for mass production. © The Royal Society of Chemistry 2010.

  4. Fabrication of hybrid molecular devices using multi-layer graphene break junctions.

    Science.gov (United States)

    Island, J O; Holovchenko, A; Koole, M; Alkemade, P F A; Menelaou, M; Aliaga-Alcalde, N; Burzurí, E; van der Zant, H S J

    2014-11-26

    We report on the fabrication of hybrid molecular devices employing multi-layer graphene (MLG) flakes which are patterned with a constriction using a helium ion microscope or an oxygen plasma etch. The patterning step allows for the localization of a few-nanometer gap, created by electroburning, that can host single molecules or molecular ensembles. By controlling the width of the sculpted constriction, we regulate the critical power at which the electroburning process begins. We estimate the flake temperature given the critical power and find that at low powers it is possible to electroburn MLG with superconducting contacts in close proximity. Finally, we demonstrate the fabrication of hybrid devices with superconducting contacts and anthracene-functionalized copper curcuminoid molecules. This method is extendable to spintronic devices with ferromagnetic contacts and a first step towards molecular integrated circuits.

  5. Fabrication of Multi-layered Shock Wave Tube for Hydrodynamic Instability Experiment

    Science.gov (United States)

    Zhu, Xiurong; Zhou, Bin; Xu, Xiang; Zhong, Yanhong; Du, Ai; Li, Yunong; Zhang, Zhihua; Shen, Jun; Wu, Guangming; Ni, Xingyuan

    2011-12-01

    In inertial confinement fusion (ICF) experiments, the growth of hydrodynamic instability occurred at the layer-to-layer interface of multilayer capsule is of the main importance to obtain ignition and high gain. In order to investigate and simulate the growth of hydrodynamic instability at "SG II"laser facility, we designed and fabricated a multi-layered shock wave tube (MSWT) in this article. The MSWT consisted of four functional units: planar polystyrene (CH) film, Al film with perturbation patterns, polyimide (PI) plastic and cylindrical carbonized-resorcinol-formaldehyde (CRF) aerogel, which were assembled into a cylindrical CH tube. The design, preparation process and assembly process of MSWT were detailed described. The assembly deviations and packaging material were discussed.

  6. Fabrication and applications of multi-layer graphene stack on transparent polymer

    Science.gov (United States)

    Krajewska, Aleksandra; Pasternak, Iwona; Sobon, Grzegorz; Sotor, Jaroslaw; Przewloka, Aleksandra; Ciuk, Tymoteusz; Sobieski, Jan; Grzonka, Justyna; Abramski, Krzysztof M.; Strupinski, Wlodek

    2017-01-01

    In this report, we demonstrate the preparation method of a multi-layer stack with a pre-defined number of graphene layers, which was obtained using chemical vapor deposition graphene deposited on a copper substrate and subsequently transferred onto a poly(methyl methacrylate) (PMMA) substrate. The prepared multi-layer stack can also be transferred onto an arbitrary substrate and in the end, the polymer can be removed, which in consequence significantly increases the range of possible graphene applications. The multi-layer character was confirmed by optical transmittance measurements and Raman spectroscopy, whereas the microstructure of the multi-layer graphene stack was investigated using Scanning Electron Microscopy. The electrical properties in the function of the number of graphene layers were assessed with standard Hall Effect measurements. Finally, we showed the practical application of the multi-layer graphene stack as a saturable absorber of a mode-locked Er-doped fiber laser.

  7. Rapid fabricating technique for multi-layered human hepatic cell sheets by forceful contraction of the fibroblast monolayer.

    Directory of Open Access Journals (Sweden)

    Yusuke Sakai

    Full Text Available Cell sheet engineering is attracting attention from investigators in various fields, from basic research scientists to clinicians focused on regenerative medicine. However, hepatocytes have a limited proliferation potential in vitro, and it generally takes a several days to form a sheet morphology and multi-layered sheets. We herein report our rapid and efficient technique for generating multi-layered human hepatic cell (HepaRG® cell sheets using pre-cultured fibroblast monolayers derived from human skin (TIG-118 cells as a feeder layer on a temperature-responsive culture dish. Multi-layered TIG-118/HepaRG cell sheets with a thick morphology were harvested on day 4 of culturing HepaRG cells by forceful contraction of the TIG-118 cells, and the resulting sheet could be easily handled. In addition, the human albumin and alpha 1-antitrypsin synthesis activities of TIG-118/HepaRG cells were approximately 1.2 and 1.3 times higher than those of HepaRG cells, respectively. Therefore, this technique is considered to be a promising modality for rapidly fabricating multi-layered human hepatocyte sheets from cells with limited proliferation potential, and the engineered cell sheet could be used for cell transplantation with highly specific functions.

  8. Fabrication and flexural strength of multi-layer alumina with aligned acicular pores

    Science.gov (United States)

    Park, Dong-Soo; Lee, Myoung-Won; Kim, Hai-Doo; Jung, Yeon-Gil

    2004-07-01

    Multi-layer alumina with alternating dense and porous layers with aligned acicular pores was successfully prepared by tape casting the slurry with chopped carbon fibers followed by pressureless sintering. As the content of the chopped carbon fiber increased, the open porosity was increased, in part due to impingement among the carbon fibers inside the sample. The three-point flexural strength of the sample with total porosity of 11% was approximately 80% that of a dense sample. However, a sample with a porous layer with 5% chopped carbon fiber exhibited only 60% flexural strength of the dense sample, in part due to a low degree of alignment among the chopped fibers.

  9. Fully Solution-Processable Fabrication of Multi-Layered Circuits on a Flexible Substrate Using Laser Processing

    Directory of Open Access Journals (Sweden)

    Seok Young Ji

    2018-02-01

    Full Text Available The development of printing technologies has enabled the realization of electric circuit fabrication on a flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of the laser focal position and intensity. Based on these methods, a flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated to have functional operations.

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

    Directory of Open Access Journals (Sweden)

    Md Faruk Hossain

    Full Text Available 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.

  11. 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.

  12. Fabrication of multi-layered biodegradable drug delivery device based on micro-structuring of PLGA polymers.

    Science.gov (United States)

    Ryu, Won Hyoung; Vyakarnam, Murty; Greco, Ralph S; Prinz, Fritz B; Fasching, Rainer J

    2007-12-01

    A programmable and biodegradable drug delivery device is desirable when a drug needs to be administered locally. While most local drug delivery devices made of biodegradable polymers relied on the degradation of the polymers, the degradation-based release control is often limited by the property of the polymers. Thus, we propose micro-geometry as an alternative measure of controlling drug release. The proposed devices consist of three functional layers: diffusion control layer via micro-orifices, diffusion layer, and drug reservoir layers. A micro-fabrication technology was used to shape an array of micro-orifices and micro-cavities in 85/15PLGA layers. A thin layer of fast degrading 50/50PLGA was placed as the diffusion layer between the 85/15PLGA layers to prevent any burst-type release. To modulate the release of the devices, the dimension and location of the micro-orifices were varied and the responding in vitro release response of tetracycline was monitored over 2 weeks. The release response to the different micro-geometry was prominent and further analyzed by FEM simulation. Comparison of the experiments to the simulated results identified that the variation of micro-geometry influenced also the volume-dependent degradation rate and induced the osmotic pressure.

  13. Design and fabrication of a multi-layered solid dynamic phantom: validation platform on methods for reducing scalp-hemodynamic effect from fNIRS signal

    Science.gov (United States)

    Kawaguchi, Hiroshi; Tanikawa, Yukari; Yamada, Toru

    2017-02-01

    Scalp hemodynamics contaminates the signals from functional near-infrared spectroscopy (fNIRS). Numerous methods have been proposed to reduce this contamination, but no golden standard has yet been established. Here we constructed a multi-layered solid phantom to experimentally validate such methods. This phantom comprises four layers corresponding to epidermides, dermis/skull (upper dynamic layer), cerebrospinal fluid and brain (lower dynamic layer) and the thicknesses of these layers were 0.3, 10, 1, and 50 mm, respectively. The epidermides and cerebrospinal fluid layers were made of polystyrene and an acrylic board, respectively. Both of these dynamic layers were made of epoxy resin. An infrared dye and titanium dioxide were mixed to match their absorption and reduced scattering coefficients (μa and μs', respectively) with those of biological tissues. The bases of both upper and lower dynamic layers have a slot for laterally sliding a bar that holds an absorber piece. This bar was laterally moved using a programmable stepping motor. The optical properties of dynamic layers were estimated based on the transmittance and reflectance using the Monte Carlo look-up table method. The estimated coefficients for lower and upper dynamic layers approximately coincided with those for biological tissues. We confirmed that the preliminary fNIRS measurement using the fabricated phantom showed that the signals from the brain layer were recovered if those from the dermis layer were completely removed from their mixture, indicating that the phantom is useful for evaluating methods for reducing the contamination of the signals from the scalp.

  14. The multi-layer network nature of systemic risk and its implications for the costs of financial crises

    NARCIS (Netherlands)

    Poledna, S.; Molina-Borboa, J.L.; Martínez-Jaramillo, S.; van der Leij, M.; Thurner, S.

    2015-01-01

    The inability to see and quantify systemic financial risk comes at an immense social cost. Systemic risk in the financial system arises to a large extent as a consequence of the interconnectedness of its institutions, which are linked through networks of different types of financial contracts, such

  15. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2010-01-01

    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  16. Material optimization of multi-layered enhanced nanostructures

    Science.gov (United States)

    Strobbia, Pietro

    The employment of surface enhanced Raman scattering (SERS)-based sensing in real-world scenarios will offer numerous advantages over current optical sensors. Examples of these advantages are the intrinsic and simultaneous detection of multiple analytes, among many others. To achieve such a goal, SERS substrates with throughput and reproducibility comparable to commonly used fluorescence sensors have to be developed. To this end, our lab has discovered a multi-layer geometry, based on alternating films of a metal and a dielectric, that amplifies the SERS signal (multi-layer enhancement). The advantage of these multi-layered structures is to amplify the SERS signal exploiting layer-to-layer interactions in the volume of the structures, rather than on its surface. This strategy permits an amplification of the signal without modifying the surface characteristics of a substrate, and therefore conserving its reproducibility. Multi-layered structures can therefore be used to amplify the sensitivity and throughput of potentially any previously developed SERS sensor. In this thesis, these multi-layered structures were optimized and applied to different SERS substrates. The role of the dielectric spacer layer in the multi-layer enhancement was elucidated by fabricating spacers with different characteristics and studying their effect on the overall enhancement. Thickness, surface coverage and physical properties of the spacer were studied. Additionally, the multi-layered structures were applied to commercial SERS substrates and to isolated SERS probes. Studies on the dependence of the multi-layer enhancement on the thickness of the spacer demonstrated that the enhancement increases as a function of surface coverage at sub-monolayer thicknesses, due to the increasing multi-layer nature of the substrates. For fully coalescent spacers the enhancement decreases as a function of thickness, due to the loss of interaction between proximal metallic films. The influence of the

  17. Investigation on Ti6Al4V-V-Cr-Fe-SS316 Multi-layers Metallic Structure Fabricated by Laser 3D Printing.

    Science.gov (United States)

    Li, Wei; Liou, Frank; Newkirk, Joseph; Taminger, Karen M Brown; Seufzer, William J

    2017-08-11

    Joining titanium alloy and stainless steel is becoming an urgent need since their outstanding mechanical properties can be utilized integratedly. However, direct fusion joining of Ti6Al4V to SS316 can cause brittle Ti-Fe intermetallics which compromise join bonds' mechanical properties. In this research, Laser 3D Printing was applied to explore a new Ti6Al4V to SS316 multi-metallic structure. A novel filler transition route was introduced (Ti6Al4V → V → Cr → Fe → SS316) to avoid the Ti-Fe intermetallics. Two experimental cases were performed for comparison to evaluate this novel route's effect. In the first case, SS316 layer was directly deposited on Ti6Al4V substrate by laser 3D printing, but the sample cracked in the printing process. Then fracture morphology, phase identification, and micro-hardness were analyzed. In the second case, a multi-metallic structure was fabricated via laser 3D printing following the transition route. Microstructure characterization and composition distribution were analyzed via scanning electron microscope(SEM) and energy dispersive spectrometry(EDS). x-ray diffraction(XRD) tests demonstrated the intermetallics were effectively avoided following the transition route. Vickers hardness number(VHN) showed no significant hard brittle phases in the sample. Comparing with directly depositing SS316 on Ti6Al4V, the usage of the novel transition route can eliminate the intermetallics effectively. These research results are good contributions in joining titanium alloy and stainless steel.

  18. Multi-layer seal for electrochemical devices

    Science.gov (United States)

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-09-14

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  19. Multi-Layer E-Textile Circuits

    Science.gov (United States)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  20. Young's modulus of multi-layer microcantilevers

    Science.gov (United States)

    Deng, Zhikang; Deng, Jinglan; He, Liang; Zhuo, Rongshu; Zhu, Ruiqi; Shi, Yang; Liu, Hui; Yang, Wei; Yuan, Hui; Chen, Yiming; Huang, Yue; Zheng, Yi

    2017-12-01

    A theoretical model for calculating the Young's modulus of multi-layer microcantilevers with a coating is proposed, and validated by a three-dimensional (3D) finite element (FE) model using ANSYS parametric design language (APDL) and atomic force microscopy (AFM) characterization. Compared with typical theoretical models (Rayleigh-Ritz model, Euler-Bernoulli (E-B) beam model and spring mass model), the proposed theoretical model can obtain Young's modulus of multi-layer microcantilevers more precisely. Also, the influences of coating's geometric dimensions on Young's modulus and resonant frequency of microcantilevers are discussed. The thickness of coating has a great influence on Young's modulus and resonant frequency of multi-layer microcantilevers, and the coating should be considered to calculate Young's modulus more precisely, especially when fairly thicker coating is employed.

  1. Vehicular Platooning: Multi-Layer Consensus Seeking

    NARCIS (Netherlands)

    Fusco, M.; Semsar Kazerooni, E.; Ploeg, J.; Wouw, N. van de

    2016-01-01

    In this paper, a novel Multi-Layer Consensus Seeking (MLCS) framework is proposed, focusing on the vehicular platooning problem. The vehicles are described by linear heterogeneous dynamics. For example, we consider thirdorder systems, however the algorithms discussed are suitable for any

  2. Multi-layered tissue head phantoms for noninvasive optical diagnostics

    Directory of Open Access Journals (Sweden)

    M. S. Wróbel

    2015-05-01

    Full Text Available Extensive research in the area of optical sensing for medical diagnostics requires development of tissue phantoms with optical properties similar to those of living human tissues. Development and improvement of in vivo optical measurement systems requires the use of stable tissue phantoms with known characteristics, which are mainly used for calibration of such systems and testing their performance over time. Optical and mechanical properties of phantoms depend on their purpose. Nevertheless, they must accurately simulate specific tissues they are supposed to mimic. Many tissues and organs including head possess a multi-layered structure, with specific optical properties of each layer. However, such a structure is not always addressed in the present-day phantoms. In this paper, we focus on the development of a plain-parallel multi-layered phantom with optical properties (reduced scattering coefficient $\\mu_{s}^{\\prime}$ and absorption coefficient μa corresponding to the human head layers, such as skin, skull, and gray and white matter of the brain tissue. The phantom is intended for use in noninvasive diffuse near-infrared spectroscopy (NIRS of human brain. Optical parameters of the fabricated phantoms are reconstructed using spectrophotometry and inverse adding-doubling calculation method. The results show that polyvinyl chloride-plastisol (PVCP and zinc oxide (ZnO nanoparticles are suitable materials for fabrication of tissue mimicking phantoms with controlled scattering properties. Good matching was found between optical properties of phantoms and the corresponding values found in the literature.

  3. Reference Models for Multi-Layer Tissue Structures

    Science.gov (United States)

    2016-09-01

    mechanically simplified yet  visually  and haptically realistic surrogate  models to be used for surgical simulation. At the time when this report was written...leg specimens, mechanical manipulations using instrumented tools, magnetic resonance imaging, sampling and testing of skin, muscle, fat and their...simplification to develop cost-effective models of surface manipulation of multi-layer tissues. Deliverables. Specimen- (or subject) and region-specific

  4. Multi-layered breathing architectural envelope

    DEFF Research Database (Denmark)

    Lund Larsen, Andreas; Foged, Isak Worre; Jensen, Rasmus Lund

    2014-01-01

    A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage....... The performance of the envelope is simulated and put through an optimization process. The impact of a design system on the architectural potential of Performance -based design was investigated.......A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage...

  5. Improvement on p-type CVD diamond semiconducting properties by fabricating thin heavily-boron-doped multi-layer clusters isolated each other in unintentionally boron-doped diamond layer

    Science.gov (United States)

    Maida, Osamu; Tabuchi, Tomohiro; Ito, Toshimichi

    2017-12-01

    We have developed a new fabrication process to decrease the effective activation energy of B atoms doped in diamond without a significant decrease in the carrier mobility by fabricating heavily B-doped clusters with very low mobility which are embedded in lightly-B-doped diamond layers. The resistivities of the heavily B-doped and unintentionally B-doped diamond stacked layers had almost no temperature dependence, suggesting the presence of an impurity-band conduction in these diamond layers. On the other hand, the resistivities of the samples after the embedding growth process of the stacked layers that had been appropriately divided to innumerable small clusters by means of a suitable etching process increased with decreasing the temperature from 330 to 130 K. The effective activation energies and Hall mobilities at room temperature of both samples were estimated to be 0.21 eV, 106 cm2 V-1 s-1 for micron-sized clusters and 0.23 eV, 470 cm2 V-1 s-1 for nano-sized clusters, respectively, indicating that the diamond film structure fabricated in this work is effective for the improvement of the p-type performance for the B-doped CVD diamond.

  6. Multi-Layer Far-Infrared Component Technology

    Science.gov (United States)

    Edwards, Oliver

    2012-01-01

    A method has been developed for fabricating high-reflectivity, multi-layer optical films for the terahertz wavelength region. A silicon mirror with 99.997-percent reflectivity at 70 micrometer wavelength requires an air gap of 17.50 micrometers and a silicon thickness of 5.12 micrometers. This approach obtains pre-thinned wafers of about 20 mm thickness in order to measure their thickness precisely. A gold annulus of appropriate thickness is deposited to reach the required total thickness. This, in turn, has the central aperture etched down to the desired final silicon thickness. Also, the novel Bragg stack optics in this innovation are key to providing Fabry-Perot spectroscopy and improved spectral component technologies of unprecedented resolution, free spectral range, and aperture.

  7. Multi-chamber and multi-layer thiol-ene microchip for cell culture

    DEFF Research Database (Denmark)

    Tan, H. Y.; Hemmingsen, Mette; Lafleur, Josiane P.

    2014-01-01

    We present a multi-layer and multi-chamber microfluidic chip fabricated using two different thiol-ene mixtures. Sandwiched between the thiol-ene chip layers is a commercially available membrane whose morphology has been altered with coatings of thiol-ene mixtures. Experiments have been conducted ...... with the microchip and shown that the fabricated microchip is suitable for long term cell culture....

  8. GMR sensing array technique validation study for the inspection of multi-layer metallic structures

    Science.gov (United States)

    Motes, Doyle; Aldrin, John C.; Keiser, Mark; Steffes, Gary; Forsyth, David S.

    2013-01-01

    Giant Magnetoresistive (GMR) sensing arrays have been developed to detect fatigue cracks in thick, multi-layered metallic structures. As part of a program conducted by the U.S. Air Force Research Laboratory, fatigue crack specimens were fabricated to provide inspection targets for a GMR array. These specimens were mounted to simulate a wing structure and inspected using a Boeing Mobile Automated Scanner (MAUS). Probability of Detection (POD) from inspections and the results of capability studies are presented.

  9. COST-EFFECTIVE TARGET FABRICATION FOR INERTIAL FUSION ENERGY

    Energy Technology Data Exchange (ETDEWEB)

    GOODIN,D.T; NOBILE,A; SCHROEN,D.G; MAXWELL,J.L; RICKMAN,W.S

    2004-03-01

    A central feature of an Inertial Fusion Energy (IFE) power plant is a target that has been compressed and heated to fusion conditions by the energy input of the driver. The IFE target fabrication programs are focusing on methods that will scale to mass production, and working closely with target designers to make material selections that will satisfy a wide range of required and desirable characteristics. Targets produced for current inertial confinement fusion experiments are estimated to cost about $2500 each. Design studies of cost-effective power production from laser and heavy-ion driven IFE have found a cost requirement of about $0.25-0.30 each. While four orders of magnitude cost reduction may seem at first to be nearly impossible, there are many factors that suggest this is achievable. This paper summarizes the paradigm shifts in target fabrication methodologies that will be needed to economically supply targets and presents the results of ''nth-of-a-kind'' plant layouts and concepts for IFE power plant fueling. Our engineering studies estimate the cost of the target supply in a fusion economy, and show that costs are within the range of commercial feasibility for laser-driven and for heavy ion driven IFE.

  10. Low-Cost Detection of Thin Film Stress during Fabrication

    Science.gov (United States)

    Nabors, Sammy A.

    2015-01-01

    NASA's Marshall Space Flight Center has developed a simple, cost-effective optical method for thin film stress measurements during growth and/or subsequent annealing processes. Stress arising in thin film fabrication presents production challenges for electronic devices, sensors, and optical coatings; it can lead to substrate distortion and deformation, impacting the performance of thin film products. NASA's technique measures in-situ stress using a simple, noncontact fiber optic probe in the thin film vacuum deposition chamber. This enables real-time monitoring of stress during the fabrication process and allows for efficient control of deposition process parameters. By modifying process parameters in real time during fabrication, thin film stress can be optimized or controlled, improving thin film product performance.

  11. Design considerations for energy efficient, resilient, multi-layer networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Hansen, Line Pyndt; Ruepp, Sarah Renée

    2016-01-01

    This work investigates different network design considerations with respect to energy-efficiency, under green-field resilient multi-layer network deployment. The problem of energy efficient, reliable multi-layer network design is known to result in different trade-offs between key performance...... in multi-layer networks and performance measures such as network resource utilization, availability, agility to traffic fluctuations and energy consumption. A green-field network deployment scenario is considered, where different resiliency methods, design methodologies and grooming strategies are applied...

  12. Design criteria for bi-stable behavior in a buckled multi-layered MEMS bridge

    Science.gov (United States)

    Michael, Aron; Kwok, Chee Yee

    2006-10-01

    In this paper, the bi-stability of a buckled multi-layered micro-bridge with elastically constrained boundary conditions is studied theoretically and experimentally. The residual moment due to non-symmetric distribution of residual stress in the layers of the micro-bridge is taken into consideration. The buckled shape model, which characterizes the initial buckled deflection, is employed in this study. A systematic method of designing bi-stable buckled micro-bridges has been developed and applied to multi-layered structures. The method is tested against ANSYS simulation and shown to be in excellent agreement. Two multi-layer micro-bridges have been fabricated: (i) 2.5 µm thick low stress SiO2/1 µm thick high compressive stress SiO2/2 µm thick SCS Si; (ii) 1 µm thick high compressive stress SiO2/2 µm thick SCS Si. The fabricated bridges are tested for bi-stability by thermal actuation and the results agree well with the analysis. The intrinsic bi-stable nature of a buckled micro-bridge can only be guaranteed as long as the residual moment is within a certain threshold value.

  13. Multi-layer micro/nanofluid devices with bio-nanovalves

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao; Ocola, Leonidas E.; Auciello, Orlando H.; Firestone, Millicent A.

    2013-01-01

    A user-friendly multi-layer micro/nanofluidic flow device and micro/nano fabrication process are provided for numerous uses. The multi-layer micro/nanofluidic flow device can comprise: a substrate, such as indium tin oxide coated glass (ITO glass); a conductive layer of ferroelectric material, preferably comprising a PZT layer of lead zirconate titanate (PZT) positioned on the substrate; electrodes connected to the conductive layer; a nanofluidics layer positioned on the conductive layer and defining nanochannels; a microfluidics layer positioned upon the nanofluidics layer and defining microchannels; and biomolecular nanovalves providing bio-nanovalves which are moveable from a closed position to an open position to control fluid flow at a nanoscale.

  14. Multi-layer Far-Infrared Component Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR will demonstrate the feasibility of a process to create multi-layer thin-film optics for the far-infrared/sub-millimeter wave spectral region. The...

  15. Multi-layer protective armour for underwater shock wave mitigation

    Directory of Open Access Journals (Sweden)

    Ahmed Hawass

    2015-12-01

    The strain gauge data and displacement sensors results showed that the multi-layer plates have higher level of underwater shock wave mitigation than the triple aluminum plates with strain and deflection of nearly 50%.

  16. High conductivity and transparent aluminum-based multi-layer source/drain electrodes for thin film transistors

    Science.gov (United States)

    Yao, Rihui; Zhang, Hongke; Fang, Zhiqiang; Ning, Honglong; Zheng, Zeke; Li, Xiaoqing; Zhang, Xiaochen; Cai, Wei; Lu, Xubing; Peng, Junbiao

    2018-02-01

    In this study, high conductivity and transparent multi-layer (AZO/Al/AZO-/Al/AZO) source/drain (S/D) electrodes for thin film transistors were fabricated via conventional physical vapor deposition approaches, without toxic elements or further thermal annealing process. The 68 nm-thick multi-layer films with excellent optical properties (transparency: 82.64%), good electrical properties (resistivity: 6.64  ×  10‑5 Ω m, work function: 3.95 eV), and superior surface roughness (R q   =  0.757 nm with scanning area of 5  ×  5 µm2) were fabricated as the S/D electrodes. Significantly, comprehensive performances of AZO films are enhanced by the insertion of ultra-thin Al layers. The optimal transparent TFT with this multi-layer S/D electrodes exhibited a decent electrical performance with a saturation mobility (µ sat) of 3.2 cm2 V‑1 s‑1, an I on/I off ratio of 1.59  ×  106, a subthreshold swing of 1.05 V/decade. The contact resistance of AZO/Al/AZO/Al/AZO multi-layer electrodes is as low as 0.29 MΩ. Moreover, the average visible light transmittance of the unpatterned multi-layers constituting a whole transparent TFT could reach 72.5%. The high conductivity and transparent multi-layer S/D electrodes for transparent TFTs possessed great potential for the applications of the green and transparent displays industry.

  17. Low cost fabrication and assembly process for re-usable 3D polydimethylsiloxane (PDMS) microfluidic networks.

    Science.gov (United States)

    Land, Kevin J; Mbanjwa, Mesuli B; Govindasamy, Klariska; Korvink, Jan G

    2011-09-01

    A method to easily manufacture and assemble a polydimethylsiloxane (PDMS) based microfluidic device is described. The method uses low cost materials and re-usable laser cut polymethyl methacrylate (PMMA) parts. In addition, the thickness of PDMS layers can be controlled and both PDMS layer surfaces are flat, which allows for multi-layer PDMS structures to be assembled. The use of mechanical clamping to seal the structure allows for easy cleaning and re-use of the manufactured part as it can be taken apart at any time. In this way, selected layers can be re-used or replaced. The process described can be easily adopted and utilised without the need for any costly clean room facilities or equipment such as oxygen bonders, making it ideal for laboratories, universities, and classrooms exploring microfluidics applications.

  18. Analysis of thermal performance of penetrated multi-layer insulation

    Science.gov (United States)

    Foster, Winfred A., Jr.; Jenkins, Rhonald M.; Yoo, Chai H.; Barrett, William E.

    1988-01-01

    Results of research performed for the purpose of studying the sensitivity of multi-layer insulation blanket performance caused by penetrations through the blanket are presented. The work described in this paper presents the experimental data obtained from thermal vacuum tests of various penetration geometries similar to those present on the Hubble Space Telescope. The data obtained from these tests is presented in terms of electrical power required sensitivity factors referenced to a multi-layer blanket without a penetration. The results of these experiments indicate that a significant increase in electrical power is required to overcome the radiation heat losses in the vicinity of the penetrations.

  19. A multi-layer flood safety approach towards resilient cities

    NARCIS (Netherlands)

    Leskens, Anne; Boomgaard, Marcel; van Zuijlen, Conny; Hollanders, Peter; Butler, D.; Djordjevic, S.; Hammond, M.J.

    2013-01-01

    The multi-layer safety approach focuses on flood risk reduction through three types of measures: (1) prevention through dikes, levees and dams , (2) a flood resilient spatial planning and (3) an adequate crisis management. Whereas the official Dutch policy propagates the multi-level safety approach,

  20. Effect of Multi-layer Compression Bandage Systems on Leg Ulcers Associated with Chronic Venous Insufficiency

    Directory of Open Access Journals (Sweden)

    Hüseyin Kuplay

    2013-03-01

    Full Text Available Introduction: Venous leg ulcer is a major health problem in terms of high prevalence and high cost for treatment. Multi-layer compression bandage systems for venous leg ulcers are supposed to be the gold standard for the treatment of venous ulcers. The aim of the current study is to investigate the effectiveness of multi-layer compression bandage systems for the treatment of venous leg ulcers.Patients and Methods: Nineteen consecutive patients diagnosed to have leg ulcers were evaluated and four patients were excluded from the study due to the peripheral arterial disease. Fifteen patients, enrolled in the study, were classified according to CEAP classification and belonged to the same class. Betaven® multi-layer compression bandage was applied to patients. Patients were followed-up in terms of wound healing and reduction in wound diameter.Results: Twelve male and three female patients underwent multi-layer bandage system. Mean age of patients was 38.2 ± 4.2 years. Ulcer size was measured planimetrically and baseline ulcer size was 4-10 cm². The location of ulcer was on medial malloelus in seven patients, lateral malleolus in three patients, anterior surface of the leg in four patients and lateral side of the leg in one patient. Patients had chronic venous insuuficiency for a mean of 5.1 ± 2.1 years. CEAP classifications were C6, Ep, As2,3-p18, Pr2,3, 18. Each bandage was changed five days after application along with wound care. Mean duration of treatment was 6 ± 2 weeks. Complete healing of the venous ulcers occurred in all patients except for one. This patient was referred to plastic surgery clinic for reconstruction.Conclusion: Multi-layer compression bandage system is an effective method of treatment for venous leg ulcers associated with chronic venous insufficiency by reducing venous return and increasing intertitial tissue pressure. This effect occurred in the shortrun as well as with a low cost and prevented loss of labor.

  1. Electrochromic Windows: Process and Fabrication Improvements for Lower Total Costs

    Energy Technology Data Exchange (ETDEWEB)

    Mark Burdis; Neil Sbar

    2007-03-31

    The overall goal with respect to the U.S. Department of Energy (DOE) is to achieve significant national energy savings through maximized penetration of EC windows into existing markets so that the largest cumulative energy reduction can be realized. The speed with which EC windows can be introduced and replace current IGU's (and current glazings) is clearly a strong function of cost. Therefore, the aim of this project was to investigate possible improvements to the SageGlass{reg_sign} EC glazing products to facilitate both process and fabrication improvements resulting in lower overall costs. The project was split into four major areas dealing with improvements to the electrochromic layer, the capping layer, defect elimination and general product improvements. Significant advancements have been made in each of the four areas. These can be summarized as follows: (1) Plasma assisted deposition for the electrochromic layer was pursued, and several improvements made to the technology for producing a plasma beam were made. Functional EC devices were produced using the new technology, but there are still questions to be answered regarding the intrinsic properties of the electrochromic films produced by this method. (2) The capping layer work was successfully implemented into the existing SageGlass{reg_sign} product, thereby providing a higher level of transparency and somewhat lower reflectivity than the 'standard' product. (3) Defect elimination is an ongoing effort, but this project spurred some major defect reduction programs, which led to significant improvements in yield, with all the implicit benefits afforded. In particular, major advances were made in the development of a new bus bar application process aimed at reducing the numbers of 'shorts' developed in the finished product, as well as making dramatic improvements in the methods used for tempering the glass, which had previously been seen to produce a defect which appeared as a

  2. Ultra-low cost coil fabrication approach for ARIES-ST

    Energy Technology Data Exchange (ETDEWEB)

    Waganer, L.M.; Deuser, D.A.; Slattery, K.T.; Wille, G.W.; Arcella, F.; Cleveland, B

    2003-02-01

    The extremely large capital expense of fusion power core components has severely diminished the overall attractive features of fusion-generated electrical power. A fresh examination of possible new manufacturing techniques yielded two ultra-low cost methods to fabricate the massive toroidal field (TF) coils of the ARIES-Spherical Torus (ARIES-ST) conceptual power plant. These innovative fabrication approaches are estimated to reduce the capital costs of the TF centerpost and return leg shell by an order of magnitude from conventional fabrication processes. This capital cost reduction will, in turn, reduce the cost of electricity by approximately 10%.

  3. Ablative Laser Propulsion Using Multi-Layered Material Systems

    Science.gov (United States)

    Nehls, Mary; Edwards, David; Gray, Perry; Schneider, T.

    2002-01-01

    Experimental investigations are ongoing to study the force imparted to materials when subjected to laser ablation. When a laser pulse of sufficient energy density impacts a material, a small amount of the material is ablated. A torsion balance is used to measure the momentum produced by the ablation process. The balance consists of a thin metal wire with a rotating pendulum suspended in the middle. The wire is fixed at both ends. Recently, multi-layered material systems were investigated. These multi-layered materials were composed of a transparent front surface and opaque sub surface. The laser pulse penetrates the transparent outer surface with minimum photon loss and vaporizes the underlying opaque layer.

  4. A multi-layer flood safety approach towards resilient cities

    OpenAIRE

    Leskens, Anne; Boomgaard, Marcel; van Zuijlen, Conny; Hollanders, Peter; Butler, D; Djordjevic, S.; Hammond, M.J.

    2013-01-01

    The multi-layer safety approach focuses on flood risk reduction through three types of measures: (1) prevention through dikes, levees and dams , (2) a flood resilient spatial planning and (3) an adequate crisis management. Whereas the official Dutch policy propagates the multi-level safety approach, the current Dutch water safety policy is still focused on prevention only (layer 1). The integration with the two other layers (i.e. a flood resilient spatial planning and an adequate disaster man...

  5. Crimp-Imbalanced Fabrics

    Science.gov (United States)

    2011-03-30

    references of Howland describe plain-woven fabrics possessing cover factors (CF) up to one hundred percent for warp fibers at the weft center and in excess...iso-crimped multi-layered fabrics. [0087] Key advantages over current crimped fabric armor systems are discussed here. First, regions of oblique

  6. Global multi-layer network of human mobility.

    Science.gov (United States)

    Belyi, Alexander; Bojic, Iva; Sobolevsky, Stanislav; Sitko, Izabela; Hawelka, Bartosz; Rudikova, Lada; Kurbatski, Alexander; Ratti, Carlo

    2017-07-03

    Recent availability of geo-localized data capturing individual human activity together with the statistical data on international migration opened up unprecedented opportunities for a study on global mobility. In this paper, we consider it from the perspective of a multi-layer complex network, built using a combination of three datasets: Twitter, Flickr and official migration data. Those datasets provide different, but equally important insights on the global mobility - while the first two highlight short-term visits of people from one country to another, the last one - migration - shows the long-term mobility perspective, when people relocate for good. The main purpose of the paper is to emphasize importance of this multi-layer approach capturing both aspects of human mobility at the same time. On the one hand, we show that although the general properties of different layers of the global mobility network are similar, there are important quantitative differences among them. On the other hand, we demonstrate that consideration of mobility from a multi-layer perspective can reveal important global spatial patterns in a way more consistent with those observed in other available relevant sources of international connections, in comparison to the spatial structure inferred from each network layer taken separately.

  7. Heat resistive dielectric multi-layer micro-mirror array in epitaxial lateral overgrowth gallium nitride.

    Science.gov (United States)

    Huang, Chen-Yang; Ku, Hao-Min; Liao, Wei-Tsai; Chao, Chu-Li; Tsay, Jenq-Dar; Chao, Shiuh

    2009-03-30

    Ta2O5 / SiO2 dielectric multi-layer micro-mirror array (MMA) with 3mm mirror size and 6mm array period was fabricated on c-plane sapphire substrate. The MMA was subjected to 1200 degrees C high temperature annealing and remained intact with high reflectance in contrast to the continuous multi-layer for which the layers have undergone severe damage by 1200 degrees C annealing. Epitaxial lateral overgrowth (ELO) of gallium nitride (GaN) was applied to the MMA that was deposited on both sapphire and sapphire with 2:56 mm GaN template. The MMA was fully embedded in the ELO GaN and remained intact. The result implies that our MMA is compatible to the high temperature growth environment of GaN and the MMA could be incorporated into the structure of the micro-LED array as a one to one micro backlight reflector, or as the patterned structure on the large area LED for controlling the output light.

  8. Design study of a miniaturized multi-layered metamaterial-inspired dynamically tunable antenna

    Science.gov (United States)

    Myers, Joshua C.

    A multi-layered metamaterial inspired minaturized antenna with a pixel grid loading structure is introduced in this work. The antenna consists of two layers separated by a thin dielectric substrate. The first layer contains a folded monopole antenna surrounded by a metal pixel based loading structure, while the second layer is envisioned to consist of a photo conductive pixel grid utilized to tune the antenna. The state of each pixel is controlled by a binary genetic algorithm, which is implemented with a Matlab-HFSS interface. As a proof of concept, the pixel grid on the second layer is initially made of a metal conductor. HFSS simulations show that the second layer has a wide tuning ability with the appropriate state formed through optimization. A wide range of other conductivities are also shown to provide pixel combinations that meet the required antenna characteristics. The radiation efficiency of the antenna with the second layer is also examined and optimized, and the theoretical tuning range is investigated. The fabrication of multiple antenna configurations with the pixels made of a metal conductor are explored. Thin PET films are first investigated to be used as simple loading elements that can be placed directly on the antenna. However, the airgap and misalignment between the layers caused by this method is shown to be too large to overcome. A novel multi layer fabrication technique is then investigated which uses a SU-8 photoresist as the dielectric layer. This layer can be spun directly onto the antenna, essentially eliminating any airgap problems. The alignment with this process is also much better than the previews method. Multiple antenna configurations corresponding to a wide frequency range are constructed using this fabrication method. The measured reflection coefficients and radiation patterns are shown to be in good agreement with HFSS simulations, successfully demonstrating the ability to dramatically tune the antenna with a second pixel grid.

  9. Comparative Study on Acoustic Behavior Between Light Multi-layered and Traditional Façades

    Directory of Open Access Journals (Sweden)

    Ruiz, L.

    2012-09-01

    Full Text Available Light multi-layered facade systems in general have been acoustically little studied. The data available suggests they do not usually fulfil the sound insulation values required in the Technical Building Code (CTE in particularly in noisy environments. Therefore the main objectives of this study, is to obtain light multi-layered façade systems with a high degree of acoustic insulation that can be used in noisy environments. While in turn showing excellent thermal characteristics, without neglecting important aspects such as the sustainability of materials, industrialization, costs, among others. This article will explain the process that has been followed to carry out an investigation on the acoustic behaviour of light multi-layered facades. For this purpose acoustic behaviour and sound intensimetry measurement methods have been used. After obtaining these results, a comparison between light multi-layered and traditional facades was made.Los sistemas de fachadas multicapas ligeras acústicamente, en general han sido poco estudiados. Los primeros datos que se tienen es que no suelen alcanzar los valores de aislamiento acústico requeridos en el Código Técnico de la Edificación (CTE en entornos especialmente ruidosos. Los objetivos principales de esta investigación son obtener fachadas multicapas ligeras con un alto grado de aislamiento acústico, que puedan ser empleados en entornos ruidosos. Al mismo tiempo que presenten excelentes características térmicas, sin descuidar aspectos tan importantes como la sostenibilidad, industrialización, costes, etc. En este artículo se explicará el proceso que se ha llevado a cabo para realizar una investigación relacionada con el comportamiento acústico de fachadas multicapas ligeras. Para ello se han empleado los métodos de medida del comportamiento acústico a ruido aéreo e intensimetría sonora. Una vez obtenidos estos resultados se realiza una comparativa entre las fachadas multicapas ligeras

  10. Low-Cost, Silicon Carbide Replication Technique for LWIR Mirror Fabrication Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SSG proposes an innovative optical manufacturing approach that will enable the low-cost fabrication of lightweighted, Long Wave Infrared (LWIR) Silicon Carbide (SiC)...

  11. Enhanced RF Behavior Multi-Layer Thermal Insulation.

    Science.gov (United States)

    Mazzinghi, A; Sabbadini, M; Freni, A

    2018-01-08

    This paper shows that it is possible to exploit the modulated metasurface concept to control the unwanted coupling between antennas that are installed on the same satellite. The metasurface is combined with a Multi-Layer thermal Insulation blanket to reduce its specular reflection by spreading the energy incoherently in the surrounding space. In the design, sub-wavelength radiating elements printed on thin substrate have been used to make the metasurface response azimuthally independent, and to keep the weight of blanket down. The comparison between simulations and measurements confirms the validity of the idea.

  12. Multi-Layer Visualization of Mobile Mapping Data

    Directory of Open Access Journals (Sweden)

    D. Eggert

    2013-10-01

    Full Text Available application various different visualization schemes are conceivable. This paper presents a multi-layer based visualization method, enabling fast data browsing of mobile mapping data. In contrast to systems like Google Street View the proposed visualization does not base on 360° panoramas, but on colored point clouds projected on partially translucent images. Those images are rendered as overlapping textures, preserving the depth of the recorded data and still enabling fast rendering on any kind of platform. Furthermore the proposed visualization allows the user to inspect the mobile mapping data in a panoramic fashion with an immersive depth illusion using the parallax scrolling technic.

  13. Information Extraction from Large-Multi-Layer Social Networks

    Science.gov (United States)

    2015-08-06

    fi(C1) ≤ fi(C2) for every objective function fi and there exists some j such that fj(C1) < fj(C2). The first Pareto front is the set of weakly non...of Pareto optimality, community detection in this multi-layer setting is formulated as a multiple criterion optimization problem. We propose an...algorithm for finding an approximate Pareto frontier containing a family of solutions. The power of this approach is demonstrated on a Twitter dataset

  14. Multi-layer canard cycles and translated power functions

    OpenAIRE

    Dumortier, Freddy; Roussarie, Robert

    2008-01-01

    The paper deals with two-dimensional slow-fast systems and more specifically with multi-layer canard cycles. These are canard cycles passing through n layers of fast orbits, with n >= 2. The canard cycles are subject to n generic breaking mechanisms and we study the limit cycles that can be perturbed from the generic canard cycles of codimension n. We prove that this study can be reduced to the investigation of the fixed points of iterated translated power functions. (c) 2007 El...

  15. Nanostructured SnO2-Ge Multi-layer thin Films with Quantum Confinement Effects for Solar Cell.

    Science.gov (United States)

    Khan, Abdul Faheem; Sajjad, Wasim; Rahim, Nasrudin A

    2016-01-01

    It is well-known that multi-layer films with nanostructure can give novel properties by interfacial phenomenon and quantum confinement effects. Nanostructured multi-layer thin films are presently being analyzed for their vast applications in the area of optoelectronics technology particularly photovoltaics. Hereof, two dimensional thin films with nanostructure are of prime importance due to their structure dependent optical, electrical, and opto-electronic properties. It has been revealed that these films exhibit quantum confinement effects with band gap engineering. The main focus of the research is to evaluate the effect on structural and optical properties with number of layers. Nanostructured SnO2-Ge multi-layer thin films were fabricated using electron beam evaporation and resistive heating techniques. Alternate layers of SnO2 and Ge were deposited on glass substrate at a substrate temperature of 300 °C in order to obtain uniform and homogeneous deposition. The substrate temperature of 300 °C has been determined to be effective for the deposition of these multi-layer films from our previous studies. The films were characterized by investigating their structural and optical properties. The structural properties of the as-deposited films were characterized by Rutherford Backscattering Spectroscopy (RBS) and Raman spectroscopy and optical properties by Ultra-Violet-Near infrared (UV-VIS-NIR) spectroscopy. RBS studies confirmed that the layer structure has been effectively formed. Raman spectroscopy results show that the peaks of both Ge and SnO2 shifts towards lower wavenumbers (in comparison with bulk Ge and SnO2, suggesting that the films consist of nanostructures and demonstrate quantum confinement effects. UV-VIS-NIR spectroscopy showed an increase in the band gap energy of Ge and SnO2 and shifting of transmittance curves toward higher wavelength by increasing the number of layers. The band gap lies in the range of 0.9 to 1.2 eV for Ge, while for SnO2, it

  16. A multi-layer MRI description of Parkinson's disease

    Science.gov (United States)

    La Rocca, M.; Amoroso, N.; Lella, E.; Bellotti, R.; Tangaro, S.

    2017-09-01

    Magnetic resonance imaging (MRI) along with complex network is currently one of the most widely adopted techniques for detection of structural changes in neurological diseases, such as Parkinson's Disease (PD). In this paper, we present a digital image processing study, within the multi-layer network framework, combining more classifiers to evaluate the informative power of the MRI features, for the discrimination of normal controls (NC) and PD subjects. We define a network for each MRI scan; the nodes are the sub-volumes (patches) the images are divided into and the links are defined using the Pearson's pairwise correlation between patches. We obtain a multi-layer network whose important network features, obtained with different feature selection methods, are used to feed a supervised multi-level random forest classifier which exploits this base of knowledge for accurate classification. Method evaluation has been carried out using T1 MRI scans of 354 individuals, including 177 PD subjects and 177 NC from the Parkinson's Progression Markers Initiative (PPMI) database. The experimental results demonstrate that the features obtained from multiplex networks are able to accurately describe PD patterns. Besides, also if a privileged scale for studying PD disease exists, exploring the informative content of more scales leads to a significant improvement of the performances in the discrimination between disease and healthy subjects. In particular, this method gives a comprehensive overview of brain regions statistically affected by the disease, an additional value to the presented study.

  17. Vulnerability of multi-layer networks under malware spreading

    CERN Document Server

    Vida, Rafael; Cuenda, Sara

    2013-01-01

    Computer viruses are evolving by developing spreading mechanisms based on the use of multiple vectors of propagation. The use of the social network as an extra vector of attack to penetrate the security measures in IP networks is improving the effectiveness of the malware, and have therefore been used by the most aggressive viruses, like Conficker and Stuxnet. In this work we use multi-layer networks to model the propagation of these kind of viruses. In particular, we study the propagation of a SIS model on a multi-layer network where the state of each node is layer-independent and the dynamics in each network follows either a contact process or a reactive process, with different propagation rates. We show that the interplay between the layers leads to a non-trivial dynamics, with an epidemic onset that may trigger before it triggers in each isolated network. We apply this study to the case of a real two-layer network: a Spanish scientific community of Statistical Physics, formed by a social network of scient...

  18. Elastic Buckling Behaviour of General Multi-Layered Graphene Sheets

    Directory of Open Access Journals (Sweden)

    Rong Ming Lin

    2015-04-01

    Full Text Available Elastic buckling behaviour of multi-layered graphene sheets is rigorously investigated. Van der Waals forces are modelled, to a first order approximation, as linear physical springs which connect the nodes between the layers. Critical buckling loads and their associated modes are established and analyzed under different boundary conditions, aspect ratios and compressive loading ratios in the case of graphene sheets compressed in two perpendicular directions. Various practically possible loading configurations are examined and their effect on buckling characteristics is assessed. To model more accurately the buckling behaviour of multi-layered graphene sheets, a physically more representative and realistic mixed boundary support concept is proposed and applied. For the fundamental buckling mode under mixed boundary support, the layers with different boundary supports deform similarly but non-identically, leading to resultant van der Waals bonding forces between the layers which in turn affect critical buckling load. Results are compared with existing known solutions to illustrate the excellent numerical accuracy of the proposed modelling approach. The buckling characteristics of graphene sheets presented in this paper form a comprehensive and wholesome study which can be used as potential structural design guideline when graphene sheets are employed for nano-scale sensing and actuation applications such as nano-electro-mechanical systems.

  19. Optimization Model for the Design of Multi-layered Permeable Reactive Barriers

    Science.gov (United States)

    Połoński, Mieczysław; Pawluk, Katarzyna; Rybka, Iwona

    2017-10-01

    Permeable reactive barriers (PRBs) are employed as in situ groundwater remediation technology. The installation of PRBs is usually a major investment, where one of the biggest cost drivers are material costs. PRBs are barriers against contaminants moving under the natural gradient, however not against groundwater contaminants. The most common construction of a PRB is a single barrier, but in the case of contaminant mixtures a multi-layered construction, i.e. a combination of different reactive materials and removal processes, is required. The most important parameters for PRB design are dimensions. The barrier must be long enough to treat the entire width of the plume (dimension perpendicular to groundwater flow) and should extend to and be keyed into an impermeable layer. The problem is to determine the optimal thickness of a PRB, which should provide a residence time appropriate for reducing the concentration of contaminants to the desired effluent concentration. In PRBs, design is accomplished using numerical methods or simulators, which are useful to predict the scenarios and evaluate the resulting groundwater flow systems to specific site conditions. On the other hand, numerical methods are complicated and may have significant errors if the discretization is too coarse or is incorrectly aligned. This paper deals with a simple, conceptual model of a one-approach optimization method for multi-layered PRB design. Based on literature and laboratory test results (residence time, density and hydraulic coefficient), a selection of layers of reactive materials was determined. Considering the lowest cost of the reactive materials, the required thicknesses of activated carbon, zeolite and zero valent iron were calculated using two different algorithms. The simple model may be used for preliminary barrier design and cost calculations. Using the optimization model in a preliminary design stage, it is possible to reject the PRB concept and avoid losing time for the

  20. Reduction in Fabrication Costs of Gas Diffusion Layers

    Energy Technology Data Exchange (ETDEWEB)

    Jason Morgan; Donald Connors; Michael Hickner

    2012-07-10

    Ballard Material Products (BMP) performed a pre-design technical and cost analysis of state of the art production technologies feasible for high volume GDL manufacturing. Based upon criteria that also included environmental health and safety, customer quality requirements, and future needs, BMP selected technologies that can be integrated into its current manufacturing process. These selections included Many-At-A-Time (MAAT) coating and continuous mixing technologies, as well as various on-line process control tools. These processes have allowed BMP to produce high performance GDLs at lower cost for near-term markets, as well as to define the inputs needed to develop a conceptual Greenfield facility to meet the cost targets for automotive volumes of 500,000 vehicles per year.

  1. Multi-layer structures with thermal and acoustic properties for building rehabilitation

    Science.gov (United States)

    Bessa, J.; Mota, C.; Cunha, F.; Merino, F.; Fangueiro, R.

    2017-10-01

    This work compares the use of different sustainable materials in the design of multilayer structures for the rehabilitation of buildings in terms of thermal and acoustic properties. These structures were obtained by compression moulding and thermal and acoustic tests were further carried out for the quantification of the respective insulation properties of composite materials obtained. The experimental results show that the use of polyurethane (PUR) foams and jute fabric reinforcing biocomposites promotes interesting properties of thermal and acoustic insulation. A multi-layer structure composed by PUR foam on the intermediate layer revealed thermal resistances until 0.272 m2 K W‑1. On the other hand, the use of jute fabric reinforcing biocomposites on exterior layer promoted a noise reduction at 500 Hz until 8.3 dB. These results allow to conclude that the use of PUR foams and jute fabric reinforcing biocomposites can be used successfully in rehabilitation of buildings, when the thermal and acoustic insulation is looked for.

  2. The Significance of Pore Microarchitecture in a Multi-Layered Elastomeric Scaffold for Contractile Cardiac Muscle Constructs

    Science.gov (United States)

    Park, H.; Larson, B.L.; Guillemette, M.D.; Jain, S.R.; Hua, C.; Engelmayr, G.C.; Freed, L.E.

    2010-01-01

    Multi-layered poly(glycerol sebacate) (PGS) scaffolds with controlled pore microarchitectures were fabricated, combined with heart cells, and cultured with perfusion to engineer contractile cardiac muscle constructs. First, one-layered (1L) scaffolds with accordion-like honeycomb shaped pores and elastomeric mechanical properties were fabricated by laser microablation of PGS membranes. Second, two-layered (2L) scaffolds with fully interconnected three dimensional pore networks were fabricated by oxygen plasma treatment of 1L scaffolds followed by stacking with off-set laminae to produce a tightly bonded composite. Third, heart cells were cultured on scaffolds with or without interstitial perfusion for 7 days. The laser-microablated PGS scaffolds exhibited ultimate tensile strength and strain-to-failure higher than normal adult rat left ventricular myocardium, and effective stiffnesses ranging from 220 to 290 kPa. The 7 day constructs contracted in response to electrical field stimulation. Excitation thresholds were unaffected by scaffold scale up from 1L to 2L. The 2L constructs exhibited reduced apoptosis, increased expression of connexin-43 (Cx-43) and matrix metalloprotease-2 (MMP-2) genes, and increased Cx-43 and cardiac troponin-I proteins when cultured with perfusion as compared to static controls. Together, these findings suggest that multi-layered, microfabricated PGS scaffolds may be applicable to myocardial repair applications requiring mechanical support, cell delivery and active implant contractility. PMID:21144580

  3. Identifikasi Tanda Tangan Berdasarkan Grid Entropy Menggunakan Multi Layer Perceptron

    Directory of Open Access Journals (Sweden)

    Muhammad Zidny Naf'an

    2017-05-01

    Full Text Available Tanda tangan merupakan salah satu bukti pengesahan dokumen yang sering digunakan. Pentingnya mengenal bentuk tanda tangan seseorang diperlukan untuk melakukan verifikasi terhadap dokumen apakah benar yang memberikan tanda tangan adalah orang yang bersangkutan atau orang lain. Pada penelitian ini penulis mendesain sistem identifikasi tanda tangan dengan fitur yang digunakan adalah nilai entropy yang diambil dari grid image (sub-citra suatu citra tanda tangan. Model pelatihan dan pengujian menggunakan multi layer perceptron dan cross validation dengan tiga ukuran grid (4x4, 8x8, dan 16x16 dan dua jenis representasi citra (citra biner dan citra outline. Hasil pengujian terbaik adalah untuk pengujian ukuran grid sebanyak 8x8 dan menggunakan citra outline yaitu dengan tingkat akurasi sebesar 97.78%, nilai korelasi 0.981, dan nilai kappa 0.977.

  4. A Multi-Layered Image Cache for Scientific Visualization

    Energy Technology Data Exchange (ETDEWEB)

    LaMar, E C

    2003-06-26

    We introduce a multi-layered image cache system that is designed to work with a pool of rendering engines to facilitate an interactive, frameless, asynchronous rendering environment. Our system decouples the rendering from the display of imagery. Therefore, it decouples render frequency and resolution from display frequency and resolution, and allows asynchronous transmission of imagery instead of the compute/send cycle of standard parallel systems. It also allows local, incremental refinement of imagery without requiring all imagery to be re-rendered. Images are placed in fixed position in camera (vs. world) space to eliminate occlusion artifacts. Display quality is improved by increasing the number of images. Interactivity is improved by decreasing the number of images.

  5. Self-damping cementitious composites with multi-layer graphene

    Science.gov (United States)

    Ruan, Yanfeng; Zhou, Daocheng; Sun, Shengwei; Wu, Xinyi; Yu, Xun; Hou, Jilin; Dong, Xufeng; Han, Baoguo

    2017-07-01

    Cementitious composites are quasi-brittle and susceptible to damage under dynamic loads. The addition of nanoscale fillers into cementitious composites is an effective approach to address this issue. In this paper, multi-layer graphenes (MLGs) are incorporated into cementitious composites to enhance its damping property. The underlying modification mechanism of MLGs to cementitous composites is also investigated. Experimental results showed that the addition of MLGs can effectively modify the damping property of cementitious composites. Compared with cementitious composites without MLGs, the damping ratio of cementitious composites filled with 1% and 5% of MLGs increases by 16.22% and 45.73%, respectively. The improvement of MLGs to damping property of cementitious composites can be attributed to the interlayer slip of MLGs, viscous friction between MLGs and matrix, and excellent thermal conductivity of MLGs. Moreover, the damping ratio measured by time-domain exponential decay method and frequency-domain half-power bandwidth method is consistent.

  6. Simulations of a multi-layer extended gating grid

    CERN Document Server

    INSPIRE-00507724

    2016-01-01

    A novel idea to control ion back-flow in time projection chambers is to use a multi-layer extended gating grid to capture back-flowing ions at the expense of live time and electron transparency. In this initial study, I perform simulations of a four-layer grid for the ALICE and STAR time projection chambers, using $\\text{Ne}-\\text{CO}_{2}\\;(90-10)$ and $\\text{Ar}-\\text{CH}_{4}\\;(90-10)$ gas mixtures, respectively. I report the live time and electron transparency for both 90% and 99% ion back-flow suppression. Additionally, for the ALICE configuration I study several effects: using a mesh vs. wire-plane grid, including a magnetic field, and varying the over-voltage distribution in the gating region. For 90% ion back-flow suppression, I achieve 75% live time with 86% electron transparency for ALICE, and 95% live time with 83% electron transparency for STAR.

  7. Packer Detection for Multi-Layer Executables Using Entropy Analysis

    Directory of Open Access Journals (Sweden)

    Munkhbayar Bat-Erdene

    2017-03-01

    Full Text Available Packing algorithms are broadly used to avoid anti-malware systems, and the proportion of packed malware has been growing rapidly. However, just a few studies have been conducted on detection various types of packing algorithms in a systemic way. Following this understanding, we elaborate a method to classify packing algorithms of a given executable into three categories: single-layer packing, re-packing, or multi-layer packing. We convert entropy values of the executable file loaded into memory into symbolic representations, for which we used SAX (Symbolic Aggregate Approximation. Based on experiments of 2196 programs and 19 packing algorithms, we identify that precision (97.7%, accuracy (97.5%, and recall ( 96.8% of our method are respectively high to confirm that entropy analysis is applicable in identifying packing algorithms.

  8. Numerical Analysis of Deflections of Multi-Layered Beams

    Directory of Open Access Journals (Sweden)

    Biliński Tadeusz

    2015-03-01

    Full Text Available The paper concerns the rheological bending problem of wooden beams reinforced with embedded composite bars. A theoretical model of the behaviour of a multi-layered beam is presented. The component materials of this beam are described with equations for the linear viscoelastic five-parameter rheological model. Two numerical analysis methods for the long-term response of wood structures are presented. The first method has been developed with SCILAB software. The second one has been developed with the finite element calculation software ABAQUS and user subroutine UMAT. Laboratory investigations were conducted on sample beams of natural dimensions in order to validate the proposed theoretical model and verify numerical simulations. Good agreement between experimental measurements and numerical results is observed.

  9. Dyadic Green's functions for multi-layer SAW substrates.

    Science.gov (United States)

    Smith, P M

    2001-01-01

    Recent formulations of the dyadic (or generalized) Green's function describe the relationship between sources (both mechanical stresses and electrical charge) and waves (both mechanical displacements and acoustic potential) on the surface of a substrate. The 16 elements of the function intrinsically describe all propagation modes, whether Rayleigh or leaky, and are therefore, extremely useful in the design of surface acoustic wave devices. In addition to requiring little computational effort, the dyadic Green's function provides much more information than the traditional effective permittivity function. In this paper, we extend the calculation of the dyadic Green's function to multi-layer substrates. We show that its computation involves a simple cascaded matrix multiplication. The resulting function fully contains the substrate characteristics and, once obtained, can be used to describe the surface behavior with no further regard to the substrate's composition.

  10. Investigation of multi-layer thin films for energy storage.

    Energy Technology Data Exchange (ETDEWEB)

    Renk, Timothy Jerome; Monson, Todd

    2009-01-01

    We investigate here the feasibility of increasing the energy density of thin-film capacitors by construction of a multi-layer capacitor device through ablation and redeposition of the capacitor materials using a high-power pulsed ion beam. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The dielectric capacitor filler material was a composition of Lead-Lanthanum-Zirconium-Titanium oxide (PLZT). The energy storage can be increased by using material of intrinsically high dielectric constant, and constructing many thin layers of this material. For successful device construction, there are a number of challenging requirements including correct stoichiometric and crystallographic composition of the deposited PLZT. This report details some success in satisfying these requirements, even though the attempt at device manufacture was unsuccessful. The conclusion that 900 C temperatures are necessary to reconstitute the deposited PLZT has implications for future manufacturing capability.

  11. Competitive dynamics of lexical innovations in multi-layer networks

    Science.gov (United States)

    Javarone, Marco Alberto

    2014-04-01

    We study the introduction of lexical innovations into a community of language users. Lexical innovations, i.e. new term added to people's vocabulary, plays an important role in the process of language evolution. Nowadays, information is spread through a variety of networks, including, among others, online and offline social networks and the World Wide Web. The entire system, comprising networks of different nature, can be represented as a multi-layer network. In this context, lexical innovations diffusion occurs in a peculiar fashion. In particular, a lexical innovation can undergo three different processes: its original meaning is accepted; its meaning can be changed or misunderstood (e.g. when not properly explained), hence more than one meaning can emerge in the population. Lastly, in the case of a loan word, it can be translated into the population language (i.e. defining a new lexical innovation or using a synonym) or into a dialect spoken by part of the population. Therefore, lexical innovations cannot be considered simply as information. We develop a model for analyzing this scenario using a multi-layer network comprising a social network and a media network. The latter represents the set of all information systems of a society, e.g. television, the World Wide Web and radio. Furthermore, we identify temporal directed edges between the nodes of these two networks. In particular, at each time-step, nodes of the media network can be connected to randomly chosen nodes of the social network and vice versa. In doing so, information spreads through the whole system and people can share a lexical innovation with their neighbors or, in the event they work as reporters, by using media nodes. Lastly, we use the concept of "linguistic sign" to model lexical innovations, showing its fundamental role in the study of these dynamics. Many numerical simulations have been performed to analyze the proposed model and its outcomes.

  12. Low-Cost Facile Fabrication of Flexible Transparent Copper Electrodes by Nanosecond Laser Ablation

    KAUST Repository

    Paeng, Dongwoo

    2015-03-27

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Low-cost Cu flexible transparent conducting electrodes (FTCEs) are fabricated by facile nanosecond laser ablation. The fabricated Cu FTCEs show excellent opto-electrical properties (transmittance: 83%, sheet resistance: 17.48 Ω sq-1) with outstanding mechanical durability. Successful demonstration of a touch-screen panel confirms the potential applicability of Cu FTCEs to the flexible optoelectronic devices.

  13. Fabrication of low cost soft tissue prostheses with the desktop 3D printer

    Science.gov (United States)

    He, Yong; Xue, Guang-Huai; Fu, Jian-Zhong

    2014-11-01

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

  14. Fabrication of low cost soft tissue prostheses with the desktop 3D printer.

    Science.gov (United States)

    He, Yong; Xue, Guang-huai; Fu, Jian-zhong

    2014-11-27

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

  15. Fabrication of low cost soft tissue prostheses with the desktop 3D printer

    Science.gov (United States)

    He, Yong; Xue, Guang-huai; Fu, Jian-zhong

    2014-01-01

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods. PMID:25427880

  16. Direct formation of large-scale multi-layered germanene on Si substrate.

    Science.gov (United States)

    Tsai, Hsu-Sheng; Chen, Yu-Ze; Medina, Henry; Su, Teng-Yu; Chou, Ta-Shun; Chen, Yi-Hsuan; Chueh, Yu-Lun; Liang, Jenq-Horng

    2015-09-07

    Germanene layers with lonsdaleite structure has been synthesized from a SiGe thin film for the first time using a N2 plasma-assisted process in this investigation. Multi-layered germanene can be directly observed, and the derived lattice parameters are nearly consistent with the theoretical results. Furthermore, large-scale multi-layered germanene has also been demonstrated for applications.

  17. 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

  18. Low-Cost Fabrication of Hollow Microneedle Arrays Using CNC Machining and UV Lithography

    DEFF Research Database (Denmark)

    Lê Thanh, Hoà; Ta, B.Q.; Le The, H.

    2015-01-01

    In order to produce disposable microneedles for blood-collection devices in smart homecare monitoring systems, we have developed a simple low-cost scalable process for mass fabrication of sharp-tipped microneedle arrays. The key feature in this process is a design of computer numerical control-machined...

  19. Two-photon reduction: a cost-effective method for fabrication of functional metallic nanostructures

    Science.gov (United States)

    Tabrizi, Sahar; Cao, YaoYu; Lin, Han; Jia, BaoHua

    2017-03-01

    Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience. The key to realizing functional plasmonic resonances that can manipulate light at the optical frequencies relies on the creation of conductive metallic structures at the nanoscale with low structural defects. Currently, most plasmonic nanostructures are fabricated either by electron beam lithography (EBL) or by focused ion beam (FIB) milling, which are expensive, complicated and time-consuming. In comparison, the direct laser writing (DLW) technique has demonstrated its high spatial resolution and cost-effectiveness in three-dimensional fabrication of micro/nanostructures. Furthermore, the recent breakthroughs in superresolution nanofabrication and parallel writing have significantly advanced the fabrication resolution and throughput of the DLW method and made it one of the promising future nanofabrication technologies with low-cost and scalability. In this review, we provide a comprehensive summary of the state-of-the-art DLW fabrication technology for nanometer scale metallic structures. The fabrication mechanisms, different material choices, fabrication capability, including resolution, conductivity and structure surface smoothness, as well as the characterization methods and achievable devices for different applications are presented. In particular, the development trends of the field and the perspectives for future opportunities and challenges are provided at the end of the review. It has been demonstrated that the quality of the metallic structures fabricated using the DLW method is excellent compared with other methods providing a new and enabling platform for functional nanophotonic device fabrication.

  20. Soil moisture dynamics modeling considering multi-layer root zone.

    Science.gov (United States)

    Kumar, R; Shankar, V; Jat, M K

    2013-01-01

    The moisture uptake by plant from soil is a key process for plant growth and movement of water in the soil-plant system. A non-linear root water uptake (RWU) model was developed for a multi-layer crop root zone. The model comprised two parts: (1) model formulation and (2) moisture flow prediction. The developed model was tested for its efficiency in predicting moisture depletion in a non-uniform root zone. A field experiment on wheat (Triticum aestivum) was conducted in the sub-temperate sub-humid agro-climate of Solan, Himachal Pradesh, India. Model-predicted soil moisture parameters, i.e., moisture status at various depths, moisture depletion and soil moisture profile in the root zone, are in good agreement with experiment results. The results of simulation emphasize the utility of the RWU model across different agro-climatic regions. The model can be used for sound irrigation management especially in water-scarce humid, temperate, arid and semi-arid regions and can also be integrated with a water transport equation to predict the solute uptake by plant biomass.

  1. Addressing stress corrosion cracking on multi layer pipeline coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, Scott B.; Marr, James E. [Tuboscope Pipeline Services, Houston, TX (United States); Willmot, Martyn [Jotun Group (Norway); Norman, David [David Norman Corrosion Control, Cornwall (United Kingdom); Khera, Ashish [Allied Engineering, Portland, ME (United States)

    2005-07-01

    Stress corrosion cracking (SCC) is now recognized by operators worldwide as a significant threat to the safe operation of their pipeline systems. Gas, oil, and refined products lines have all been susceptible to this form of environmentally assisted cracking. As a result, operators and regulators have been incorporating data related to the development and prevalence of SCC into their risk management systems in order that they may effectively address this time-dependant threat. The National Association of Corrosion Engineers (NACE) published the first structured methodology for stress corrosion cracking direct assessment (SCCDA) in 2004 (RP0204-2004). Operators are now beginning to apply the methods outlined in the standard to assess their systems. Research and industry experience have shown that various pipeline coating systems can be more or less effective in preventing the formation and growth of SCC. Newer pipeline coatings, such as multi layer epoxy/extruded polyolefin systems have been widely regarded as effective coating systems to address the threat posed by SCC when they are properly applied. New field studies performed on a pipeline coated with a three layer epoxy/polyethylene system have raised the possibility that operators utilizing these types of coatings may need to reassess how they manage the SCC threat. (author)

  2. A low-cost, high-yield fabrication method for producing optimized biomimetic dry adhesives

    Science.gov (United States)

    Sameoto, D.; Menon, C.

    2009-11-01

    We present a low-cost, large-scale method of fabricating biomimetic dry adhesives. This process is useful because it uses all photosensitive polymers with minimum fabrication costs or complexity to produce molds for silicone-based dry adhesives. A thick-film lift-off process is used to define molds using AZ 9260 photoresist, with a slow acting, deep UV sensitive material, PMGI, used as both an adhesion promoter for the AZ 9260 photoresist and as an undercutting material to produce mushroom-shaped fibers. The benefits to this process are ease of fabrication, wide range of potential layer thicknesses, no special surface treatment requirements to demold silicone adhesives and easy stripping of the full mold if process failure does occur. Sylgard® 184 silicone is used to cast full sheets of biomimetic dry adhesives off 4" diameter wafers, and different fiber geometries are tested for normal adhesion properties. Additionally, failure modes of the adhesive during fabrication are noted and strategies for avoiding these failures are discussed. We use this fabrication method to produce different fiber geometries with varying cap diameters and test them for normal adhesion strengths. The results indicate that the cap diameters relative to post diameters for mushroom-shaped fibers dominate the adhesion properties.

  3. Multi-layer cultivation in practice. Energy efficient forcing; Meerlagenteelt in de praktijk. Energie-efficienter broeien

    Energy Technology Data Exchange (ETDEWEB)

    Wildschut, J. [Praktijkonderzoek Plant en Omgeving PPO, Wageningen UR, Lisse (Netherlands); Campen, J.C. (Glastuinbouw, Wageningen UR, Wageningen (Netherlands)

    2010-11-15

    Next to possible benefits such as improved greenhouse utilization, resulting in a lower cost price and production expansion without expanding the greenhouse, multi-layer heating (in the greenhouse and/or cell) offers significant opportunities to reduce the energy use in the forcing process [Dutch] Naast mogelijke voordelen als een betere kasbenutting, waardoor een lagere kostprijs, en productieuitbreiding zonder kasuitbreiding, biedt het broeien in meerdere lagen (in de kas en/of in de cel) grote mogelijkheden om het energieverbruik in de broeierij terug te dringen.

  4. Polymer Microfluidics: Simple, Low-Cost Fabrication Process Bridging Academic Lab Research to Commercialized Production

    Directory of Open Access Journals (Sweden)

    Chia-Wen Tsao

    2016-12-01

    Full Text Available Using polymer materials to fabricate microfluidic devices provides simple, cost effective, and disposal advantages for both lab-on-a-chip (LOC devices and micro total analysis systems (μTAS. Polydimethylsiloxane (PDMS elastomer and thermoplastics are the two major polymer materials used in microfluidics. The fabrication of PDMS and thermoplastic microfluidic device can be categorized as front-end polymer microchannel fabrication and post-end microfluidic bonding procedures, respectively. PDMS and thermoplastic materials each have unique advantages and their use is indispensable in polymer microfluidics. Therefore, the proper selection of polymer microfabrication is necessary for the successful application of microfluidics. In this paper, we give a short overview of polymer microfabrication methods for microfluidics and discuss current challenges and future opportunities for research in polymer microfluidics fabrication. We summarize standard approaches, as well as state-of-art polymer microfluidic fabrication methods. Currently, the polymer microfluidic device is at the stage of technology transition from research labs to commercial production. Thus, critical consideration is also required with respect to the commercialization aspects of fabricating polymer microfluidics. This article provides easy-to-understand illustrations and targets to assist the research community in selecting proper polymer microfabrication strategies in microfluidics.

  5. Multi-Layer and Recursive Neural Networks for Metagenomic Classification.

    Science.gov (United States)

    Ditzler, Gregory; Polikar, Robi; Rosen, Gail

    2015-09-01

    Recent advances in machine learning, specifically in deep learning with neural networks, has made a profound impact on fields such as natural language processing, image classification, and language modeling; however, feasibility and potential benefits of the approaches to metagenomic data analysis has been largely under-explored. Deep learning exploits many layers of learning nonlinear feature representations, typically in an unsupervised fashion, and recent results have shown outstanding generalization performance on previously unseen data. Furthermore, some deep learning methods can also represent the structure in a data set. Consequently, deep learning and neural networks may prove to be an appropriate approach for metagenomic data. To determine whether such approaches are indeed appropriate for metagenomics, we experiment with two deep learning methods: i) a deep belief network, and ii) a recursive neural network, the latter of which provides a tree representing the structure of the data. We compare these approaches to the standard multi-layer perceptron, which has been well-established in the machine learning community as a powerful prediction algorithm, though its presence is largely missing in metagenomics literature. We find that traditional neural networks can be quite powerful classifiers on metagenomic data compared to baseline methods, such as random forests. On the other hand, while the deep learning approaches did not result in improvements to the classification accuracy, they do provide the ability to learn hierarchical representations of a data set that standard classification methods do not allow. Our goal in this effort is not to determine the best algorithm in terms accuracy-as that depends on the specific application-but rather to highlight the benefits and drawbacks of each of the approach we discuss and provide insight on how they can be improved for predictive metagenomic analysis.

  6. Energy management and multi-layer control of networked microgrids

    Science.gov (United States)

    Zamora, Ramon

    Networked microgrids is a group of neighboring microgrids that has ability to interchange power when required in order to increase reliability and resiliency. Networked microgrid can operate in different possible configurations including: islanded microgrid, a grid-connected microgrid without a tie-line converter, a grid-connected microgrid with a tie-line converter, and networked microgrids. These possible configurations and specific characteristics of renewable energy offer challenges in designing control and management algorithms for voltage, frequency and power in all possible operating scenarios. In this work, control algorithm is designed based on large-signal model that enables microgrid to operate in wide range of operating points. A combination between PI controller and feed-forward measured system responses will compensate for the changes in operating points. The control architecture developed in this work has multi-layers and the outer layer is slower than the inner layer in time response. The main responsibility of the designed controls are to regulate voltage magnitude and frequency, as well as output power of the DG(s). These local controls also integrate with a microgrid level energy management system or microgrid central controller (MGCC) for power and energy balance for. the entire microgrid in islanded, grid-connected, or networked microgid mode. The MGCC is responsible to coordinate the lower level controls to have reliable and resilient operation. In case of communication network failure, the decentralized energy management will operate locally and will activate droop control. Simulation results indicate the superiority of designed control algorithms compared to existing ones.

  7. Multi-Layer Electrospun Membrane Mimicking Tendon Sheath for Prevention of Tendon Adhesions

    Directory of Open Access Journals (Sweden)

    Shichao Jiang

    2015-03-01

    Full Text Available Defect of the tendon sheath after tendon injury is a main reason for tendon adhesions, but it is a daunting challenge for the biomimetic substitute of the tendon sheath after injury due to its multi-layer membrane-like structure and complex biologic functions. In this study, a multi-layer membrane with celecoxib-loaded poly(l-lactic acid-polyethylene glycol (PELA electrospun fibrous membrane as the outer layer, hyaluronic acid (HA gel as middle layer, and PELA electrospun fibrous membrane as the inner layer was designed. The anti-adhesion efficacy of this multi-layer membrane was compared with a single-layer use in rabbit flexor digitorum profundus tendon model. The surface morphology showed that both PELA fibers and celecoxib-loaded PELA fibers in multi-layer membrane were uniform in size, randomly arrayed, very porous, and smooth without beads. Multi-layer membrane group had fewer peritendinous adhesions and better gliding than the PELA membrane group and control group in gross and histological observation. The similar mechanical characteristic and collagen expression of tendon repair site in the three groups indicated that the multi-layer membrane did not impair tendon healing. Taken together, our results demonstrated that such a biomimetic multi-layer sheath could be used as a potential strategy in clinics for promoting tendon gliding and preventing adhesion without poor tendon healing.

  8. Pronounced Photovoltaic Response from Multi-layered MoTe2Phototransistor with Asymmetric Contact Form.

    Science.gov (United States)

    Liu, Junku; Guo, Nan; Xiao, Xiaoyang; Zhang, Kenan; Jia, Yi; Zhou, Shuyun; Wu, Yang; Li, Qunqing; Xiao, Lin

    2017-11-22

    In this study, we fabricate air-stable p-type multi-layered MoTe 2 phototransistor using Au as electrodes, which shows pronounced photovoltaic response in off-state with asymmetric contact form. By analyzing the spatially resolved photoresponse using scanning photocurrent microscopy, we found that the potential steps are formed in the vicinity of the electrodes/MoTe 2 interface due to the doping of the MoTe 2 by the metal contacts. The potential step dominates the separation of photoexcited electron-hole pairs in short-circuit condition or with small V sd biased. Based on these findings, we infer that the asymmetric contact cross-section between MoTe 2 -source and MoTe 2 -drain electrodes is the reason to form non-zero net current and photovoltaic response. Furthermore, MoTe 2 phototransistor shows a faster response in short-circuit condition than that with higher biased V sd within sub-millisecond, and its spectral range can be extended to the infrared end of 1550 nm.

  9. A smooth impact rotation motor using a multi-layered torsional piezoelectric actuator.

    Science.gov (United States)

    Morita, T; Yoshida, R; Okamoto, Y; Kurosawa, M K; Higuchi, T

    1999-01-01

    A smooth impact rotation motor was fabricated and successfully operated using a torsional piezo actuator. Yoshida et al. reported a linear type smooth impact motor in 1997. This linear motor demonstrated a high output force and a long stroke. A superior feature of the smooth impact drive is a high positioning resolution compared with an impact drive. The positioning resolution of SIDM (smooth impact drive mechanism) is equal to the piezo displacement. The reported positioning resolution of the linear type was 5 nm. Our rotation motor utilized a torsional actuator containing multi-layered piezoelectric material. The torsional actuator was cylindrical in shape with an outer diameter of 15 mm, an inner diameter of 10 mm, and a length of 11 mm. Torsional vibration performance was measured with a laser Doppler vibrometer. The obtained torsional displacement agreed with the calculated values and was sufficient to drive a rotor. The rotor was operated with a saw-shaped input voltage (180 V; 8 kHz). The revolution direction was reversible. The maximum revolution speed was 27 rpm, and the maximum output torque was 56 gfcm. In general, smooth-impact drives do not show high efficiency; however, the level of efficiency of our results (max., 0.045%) could be increased by improving the contact surface material. In addition, we are studying quantitative consideration, for example, about the optimum pre-load or frictional force.

  10. Design, simulation and testing of a novel radial multi-pole multi-layer magnetorheological brake

    Science.gov (United States)

    Wu, Jie; Li, Hua; Jiang, Xuezheng; Yao, Jin

    2018-02-01

    This paper deals with design, simulation and experimental testing of a novel radial multi-pole multi-layer magnetorheological (MR) brake. This MR brake has an innovative structural design with superposition principle of two magnetic fields generated by the inner coils and the outer coils. The MR brake has several media layers of magnetorheological (MR) fluid located between the inner coils and the outer coils, and it can provide higher torque and higher torque density than conventional single-disk or multi-disk or multi-pole single-layer MR brakes can. In this paper, a brief introduction to the structure of the proposed MR brake was given first. Then, theoretical analysis of the magnetic circuit and the braking torque was conducted. In addition, a 3D electromagnetic model of the MR brake was developed to simulate and examine the magnetic flux intensity and corresponding braking torque. A prototype of the brake was fabricated and several tests were carried out to validate its torque capacity. The results show that the proposed MR brake can produce a maximum braking torque of 133 N m and achieve a high torque density of 25.0 kN m‑2, a high torque range of 42 and a high torque-to-power ratio of 0.95 N m W‑1.

  11. Multi-Layered TiO2 Films towards Enhancement of Escherichia coli Inactivation

    National Research Council Canada - National Science Library

    Yoriya, Sorachon; Chumphu, Angkana; Pookmanee, Pusit; Laithong, Wreerat; Thepa, Sirichai; Songprakorp, Roongrojana

    2016-01-01

    .... This work presents a design fabrication of low-cost, layered TiO2 films assembled reactors and a study of their performance for a better understanding to elucidate the photocatalytic effect on inactivation of E. coli in water...

  12. Tribological and Wear Properties of Multi-Layered Materials

    Directory of Open Access Journals (Sweden)

    V. Bria

    2011-09-01

    Full Text Available The usage of fabrics as reinforcements in composites is spreading due to fabrics’ properties. The use of fabrics allows obtaining of sinuous surfaces, for instance, unlike the use of prepregs. Using fabrics as reinforcements it is also possible to obtain laminate-like materials having the same matrix in all their volume. In the case of pre-pregs usage always it is necessary to discuss about the bonding between individual plies. For this study eight materials were formed. The forming method consisted in placing the pre-polymer imbued fabric pieces into a mould to obtain plates of composites. Two types of fabric were used: one simple type of untwisted tows of carbon fibres and the second one simple type of alternated untwisted tows of carbon and aramide fibres. Both fabrics were prepared in order to ensure the matrix adherence. The polymer matrix is realised from epoxy system EPIPHEN RE 4020 / EPIPHEN DE 4020 filled with clay and talc in equal amounts of 5% (weight ratio. The use of clay and talc were meant to improve the thermal dimensional stability of final materials. Tribological properties of formed materials were studied using pin-on-disk method with steel disk and pins made of materials. Both orientation of reinforcement fibres relative to friction direction were taken into account. Results are encouraging further studies in order to identify the best solution of forming a multi-component material with more than one designable property.

  13. Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique.

    Science.gov (United States)

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Suhasril, Andril Arafat; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Omar, Mohd Afian; Abd Kader, Ab Saman; Mohd Noor, Alias; A Harris, Arief Ruhullah; Abdul Majid, Norazman

    2014-07-01

    Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries. Copyright © 2013 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  14. The effects of fabric type, fabric width and model type on the cost of unit raw material in terms of apparel

    Science.gov (United States)

    Bilgiç, H.; Duru Baykal, P.

    2017-10-01

    The cost of the fabric which is the raw material of apparel constitutes approximately the half of the total product cost. So, it is highly important that the fabric should be used with the greatest productivity. Cost analysis are of great importance in terms of competitiveness of readymade clothing and apparel sector both in national and international markets. The proximity of costs to international average and the average cost of the countries that are competitors of Turkey in clothing market is essential for Turkey to sustain its effect in textile sector. In the contrary case, the sector won’t be able to maintain its competitive capacity sustainably [1].The main cost elements of textile and apparel sector consist of raw material, labor, energy and financing [2].

  15. Naturalness Preserved Image Enhancement Using a priori Multi-Layer Lightness Statistics.

    Science.gov (United States)

    Wang, Shuhang; Luo, Gang

    2018-02-01

    Enhancement of non-uniformly illuminated images often suffers from over-enhancement and produces unnatural results. This paper presents a naturalness preserved enhancement method for non-uniformly illuminated images, using a priori multi-layer lightness statistics acquired from high-quality images. Our work makes three important contributions: designing a novel multi-layer image enhancement model; deriving the multi-layer lightness statistics of high-quality outdoor images, which are incorporated into the multi-layer enhancement model; and showing that the overall quality rating of enhanced images is consistent with a combination of contrast enhancement and naturalness preservation. Two separate human observer evaluation studies were conducted on naturalness preservation and overall image quality. The results showed the proposed method outperformed four compared state-of-the-art enhancement methods.

  16. A fully dynamic model of a multi-layer piezoelectric actuator incorporating the power amplifier

    Science.gov (United States)

    Zhu, Wei; Yang, Fufeng; Rui, Xiaoting

    2017-12-01

    The dynamic input–output characteristics of the multi-layer piezoelectric actuator (PA) are intrinsically rate-dependent and hysteresis. Meanwhile, aiming at the strong capacitive impedance of multi-layer PA, the power amplifier of the actuator can greatly affect the dynamic performances of the actuator. In this paper, a novel dynamic model that includes a model of the electric circuit providing voltage to the actuator, an inverse piezoelectric effect model describing the hysteresis and creep behavior of the actuator, and a mechanical model, in which the vibration characteristics of the multi-layer PA is described, is put forward. Validation experimental tests are conducted. Experimental results show that the proposed dynamic model can accurately predict the fully dynamic behavior of the multi-layer PA with different driving power.

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

    Energy Technology Data Exchange (ETDEWEB)

    Summerhill, Richard [Internet2, Washington, DC (United States); Lehman, Tom [Univ. of Southern California, Los Angeles, CA (United States). Information Sciences Inst. (ISI); Ghani, Nasir [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical & Computer Engineering; Boyd, Eric [Univ. Corporation for Advanced Internet Development (UCAID), Washington, DC (United States)

    2009-08-14

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

  18. Load-Bearing Tank-Applied Multi-Layer Insulation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed load-bearing, tank-applied, multi-layer insulation system consists of a set of highly reflective radiation shields made from 1 mil thick aluminized...

  19. A Comparison of Homogeneous and Multi-layered Berm Breakwaters with Respect to Overtopping and Stability

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Skals, Kasper; Burcharth, Hans F.

    2008-01-01

    The paper deals with homogeneous and multi-layer berm breakwaters designed to maximize the utilization of the quarry material. Two wide stone classes are typically used for berm breakwaters with a homogeneous berm.......The paper deals with homogeneous and multi-layer berm breakwaters designed to maximize the utilization of the quarry material. Two wide stone classes are typically used for berm breakwaters with a homogeneous berm....

  20. Depth enhancement of multi-layer light field display using polarization dependent internal reflection.

    Science.gov (United States)

    Jo, Na-Young; Lim, Hong-Gi; Lee, Sung-Keun; Kim, Yong-Soo; Park, Jae-Hyeung

    2013-12-02

    A technique to enhance the depth range of the multi-layer light field three-dimensional display is proposed. A set of the optical plates are stacked in front of the conventional multi-layer light field display, creating additional internal reflection for one polarization state. By switching between two orthogonal polarization states in synchronization with the displayed three-dimensional images, the depth range of the display can be doubled. The proposed method is verified experimentally, confirming its feasibility.

  1. Development of Low-Cost Method for Fabrication of Metal Neutron Guides

    Energy Technology Data Exchange (ETDEWEB)

    Engelhaupt, Darell [Dawn Research Inc., Madison, AL (United States); Khaykovich, Boris [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Romaine, Suzanne [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

    2017-12-19

    Neutron scattering is one of the most useful methods of studying the structure and dynamics of matter. US DOE neutron scattering research facilities at Oak Ridge National Laboratory are among the World’s most advanced, providing researchers with unmatched capabilities for probing the structure and properties of materials, including engineering and biological systems. This task is to develop a lower cost process to optimize and produce the required neutron guides capable of efficiently delivering neutron beams for tens of meters between neutron moderators and instruments. Therefore, our effort is to improve the performance and lower the production cost of neutron guides. Our approach aims at improving guide quality while controlling their rising costs by adopting a novel electroforming replication approach to their fabrication. These guides will be especially advantageous when used near the neutron source since the radiation resistance of nickel is superior to glass. Additionally, we are depositing low-stress nickel from an extremely low impurity solution completely free of stress-reducing agents, which nominally contain and impart sulfur, carbon and other elements that potentially activate in the neutron environment. This is achieved by using a pulsed periodically reversed current methodology. The best guides quote waviness of 0.1 mrad. It is reasonable to prepare just one mandrel of about 0.5 m long, for production of tens of guide segments, saving both the cost and supply time of guides to neutron facilities. We estimate that we can fabricate a single mandrel for the current cost of an individual one-meter guide, but from this, we can produce tens of meters of guide very inexpensively without mandrel refurbishment. While a multilayer coating will add to the overall cost, we expect this will be less than that of commercially available guides today. Therefore, we will produce higher quality guides, which are less susceptible to radiation damage, at the lower cost

  2. ITER vacuum vessel fabrication plan and cost study (D 68) for the international thermonuclear experimental reactor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    ITER Task No. 8, Vacuum Vessel Fabrication Plan and Cost Study (D68), was initiated to assess ITER vacuum vessel fabrication, assembly, and cost. The industrial team of Raytheon Engineers & Constructors and Chicago Bridge & Iron (Raytheon/CB&I) reviewed the current vessel basis and prepared a manufacturing plan, assembly plan, and cost estimate commensurate with the present design. The guidance for the Raytheon/CB&I assessment activities was prepared by the ITER Garching Work Site. This guidance provided in the form of work descriptions, sketches, drawings, and costing guidelines for each of the presently identified vacuum vessel Work Breakdown Structure (WBS) elements was compiled in ITER Garching Joint Work Site Memo (Draft No. 9 - G 15 MD 01 94-17-05 W 1). A copy of this document is provided as Appendix 1 to this report. Additional information and clarifications required for the Raytheon/CB&I assessments were coordinated through the US Home Team (USHT) and its technical representative. Design details considered essential to the Task 8 assessments but not available from the ITER Joint Central Team (JCT) were generated by Raytheon/CB&I and documented accordingly.

  3. Fabricating low cost and high performance elastomer lenses using hanging droplets

    Science.gov (United States)

    Lee, W. M.; Upadhya, A.; Reece, P. J.; Phan, Tri Giang

    2014-01-01

    Existing methods for low cost lenses using parallel mold stamping and high temperature reflow requires complex engineering controls to produce high quality lenses. These manufacturing techniques rely on expensive equipment. In this paper, we propose a low cost (< $ 0.01 per pc) flexible moldless lens fabrication method based on curing a hanging transparent polydimethylsiloxane (PDMS) elastomer droplet on a curved substrate. Additional deposition of hanging droplets in the same manner led to a substantial increase in the lens curvature and concomitant decrease in the focal length of the PDMS lenses down to ~2 mm. The shortest focal length lenses were shown to collimate light from a bare light emitting diode (LED) and image microscopic structures down to around 4 µm with 160x magnification. Our hanging droplet lens fabrication technique heralds a new paradigm in the manufacture of low cost, high performance optical lenses for the masses. Using these lenses, we were able to transform an ordinary commercial smartphone camera into a low-cost digital dermascope (60x magnification) that can readily visualize microscopic structures on skin such as sweat pores. PMID:24877020

  4. Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Wang, Yundong [Department of Chemical Engineering, Tsinghua University, State Key Lab of Chemical Engineering, Beijing 100084 (China); Fan, Xing, E-mail: foxcqdx@cqu.edu.cn [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Tao, Changyuan [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China)

    2016-02-15

    Graphical abstract: - Highlights: • Fabric-type flexible solar cells have been assembled on Zn-plated wires and meshes. • Metal Zn can improve the carriers transfer over the metal/ZnO nanoarrays interface. • A current increase by ∼6 mA/cm{sup 2} was realized by plating Zn on various metal substrates. • All-solid fabric-type DSSC was also assembled on Zn-plated metal wires. - Abstract: Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm{sup 2} could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

  5. Preparation and Evaluation of Multi-Layer Anodes of Solid Oxide Fuel Cell

    Science.gov (United States)

    Santiago, Diana; Farmer, Serene C.; Setlock, John A.

    2012-01-01

    The development of an energy device with abundant energy generation, ultra-high specific power density, high stability and long life is critical for enabling longer missions and for reducing mission costs. Of all different types of fuel cells, the solid oxide fuel cells (SOFC) is a promising high temperature device that can generate electricity as a byproduct of a chemical reaction in a clean way and produce high quality heat that can be used for other purposes. For aerospace applications, a power-to-weight of (is) greater than 1.0 kW/kg is required. NASA has a patented fuel cell technology under development, capable of achieving the 1.0 kW/kg figure of merit. The first step toward achieving these goals is increasing anode durability. The catalyst plays an important role in the fuel cells for power generation, stability, efficiency and long life. Not only the anode composition, but its preparation and reduction are key to achieving better cell performance. In this research, multi-layer anodes were prepared varying the chemistry of each layer to optimize the performance of the cells. Microstructure analyses were done to the new anodes before and after fuel cell operation. The cells' durability and performance were evaluated in 200 hrs life tests in hydrogen at 850 C. The chemistry of the standard nickel anode was modified successfully reducing the anode degradation from 40% to 8.4% in 1000 hrs and retaining its microstructure.

  6. Rapid and low-cost fabrication of polystyrene-based molds for PDMS microfluidic devices using a CO2 laser

    KAUST Repository

    Li, Huawei

    2011-11-01

    In this article, we described a rapid and low-cost method to fabricate polystyrene molds for PDMS microfluidic devices using a CO2 laser system. It takes only several minutes to fabricate the polystyrene mold with bump pattern on top of it using a CO2 laser system. The bump pattern can be easily transferred to PDMS and fabricate microchannles as deep as 3μm on PDMS. © (2012) Trans Tech Publications, Switzerland.

  7. Cost-effective fabrication of thermal- and chemical-stable ZIF-9 nanocrystals at ammonia atmosphere

    Science.gov (United States)

    Ebrahimi, Arash; Mansournia, Mohammadreza

    2017-12-01

    In this study, room temperature synthesis of zeolitic imidazolate framework-9 (ZIF-9) nanocrystals is reported for the first time at ammonia atmosphere in the absence of any organic additive. High thermal stability of the as-fabricated ZIF-9 up to 300 °C is illustrated by TG and XRD data. Also, the chemical resistance of product to harsh and severe solvothermal conditions introduces it to be an objective as potential material in many applications. Besides, the modest microporosity of the as-obtained ZIF-9 materials attracts more attentions for further investigation compared to those fabricated in organic solvents. By and large, the represented low-cost and room temperature synthetic method can be applicable in the large scale preparation of ZIF-9 for potentially practical utilization.

  8. A low-cost fabrication method for sub-millimeter wave GaAs Schottky diode

    Science.gov (United States)

    Jenabi, Sarvenaz; Deslandes, Dominic; Boone, Francois; Charlebois, Serge A.

    2017-10-01

    In this paper, a submillimeter-wave Schottky diode is designed and simulated. Effect of Schottky layer thickness on cut-off frequency is studied. A novel microfabrication process is proposed and implemented. The presented microfabrication process avoids electron-beam (e-beam) lithography which reduces the cost. Also, this process provides more flexibility in selection of design parameters and allows significant reduction in the device parasitic capacitance. A key feature of the process is that the Schottky contact, the air-bridges, and the transmission lines, are fabricated in a single lift-off step. This process relies on a planarization method that is suitable for trenches of 1-10 μm deep and is tolerant to end-point variations. The fabricated diode is measured and results are compared with simulations. A very good agreement between simulation and measurement results are observed.

  9. Technology, safety and costs of decommissioning a reference small mixed oxide fuel fabrication plant. Volume 2. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, C. E.; Murphy, E. S.; Schneider, K. J.

    1979-01-01

    Volume 2 contains appendixes on small MOX fuel fabrication facility description, site description, residual radionuclide inventory estimates, decommissioning, financing, radiation dose methodology, general considerations, packaging and shipping of radioactive materials, cost assessment, and safety (JRD)

  10. Generalized approach to design multi-layer stacks for enhanced optical detectability of ultrathin layers

    Science.gov (United States)

    Hutzler, A.; Matthus, C. D.; Rommel, M.; Frey, L.

    2017-01-01

    The optical detectability of ultrathin conductive films (down to one atomic layer) can be enhanced by choosing distinct layer-stacks. A simple analytical approach using the transfer matrix method is applied for calculating the reflectance of arbitrary multi-layer stack systems with and without the ultrathin layer of interest on top in a wide wavelength range, including both the visible spectrum and the ultraviolet spectrum. Then, the detectability defined by the Michelson contrast was calculated. Performing these calculations for thickness variations of the individual layers in the stack allows determining optimum layer thicknesses, e.g., maximum overall contrast or maximum contrast for a given wavelength. To demonstrate the validity of the methodology, two thin film stacks were investigated, which use p-type silicon as a substrate material and partially covered by a single-layer graphene as a top layer. For each stack, two samples with different layer thicknesses were fabricated and their experimentally determined reflectance was compared to the calculated values. The first system consists of a single SiO2 layer with a thickness of 147 nm and 304 nm, respectively, and the second is a double layer stack consisting of a Si3N4 layer with a thickness of 54 nm and 195 nm, respectively, on top of an 11 nm SiO2 film. The Michelson contrast of single-layer graphene flakes on the latter layer stacks becomes very high (absolute value of more than 0.3) in the visible wavelength range. Additionally, in the UV-B range a large difference in the reflection of selected SiO2 layer thicknesses on silicon substrates with and without single-layer graphene on top is found with a decrease in the measured reflectance of up to 33%. The measured and calculated values showed a high conformity suggesting this approach usable for the calculation of reflectance and transmittance properties of arbitrary layer stack systems including thin conductive layers.

  11. High Speed, Low Cost Fabrication of Gas Diffusion Electrodes for Membrane Electrode Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    DeCastro, Emory S.; Tsou, Yu-Min; Liu, Zhenyu

    2013-09-20

    Fabrication of membrane electrode assemblies (MEAs) depends on creating inks or pastes of catalyst and binder, and applying this suspension to either the membrane (catalyst coated membrane) or gas diffusion media (gas diffusion electrode) and respectively laminating either gas diffusion media or gas diffusion electrodes (GDEs) to the membrane. One barrier to cost effective fabrication for either of these approaches is the development of stable and consistent suspensions. This program investigated the fundamental forces that destabilize the suspensions and developed innovative approaches to create new, highly stable formulations. These more concentrated formulations needed fewer application passes, could be coated over longer and wider substrates, and resulted in significantly lower coating defects. In March of 2012 BASF Fuel Cell released a new high temperature product based on these advances, whereby our customers received higher performing, more uniform MEAs resulting in higher stack build yields. Furthermore, these new materials resulted in an “instant” increase in capacity due to higher product yields and material throughput. Although not part of the original scope of this program, these new formulations have also led us to materials that demonstrate equivalent performance with 30% less precious metal in the anode. This program has achieved two key milestones in DOE’s Manufacturing R&D program: demonstration of processes for direct coating of electrodes and continuous in-line measurement for component fabrication.

  12. Low cost, p-ZnO/n-Si, rectifying, nano heterojunction diode: Fabrication and electrical characterization.

    Science.gov (United States)

    Kabra, Vinay; Aamir, Lubna; Malik, M M

    2014-01-01

    A low cost, highly rectifying, nano heterojunction (p-ZnO/n-Si) diode was fabricated using solution-processed, p-type, ZnO nanoparticles and an n-type Si substrate. p-type ZnO nanoparticles were synthesized using a chemical synthesis route and characterized by XRD and a Hall effect measurement system. The device was fabricated by forming thin film of synthesized p-ZnO nanoparticles on an n-Si substrate using a dip coating technique. The device was then characterized by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The effect of UV illumination on the I-V characteristics was also explored and indicated the formation of a highly rectifying, nano heterojunction with a rectification ratio of 101 at 3 V, which increased nearly 2.5 times (232 at 3 V) under UV illumination. However, the cut-in voltage decreases from 1.5 V to 0.9 V under UV illumination. The fabricated device could be used in switches, rectifiers, clipper and clamper circuits, BJTs, MOSFETs and other electronic circuitry.

  13. Low cost, p-ZnO/n-Si, rectifying, nano heterojunction diode: Fabrication and electrical characterization

    Directory of Open Access Journals (Sweden)

    Vinay Kabra

    2014-11-01

    Full Text Available A low cost, highly rectifying, nano heterojunction (p-ZnO/n-Si diode was fabricated using solution-processed, p-type, ZnO nanoparticles and an n-type Si substrate. p-type ZnO nanoparticles were synthesized using a chemical synthesis route and characterized by XRD and a Hall effect measurement system. The device was fabricated by forming thin film of synthesized p-ZnO nanoparticles on an n-Si substrate using a dip coating technique. The device was then characterized by current–voltage (I–V and capacitance–voltage (C–V measurements. The effect of UV illumination on the I–V characteristics was also explored and indicated the formation of a highly rectifying, nano heterojunction with a rectification ratio of 101 at 3 V, which increased nearly 2.5 times (232 at 3 V under UV illumination. However, the cut-in voltage decreases from 1.5 V to 0.9 V under UV illumination. The fabricated device could be used in switches, rectifiers, clipper and clamper circuits, BJTs, MOSFETs and other electronic circuitry.

  14. Cost-efficient fabrication techniques for microchips and interconnects enabled by polycaprolactone

    Science.gov (United States)

    Koesdjojo, Myra T.; Nammoonnoy, Jintana; Wu, Yuanyuan; Frederick, Ryan T.; Remcho, Vincent T.

    2012-11-01

    In this paper we present a novel fabrication technique that utilizes polycaprolactone (PCL) as a bonding medium due to its low melting temperature property. PCL is biodegradable polyester with a melting point of 60 °C, and a glass transition temperature of -60 °C [1-10]. It is used as a rapid bonding medium in the fabrication process that readily produces complete microfluidic chips. The microchannels are produced via laser ablation micromachining and thermal embossing, followed by bonding with PCL. The PCL is uniformly coated on a piece of polymer sheet to produce a thin film on its surface. A complete microfluidic channel is formed by enclosing the open channel with the PCL-coated polymer piece. This fabrication technique lends itself readily to various polymers, such as (poly)methylmethacrylate (PMMA), polycarbonate (PC), polyetherimide (PEI) and poly(ethylene terephthalate) (PETE), facilitating device production for a variety of application, even permitting hybrid polymer chips. The bonding was performed rapidly at 60 °C. This approach provides a more direct method to generate hard polymer microfluidic chips than classical techniques and is therefore highly amendable to rapid prototyping. This work also explores the use of PCL as an alternative approach to making simple, cost-effective universal adhesive for bonding interconnects. Bonding is performed at 60 °C, by placing the adhesive layer in between an interconnect port and a microchip. This method allows for connections to be made easily and quickly.

  15. Near-Net Shape Fabrication Using Low-Cost Titanium Alloy Powders

    Energy Technology Data Exchange (ETDEWEB)

    Dr. David M. Bowden; Dr. William H. Peter

    2012-03-31

    The use of titanium in commercial aircraft production has risen steadily over the last half century. The aerospace industry currently accounts for 58% of the domestic titanium market. The Kroll process, which has been used for over 50 years to produce titanium metal from its mineral form, consumes large quantities of energy. And, methods used to convert the titanium sponge output of the Kroll process into useful mill products also require significant energy resources. These traditional approaches result in product forms that are very expensive, have long lead times of up to a year or more, and require costly operations to fabricate finished parts. Given the increasing role of titanium in commercial aircraft, new titanium technologies are needed to create a more sustainable manufacturing strategy that consumes less energy, requires less material, and significantly reduces material and fabrication costs. A number of emerging processes are under development which could lead to a breakthrough in extraction technology. Several of these processes produce titanium alloy powder as a product. The availability of low-cost titanium powders may in turn enable a more efficient approach to the manufacture of titanium components using powder metallurgical processing. The objective of this project was to define energy-efficient strategies for manufacturing large-scale titanium structures using these low-cost powders as the starting material. Strategies include approaches to powder consolidation to achieve fully dense mill products, and joining technologies such as friction and laser welding to combine those mill products into near net shape (NNS) preforms for machining. The near net shape approach reduces material and machining requirements providing for improved affordability of titanium structures. Energy and cost modeling was used to define those approaches that offer the largest energy savings together with the economic benefits needed to drive implementation. Technical

  16. Effect of antiferromagnetic interfacial coupling on spin-wave resonance frequency of multi-layer film

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Rong-ke, E-mail: rkqiu@163.com; Cai, Wei

    2017-08-15

    Highlights: • A quantum approach is developed to study the SWR of a bicomponent multi-layer films. • The comparison of the SWR in films with FM and AFM interfacial coupling has been made. • The present results show the method to enhance and adjust the SWR frequency of films. - Abstract: We investigate the spin-wave resonance (SWR) frequency in a bicomponent bilayer and triple-layer films with antiferromagnetic or ferromagnetic interfacial couplings, as function of interfacial coupling, surface anisotropy, interface anisotropy, thickness and external magnetic field, using the linear spin-wave approximation and Green’s function technique. The microwave properties for multi-layer magnetic film with antiferromagnetic interfacial coupling is different from those for multi-layer magnetic film with ferromagnetic interfacial coupling. For the bilayer film with antiferromagnetic interfacial couplings, as the lower (upper) surface anisotropy increases, only the SWR frequencies of the odd (even) number modes increase. The lower (upper) surface anisotropy does not affect the SWR frequencies of the even (odd) number modes{sub .} For the multi-layer film with antiferromagnetic interfacial coupling, the SWR frequency of modes m = 1, 3 and 4 decreases while that of mode m = 2 increases with increasing thickness of the film within a proper parameter region. The present results could be useful in enhancing our fundamental understanding and show the method to enhance and adjust the SWR frequency of bicomponent multi-layer magnetic films with antiferromagnetic or ferromagnetic interfacial coupling.

  17. Fabrication and performance analysis of a low cost parabolic type solar cooker

    Science.gov (United States)

    Akter, Farhana Nasrin; Islam, Muhammed Kamrul; Begum, Nurun Nahar

    2017-06-01

    Developing countries depend mostly on natural fuel sources such as wood fuel, fossil fuel (kerosene and liquid petroleum gas) etc. for cooking purpose. However, these are expensive and also lead to the threads like deforestation as well as environmental degradation. An alternative renewable energy source like solar energy can contribute a solution towards the adverse crisis of fuel consumption along with environmental pollution of developing countries. Therefore, this study aims to design and fabricate a cost effective solar cooker for domestic purposes as well as performance analysis in order to evaluate its effectiveness. The cooker has been made of cardboard, tin, aluminum foil (polished and non-polished) and glass. Simple construction with reflectors surrounded by tin was fabricated with 1000ml load of water in the cooker hanging by a stand and observed that the best comparative performance in areas with longest durations of clear sky greatest direct ray falling on the collector cookers under moderate cloudy conditions. By applying better techniques for construction of solar cooker with low maintenance through testing and graphing the result, increasing of temperature with minimum cost for cooking purpose was outcome with portable cooker. In this analysis, analytical and experimental values varied due to fickle weather, however, maximum temperature variation was found 36 degree Celsius with efficiency 8.8% in the cooker made of aluminum foil (non-polished).

  18. Fabrication of low-cost Mod-0A wood-composite wind-turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Lark, R.F.; Gougeon, M.; Thomas, G.; Zuteck, M.

    1983-02-01

    A contract was awarded to Gougeon Brothers, Inc., by NASA Lewis Research Center, under Department of Energy sponsorship, for the development and fabrication of two 60-foot, low-cost wood composite blades for service on a 200-kW Mod-0A wind turbine machine. The contractural effort consisted of blade design and analysis and fabrication phases. This report provides a brief summary of the design and analysis phase, and an indepth review of the blade fabrication phase. The wood composite blades were fabricated by using epoxy resin-bonded laminates of Douglas fir veneers for the leading edge spar sections and honeycomb-cored birch plywood panels for the blade trailing edge or afterbody sections. The blade was joined to the wind turbine hub assembly by epoxy resin-bonded steel load takeoff studs. The wood composite blades were installed in the newest Mod-0A wind turbine test facility at Kukuku, Hawaii called Makini Huila (wind wheel) by the Hawaiians. The wood composite blades have successfully completed high power (average of 150 kW) operations for an 18-month period (nearly 8000 h) prior to replacement with another set of wood composite blades. The original set of blades were taken out of service because of the failure of the shank on one stud. An inspection of the blades at NASA Lewis showed that the shank failure was caused by a high stress concentration at a corrosion pit on the shank fillet radius which resulted in fatigue stresses in excess of the endurance limit. The remainder of the blade, including the embedded portion of the fractured stud, and the entire wood structure was found to be in excellent condition. All of the remaining studs, with the exception of four studs that showed an onset of corrosion, were also in excellent condition. The failed stud, as well as four of the corroded studs were successfully replaced with new studs. The blade is currently in a service-ready condition.

  19. Multi-layered metal nanocrystals in a sol-gel spin-on-glass matrix for flash memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Meiyu Stella [Department of Chemical and Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); Globalfoundries Singapore Pte Ltd, 60 Woodlands Industrial Park D, 738406 (Singapore); Suresh, Vignesh [Department of Chemical and Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); Agency for Science, Technology and Research - A*Star, Institute of Materials Research and Engineering (IMRE), #08-03, 2 Fusionopolis Way, Innovis, 138634 (Singapore); Chan, Mei Yin [School of Materials Science and Engineering (MSE), Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 (Singapore); Ma, Yu Wei [Globalfoundries Singapore Pte Ltd, 60 Woodlands Industrial Park D, 738406 (Singapore); Lee, Pooi See [School of Materials Science and Engineering (MSE), Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 (Singapore); Krishnamoorthy, Sivashankar [Agency for Science, Technology and Research - A*Star, Institute of Materials Research and Engineering (IMRE), #08-03, 2 Fusionopolis Way, Innovis, 138634 (Singapore); Science et Analyse des Materiaux Unit (SAM), Centre de Recherche Public-Gabriel Lippmann, 41, rue du Brill, Belvaux, 4422 (Luxembourg); Srinivasan, M.P., E-mail: srinivasan.madapusi@rmit.edu.au [Department of Chemical and Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); School of Engineering, RMIT University, Building 10, Level 11, Room 14, 376-392 Swanston Street, Melbourne, Victoria, 3001 (Australia)

    2017-01-15

    A simple and low-cost process of embedding metal nanocrystals as charge storage centers within a dielectric is demonstrated to address leakage issues associated with the scaling of the tunnelling oxide in flash memories. Metal nanocrystals with high work functions (nickel, platinum and palladium) were prepared as embedded species in methyl siloxane spin-on-glass (SOG) films on silicon substrates. Sub-10 nm-sized, well-isolated, uniformly distributed, multi-layered nanocrystals with high particle densities (10{sup 11}–10{sup 12} cm{sup −2}) were formed in the films by thermal curing of the spin-coated SOG films containing the metal precursors. Capacitance-Voltage measurements performed on metal-insulator-semiconductor capacitors with the SOG films show that the presence of metal nanocrystals enhanced the memory window of the films to 2.32 V at low operating voltages of ±5 V. These SOG films demonstrated the ability to store both holes and electrons. Capacitance-time measurements show good charge retention of more than 75% after 10{sup 4} s of discharging. This work demonstrates the applicability of the low-cost in-situ sol-gel preparation in contrast to conventional methods that involve multiple and expensive processing steps. - Highlights: • Sub-10 nm sized, well-isolated, uniformly distributed nanoparticle based charge trap memories. • Preparation of multi-layer high work function metal nanocrystals at low cost. • Large memory window of 2.32 V at low operating voltages of ±5 V. • Good charge retention of more than 90% and 75% after 10{sup 3} and 10{sup 4} s of discharging respectively. • Use of a 3 nm thick tunnelling oxide in compliance with ITRS specifications.

  20. Technology, safety and costs of decommissioning a reference small mixed oxide fuel fabrication plant. Volume 1. Main report

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, C. E.; Murphy, E. S.; Schneider, K J

    1979-01-01

    Detailed technology, safety and cost information are presented for the conceptual decommissioning of a reference small mixed oxide fuel fabrication plant. Alternate methods of decommissioning are described including immediate dismantlement, safe storage for a period of time followed by dismantlement and entombment. Safety analyses, both occupational and public, and cost evaluations were conducted for each mode.

  1. Effect of Multi-Layered Corium Formations on Integrity of Steel Components under Steam Explosion Condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hyun; Kim, Tae Hyun; Chang, Yoon-Suk [Kyung Hee University, Yongin (Korea, Republic of); Cho, Yong-Jin [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-10-15

    The object of the present study is to examine effect of multi-layered corium formations on the integrity of steel components under a representative steam explosion condition. In this context, multi-layered corium formation conditions are assumed based on a previous study. Subsequently, stress evaluation of steel components is performed by TNT (trinitrotoluene) model for the steam explosion analysis and their results are discussed. In this paper, comparative numerical analyses were carried out to examine effect of the multi-layered corium formations on integrity of steel components under a typical steam explosion condition and the following conclusions were derived. (1) The highest maximum von Mises stress was calculated at RPV. However, stress values of all components did not exceed their yield strengths. (2) Effect of the 3-layer corium formation was higher than 2-layer corium formation. Resulting von Mises stress increased 20% than that of no corium formation and 16% than that of 2-layer corium formation.

  2. Can we neglect the multi-layer structure of functional networks?

    Science.gov (United States)

    Zanin, Massimiliano

    2015-07-01

    Functional networks, i.e. networks representing dynamic relationships between the components of a complex system, have been instrumental for our understanding of, among others, the human brain. Due to limited data availability, the multi-layer nature of numerous functional networks has hitherto been neglected, and nodes are endowed with a single type of links even when multiple relationships coexist at different physical levels. A relevant problem is the assessment of the benefits yielded by studying a multi-layer functional network, against the simplicity guaranteed by the reconstruction and use of the corresponding single layer projection. Here, I tackle this issue by using as a test case, the functional network representing the dynamics of delay propagation through European airports. Neglecting the multi-layer structure of a functional network has dramatic consequences on our understanding of the underlying system, a fact to be taken into account when a projection is the only available information.

  3. Coordinated Multi-layer Multi-domain Optical Network (COMMON) for Large-Scale Science Applications (COMMON)

    Energy Technology Data Exchange (ETDEWEB)

    Vokkarane, Vinod [University of Massachusetts

    2013-09-01

    We intend to implement a Coordinated Multi-layer Multi-domain Optical Network (COMMON) Framework for Large-scale Science Applications. In the COMMON project, specific problems to be addressed include 1) anycast/multicast/manycast request provisioning, 2) deployable OSCARS enhancements, 3) multi-layer, multi-domain quality of service (QoS), and 4) multi-layer, multidomain path survivability. In what follows, we outline the progress in the above categories (Year 1, 2, and 3 deliverables).

  4. Research of human gesture recognition algorithm based on multi-layer perceptron

    Science.gov (United States)

    Wei, Xiaojuan; Wang, Mingling; Xiao, Liyi

    2017-08-01

    This paper mainly introduces the research of human body state recognition technology based on multi-layer perceptron. By using the application environment of ASUS Xtion pro live infrared camera, this paper focuses on the daily behavior recognition of human body in small area. First is the depth image analysis, this paper extracts the characteristics of the postures that need to be classified and we need a large number of samples. Then the collected samples are trained and classified by the multi-layer perceptron model. Finally, the human state collected by the camera can be identified in real time.

  5. 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.

  6. High quality factor multi-layer symmetric hybrid plasmonic microresonator for sensing applications

    Science.gov (United States)

    Zhang, Meng; Wu, Genzhu

    2017-11-01

    A multi-layer symmetric hybrid plasmonic microresonator with two high-index dielectric microrings symmetrically near the metallic structure is proposed. Benefiting from introducing two dielectric rings near the metal, the multi-layer hybrid plasmonic microresonator has a high quality factor about 10,000, while still capable of retaining a small mode volume around 1 . 27 μm3. As a potential application, the symmetric hybrid microresonator with air-filled gap regions could be used for sensing with a sensitivity high of 210 nm per refraction index unit, a large figure of merit of 1319 due to the high quality factor.

  7. 3D printing scanning electron microscopy sample holders: A quick and cost effective alternative for custom holder fabrication.

    Science.gov (United States)

    Meloni, Gabriel N; Bertotti, Mauro

    2017-01-01

    A simple and cost effective alternative for fabricating custom Scanning Electron Microscope (SEM) sample holders using 3D printers and conductive polylactic acid filament is presented. The flexibility of the 3D printing process allowed for the fabrication of sample holders with specific features that enable the high-resolution imaging of nanoelectrodes and nanopipettes. The precise value of the inner semi cone angle of the nanopipettes taper was extracted from the acquired images and used for calculating their radius using electrochemical methods. Because of the low electrical resistivity presented by the 3D printed holder, the imaging of non-conductive nanomaterials, such as alumina powder, was found to be possible. The fabrication time for each sample holder was under 30 minutes and the average cost was less than $0.50 per piece. Despite being quick and economical to fabricate, the sample holders were found to be sufficiently resistant, allowing for multiple uses of the same holder.

  8. 3D printing scanning electron microscopy sample holders: A quick and cost effective alternative for custom holder fabrication.

    Directory of Open Access Journals (Sweden)

    Gabriel N Meloni

    Full Text Available A simple and cost effective alternative for fabricating custom Scanning Electron Microscope (SEM sample holders using 3D printers and conductive polylactic acid filament is presented. The flexibility of the 3D printing process allowed for the fabrication of sample holders with specific features that enable the high-resolution imaging of nanoelectrodes and nanopipettes. The precise value of the inner semi cone angle of the nanopipettes taper was extracted from the acquired images and used for calculating their radius using electrochemical methods. Because of the low electrical resistivity presented by the 3D printed holder, the imaging of non-conductive nanomaterials, such as alumina powder, was found to be possible. The fabrication time for each sample holder was under 30 minutes and the average cost was less than $0.50 per piece. Despite being quick and economical to fabricate, the sample holders were found to be sufficiently resistant, allowing for multiple uses of the same holder.

  9. Low Cost Fabrication of Silicon Carbide Based Ceramics and Fiber Reinforced Composites

    Science.gov (United States)

    Singh, M.; Levine, S. R.

    1995-01-01

    A low cost processing technique called reaction forming for the fabrication of near-net and complex shaped components of silicon carbide based ceramics and composites is presented. This process consists of the production of a microporous carbon preform and subsequent infiltration with liquid silicon or silicon-refractory metal alloys. The microporous preforms are made by the pyrolysis of a polymerized resin mixture with very good control of pore volume and pore size thereby yielding materials with tailorable microstructure and composition. Mechanical properties (elastic modulus, flexural strength, and fracture toughness) of reaction-formed silicon carbide ceramics are presented. This processing approach is suitable for various kinds of reinforcements such as whiskers, particulates, fibers (tows, weaves, and filaments), and 3-D architectures. This approach has also been used to fabricate continuous silicon carbide fiber reinforced ceramic composites (CFCC's) with silicon carbide based matrices. Strong and tough composites with tailorable matrix microstructure and composition have been obtained. Microstructure and thermomechanical properties of a silicon carbide (SCS-6) fiber reinforced reaction-formed silicon carbide matrix composites are discussed.

  10. Modelling of migration from multi-layers and functional barriers: Estimation of parameters

    NARCIS (Netherlands)

    Dole, P.; Voulzatis, Y.; Vitrac, O.; Reynier, A.; Hankemeier, T.; Aucejo, S.; Feigenbaum, A.

    2006-01-01

    Functional barriers form parts of multi-layer packaging materials, which are deemed to protect the food from migration of a broad range of contaminants, e.g. those associated with reused packaging. Often, neither the presence nor the identity of the contaminants is known, so that safety assessment

  11. Development of a multi-layered psychosocial care system for children in areas of political violence

    NARCIS (Netherlands)

    Jordans, M.J.D.; Tol, W.A.; Komproe, I.H.; Susanty, D.; Vallipuram, A.; Ntamatumba, P.; de Jong, J.T.V.M.

    2010-01-01

    Few psychosocial and mental health care systems have been reported for children affected by political violence in low- and middle income settings and there is a paucity of research-supported recommendations. This paper describes a field tested multi-layered psychosocial care system for children

  12. Simulating ozone dry deposition at a boreal forest with a multi-layer canopy deposition model

    NARCIS (Netherlands)

    Zhou, Putian; Ganzeveld, Laurens; Rannik, Ullar; Zhou, Luxi; Gierens, Rosa; Taipale, Ditte; Mammarella, Ivan; Boy, Michael

    2017-01-01

    A multi-layer ozone (O3) dry deposition model has been implemented into SOSAA (a model to Simulate the concentrations of Organic vapours, Sulphuric Acid and Aerosols) to improve the representation of O3 concentration and flux within and above the forest canopy in the planetary boundary layer. We

  13. From Internationalisation to Education for Global Citizenship: A Multi-Layered History

    Science.gov (United States)

    Haigh, Martin

    2014-01-01

    The evolving narrative on internationalisation in higher education is complex and multi-layered. This overview explores the evolution of thinking about internationalisation among different stakeholder groups in universities. It parses out eight coexisting layers that progress from concerns based largely upon institutional survival and competition…

  14. Large-scale delamination of multi-layers transition metal carbides and carbonitrides "MXenes".

    Science.gov (United States)

    Naguib, Michael; Unocic, Raymond R; Armstrong, Beth L; Nanda, Jagjit

    2015-05-28

    Herein we report on a general approach to delaminate multi-layered MXenes using an organic base to induce swelling that in turn weakens the bonds between the MX layers. Simple agitation or mild sonication of the swollen MXene in water resulted in the large-scale delamination of the MXene layers. The delamination method is demonstrated for vanadium carbide and titanium carbonitride MXenes.

  15. A multi-layered risk exposure assessment approach for the shipping industry

    NARCIS (Netherlands)

    S. Vander Hoorn (Stephen); S. Knapp (Sabine)

    2014-01-01

    markdownabstract__Abstract__ Shipping activity has increased worldwide and maritime administrations are trying to enhance risk mitigation strategies by using proactive approaches. We present and discuss a conceptual framework to minimize potential harm based on a multi-layered approach which can

  16. Comparative proteome analysis of multi-layer cocoon of the silkworm, Bombyx mori.

    Science.gov (United States)

    Zhang, Yan; Zhao, Ping; Dong, Zhaoming; Wang, Dandan; Guo, Pengchao; Guo, Xiaomeng; Song, Qianru; Zhang, Weiwei; Xia, Qingyou

    2015-01-01

    Bombyx mori cocoon has a multi-layer structure that provides optimal protection for silkworm pupa. Research on the mechanical properties of the multi-layer structure revealed structure-property relationships of the cocoon. Here, we investigated the protein components of the B. mori cocoon in terms of its multi-layer structure. Liquid chromatography-tandem mass spectrometry identified 286 proteins from the multiple cocoon layers. In addition to fibroins and sericins, we identified abundant protease inhibitors, seroins and proteins of unknown function. By comparing protein abundance across layers, we found that the outermost layer contained more sericin1 and protease inhibitors and the innermost layer had more seroin1. As many as 36 protease inhibitors were identified in cocoons, showing efficient inhibitory activities against a fungal protease. Thus, we propose that more abundant protease inhibitors in the outer cocoon layers may provide better protection for the cocoon. This study increases our understanding of the multi-layer mechanism of cocoons, and helps clarify the biological characteristics of cocoons. The data have been deposited to the ProteomeXchange with identifier PXD001469.

  17. Comparative proteome analysis of multi-layer cocoon of the silkworm, Bombyx mori.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available Bombyx mori cocoon has a multi-layer structure that provides optimal protection for silkworm pupa. Research on the mechanical properties of the multi-layer structure revealed structure-property relationships of the cocoon. Here, we investigated the protein components of the B. mori cocoon in terms of its multi-layer structure. Liquid chromatography-tandem mass spectrometry identified 286 proteins from the multiple cocoon layers. In addition to fibroins and sericins, we identified abundant protease inhibitors, seroins and proteins of unknown function. By comparing protein abundance across layers, we found that the outermost layer contained more sericin1 and protease inhibitors and the innermost layer had more seroin1. As many as 36 protease inhibitors were identified in cocoons, showing efficient inhibitory activities against a fungal protease. Thus, we propose that more abundant protease inhibitors in the outer cocoon layers may provide better protection for the cocoon. This study increases our understanding of the multi-layer mechanism of cocoons, and helps clarify the biological characteristics of cocoons. The data have been deposited to the ProteomeXchange with identifier PXD001469.

  18. Multi-Layer Mobility Load Balancing in a Heterogeneous LTE Network

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Laselva, Daniela

    2012-01-01

    This paper analyzes the behavior of a distributed Mobility Load Balancing (MLB) scheme in a multi-layer 3GPP (3rd Generation Partnership Project) Long Term Evolution (LTE) deployment with different User Equipment (UE) densities in certain network areas covered with pico cells. Target of the study...

  19. A multi-layered safety perspective on the tsunami disaster in Tohoku, Japan

    NARCIS (Netherlands)

    Tsimopoulou, V.; Jonkman, S.N.; Kolen, B.; Maaskant, B.; Mori, N.; Yasuda, T.

    2012-01-01

    This paper presents an assessment of the multi-layered safety system in Tohoku, Japan based on the tsunami disaster of March 2011. The performed analysis has been based on data provided by local researchers and field observations. First an overview of the tsunami behaviour along the affected

  20. Plane strain deformation of a multi-layered poroelastic half-space by ...

    Indian Academy of Sciences (India)

    The Biot linearized quasi-static theory of fluid-infiltrated porous materials is used to formu- late the problem of the two-dimensional plane strain deformation of a multi-layered poroelastic half-space by surface loads. The Fourier–Laplace transforms of the stresses, displacements, pore pressure and fluid flux in each ...

  1. A multi-layered network of the (Colombian) sovereign securities market

    NARCIS (Netherlands)

    Renneboog, Luc; Leon Rincon, Carlos; Pérez, Jhonatan; Alexandrova-Kabadjova, Bilana; Diehl, Martin; Heuver, Richard; Martinez-Jaramillo, Serafín

    2015-01-01

    We study the network of Colombian sovereign securities settlements. With data from the settlement market infrastructure we study financial institutions’ transactions from three different trading and registering individual networks that we combine into a multi-layer network. Examining this network of

  2. Application of Multi-Layered Polyurethane Foams for Flat-Walled Anechoic Linings

    DEFF Research Database (Denmark)

    Xu, J. F.; Buchholz, Jörg; Fricke, Fergus R.

    2006-01-01

    of the application of multi-layered polyurethane foams as the flat-walled anechoic lining. The investigation includes aspects such as the efficacy of a single layer of material, the minimum number of layers of linings to achieve the minimum overall thickness for low (100Hz), mid (250Hz) and high (500Hz) cut...

  3. Demonstrating multi-layered MAS in control of offshore oil and gas production

    DEFF Research Database (Denmark)

    Lindegaard Mikkelsen, Lars; Næumann, J. R.; Demazeau, Y.

    2013-01-01

    From a control perspective, offshore oil and gas production is very challenging due to the many and potentially conflicting production objectives that arise from the intrinsic complexity of the oil and gas domain. In this paper, we demonstrate how a multi-layered multi-agent system can be used...

  4. Multi-layered satisficing decision making in oil and gas production platforms

    DEFF Research Database (Denmark)

    Lindegaard Mikkelsen, Lars; Demazeau, Yves; Jørgensen, B. N.

    2013-01-01

    From a control perspective, offshore oil and gas production is very challenging due to the many and potentially conflicting production objectives that arise from the intrinsic complexity of the oil and gas domain. In this paper, we show how a multi-layered multi-agent system can be used...

  5. Approximate analysis of rigid plate loading on elastic multi-layered systems

    CSIR Research Space (South Africa)

    Maina, JW

    2008-07-01

    Full Text Available Games software is well known for its capability to compute responses for uniformly distributed load acting on the surface of a multi-layered linear elastic system. In this study a method was developed to approximate rigid plate loading to be used...

  6. Novel techniques for optical sensor using single core multi-layer structures for electric field detection

    Science.gov (United States)

    Ali, Amir R.; Kamel, Mohamed A.

    2017-05-01

    This paper studies the effect of the electrostriction force on the single optical dielectric core coated with multi-layers based on whispering gallery mode (WGM). The sensing element is a dielectric core made of polymeric material coated with multi-layers having different dielectric and mechanical properties. The external electric field deforming the sensing element causing shifts in its WGM spectrum. The multi-layer structures will enhance the body and the pressure forces acting on the core of the sensing element. Due to the gradient on the dielectric permittivity; pressure forces at the interface between every two layers will be created. Also, the gradient on Young's modulus will affect the overall stiffness of the optical sensor. In turn the sensitivity of the optical sensor to the electric field will be increased when the materials of each layer selected properly. A mathematical model is used to test the effect for that multi-layer structures. Two layering techniques are considered to increase the sensor's sensitivity; (i) Pressure force enhancement technique; and (ii) Young's modulus reduction technique. In the first technique, Young's modulus is kept constant for all layers, while the dielectric permittivity is varying. In this technique the results will be affected by the value dielectric permittivity of the outer medium surrounding the cavity. If the medium's dielectric permittivity is greater than that of the cavity, then the ascending ordered layers of the cavity will yield the highest sensitivity (the core will have the smallest dielectric permittivity) to the applied electric field and vice versa. In the second technique, Young's modulus is varying along the layers, while the dielectric permittivity has a certain constant value per layer. On the other hand, the descending order will enhance the sensitivity in the second technique. Overall, results show the multi-layer cavity based on these techniques will enhance the sensitivity compared to the typical

  7. A Rapid and Low-Cost Nonlithographic Method to Fabricate Biomedical Microdevices for Blood Flow Analysis

    Directory of Open Access Journals (Sweden)

    Elmano Pinto

    2014-12-01

    Full Text Available Microfluidic devices are electrical/mechanical systems that offer the ability to work with minimal sample volumes, short reactions times, and have the possibility to perform massive parallel operations. An important application of microfluidics is blood rheology in microdevices, which has played a key role in recent developments of lab-on-chip devices for blood sampling and analysis. The most popular and traditional method to fabricate these types of devices is the polydimethylsiloxane (PDMS soft lithography technique, which requires molds, usually produced by photolithography. Although the research results are extremely encouraging, the high costs and time involved in the production of molds by photolithography is currently slowing down the development cycle of these types of devices. Here we present a simple, rapid, and low-cost nonlithographic technique to create microfluidic systems for biomedical applications. The results demonstrate the ability of the proposed method to perform cell free layer (CFL measurements and the formation of microbubbles in continuous blood flow.

  8. Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices

    Directory of Open Access Journals (Sweden)

    Nhi M. Doan

    2015-03-01

    Full Text Available Integrated microfluidic devices with nanosized array electrodes and microfiltration capabilities can greatly increase sensitivity and enhance automation in immunoassay devices. In this contribution, we utilize the edge-patterning method of thin aluminum (Al films in order to form nano- to micron-sized gaps. Evaporation of high work-function metals (i.e., Au, Ag, etc. on these gaps, followed by Al lift-off, enables the formation of electrical uniform nanowires from low-cost, plastic-based, photomasks. By replacing Al with chromium (Cr, the formation of high resolution, custom-made photomasks that are ideal for low-cost fabrication of a plurality of array devices were realized. To demonstrate the feasibility of such Cr photomasks, SU-8 micro-pillar masters were formed and replicated into PDMS to produce micron-sized filters with 3–4 µm gaps and an aspect ratio of 3. These microfilters were capable of retaining 6 µm beads within a localized site, while allowing solvent flow. The combination of nanowire arrays and micro-pillar filtration opens new perspectives for rapid R&D screening of various microfluidic-based immunoassay geometries, where analyte pre-concentration and highly sensitive, electrochemical detection can be readily co-localized.

  9. Facile synthesis of Ni-decorated multi-layers graphene sheets as effective anode for direct urea fuel cells

    Directory of Open Access Journals (Sweden)

    Ahmed Yousef

    2017-09-01

    Full Text Available A large amount of urea-containing wastewater is produced as a by-product in the fertilizer industry, requiring costly and complicated treatment strategies. Considering that urea can be exploited as fuel, this wastewater can be treated and simultaneously exploited as a renewable energy source in a direct urea fuel cell. In this study, multi-layers graphene/nickel nanocomposites were prepared by a one-step green method for use as an anode in the direct urea fuel cell. Typically, commercial sugar was mixed with nickel(II acetate tetrahydrate in distilled water and then calcined at 800 °C for 1 h. Raman spectroscopy, X-ray diffraction (XRD, scanning electron microscope (SEM, transmission electron microscope (TEM and energy dispersive spectroscopy (EDS were employed to characterize the final product. The results confirmed the formation of multi-layers graphene sheets decorated by nickel nanoparticles. To investigate the influence of metal nanoparticles content, samples were prepared using different amounts of the metal precursor; nickel acetate content was changed from 0 to 5 wt.%. Investigation of the electrochemical characterizations indicated that the sample prepared using the original solution with 3 wt.% nickel acetate had the best current density, 81.65 mA/cm2 in a 0.33 M urea solution (in 1 M KOH at an applied voltage 0.9 V vs Ag/AgCl. In a passive direct urea fuel cell based on the optimal composition, the observed maximum power density was 4.06 × 10−3 mW/cm2 with an open circuit voltage of 0.197 V at room temperature in an actual electric circuit. Overall, this study introduces a cheap and beneficial methodology to prepare effective anode materials for direct urea fuel cells.

  10. Influence of the type of fastening of multi-layered closing panels on the estimate of the sound transmission loss

    Directory of Open Access Journals (Sweden)

    Rovadávia Aline de Jesus Ribas

    Full Text Available Abstract Industrialized closing systems appear as rational solutions in steel-structured construction. These closing systems, consisting of multi-layered panels, have been applied in projects where it is intended to obtain a high sound transmission loss without raising the cost and without using a lot of mass. However, acoustic isolation depends on several factors, including the type of connection between the panels, requiring a preliminary study of the acoustic performance of the closing system to prevent future interventions. This paper uses a simplified graphical method to evaluate the influence of the type of connection (line-line, line-punctual or punctual-punctual of industrialized closing panels on the estimation of the sound transmission loss that occurs across the wall constituted by these panels. The panels are combined, forming multi-layered closings interleaved by a layer of air, either without or with a sound-absorbing material between them. The results show that it is necessary to check the effectiveness of each type of fastening of the closing systems because, for example, for the frequency range between 500 and 2,000 Hz, the sound transmission loss of a closing system consisting of cementitious plate with glass wool and line-punctual and punctual-punctual connections exceeds in 6.25% the sound transmission loss of the same system with line-line fastening. For a system composed of expanded polystyrene with glass wool, the sound transmission loss provided by line-line fastening exceeds in 7.0% the sound transmission loss of the same closing system with line-punctual and punctual-punctual fastenings.

  11. Role of multi-layer foam dressings with Safetac in the prevention of pressure ulcers: a review of the clinical and scientific data.

    Science.gov (United States)

    Davies, Phil

    2016-01-01

    controlled trials, to assess the efficacy and cost-effectiveness of using multi-layer foam dressings with Safetac as a component of standard PU prevention strategies. The results of these studies indicate that the application of multi-layer foam dressings containing Safetac can reduce the occurrence of PUs on anatomical locations such as the sacrum and the heel, and underneath medical devices. Scientists have also developed and used laboratory methods to gain a better understanding of how prophylactic dressings work. The results of these studies indicate that the composition of foam dressings containing Safetac (i.e. their multi-layer structure) sets them apart from other dressings due to their ability to mediate the effects of physical forces (i.e. pressure, friction and shear) and control microclimate, all of which contribute to pressure ulceration. The evidence pool clearly indicates that the prophylactic use of multi-layer foam dressings with Safetac as a component of standard prevention measures is beneficial to the clinician, the health-care provider and the patient. It should be noted that the findings outlined in this review may not be transferable to other products as their makeup and components are likely to differ significantly from those of multi-layer foam dressings with Safetac. As the importance of evidence-based practice and the need for cost-effective care continues to grow, clinicians and provider should carefully consider this point when selecting prophylactic dressings for PU prevention.

  12. HEDL contribution to SRL fuel recycle program. Quarterly report, January--March 1977. [Sensitivity analysis of LMFBR fuel fabrication cost

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, J.F.

    1977-08-01

    Research on LWR fuel cycle is being done in the following categories: economic studies (sensitivity analysis of LMFBR fuel fabrication costs), spent fuel receipt and storage (failure of PWR and BWR fuel assemblies), fuel materials preparation or finishing processes, reduction of TRU waste generation, and environmental impacts. 12 tables. (DLC)

  13. Internet of "printed" Things: low-cost fabrication of autonomous sensing nodes by inkjet printing

    Science.gov (United States)

    Kawahara, Yoshihiro

    2014-11-01

    "What if electronics devices are printed using an inkjet printer even at home?" "What if those devices no longer need a battery?" I will introduce two enabling technologies for the Internet of Things concept. 1. Instant Inkjet Circuits: A low cost, fast and accessible technology to support the rapid prototyping of electronic devices. We demonstrated that "sintering-free" silver nano particle ink with a commodity inkjet printer can be used to fabricate printed circuit board and high-frequency applications such as antennas and sensors. The technology is now commercialized by AgIC, Inc. 2. Wireless Power: Although large amounts of data can be exchanged over a wireless communication link, mobile devices are still tethered by power cables. We are trying to solve this problem by two different approaches: energy harvesting. A simple circuitry comprised of diodes and capacitor can convert ambient radio signals into DC current. Our research revealed the signals from TV tower located 6.5km apart could be used to feed 100 microwatts to power microcontrollers.

  14. Ultra-small coherent thermal conductance using multi-layer photonic crystal

    Science.gov (United States)

    Lau, W. T.; Shen, J.-T.; Veronis, G.; Fan, S.

    2009-02-01

    A multi-layer photonic crystal can be used to suppress coherent thermal conductance below the vacuum conductance value, over the entire high-temperature range. With interlacing layers of silicon and vacuum, heat can only be carried by photons. The thermal conductance of the crystal would then be determined by the photonic band structure. Partial photonic band gaps that present over most of the thermal spectrum, as well as the suppression of evanescent coupling of photons across the vacuum layers at high frequencies, would reduce the amount heat conducting photon channels below that of the vacuum. Thus such multi-layer structures can be very efficient thermal insulators. Besides, the thermal conductance of such structures can exhibit substantial tunability, by merely changing the size of the vacuum spacing.

  15. Extraordinary optical transmission through multi-layered systems of corrugated metallic thin films.

    Science.gov (United States)

    Gan, Choon How; Gbur, Greg

    2009-10-26

    Optical transmission through multi-layered systems of corrugated metallic thin films is investigated by rigorous electromagnetic simulations based on an exact Green tensor method. Compared to a single metal slab of equivalent thickness and volume, it was found that the multi-layered system can significantly impede the field decay, often leading to transmission greater than that expected from the Fabry-Perot resonance-like behavior exhibited by subwavelength slits in a single slab. Extraordinary optical transmission is also observable for systems of layers whose combined thicknesses are much greater than the skin depth of the metal. Structures consisting of up to five layers with a net thickness of 500 nm for the metal films were considered in our study. These findings demonstrate that an appreciable fraction of the optical power that is incident on the thin metal films can be transmitted over distances greater than their skin depth using plasmonic resonances.

  16. PRESSURE-IMPULSE DIAGRAM OF MULTI-LAYERED ALUMINUM FOAM PANELS UNDER BLAST PRESSURE

    Directory of Open Access Journals (Sweden)

    CHANG-SU SHIM

    2013-06-01

    Full Text Available Anti-terror engineering has increasing demand in construction industry, but basis of design (BOD is normally not clear for designers. Hardening of structures has limitations when design loads are not defined. Sacrificial foam claddings are one of the most efficient methods to protect blast pressure. Aluminum foam can have designed yield strength according to relative density and mitigate the blast pressure below a target transmitted pressure. In this paper, multi-layered aluminum foam panels were proposed to enhance the pressure mitigation by increasing effective range of blast pressure. Through explicit finite element analyses, the performance of blast pressure mitigation by the multi-layered foams was evaluated. Pressure-impulse diagrams for the foam panels were developed from extensive analyses. Combination of low and high strength foams showed better applicability in wider range of blast pressure.

  17. Efficient Exciton Diffusion and Resonance-Energy Transfer in Multi-Layered Organic Epitaxial Nanofibers

    DEFF Research Database (Denmark)

    Tavares, Luciana; Cadelano, Michele; Quochi, Francesco

    2015-01-01

    Multi-layered epitaxial nanofibers are exemplary model systems for the study of exciton dynamics and lasing in organic materials due to their well-defined morphology, high luminescence efficiencies, and color tunability. We resort to temperature-dependent cw and picosecond photoluminescence (PL......) spectroscopy to quantify exciton diffusion and resonance-energy transfer (RET) processes in multi-layered nanofibers consisting of alternating layers of para-hexaphenyl (p6P) and α-sexithiophene (6T), serving as exciton donor and acceptor material, respectively. The high probability for RET processes...... is confirmed by Quantum Chemical calculations. The activation energy for exciton diffusion in p6P is determined to be as low as 19 meV, proving p6P epitaxial layers also as a very suitable donor material system. The small activation energy for exciton diffusion of the p6P donor material, the inferred high p6P...

  18. Multi-layer holographic bifurcative neural network system for real-time adaptive EOS data analysis

    Science.gov (United States)

    Liu, Hua-Kuang; Huang, K. S.; Diep, J.

    1993-01-01

    Optical data processing techniques have the inherent advantage of high data throughout, low weight and low power requirements. These features are particularly desirable for onboard spacecraft in-situ real-time data analysis and data compression applications. the proposed multi-layer optical holographic neural net pattern recognition technique will utilize the nonlinear photorefractive devices for real-time adaptive learning to classify input data content and recognize unexpected features. Information can be stored either in analog or digital form in a nonlinear photofractive device. The recording can be accomplished in time scales ranging from milliseconds to microseconds. When a system consisting of these devices is organized in a multi-layer structure, a feedforward neural net with bifurcating data classification capability is formed. The interdisciplinary research will involve the collaboration with top digital computer architecture experts at the University of Southern California.

  19. A Multi-layered target for the Study of Neutron-Unbound Nuclei

    Science.gov (United States)

    Gueye, Paul; Frank, Nathan; Thoennessen, Michael

    2013-04-01

    The MoNA/LISA setup at the National Superconducting Cyclotron Laboratory at Michigan State University has provided an avenue to study the nuclear structure of unbound states/nuclei at and beyond the neutron drip line for the past decade using secondary beams from the Coupled Cyclotron Facility. A new multi-layered Si/Be active target is planned to be built to specifically study neutron unbound nuclei. In these experiments the decay energy is reconstructed from fragment-neutron coincidence measurements which are typically low in count rate. The multi-layered target will allow the use of thicker targets to increase the reaction rates, thus enabling to study currently out of reach nuclei such as 21C, 23C, and 24N. A description of the new setup and physics impact will be discussed.

  20. Observation on the thermal stability of multi-layer graphene with metal nanoparticles with 0D structure

    Science.gov (United States)

    Lee, Jung Woo; Kim, Sun Woo; Shin, Jin Ha; Park, Jong Hwan; Kim, Seok Hun; Song, Young Il; Suh, Su Jeong

    2017-10-01

    We studied the effect of rapid thermal treatment on multi-layer graphene with metal particles in an oxygen gas atmosphere. The multi-layer graphene-coated copper nanoparticles (MGCNs) were produced via electrical explosion in an isopropyl alcohol liquid medium. The MGCNs usually consist of multi-layer graphene shells that tightly surround the core copper nanoparticles without obvious voids. A fracture is induced by tearing the multi-layer graphene structure and the oxidized copper metal particles of the MGCNs after thermal treatment in oxygen gas at a low temperatures, including 25, 100, 200, and 300 °C. The MGCNs were characterized via Raman spectroscopy to obtain the graphene peak and its variation according to the oxygen gas temperature. Transmission electron microscopy was conducted to confirm the effect of the oxygen on the multi-layer graphene and copper nanoparticles phase using oxygen gas. The structure of the copper nanoparticles was observed via x-ray diffraction, and x-ray photoelectron spectroscopy was used to measure the chemical bonding on the multi-layer graphene surfaces treated with oxygen gas. We can show systematically optical images of changes in multi-layer graphene morphology like the 0D structure and existence of functional groups through various analyses after rapid thermal treatment in oxygen.

  1. A KLM-circuit model of a multi-layer transducer for acoustic bladder volume measurements.

    Science.gov (United States)

    Merks, E J W; Borsboom, J M G; Bom, N; van der Steen, A F W; de Jong, N

    2006-12-22

    In a preceding study a new technique to non-invasively measure the bladder volume on the basis of non-linear wave propagation was validated. It was shown that the harmonic level generated at the posterior bladder wall increases for larger bladder volumes. A dedicated transducer is needed to further verify and implement this approach. This transducer must be capable of both transmission of high-pressure waves at fundamental frequency and reception of up to the third harmonic. For this purpose, a multi-layer transducer was constructed using a single element PZT transducer for transmission and a PVDF top-layer for reception. To determine feasibility of the multi-layer concept for bladder volume measurements, and to ensure optimal performance, an equivalent mathematical model on the basis of KLM-circuit modeling was generated. This model was obtained in two subsequent steps. Firstly, the PZT transducer was modeled without PVDF-layer attached by means of matching the model with the measured electrical input impedance. It was validated using pulse-echo measurements. Secondly, the model was extended with the PVDF-layer. The total model was validated by considering the PVDF-layer as a hydrophone on the PZT transducer surface and comparing the measured and simulated PVDF responses on a wave transmitted by the PZT transducer. The obtained results indicated that a valid model for the multi-layer transducer was constructed. The model showed feasibility of the multi-layer concept for bladder volume measurements. It also allowed for further optimization with respect to electrical matching and transmit waveform. Additionally, the model demonstrated the effect of mechanical loading of the PVDF-layer on the PZT transducer.

  2. Deconsolidation and combustion performance of thermally consolidated propellants deterred by multi-layers coating

    Directory of Open Access Journals (Sweden)

    Zheng-gang Xiao

    2014-06-01

    Full Text Available Both heating and solvent-spray methods are used to consolidate the standard grains of double-base oblate sphere propellants plasticized with triethyleneglycol dinitrate (TEGDN (TEGDN propellants to high density propellants. The obtained consolidated propellants are deterred and coated with the slow burning multi-layer coating. The maximum compaction density of deterred and coated consolidated propellants can reach up to 1.39 g/cm3. Their mechanic, deconsolidation and combustion performances are tested by the materials test machine, interrupted burning set-up and closed vessel, respectively. The static compression strength of consolidated propellants deterred by multi-layer coating increases significantly to 18 MPa, indicating that they can be applied in most circumstances of charge service. And the samples are easy to deconsolidate in the interrupted burning test. Furthermore, the closed bomb burning curves of the samples indicate a two-stage combustion phenomenon under the condition of certain thickness of coated multi-layers. After the outer deterred multi-layer coating of consolidated samples is finished burning, the inner consolidated propellants continue to burn and breakup into aggregates and grains. The high burning progressivity can be carefully obtained by the smart control of deconsolidation process and duration of consolidated propellants. The preliminary results of consolidated propellants show that a rapid deconsolidation process at higher deconsolidation pressure is presented in the dynamic vivacity curves of closed bomb test. Higher density and higher macro progressivity of consolidated propellants can be obtained by the techniques in this paper.

  3. A gel-ceramic multi-layer electrolyte for long-life lithium sulfur batteries.

    Science.gov (United States)

    Wang, Qingsong; Wen, Zhaoyin; Jin, Jun; Guo, Jing; Huang, Xiao; Yang, Jianhua; Chen, Chunhua

    2016-01-28

    A newly designed gel-ceramic multi-layer electrolyte has been used as the separator and electrolyte for lithium sulfur (Li-S) batteries. The Li-S cells, free of the shuttle effect, exhibit superior electrochemical performance. With almost no self-discharge, the cell demonstrates an initial discharge specific capacity of up to 725 mA h g(-1) and remains at 700 mA h g(-1) after 300 cycles at the C/2 rate.

  4. Excitation spectrum and high energy plasmons in single- and multi-layer graphene

    OpenAIRE

    Yuan, Shengjun; Roldán, Rafael; Katsnelson, Mikhail I.

    2011-01-01

    In this paper we study the excitation spectrum of single- and multi-layer graphene beyond the Dirac cone approximation. The dynamical polarizability of graphene is computed using a full $\\pi$-band tight-binding model, considering the possibility of inter-layer hopping in the calculation. The effect of electron-electron interaction is considered within the random phase approximation. We further discuss the effect of disorder in the spectrum, which leads to a smearing of the absorption peaks. O...

  5. Taxonomy-driven adaptation of multi-layer applications using templates

    OpenAIRE

    Popescu, Razvan; STAIKOPOULOS, ATHANASIOS; Liu, Peng; Brogi, Antonio; Clarke, Siobh??n

    2010-01-01

    peer-reviewed Current adaptation approaches mainly work in isolation and cannot be easily integrated to tackle complex adaptation scenarios. The few existing cross-layer adaptation techniques are somewhat inflexible because the adaptation process is predefined and static. In this paper we propose a methodology for the dynamic and flexible adaptation of multi-layer applications. We use events to trigger the process of matching adaptation templates, which expose adaptation logic as BPEL pro...

  6. Evaluation of Multi Layers Web-based GIS Approach in Retrieving Tourist Related Information

    OpenAIRE

    Rosilawati Zainol; Zainab Abu Bakar

    2014-01-01

    Geo-based information is getting greater importance among tourists. However, retrieving this information on the web depends heavily on the methods of dissemination. Therefore, this study intends to evaluate methods used in disseminating tourist related geo-based information on the web using partial match query, firstly, in default system which is a single layer approach and secondly, using multi layer web-based Geographic Information System (GIS) approaches. Shah Alam tourist related data are...

  7. Multi-layer canard cycles and translated power functions (vol 244, pg 1329, 2008) Correction

    OpenAIRE

    Dumortier, Freddy; Roussarie, Robert

    2008-01-01

    The paper deals with two-dimensional slow-fast systems and more specifically with multi-layer canard cycles. These are canard cycles passing through n layers of fast orbits, with n⩾2. The canard cycles are subject to n generic breaking mechanisms and we study the limit cycles that can be perturbed from the generic canard cycles of codimension n. We prove that this study can be reduced to the investigation of the fixed points of iterated translated power functions.

  8. High quality reduced graphene oxide through repairing with multi-layered graphene ball nanostructures

    OpenAIRE

    Kyoung Hwan Kim; MinHo Yang; Kyeong Min Cho; Young-Si Jun; Sang Bok Lee; Hee-Tae Jung

    2013-01-01

    We present a simple and up-scalable method to produce highly repaired graphene oxide with a large surface area, by introducing spherical multi-layered graphene balls with empty interiors. These graphene balls are prepared via chemical vapor deposition (CVD) of Ni particles on the surface of the graphene oxides (GO). Transmission electron microscopy and Raman spectroscopy results reveal that defects in the GO surfaces are well repaired during the CVD process, with the help of nickel nanopartic...

  9. MUSIC imaging method for low-high frequency inspection of composite multi-layers

    OpenAIRE

    Rodeghiero, Giacomo; Ding, Ping-Ping; Zhong, Yu; Lambert, Marc; Lesselier, Dominique

    2014-01-01

    International audience; Non-destructive Testing-Evaluation (NdT-E) of damaged multi-layer structures like fiber-made composite materials involved in aeronautic and automotive industries is a topic of great interest to solve problems of viability and security. From eddy currents to test graphite-based materials to microwaves and beyond to test glass-based composite structures, one aims to obtain images of the possibly damaged parts with robust, fast inversion algorithms. In this contribution, ...

  10. A Weld Position Recognition Method Based on Directional and Structured Light Information Fusion in Multi-Layer/Multi-Pass Welding

    Directory of Open Access Journals (Sweden)

    Jinle Zeng

    2018-01-01

    Full Text Available Multi-layer/multi-pass welding (MLMPW technology is widely used in the energy industry to join thick components. During automatic welding using robots or other actuators, it is very important to recognize the actual weld pass position using visual methods, which can then be used not only to perform reasonable path planning for actuators, but also to correct any deviations between the welding torch and the weld pass position in real time. However, due to the small geometrical differences between adjacent weld passes, existing weld position recognition technologies such as structured light methods are not suitable for weld position detection in MLMPW. This paper proposes a novel method for weld position detection, which fuses various kinds of information in MLMPW. First, a synchronous acquisition method is developed to obtain various kinds of visual information when directional light and structured light sources are on, respectively. Then, interferences are eliminated by fusing adjacent images. Finally, the information from directional and structured light images is fused to obtain the 3D positions of the weld passes. Experiment results show that each process can be done in 30 ms and the deviation is less than 0.6 mm. The proposed method can be used for automatic path planning and seam tracking in the robotic MLMPW process as well as electron beam freeform fabrication process.

  11. Multi-layer TiO{sub 2} films prepared by aerosol deposition method for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sung Hwan; Yoon, Young Joon, E-mail: yjyoon@kicet.re.kr

    2013-11-29

    The control of microstructure, from a compact to a porous TiO{sub 2}layer, was investigated for the fabrication of dye-sensitized solar cells (DSSCs) by employing aerosol deposition. A highly compact TiO{sub 2} layer that suppresses electron recombination was grown on fluorine-doped tin oxide electrode by strong impact and the consolidation of sub-micron-size powders. By spraying a mixture powders with different diameters during the aerosol deposition, it was possible to grow a porous TiO{sub 2} layer on the compact layer without the need for binder components. The performance of DSSCs with as-deposited TiO{sub 2}layers produced by aerosol deposition was compared with corresponding values for an annealed sample. The effect of the compact layer on the conversion efficiency of DSSCs was also investigated. The conversion efficiency of DSSCs with a compact layer was enhanced by 62% compared to those without a compact layer. - Highlights: • A TiO{sub 2} multi-layer for dye-sensitized solar cell was grown by aerosol deposition. • A highly compact TiO{sub 2} layer was used to suppress electron recombination. • A porous TiO{sub 2} layer was grown using a mixture of 700 nm and 25 nm-diameter powders. • The conversion efficiency was enhanced by 62% after adding a compact TiO{sub 2} layer.

  12. Three-dimensional cell manipulation and patterning using dielectrophoresis via a multi-layer scaffold structure.

    Science.gov (United States)

    Chu, H K; Huan, Z; Mills, J K; Yang, J; Sun, D

    2015-02-07

    Cell manipulation is imperative to the areas of cellular biology and tissue engineering, providing them a useful tool for patterning cells into cellular patterns for different analyses and applications. This paper presents a novel approach to perform three-dimensional (3D) cell manipulation and patterning with a multi-layer engineered scaffold. This scaffold structure employed dielectrophoresis as the non-contact mechanism to manipulate cells in the 3D domain. Through establishing electric fields via this multi-layer structure, the cells in the medium became polarized and were attracted towards the interior part of the structure, forming 3D cellular patterns. Experiments were conducted to evaluate the manipulation and the patterning processes with the proposed structure. Results show that with the presence of a voltage input, this multi-layer structure was capable of manipulating different types of biological cells examined through dielectrophoresis, enabling automatic cell patterning in the time-scale of minutes. The effects of the voltage input on the resultant cellular pattern were examined and discussed. Viability test was performed after the patterning operation and the results confirmed that majority of the cells remained viable. After 7 days of culture, 3D cellular patterns were observed through SEM. The results suggest that this scaffold and its automated dielectrophoresis-based patterning mechanism can be used to construct artificial tissues for various tissue engineering applications.

  13. Non-localized deformation in Cu−Zr multi-layer amorphous films under tension

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, C. [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zhang, H. [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9 (Canada); Cao, Q.P.; Wang, X.D. [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Zhang, D.X. [State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027 (China); Hu, J.W. [Hangzhou Workers Amateur University, Hangzhou 310027 (China); Liaw, P.K. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Jiang, J.Z., E-mail: jiangjz@zju.edu.cn [International Center for New-Structured Materials (ICNSM), Laboratory of New-Structured Materials, State Key Laboratory of Silicon Materials, and School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2016-09-05

    In metallic glasses (MGs), plastic deformation at room temperature is dominated by highly localized shear bands. Here we report the non-localized deformation under tension in Cu−Zr multi-layer MGs with a pure amorphous structure using large-scale atomistic simulations. It is demonstrated that amorphous samples with high layer numbers, composed of Cu{sub 64}Zr{sub 36} and Cu{sub 40}Zr{sub 60}, or Cu{sub 64}Zr{sub 36} and Cu{sub 50}Zr{sub 50}, present obviously non-localized deformation behavior. We reveal that the deformation behavior of the multi-layer-structured MG films is related but not determined by the deformation behavior of the composed individual layers. The criterion for the deformation mode change for MGs with a pure amorphous structure, in generally, was suggested, i.e., the competition between the elastic-energy density stored and the energy density needed for forming one mature shear band in MGs. Our results provide a promising strategy for designing tensile ductile MGs with a pure amorphous structure at room temperature. - Highlights: • Tensile deformation behaviors in multi-layer MG films. • Films with high layer numbers confirmed with a non-localized deformation behavior. • The deformation mode is reasonably controlled by whether U{sub p} larger than U{sub SB.}.

  14. Topological kink states at the tilt boundary in gated multi-layer graphene

    Science.gov (United States)

    Kim, Eun-Ah; Vaezi, Abolhassan; Liang, Yufeng; Ngai, Darryl; Yang, Li

    2013-03-01

    Search for new realization of symmetry protected topological states with protected edge states is an active area of research. We show that a tilt boundary in gapped multi-layer graphene supports topologically protected gapless kink states. We investigate such kink states from two perspectives: the microscopic perspective of tight-binding model and an ab-initio calculation on bilayer, and the perspective of symmetry protected topological (SPT) states for general multi-layer. We show that the bilayer tilt boundary supports gapless kink states that are undeterred by strain concentrated at the boundary. Further we establish the kink states as concrete examples of edge states of time-reversal symmetric Z-type SPT, protected by T and two U (1) symmetries in the absence of inter-valley mixing. Recent observations of such boundaries in multi-layer samples suggest that transport through these topological kink states might explain the long standing puzzle of sub-gap conductance. We discuss possible topological phase transitions upon breaking subset of symmetries from SPT perspective.

  15. Multi-layer service function chaining scheduling based on auxiliary graph in IP over optical network

    Science.gov (United States)

    Li, Yixuan; Li, Hui; Liu, Yuze; Ji, Yuefeng

    2017-10-01

    Software Defined Optical Network (SDON) can be considered as extension of Software Defined Network (SDN) in optical networks. SDON offers a unified control plane and makes optical network an intelligent transport network with dynamic flexibility and service adaptability. For this reason, a comprehensive optical transmission service, able to achieve service differentiation all the way down to the optical transport layer, can be provided to service function chaining (SFC). IP over optical network, as a promising networking architecture to interconnect data centers, is the most widely used scenarios of SFC. In this paper, we offer a flexible and dynamic resource allocation method for diverse SFC service requests in the IP over optical network. To do so, we firstly propose the concept of optical service function (OSF) and a multi-layer SFC model. OSF represents the comprehensive optical transmission service (e.g., multicast, low latency, quality of service, etc.), which can be achieved in multi-layer SFC model. OSF can also be considered as a special SF. Secondly, we design a resource allocation algorithm, which we call OSF-oriented optical service scheduling algorithm. It is able to address multi-layer SFC optical service scheduling and provide comprehensive optical transmission service, while meeting multiple optical transmission requirements (e.g., bandwidth, latency, availability). Moreover, the algorithm exploits the concept of Auxiliary Graph. Finally, we compare our algorithm with the Baseline algorithm in simulation. And simulation results show that our algorithm achieves superior performance than Baseline algorithm in low traffic load condition.

  16. Diffusion-Based Design of Multi-Layered Ophthalmic Lenses for Controlled Drug Release.

    Science.gov (United States)

    Pimenta, Andreia F R; Serro, Ana Paula; Paradiso, Patrizia; Saramago, Benilde; Colaço, Rogério

    2016-01-01

    The study of ocular drug delivery systems has been one of the most covered topics in drug delivery research. One potential drug carrier solution is the use of materials that are already commercially available in ophthalmic lenses for the correction of refractive errors. In this study, we present a diffusion-based mathematical model in which the parameters can be adjusted based on experimental results obtained under controlled conditions. The model allows for the design of multi-layered therapeutic ophthalmic lenses for controlled drug delivery. We show that the proper combination of materials with adequate drug diffusion coefficients, thicknesses and interfacial transport characteristics allows for the control of the delivery of drugs from multi-layered ophthalmic lenses, such that drug bursts can be minimized, and the release time can be maximized. As far as we know, this combination of a mathematical modelling approach with experimental validation of non-constant activity source lamellar structures, made of layers of different materials, accounting for the interface resistance to the drug diffusion, is a novel approach to the design of drug loaded multi-layered contact lenses.

  17. Evaluation of a multi-layer diffuse reflectance spectroscopy system using optical phantoms

    Science.gov (United States)

    Fredriksson, Ingemar; Saager, Rolf B.; Durkin, Anthony J.; Strömberg, Tomas

    2017-03-01

    A fiber probe-based device for assessing microcirculatory parameters, especially red blood cell (RBC) tissue fraction, their oxygen saturation and speed resolved perfusion, has been evaluated using state-of-the-art multi-layer tissue simulating phantoms. The device comprises both diffuse reflectance spectroscopy (DRS) at two source-detector separations (0.4 and 1.2 mm) and laser Doppler flowmetry (LDF) and use an inverse Monte Carlo method for identifying the parameters of a multi-layered tissue model. First, model parameters affecting scattering, absorption and geometrical parameters are fitted to measured DRS spectra, then speed parameters are fitted to LDF spectra. In this paper, the accuracy of the spectral parameters is evaluated. The measured spectral shapes at the two source-detector separations were in good agreement with forward calculated spectral shapes. In conclusion, the multi-layer skin model based on spectral features of the included chromophores, can reliably estimate the tissue fraction of RBC, its oxygen saturation and the reduced scattering coefficient spectrum of the tissue. Furthermore, it was concluded that some freedom in the relative intensity difference between the two DRS channels is necessary in order to compensate for non-modeled surface structure effects.

  18. Remote Multi-layer Soil Temperature Monitoring System Based on GPRS

    Directory of Open Access Journals (Sweden)

    Ming Kuo CHEN

    2014-02-01

    Full Text Available There is the temperature difference between the upper and lower layer of the shallow soil in the forest. It is a potential energy that can be harvested by thermoelectric generator for the electronic device in the forest. The temperature distribution at different depths of the soil is the first step for thermoelectric generation. A remote multi-layer soil temperature monitoring system based on GPRS is proposed in this paper. The MSP430F149 MCU is used as the main controller of multi-layer soil temperature monitoring system. A temperature acquisition module is designed with DS18B20 and 4 core shielded twisted-pair cable. The GPRS module sends the measured data to remote server through wireless communication network. From the experiments in the campus of Beijing Forestry University, the maximum error of measured temperature in this system is 0.2°C by comparing with professional equipment in the same condition. The results of the experiments show that the system can accurately realize real-time monitoring of multi-layer soil temperature, and the data transmission is stable and reliable.

  19. Simultaneous Multi Layer Access: A High Bandwidth and Low Cost 3D-Stacked Memory Interface

    OpenAIRE

    Lee, Donghyuk; Pekhimenko, Gennady; Khan, Samira; Ghose, Saugata; Mutlu, Onur

    2015-01-01

    Limited memory bandwidth is a critical bottleneck in modern systems. 3D-stacked DRAM enables higher bandwidth by leveraging wider Through-Silicon-Via (TSV) channels, but today's systems cannot fully exploit them due to the limited internal bandwidth of DRAM. DRAM reads a whole row simultaneously from the cell array to a row buffer, but can transfer only a fraction of the data from the row buffer to peripheral IO circuit, through a limited and expensive set of wires referred to as global bitli...

  20. Design and Fabrication of a Low-Cost Three-Dimensional Bioprinter.

    Science.gov (United States)

    McElheny, Colton; Hayes, Daniel; Devireddy, Ram

    2017-12-01

    Three-dimensional (3D) bioprinting offers innovative research vectors for tissue engineering. However, commercially available bioprinting platforms can be cost prohibitive to small research facilities, especially in an academic setting. The goal is to design and fabricate a low-cost printing platform able to deliver cell-laden fluids with spatial accuracy along the X, Y, and Z axes of 0.1 mm. The bioprinter consists of three subassemblies: a base unit, a gantry, and a shuttle component. The platform utilizes four stepper motors to position along three axes and a fifth stepper motor actuating a pump. The shuttle and gantry are each driven along their respective horizontal axes via separate single stepper motor, while two coupled stepper motors are used to control location along the vertical axis. The current shuttle configuration allows for a 5 mL syringe to be extruded within a work envelope of 180 mm × 160 mm × 120 mm (X, Y, Z). The shuttle can easily be reconfigured to accommodate larger volume syringes. An attachment for a laser pen is located such that printing material may be light-activated pre-extrusion. Positional fidelity was established with calipers possessing a resolution to the nearest hundredth millimeter. The motors associated with the X and Y axes were calibrated to approximately 0.02 mm per motor impulse. The Z axis has a theoretical step distance of ∼51 nm, generating 0.04% error over a 10 mm travel distance. The A axis, or pump motor, has an impulse distance of 0.001 mm. The volume extruded by a single impulse is dictated by the diameter of the syringe used. With a 5 mL syringe possessing an inner diameter of 12.35 mm, the pump pushes as little as 0.119 μL. While the Z axis is tuned to the highest resolution settings for the motor driver, the X, Y, and A axes can obtain higher or lower resolution via physical switches on the motor drivers.

  1. A Multi-Layer Intelligent Loss-of-Control Prevention System (LPS) for Flight Control Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main objective of the proposed work is to design and develop a multi-layer intelligent Loss-of-control Prevention System (LPS) for flight control applications....

  2. Low-cost optical fabrication of flexible copper electrode via laser-induced reductive sintering and adhesive transfer

    Science.gov (United States)

    Back, Seunghyun; Kang, Bongchul

    2018-02-01

    Fabricating copper electrodes on heat-sensitive polymer films in air is highly challenging owing to the need of expensive copper nanoparticles, rapid oxidation of precursor during sintering, and limitation of sintering temperature to prevent the thermal damage of the polymer film. A laser-induced hybrid process of reductive sintering and adhesive transfer is demonstrated to cost-effectively fabricate copper electrode on a polyethylene film with a thermal resistance below 100 °C. A laser-induced reductive sintering process directly fabricates a high-conductive copper electrode onto a glass donor from copper oxide nanoparticle solution via photo-thermochemical reduction and agglomeration of copper oxide nanoparticles. The sintered copper patterns were transferred in parallel to a heat-sensitive polyethylene film through self-selective surface adhesion of the film, which was generated by the selective laser absorption of the copper pattern. The method reported here could become one of the most important manufacturing technologies for fabricating low-cost wearable and disposable electronics.

  3. Design and fabrication of a low cost Darrieus vertical axis wing turbine system. Phase I. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1979-06-22

    The contract has two phases, a design phase and a fabrication and installation phase. Presented is the work completed in Phase I, the design phase. The Sandia 17 m was used as the background machine from which design information was drawn. By concentrating the modifications on an existing design, emphasis was focused on component cost reduction rather than selection of optimal configuration or operating modes. The resulting design is a stretched version of the Sandia 17 m preserving the same rotor diameter and many other good features, but in the meantime lighter in weight, larger in capacity, and anticipated to be more cost effective.

  4. Low cost nanomechanical surfaces stress based sensors fabricated by hybrid materials

    Science.gov (United States)

    Escudero, P.; Yeste, J.; Villa, R.; Alvarez, M.

    2017-06-01

    We present the fabrication of nanomechanical surface stress based transducers by using the nowadays knowns as smart materials, to achieve a power-free array of sensors that change their reflective color depending on the surface stress change induced on each sensor. Nanocomposite materials of elastomeric polymers and ordered nanoparticles embedded inside the polymer were chosen for the fabrication process. These composite materials, besides being cheap and easily fabricated in mass production, present a mechanochromic behavior producing a color change of the material when applying a deformation process mainly due to the change in the distance between nanoparticles. We have fabricated arrays of mechanochromic membranes by infiltrating colloidal photonic crystals of polystyrene nanoparticles with Polydimethylsiloxane (PDMS). Hybrids PDMS and 3D or 2D colloidal photonic crystals were prepared, and compared its sensitivity to strain changes. The color, due to the Bragg diffraction (3D) or light scattering (2D), was analyzed by UV-visible spectrometry.

  5. The multi-layered structure of Dps with a novel di-nuclear ferroxidase center.

    Science.gov (United States)

    Ren, Bin; Tibbelin, Gudrun; Kajino, Tsutomu; Asami, Osamu; Ladenstein, Rudolf

    2003-06-06

    The crystallization of cellular components represents a unique survival strategy for bacterial cells under stressed conditions. A highly ordered, layered structure is often formed in such a process, which may involve one or more than one type of bio-macromolecules. The main advantage of biocrystallization has been attributed to the fact that it is a physical process and thus is independent of energy consumption. Dps is a protein that crystallizes to form a multi-layered structure in starved cells in order to protect DNA against oxidative damage and other detrimental factors. The multi-layered crystal structure of a Dps protein from Bacillus brevis has been revealed for the first time at atomic resolution in the absence of DNA. Inspection of the structure provides the first direct evidence for the existence of a di-nuclear ferroxidase center, which possesses unique features among all the di-iron proteins identified so far. It constitutes the structural basis for the ferroxidase activity of Dps in the crystalline state as well as in solution. This finding proves that the enzymatic process of detoxification of metal ions, which may cause severe oxidative damage to DNA, is the other important aspect of the defense mechanism performed by Dps. In the multi-layered structure, Dps dodecamers are organized in a highly ordered manner. They adopt the classic form of hexagonal packing in each layer of the structure. Such arrangement results in reinforced structural features that would facilitate the attraction and absorption of metal ions from the environment. The highly ordered layered structure may provide an ideal basis for the accommodation of DNA between the layers so that it can be isolated and protected from harmful factors under stress conditions.

  6. Design optimization of multi-layer Silicon Carbide cladding for light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youho, E-mail: euo@unm.edu [Department of Nuclear Engineering, University of New Mexico, MSC01 1120 1 University of New Mexico, Albuquerque, NM 87131 (United States); NO, Hee Cheon, E-mail: hcno@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Jeong Ik, E-mail: jeongiklee@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2017-01-15

    Highlights: • SiC cladding designs are optimized with a multi-layer structural analysis code. • Layer radial thickness fraction that minimizes cladding fracture probability exists. • The demonstrated procedure is applicable for multi-layer SiC cladding design. • Duplex SiC with the inner composite fraction ∼0.4 is optimal in a reference case. • Increasing composite thermal conductivity markedly decreases SiC cladding stress. - Abstract: A parametric study that demonstrates a methodology for determining the optimum bilayer composition in a duplex SiC cladding is discussed. The structural performance of multi-layer SiC cladding design is significantly affected by radial thickness fraction of each layer. This study shows that there exists an optimal composite/monolith radial thickness fraction that minimizes failure probability for a duplex SiC cladding in steady-state operation. An exemplary reference case study shows that the duplex cladding with the inner composite fraction ∼0.4 and the outer CVD-SiC fraction ∼0.6 is found to be the optimal SiC cladding design for the current PWRs with the reference material choice for CVD-SiC and fiber reinforced composite. A marginal increase in the composite fraction from the presented optimal designs may lead to increase structural integrity by introducing some unquantified merits such as increasing damage tolerance. The major factors that affect the optimum cladding designs are temperature gradients and internal gas pressure. Clad wall thickness, thermal conductivity, and Weibull modulus are among the key design parameters/material properties.

  7. Vortex dynamics in Hg-based multi- and super-multi-layered cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Crisan, A; Button, T W; Abell, J S [Department of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Tanaka, Y; Iyo, A; Matsuhata, H; Shivagan, D D; Shirage, P M [National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Tokiwa, K; Watanabe, T [Tokyo University of Science, Noda, Chiba 278-8510 (Japan)], E-mail: I.A.Crisan@bham.ac.uk

    2008-02-01

    Hg-based multi- and super-multi-layered cuprates HgBa{sub 2}Ca{sub n-1}Cu{sub n}O{sub y} (Hg:12(n-1)n) (n{>=}4) are composed of the charge reservoir layer (CRL) HgBa{sub 2}O{sub x}, and of CuO{sub 2} planes: outer planes (OP) with pyramidal oxygen coordination and inner planes (IP) with square oxygen coordination, with different charge distribution. This fact gives rise to very interesting phenomena, like coexistence of superconductivity (SC) in OPs with antiferromagnetism (AF) in IPs in Hg:1245. The dependence of T{sub c} on the number n of CuO{sub 2} planes is also interesting: for n increasing from 4 to 5 and to 6, T{sub c} decrease from 125 to 108 and then to about 103 K; further increase in n keeps T{sub c} constant at about 103 K. In Hg:1245 we show that the AF ordering at T{sub N} of 60 K has no influence on vortex dynamics, and there is a quite robust c-axis supercurrent. Vortex melting lines of various samples showed that Hg-based multi-layered cuprates (n = 4, 5) behaves in the usual way (increasing n resulted in decrease of Josephson coupling (JC) and a less sharp melting line) and are well described by the usual anisotropic GL-based theory. Samples with n {>=} 6 have all the same melting line, suggesting that, in this case, the short-range JC becomes much less important than the long-range magnetic coupling (MC). However, since the JC between two pancakes in OPs of adjacent unit cells (pancakes separated by the thin CRL) is large, we suggest that the vortex matter in Hg-based super-multi-layered cuprates is composed of magnetically-coupled pancake-vortex-molecules.

  8. Cosmic radiation shielding properties of COLUMBUS and REMSIM multi-layer external shells

    Science.gov (United States)

    Durante, Marco; Manti, Lorenzo; Rusek, Adam; Belluco, Maurizio; Lobascio, Cesare

    The European module COLUMBUS has been recently installed on the International Space Station. Future plans for exploration involve the use of inflatable modules, such as the REMSIM concept proposed in a previous ESA funded study. We studied the radiation shielding properties of COLUMBUS and REMSIM external shell using 1 GeV/n Feor H-ions accelerated at the NASA Space Radiation Laboratory at the Brookhaven National Laboratory (Long Island, NY, USA). COLUMBUS has a 22 mm rigid multi-layer shell with Al, Nextel and Kevlar, as materials of the double bumper for meteoroids and debris protection, MLI for thermal reasons and again Al as pressure shell. Inside the module, astronauts are further protected by secondary structures, including racks, a number of electronic devices and payload equipment. This internal equipment has been simulated using Al and Kevlar, bringing the total thickness to about 15 g/cm2. REMSIM consists of a thermal multi-layer (MLI), four Nextel layers used to provide shock of the impacting micro-meteoroids, a ballistic restraint multi-layer of Kevlar used to absorb debris cloud's kinetic energy, a Kevlar structural restraint to support pressure loads incurred from inflating the module. To contain air inside the module, REMSIM adopts three layers of airtight material separated by two layers of Kevlar (air bladder). A final layer of Nomex provide protection against punctures and fire. In the flight configuration there are also spacer elements (foam) needed to guarantee correct spacing between consecutive bumper layers. These spacers were not included in the tests, making the total thickness about 1.1 cm. The internal equipment in REMSIM was not been defined, but due to its application for exploration missions it was decided to exploit water, valuable resource used for drinking, washing and technical usage, as a radiation shielding. In this test, we have included about 8 cm of water. Measured dose attenuation shows that the Columbus module reduces the

  9. Interdependent multi-layer networks: modeling and survivability analysis with applications to space-based networks.

    Science.gov (United States)

    Castet, Jean-Francois; Saleh, Joseph H

    2013-01-01

    This article develops a novel approach and algorithmic tools for the modeling and survivability analysis of networks with heterogeneous nodes, and examines their application to space-based networks. Space-based networks (SBNs) allow the sharing of spacecraft on-orbit resources, such as data storage, processing, and downlink. Each spacecraft in the network can have different subsystem composition and functionality, thus resulting in node heterogeneity. Most traditional survivability analyses of networks assume node homogeneity and as a result, are not suited for the analysis of SBNs. This work proposes that heterogeneous networks can be modeled as interdependent multi-layer networks, which enables their survivability analysis. The multi-layer aspect captures the breakdown of the network according to common functionalities across the different nodes, and it allows the emergence of homogeneous sub-networks, while the interdependency aspect constrains the network to capture the physical characteristics of each node. Definitions of primitives of failure propagation are devised. Formal characterization of interdependent multi-layer networks, as well as algorithmic tools for the analysis of failure propagation across the network are developed and illustrated with space applications. The SBN applications considered consist of several networked spacecraft that can tap into each other's Command and Data Handling subsystem, in case of failure of its own, including the Telemetry, Tracking and Command, the Control Processor, and the Data Handling sub-subsystems. Various design insights are derived and discussed, and the capability to perform trade-space analysis with the proposed approach for various network characteristics is indicated. The select results here shown quantify the incremental survivability gains (with respect to a particular class of threats) of the SBN over the traditional monolith spacecraft. Failure of the connectivity between nodes is also examined, and the

  10. Interdependent multi-layer networks: modeling and survivability analysis with applications to space-based networks.

    Directory of Open Access Journals (Sweden)

    Jean-Francois Castet

    Full Text Available This article develops a novel approach and algorithmic tools for the modeling and survivability analysis of networks with heterogeneous nodes, and examines their application to space-based networks. Space-based networks (SBNs allow the sharing of spacecraft on-orbit resources, such as data storage, processing, and downlink. Each spacecraft in the network can have different subsystem composition and functionality, thus resulting in node heterogeneity. Most traditional survivability analyses of networks assume node homogeneity and as a result, are not suited for the analysis of SBNs. This work proposes that heterogeneous networks can be modeled as interdependent multi-layer networks, which enables their survivability analysis. The multi-layer aspect captures the breakdown of the network according to common functionalities across the different nodes, and it allows the emergence of homogeneous sub-networks, while the interdependency aspect constrains the network to capture the physical characteristics of each node. Definitions of primitives of failure propagation are devised. Formal characterization of interdependent multi-layer networks, as well as algorithmic tools for the analysis of failure propagation across the network are developed and illustrated with space applications. The SBN applications considered consist of several networked spacecraft that can tap into each other's Command and Data Handling subsystem, in case of failure of its own, including the Telemetry, Tracking and Command, the Control Processor, and the Data Handling sub-subsystems. Various design insights are derived and discussed, and the capability to perform trade-space analysis with the proposed approach for various network characteristics is indicated. The select results here shown quantify the incremental survivability gains (with respect to a particular class of threats of the SBN over the traditional monolith spacecraft. Failure of the connectivity between nodes is also

  11. The measuring technique developed to evaluate the thermal diffusivity of the multi-layered thin film specimens

    Directory of Open Access Journals (Sweden)

    Li Tse-Chang

    2017-01-01

    Full Text Available In the present study, the thermal diffusivities of the Al, Si and ITO films deposited on the SUS304 steel substrate are evaluated via the present technique. Before applying this technique, the temperature for the thin film of the multi-layered specimen is developed theoretically for the one- dimensional steady heat conduction in response to amplitude and frequency of the periodically oscillating temperature imposed by a peltier placed beneath the specimen's substrate. By the thermal-electrical data processing system excluding the lock-in amplifier, the temperature frequency a3 has been proved first to be independent of the electrical voltage applied to the peltier and the contact position of the thermocouples. The experimental data of phase difference for three kinds of specimen are regressed well by a straight line with a slope. Then, the thermal diffusivity of the thin film is thus determined if the slope value and the film- thickness are available. In the present arrangements for the thermocouples, two thermal diffusivity values are quite close each other and valid for every kind of specimen. This technique can provide an efficient, low-cost method for the thermal diffusivity measurements of thin films.

  12. Analytical Solution for Interference Fit for Multi-Layer Thick-Walled Cylinders and the Application in Crankshaft Bearing Design

    Directory of Open Access Journals (Sweden)

    Jun Qiu

    2016-06-01

    Full Text Available Interference fit is an important contact mode used for torque transmission existing widely in engineering design. To prevent trackslip, a certain magnitude of interference has to be ensured; meanwhile, the interference needs to be controlled to avoid failure of the mechanical components caused by high assembly stress. The finite element method (FEM can be used to analyze the stress, while the computational cost of FEM involving nonlinear contact algorithm is relatively high, and likely to come across low precision and convergence problems. Therefore, a rapid and accurate analytical method for estimation is of vital need, especially for the initial design stage when the parameters vary in a large range. In this study, an analytical method to calculate the contact pressure and stress between multi-layer thick-walled cylinders (MLTWC with multi-contact pairs and temperature-raising effect is proposed, and evaluated by FEM. The analytical solution of the interference for tri-layer thick-walled cylinders is applied to the design of engine crankshaft bearing. The results indicate that the analytical method presented in this study can reduce complexity of MLTWC problems and improve the computational efficiency. It is well suited to be used for the calculation model of parameter optimization in early design.

  13. Mass Conservation in Modeling Moisture Diffusion in Multi-Layer Carbon Composite Structures

    Science.gov (United States)

    Nurge, Mark A.; Youngquist, Robert C.; Starr, Stanley O.

    2009-01-01

    Moisture diffusion in multi-layer carbon composite structures is difficult to model using finite difference methods due to the discontinuity in concentrations between adjacent layers of differing materials. Applying a mass conserving approach at these boundaries proved to be effective at accurately predicting moisture uptake for a sample exposed to a fixed temperature and relative humidity. Details of the model developed are presented and compared with actual moisture uptake data gathered over 130 days from a graphite epoxy composite sandwich coupon with a Rohacell foam core.

  14. Carbon nano-onions (multi-layer fullerenes: chemistry and applications

    Directory of Open Access Journals (Sweden)

    Juergen Bartelmess

    2014-11-01

    Full Text Available This review focuses on the development of multi-layer fullerenes, known as carbon nano-onions (CNOs. First, it briefly summarizes the most important synthetic pathways for their preparation and their properties and it gives the reader an update over new developments in the recent years. This is followed by a discussion of the published synthetic procedures for CNO functionalization, which are of major importance when elucidating future applications and addressing drawbacks for possible applications, such as poor solubility in common solvents. Finally, it gives an overview over the fields of application, in which CNO materials were successfully implemented.

  15. Carbon nano-onions (multi-layer fullerenes): chemistry and applications.

    Science.gov (United States)

    Bartelmess, Juergen; Giordani, Silvia

    2014-01-01

    This review focuses on the development of multi-layer fullerenes, known as carbon nano-onions (CNOs). First, it briefly summarizes the most important synthetic pathways for their preparation and their properties and it gives the reader an update over new developments in the recent years. This is followed by a discussion of the published synthetic procedures for CNO functionalization, which are of major importance when elucidating future applications and addressing drawbacks for possible applications, such as poor solubility in common solvents. Finally, it gives an overview over the fields of application, in which CNO materials were successfully implemented.

  16. Multi-layer architecture for realization of network virtualization using MPLS technology

    Directory of Open Access Journals (Sweden)

    Ghasem Ahmadeyan Mazhin

    2017-03-01

    Full Text Available Network virtualization (NV increases Internet flexibility by separating policies from mechanisms. This makes developing new applications, managing the Internet, and supporting different applications much easier. In this study, we introduce a multi-layer architecture which combines multi-level multiprotocol label switching (MPLS technology with NV. The proposed architecture combines the high speed advantage of MPLS with the high flexibility of NV. We use MPLS in MPLS technique and encapsulate each MPLS packet within another when it encounters a new virtual network. Our architecture has the potential to improve Internet flexibility and pave the way for deployment and commercialization of NV in next generation networks.

  17. Ti/Al Multi-Layered Sheets: Accumulative Roll Bonding (Part A

    Directory of Open Access Journals (Sweden)

    Jan Romberg

    2016-02-01

    Full Text Available Co-deformation of Al and Ti by accumulative roll bonding (ARB with intermediate heat treatments is utilized to prepare multi-layered Ti/Al sheets. These sheets show a high specific strength due to the activation of various hardening mechanisms imposed during deformation, such as: hardening by grain refinement, work hardening and phase boundary hardening. The latter is even enhanced by the confinement of the layers during deformation. The evolution of the microstructure with a special focus on grain refinement and structural integrity is traced, and the correlation to the mechanical properties is shown.

  18. Partnering with Youth to Map Their Neighborhood Environments: A Multi-Layered GIS Approach

    Science.gov (United States)

    Topmiller, Michael; Jacquez, Farrah; Vissman, Aaron T.; Raleigh, Kevin; Miller-Francis, Jenni

    2014-01-01

    Mapping approaches offer great potential for community-based participatory researchers interested in displaying youth perceptions and advocating for change. We describe a multi-layered approach for gaining local knowledge of neighborhood environments that engages youth as co-researchers and active knowledge producers. By integrating geographic information systems (GIS) with environmental audits, an interactive focus group, and sketch mapping, the approach provides a place-based understanding of physical activity resources from the situated experience of youth. Youth report safety and a lack of recreational resources as inhibiting physical activity. Maps reflecting youth perceptions aid policy-makers in making place-based improvements for youth neighborhood environments. PMID:25423245

  19. Degradation of Multi-Layer Insulation (MLI) Retrieved from the Hubble Space Telescope

    Science.gov (United States)

    Mohammed, Jelila S.; deGroh, Kim, K.

    2011-01-01

    Multi-Layer Insulation (MLI) returned during Servicing Mission 4 are still being analyzed. Analysis has revealed degradation of optical, thermal, and mechanical properties, increased crystallinity, and reduction in fluorine/carbon ratio of aluminized-Teflon fluorinated ethylene propylene (Al-FEP) FEP. These material properties can be affected by high temperatures on orbit, increased radiation exposure, and in some cases contamination from materials in close proximity to the insulation on orbit. Preliminary results support conclusions of previous studies: areas of Al-FEP that received higher levels of solar exposure show more degradation (high temperatures and radiation combined).

  20. REPEATED PHOTOGRAMMETRIC MEASUREMENTS AT SHAPING GEOTECHNICAL MODELS OF MULTI-LAYER LANDSLIDES

    Directory of Open Access Journals (Sweden)

    Želimir Ortolan

    1992-12-01

    Full Text Available Repeated photogrammetric measurements are a valuable source of »conserved« information during final shaping of geotechnical models of complex multi-layer landslides. Photogrammetric measurements of a sequence of detailed unchanged points enable establishing the clear limit between the moved and stable parts of the terrain. The paper provides a number of practical and theoretical findings resulting from an adequate interpretation of photogrammetric measurements made on a thoroughly analyzed landslide where a three-level slide was observed. The results obtained indicate that the method used in this paper should be adopted as a standard procedure.

  1. A multi-layered image format for the web with an adaptive layer selection algorithm

    Directory of Open Access Journals (Sweden)

    Tair Milan

    2017-01-01

    Full Text Available In this paper we present a proposed multi-layered image format for use on the web. The format implements an algorithm for selecting adequate layer images depending on the image container's surroundings and size. The layer selection depends on the weighted average brightness of the underlying web page background within the bounds of the image. The proposed image format supports multiple image layers with adjoined thresholds and activation conditions. Depending on these conditions and the underlying background, a layer's visibility will be adequately set. The selection algorithm takes into account the background brightness, each layer's adjoined threshold values, and other newly introduced layer conditions.

  2. Adaptive Multi-Layered Space-Time Block Coded Systems in Wireless Environments

    KAUST Repository

    Al-Ghadhban, Samir

    2014-12-23

    © 2014, Springer Science+Business Media New York. Multi-layered space-time block coded systems (MLSTBC) strike a balance between spatial multiplexing and transmit diversity. In this paper, we analyze the block error rate performance of MLSTBC. In addition, we propose an adaptive MLSTBC schemes that are capable of accommodating the channel signal-to-noise ratio variation of wireless systems by near instantaneously adapting the uplink transmission configuration. The main results demonstrate that significant effective throughput improvements can be achieved while maintaining a certain target bit error rate.

  3. Numerical Solution of Problem for Non-Stationary Heat Conduction in Multi-Layer Bodies

    Directory of Open Access Journals (Sweden)

    R. I. Еsman

    2007-01-01

    Full Text Available A mathematical model for non-stationary heat conduction of multi-layer bodies has been developed. Dirac’s δ-function is used to take into account phase and chemical transformations in one of the wall layers. While formulating a problem non-linear heat conduction equations have been used with due account of dependence of thermal and physical characteristics on temperature. Solution of the problem is realized with the help of methods of a numerical experiment and computer modeling.

  4. Techno-economic performance evaluation of solar tower plants with integrated multi-layered PCM thermocline thermal energy storage - A comparative study to conventional two-tank storage systems

    Science.gov (United States)

    Guedéz, Rafael; Ferruzza, Davide; Arnaudo, Monica; Rodríguez, Ivette; Perez-Segarra, Carlos D.; Hassar, Zhor; Laumert, Björn

    2016-05-01

    Solar Tower Power Plants with thermal energy storage are a promising technology for dispatchable renewable energy in the near future. Storage integration makes possible to shift the electricity production to more profitable peak hours. Usually two tanks are used to store cold and hot fluids, but this means both higher investment costs and difficulties during the operation of the variable volume tanks. Instead, another solution can be a single tank thermocline storage in a multi-layered configuration. In such tank both latent and sensible fillers are employed to decrease the related cost up to 30% and maintain high efficiencies. This paper analyses a multi-layered solid PCM storage tank concept for solar tower applications, and describes a comprehensive methodology to determine under which market structures such devices can outperform the more conventional two tank storage systems. A detail model of the tank has been developed and introduced in an existing techno-economic tool developed by the authors (DYESOPT). The results show that under current cost estimates and technical limitations the multi-layered solid PCM storage concept is a better solution when peaking operating strategies are desired, as it is the case for the two-tier South African tariff scheme.

  5. Direct-referencing Two-dimensional-array Digital Microfluidics Using Multi-layer Printed Circuit Board

    Science.gov (United States)

    Gong, Jian; Kim, Chang-Jin “CJ”

    2008-01-01

    Digital (i.e. droplet-based) microfluidics, by the electrowetting-on-dielectric (EWOD) mechanism, has shown great potential for a wide range of applications, such as lab-on-a-chip. While most reported EWOD chips use a series of electrode pads essentially in one-dimensional line pattern designed for specific tasks, the desired universal chips allowing user-reconfigurable paths would require the electrode pads in two-dimensional pattern. However, to electrically access the electrode pads independently, conductive lines need to be fabricated underneath the pads in multiple layers, raising a cost issue especially for disposable chip applications. In this article, we report the building of digital microfluidic plates based on a printed-circuit-board (PCB), in which multilayer electrical access lines were created inexpensively using mature PCB technology. However, due to its surface topography and roughness and resulting high resistance against droplet movement, as-fabricated PCB surfaces require unacceptably high (~500 V) voltages unless coated with or immersed in oil. Our goal is EWOD operations of aqueous droplets not only on oil-covered but also on dry surfaces. To meet varying levels of performances, three types of gradually complex post-PCB microfabrication processes are developed and evaluated. By introducing land-grid-array (LGA) sockets in the packaging, a scalable digital microfluidics system with reconfigurable and low-cost chip is also demonstrated. PMID:19234613

  6. Simple, Fast, and Cost-Effective Fabrication of Wafer-Scale Nanohole Arrays on Silicon for Antireflection

    Directory of Open Access Journals (Sweden)

    Di Di

    2014-01-01

    Full Text Available A simple, fast, and cost-effective method was developed in this paper for the high-throughput fabrication of nanohole arrays on silicon (Si, which is utilized for antireflection. Wafer-scale polystyrene (PS monolayer colloidal crystal was developed as templates by spin-coating method. Metallic shadow mask was prepared by lifting off the oxygen etched PS beads from the deposited chromium film. Nanohole arrays were fabricated by Si dry etching. A series of nanohole arrays were fabricated with the similar diameter but with different depth. It is found that the maximum depth of the Si-hole was determined by the diameter of the Cr-mask. The antireflection ability of these Si-hole arrays was investigated. The results show that the reflection decreases with the depth of the Si-hole. The deepest Si-hole arrays show the best antireflection ability (reflection 600 nm, which was about 28 percent of the nonpatterned silicon wafer’s reflection. The proposed method has the potential for high-throughput fabrication of patterned Si wafer, and the low reflectivity allows the application of these wafers in crystalline silicon solar cells.

  7. Cost-effective MEMS piezoresistive cantilever-based sensor fabrication for gait movement analysis

    Science.gov (United States)

    Saadon, Salem; Anuar, A. F. M.; Wahab, Yufridin

    2017-03-01

    The conventional photolithography of crystalline silicon technique is limited to two-dimensional and structure scaling. It's also requiring a lot of time and chemical involves for the whole process. These problems can be overcome by using laser micromachining technique, that capable to produce three-dimensional structure and simultaneously avoiding the photo mask needs. In this paper, we reported on the RapidX-250 Excimer laser micromachining with 248 nm KrF to create in-time mask design and assisting in the fabrication process of piezo-resistive micro cantilever structures. Firstly, laser micromachining parameters have been investigated in order to fabricate the acceleration sensor to analyzing human gait movement. Preliminary result shows that the fabricated sensor able to define the movement difference of human motion regarding the electrical characteristic of piezo-resistor.

  8. Engineering multi-layered skeletal muscle tissue by using 3D microgrooved collagen scaffolds.

    Science.gov (United States)

    Chen, Shangwu; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping

    2015-12-01

    Preparation of three-dimensional (3D) micropatterned porous scaffolds remains a great challenge for engineering of highly organized tissues such as skeletal muscle tissue and cardiac tissue. Two-dimensional (2D) micropatterned surfaces with periodic features (several nanometers to less than 100 μm) are commonly used to guide the alignment of muscle myoblasts and myotubes and lead to formation of pre-patterned cell sheets. However, cell sheets from 2D patterned surfaces have limited thickness, and harvesting the cell sheets for implantation is inconvenient and can lead to less alignment of myotubes. 3D micropatterned scaffolds can promote cell alignment and muscle tissue formation. In this study, we developed a novel type of 3D porous collagen scaffolds with concave microgrooves that mimic muscle basement membrane to engineer skeletal muscle tissue. Highly aligned and multi-layered muscle bundle tissues were engineered by controlling the size of microgrooves and cell seeding concentration. Myoblasts in the engineered muscle tissue were well-aligned and had high expression of myosin heavy chain and synthesis of muscle extracellular matrix. The microgrooved collagen scaffolds could be used to engineer organized multi-layered muscle tissue for implantation to repair/restore the function of diseased tissues or be used to investigate the cell-cell interaction in 3D microscale topography. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. A mixture model for robust point matching under multi-layer motion.

    Directory of Open Access Journals (Sweden)

    Jiayi Ma

    Full Text Available This paper proposes an efficient mixture model for establishing robust point correspondences between two sets of points under multi-layer motion. Our algorithm starts by creating a set of putative correspondences which can contain a number of false correspondences, or outliers, in addition to the true correspondences (inliers. Next we solve for correspondence by interpolating a set of spatial transformations on the putative correspondence set based on a mixture model, which involves estimating a consensus of inlier points whose matching follows a non-parametric geometrical constraint. We formulate this as a maximum a posteriori (MAP estimation of a Bayesian model with hidden/latent variables indicating whether matches in the putative set are outliers or inliers. We impose non-parametric geometrical constraints on the correspondence, as a prior distribution, in a reproducing kernel Hilbert space (RKHS. MAP estimation is performed by the EM algorithm which by also estimating the variance of the prior model (initialized to a large value is able to obtain good estimates very quickly (e.g., avoiding many of the local minima inherent in this formulation. We further provide a fast implementation based on sparse approximation which can achieve a significant speed-up without much performance degradation. We illustrate the proposed method on 2D and 3D real images for sparse feature correspondence, as well as a public available dataset for shape matching. The quantitative results demonstrate that our method is robust to non-rigid deformation and multi-layer/large discontinuous motion.

  10. Surface EMG signals based motion intent recognition using multi-layer ELM

    Science.gov (United States)

    Wang, Jianhui; Qi, Lin; Wang, Xiao

    2017-11-01

    The upper-limb rehabilitation robot is regard as a useful tool to help patients with hemiplegic to do repetitive exercise. The surface electromyography (sEMG) contains motion information as the electric signals are generated and related to nerve-muscle motion. These sEMG signals, representing human's intentions of active motions, are introduced into the rehabilitation robot system to recognize upper-limb movements. Traditionally, the feature extraction is an indispensable part of drawing significant information from original signals, which is a tedious task requiring rich and related experience. This paper employs a deep learning scheme to extract the internal features of the sEMG signals using an advanced Extreme Learning Machine based auto-encoder (ELMAE). The mathematical information contained in the multi-layer structure of the ELM-AE is used as the high-level representation of the internal features of the sEMG signals, and thus a simple ELM can post-process the extracted features, formulating the entire multi-layer ELM (ML-ELM) algorithm. The method is employed for the sEMG based neural intentions recognition afterwards. The case studies show the adopted deep learning algorithm (ELM-AE) is capable of yielding higher classification accuracy compared to the Principle Component Analysis (PCA) scheme in 5 different types of upper-limb motions. This indicates the effectiveness and the learning capability of the ML-ELM in such motion intent recognition applications.

  11. Biologically inspired multi-layered synthetic skin for tactile feedback in prosthetic limbs.

    Science.gov (United States)

    Osborn, Luke; Nguyen, Harrison; Betthauser, Joseph; Kaliki, Rahul; Thakor, Nitish

    2016-08-01

    The human body offers a template for many state-of-the-art prosthetic devices and sensors. In this work, we present a novel, sensorized synthetic skin that mimics the natural multi-layered nature of mechanoreceptors found in healthy glabrous skin to provide tactile information. The multi-layered sensor is made up of flexible piezoresistive textiles that act as force sensitive resistors (FSRs) to convey tactile information, which are embedded within a silicone rubber to resemble the compliant nature of human skin. The top layer of the synthetic skin is capable of detecting small loads less than 5 N whereas the bottom sensing layer responds reliably to loads over 7 N. Finite element analysis (FEA) of a simplified human fingertip and the synthetic skin was performed. Results suggest similarities in behavior during loading. A natural tactile event is simulated by loading the synthetic skin on a prosthetic limb. Results show the sensors' ability to detect applied loads as well as the ability to simulate neural spiking activity based on the derivative and temporal differences of the sensor response. During the tactile loading, the top sensing layer responded 0.24 s faster than the bottom sensing layer. A synthetic biologically-inspired skin such as this will be useful for enhancing the functionality of prosthetic limbs through tactile feedback.

  12. Smart Grid as Multi-layer Interacting System for Complex Decision Makings

    Science.gov (United States)

    Bompard, Ettore; Han, Bei; Masera, Marcelo; Pons, Enrico

    This chapter presents an approach to the analysis of Smart Grids based on a multi-layer representation of their technical, cyber, social and decision-making aspects, as well as the related environmental constraints. In the Smart Grid paradigm, self-interested active customers (prosumers), system operators and market players interact among themselves making use of an extensive cyber infrastructure. In addition, policy decision makers define regulations, incentives and constraints to drive the behavior of the competing operators and prosumers, with the objective of ensuring the global desired performance (e.g. system stability, fair prices). For these reasons, the policy decision making is more complicated than in traditional power systems, and needs proper modeling and simulation tools for assessing "in vitro" and ex-ante the possible impacts of the decisions assumed. In this chapter, we consider the smart grids as multi-layered interacting complex systems. The intricacy of the framework, characterized by several interacting layers, cannot be captured by closed-form mathematical models. Therefore, a new approach using Multi Agent Simulation is described. With case studies we provide some indications about how to develop agent-based simulation tools presenting some preliminary examples.

  13. Effects of torsion on the thermal conductivity of multi-layer graphene

    Science.gov (United States)

    Si, Chao; Lu, Gui; Cao, Bing-Yang; Wang, Xiao-Dong; Fan, Zhen; Feng, Zhi-Hai

    2017-05-01

    This work employs the equilibrium molecular dynamics method to study the effects of torsion on the thermal conductivity of multi-layer graphene. Thermal conductivities of twisted 10-layer 433.91 × 99.68 Å2 graphene with torsion angles of 0°, 11.25°, 22.5°, 33.75°, 45°, 67.5°, 90°, 112.5°, and 135° are calculated. The corresponding radial distribution functions and nearest atomic distances are calculated to reveal the effects of torsion on lattice structures. The spectral energy density (SED) method is utilized to analyze the phonon transport properties. It is very interesting that the thermal conductivity of multi-layer graphene decreases slightly at first and then increases with the increasing torsion angle, and the valley is located at θG = 22.5° with the lowest thermal conductivity of 4692.40 W m-1 K-1. The torsion effect can be considered as a combination of the compression effect and the dislocation effect. Further SED analysis confirms that the effect of dislocation on thermal conductivities can be negligible, while the compression effect decreases the phonon lifetimes of flexural out-of-plane acoustic (ZA) branches and increases the ZA group velocities and the phonon specific heat. The decrease becomes dominated when the torsion angle is small, whereas the increase becomes more and more dominated when the torsion angle becomes larger, which are responsible for the reported variation of thermal conductivities.

  14. Cross-Dependency Inference in Multi-Layered Networks: A Collaborative Filtering Perspective.

    Science.gov (United States)

    Chen, Chen; Tong, Hanghang; Xie, Lei; Ying, Lei; He, Qing

    2017-08-01

    The increasingly connected world has catalyzed the fusion of networks from different domains, which facilitates the emergence of a new network model-multi-layered networks. Examples of such kind of network systems include critical infrastructure networks, biological systems, organization-level collaborations, cross-platform e-commerce, and so forth. One crucial structure that distances multi-layered network from other network models is its cross-layer dependency, which describes the associations between the nodes from different layers. Needless to say, the cross-layer dependency in the network plays an essential role in many data mining applications like system robustness analysis and complex network control. However, it remains a daunting task to know the exact dependency relationships due to noise, limited accessibility, and so forth. In this article, we tackle the cross-layer dependency inference problem by modeling it as a collective collaborative filtering problem. Based on this idea, we propose an effective algorithm Fascinate that can reveal unobserved dependencies with linear complexity. Moreover, we derive Fascinate-ZERO, an online variant of Fascinate that can respond to a newly added node timely by checking its neighborhood dependencies. We perform extensive evaluations on real datasets to substantiate the superiority of our proposed approaches.

  15. Enhancement of electroplex emission by using multi-layer device structure

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuanmin [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Teng Feng [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China) and Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China)]. E-mail: advanced9898@126.com; Xu Zheng [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Hou Yanbing [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Wang Yongsheng [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China); Xu Xurong [Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Key Laboratory for Information Storage, Displays and Materials, Beijing 100044 (China)

    2005-04-30

    Electroplex emission based on poly(N-vinylcarbazole) (PVK) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) has been improved dramatically by using a multi-layer device structure indium-tin oxide (ITO)/poly(3,4-ethylenedioxythiophene): poly(styrenesulphonic acid) (PEDOT:PSS)/PVK/BCP/PVK/BCP/LiF/Al. Electroplex emission at 595 nm has been improved about 10 times under low voltage and four times under high voltage compared to the double layer device ITO/PVK/BCP/Al. The maximum brightness of the device also has been improved about eight times. Bright white emission via electroplex formation can be obtained with Commission International d'Eclairage (CIE) coordinates (0.336, 0.320) at 26 V with a brightness of 123 cd/m{sup 2}. Based on the analysis of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the materials, we suggest the enhancement is mainly ascribed to the confinement effect of the quantum-well-like multi-layer device structure. Every hole and electron has more possibilities to cross recombination at the PVK/BCP interface.

  16. Penetration of a Small Caliber Projectile into Single and Multi-layered Targets

    Directory of Open Access Journals (Sweden)

    Riad A.M.

    2010-06-01

    Full Text Available The normal penetration of armor-piercing projectiles into single and multi-layered steel plates has been investigated. An experimental program has been conducted to study the effect of spaced and in-contact layered targets on their ballistic resistance. Armor piercing projectiles with caliber of 7.62 mm were fired against a series of single and multi-layered steel targets. The projectile impact velocities were ranged from 300-600 m/s, whereas the total thicknesses of the tested single, spaced and in-contact layered steel targets were 3 mm. The penetration process of different tested target configurations has been simulated using Autodayn-2D hydrocode. The experimental measurements of the present work were used to discuss the effect of impact velocity, target configurations and number of layers of different spaced and in-contact layered steel targets on their ballistic resistance. In addition, the post-firing examination of the tested targets over the used impact velocity range showed that the single and each layer of spaced and in-contact laminated steel targets were failed by petalling. Finally, the obtained experimental measurements were compared with the corresponding numerical results of Autodyn-2D hydrocode, good agreement was generally obtained.

  17. A New Approach for Severity Estimation of Transversal Cracks in Multi-layered Beams

    Directory of Open Access Journals (Sweden)

    Gilbert-Rainer Gillich

    Full Text Available Abstract Nowadays, the damage severity evaluation in mechanical structures is mostly performed by analyzing the natural frequency shift. The non-isotropic materials, as the multi-layered ones, are wide-spread in industrial applications, due to their interesting physic-mechanical properties. Thus, a deeper approach of multi-layered beams becomes an important request in the research domain. This paper introduces a damage severity estimator by expressing the crack evolution as a function of stored energy. It is well known that the energy stored in a beam without damage is greater than the energy of that damaged beam. As a consequence, the beam deflection can be related to the stored energy. In this regard, the possibility to split the damage localization and the damage severity assessment has been proven, and also the graphical evolution of the natural frequency shift has been achieved as a function of the crack depth. The results achieved by the finite element method (FEM and experimental tests are given in tables and graphics. For the first five vibration modes, a comparison was made between frequencies accomplished by analytical, numerical and experimental analyses, in order to give more credibility to the accuracy of the research data presented in this paper.

  18. APT analyses of deuterium-loaded Fe/V multi-layered films

    KAUST Repository

    Gemma, R.

    2009-04-01

    Interaction of hydrogen with metallic multi-layered thin films remains as a hot topic in recent days Detailed knowledge on such chemically modulated systems is required if they are desired for application in hydrogen energy system as storage media. In this study, the deuterium concentration profile of Fe/V multi-layer was investigated by atom probe tomography (APT) at 60 and 30 K. It is firstly shown that deuterium-loaded sample can easily react with oxygen at the Pd capping layer on Fe/V and therefore, it is highly desired to avoid any oxygen exposure after D(2) loading before APT analysis. The analysis temperature also has an impact on D concentration profile. The result taken at 60 K shows clear traces of surface segregation of D atoms towards analysis surface. The observed diffusion profile of D allows us to estimate an apparent diffusion coefficient D. The calculated D at 60 K is in the order of 10(-17) cm(2)/s, deviating 6 orders of magnitude from an extrapolated value. This was interpreted with alloying, D-trapping at defects and effects of the large extension to which the extrapolation was done. A D concentration profile taken at 30 K shows nosegregation anymore and a homogeneous distribution at C(D) = 0.05(2) D/Me, which is in good accordance with that measured in the corresponding pressure-composition isotherm. (C) 2008 Elsevier B.V. All rights reserved.

  19. Non-destructive Inspection of Multi-layered Composite Using Ultrasonic Signal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Ng, S C; Ismail, N; Ali, Aidy; Sahari, Barkawi [Intelligent System and Robotic Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Yusof, J M; Chu, B W, E-mail: ngsokchoo@gmail.com [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

    2011-02-15

    Composites exhibit higher strength and stiffness, better design practice and greater corrosion resistance compare to metal material. However, composites are susceptible to impact damage and the typical damage behaviour in the laminated composites is fibre-breakage and delamination. Detection of failure in laminated composites is complicated compared with ordinary non-destructive testing for metal materials as they are sensitive to echoes drown in noise due to the properties of the constituent materials and the multi-layered structure of the composites. In the current study, the detection of failure in multi-layered composite materials is investigated. To obtain a high probability of defect detection in composite materials, signal processing algorithms were used to resolve echoes associated with defects in glass fibre-reinforced plastics (GRP) detected by using ultrasonic testing. Pulse-echo method with single transducer was used to transmit and receive ultrasound. The obtained signals were processed to reduce noise and to extract suitable features. Results were validated on GRP with and without defects in order to demonstrate the feasibility of the method on defect detection in composites.

  20. Collaborative multi-layer network coding for cellular cognitive radio networks

    KAUST Repository

    Sorour, Sameh

    2013-06-01

    In this paper, we propose a prioritized multi-layer network coding scheme for collaborative packet recovery in underlay cellular cognitive radio networks. This scheme allows the collocated primary and cognitive radio base-stations to collaborate with each other, in order to minimize their own and each other\\'s packet recovery overheads, and thus improve their throughput, without any coordination between them. This non-coordinated collaboration is done using a novel multi-layer instantly decodable network coding scheme, which guarantees that each network\\'s help to the other network does not result in any degradation in its own performance. It also does not cause any violation to the primary networks interference thresholds in the same and adjacent cells. Yet, our proposed scheme both guarantees the reduction of the recovery overhead in collocated primary and cognitive radio networks, and allows early recovery of their packets compared to non-collaborative schemes. Simulation results show that a recovery overhead reduction of 15% and 40% can be achieved by our proposed scheme in the primary and cognitive radio networks, respectively, compared to the corresponding non-collaborative scheme. © 2013 IEEE.

  1. Gated Silicon Drift Detector Fabricated from a Low-Cost Silicon Wafer

    OpenAIRE

    Hideharu Matsuura; Shungo Sakurai; Yuya Oda; Shinya Fukushima; Shohei Ishikawa; Akinobu Takeshita; Atsuki Hidaka

    2015-01-01

    Inexpensive high-resolution silicon (Si) X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs) are much cheaper to fabricate than commercial silicon drift detectors (SDDs). However, previous GSDDs were fabricated from \\(10\\)-k\\(\\Omega \\cdot\\)cm Si wafers, which are more expensive than \\(2\\)-k\\(\\Omega \\cdot\\)c...

  2. Improvement of the sensitivity of the surface plasmon resonance sensors based on multi-layer modulation techniques

    Science.gov (United States)

    Zhao, Xihong; Chu-Su, Yu; Tsai, Woo-Hu; Wang, Ching-Ho; Chuang, Tsung-Liang; Lin, Chii-Wann; Tsao, Yu-Chia; Wu, Mu-Shiang

    2015-01-01

    In this study, a multi-layer modulation technique was used in an SPR optical fiber sensor to enhance the sensitivity of the SPR optical fiber sensor by adjusting the SPR resonant wavelength. The sputtering process deposited 20 nm of TiO2, 11 nm of SiO2 and 30 nm of gold film on the material surface to change the refractive index. Regardless of the different refractive index solutions (1.32 and 1.36), the sensitivities in wavelength interrogation of the SPR optical fiber with the single gold thin film and multi-layers modulation were 1.08×10-5 RIUs and 1.74×10-6 RIUs, respectively. The results showed the significant differences between the different refractive index solutions of 1.32 and 1.36 using the 850 nm light source to analyze the SPR optical fiber sensor in real-time. The sensitivities in intensity interrogation of the SPR optical fiber with the single gold thin film and multi-layers modulation were 1.08×10-3 RIUs and 1.73×10-4 RIUs, respectively, which indicated that the multi-layer modulation techniques could enhance the sensitivity of the SPR optical fiber sensor. The compact size of the multi-layer SPR fiber sensor had a wider detecting range of the refractive index and higher sensitivity, which had the potential for other applications in biological analysis with suitable wavelength.

  3. Multi-Layered TiO2 Films towards Enhancement of Escherichia coli Inactivation

    Directory of Open Access Journals (Sweden)

    Sorachon Yoriya

    2016-09-01

    Full Text Available Crystalline TiO2 has shown its great photocatalytic properties in bacterial inactivation. This work presents a design fabrication of low-cost, layered TiO2 films assembled reactors and a study of their performance for a better understanding to elucidate the photocatalytic effect on inactivation of E. coli in water. The ability to reduce the number of bacteria in water samples for the layered TiO2 composing reactors has been investigated as a function of time, while varying the parameters of light sources, initial concentration of bacteria, and ratios of TiO2 film area and volume of water. Herein, the layered TiO2 films have been fabricated on the glass plates by thermal spray coating prior to screen printing, allowing a good adhesion of the films. Surface topology and crystallographic phase of TiO2 for the screen-printed active layer have been characterized, resulting in the ratio of anatase:rutile being 80:20. Under exposure to sunlight and a given condition employed in this study, the optimized film area:water volume of 1:2.62 has shown a significant ability to reduce the E. coli cells in water samples. The ratio of surface area of photocatalytic active base to volume of water medium is believed to play a predominant role facilitating the cells inactivation. The kinetic rate of inactivation and its behavior are also described in terms of adsorption of reaction species at different contact times.

  4. Low cost fabrication of graphite epoxy column elements for large space structures

    Science.gov (United States)

    Bluck, R. M.; Johnson, R.

    1979-01-01

    A procedure for fabricating graphite epoxy column elements used in the construction of large space platforms is described. Dry fiber is wound on a tapered aluminum mandrel in the LMSC vertical winding machine, and resin is injected between the mandrel and an outer sleeve. The winding and injection take place at elevated temperature to minimize the thermal expansion problems that arise in curing a tube on an aluminum mandrel when the end fittings are integrally wound.

  5. Gated Silicon Drift Detector Fabricated from a Low-Cost Silicon Wafer

    Directory of Open Access Journals (Sweden)

    Hideharu Matsuura

    2015-05-01

    Full Text Available Inexpensive high-resolution silicon (Si X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs are much cheaper to fabricate than commercial silicon drift detectors (SDDs. However, previous GSDDs were fabricated from \\(10\\-k\\(\\Omega \\cdot\\cm Si wafers, which are more expensive than \\(2\\-k\\(\\Omega \\cdot\\cm Si wafers used in commercial SDDs. To fabricate cheaper portable X-ray fluorescence instruments, we investigate GSDDs formed from \\(2\\-k\\(\\Omega \\cdot\\cm Si wafers. The thicknesses of commercial SDDs are up to \\(0.5\\ mm, which can detect photons with energies up to \\(27\\ keV, whereas we describe GSDDs that can detect photons with energies of up to \\(35\\ keV. We simulate the electric potential distributions in GSDDs with Si thicknesses of \\(0.5\\ and \\(1\\ mm at a single high reverse bias. GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

  6. Gated silicon drift detector fabricated from a low-cost silicon wafer.

    Science.gov (United States)

    Matsuura, Hideharu; Sakurai, Shungo; Oda, Yuya; Fukushima, Shinya; Ishikawa, Shohei; Takeshita, Akinobu; Hidaka, Atsuki

    2015-05-22

    Inexpensive high-resolution silicon (Si) X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs) are much cheaper to fabricate than commercial silicon drift detectors (SDDs). However, previous GSDDs were fabricated from 10-kΩ·cm Si wafers, which are more expensive than 2-kΩ·cm Si wafers used in commercial SDDs. To fabricate cheaper portable X-ray fluorescence instruments, we investigate GSDDs formed from 2-kΩ·cm Si wafers. The thicknesses of commercial SDDs are up to 0.5 mm, which can detect photons with energies up to 27 keV, whereas we describe GSDDs that can detect photons with energies of up to 35 keV. We simulate the electric potential distributions in GSDDs with Si thicknesses of 0.5 and 1 mm at a single high reverse bias. GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

  7. Novel low cost fabrication of microneedle arrays for drug delivery applications

    Science.gov (United States)

    Tan, Pei Ying J.; Xu, Yuan; Chew, Yong T.; Li, Zongli; Kong, Yen P.

    2002-11-01

    This paper reports a process used for the microfabrication of an array of hollow microneedles. The purpose of the array is for painless transdermal drug delivery. The fabrication process uses wet bulk silicon technology and copper electroplating technology. First, a microneedle array mold on -oriented silicon was fabricated by wet anisotropic etching using KOH solution, then the silicon mold was electroplated with copper. After which, the hollow copper microneedle array was released by a lift-off process or by etching off the silicon mold in KOH solution. The hollow copper microneedle array has been mounted on a polycarbonate platform, which consist of laser ablated cavities and channel for external connection to drug source. In consideration of the contour of human"s skin and the geometry of the microneedle tip, which has walls of sloping gradient corresponding to the (111)-planes, the height of the microneedle array is 200 μm. Two arrays of hollow copper microneedle were fabricated. They have square base of dimensions 390 μm and 400 μm and square tips of size 100 μm and 120 μm with square holes of size 88 μm and 94 μm respectively. Both arrays have microneedle tips at 1900 μm apart from one another and consist of 10 × 10 microneedle tips.

  8. Modeling Liner Shipping Service Selection and Container Flows using a Multi-layer Network

    DEFF Research Database (Denmark)

    Karsten, Christian Vad; Balakrishnan, Anant

    We introduce a new formulation for the tactical planning problem facing container shipping companies of selecting the best subset of sailing routes from a given pool of candidate routes so as to maximize profit. Since most containers are sent directly or transshipped at most twice in current liner...... shipping networks, we impose limits on the number of transshipments for each container (which most previous models do not incorporate). Our multi-layer multi-commodity model associates one commodity with each container origin port, and decides the route for each commodity on a logical network layer whose...... arcs represent segments (pairs of ports between which a container can use a single service). This approach, combined with commodity flow variables that are indexed by segment sequence permits us to incorporate the transshipment limits while also tracking the commodity’s outflow from the system...

  9. Micro-Satellite Impact Tests to Investigate Multi-Layer Insulation Fragments

    Science.gov (United States)

    Murakami, Junko; Hanada, Toshiya; Liou, J.-C.; Stansbery, Eugene

    2009-03-01

    This paper summarizes two satellite impact experiments completed in 2008. The objective of the experiments is to investigate the physical properties of satellite fragments, including those originated from Multi-Layer Insulation and a solar panel. One test generated approximately 1,800 fragments while the other produced only 1,000 fragments. This difference came from the number of needle-like fragments from carbon fiber reinforced plastics. All collected fragments were analyzed using the same method as described in the NASA standard breakup model and compared with the breakup model. This paper will present: (1) the area-to-mass ratio, size, and mass distributions of the fragments, and (2) the differences in fragment properties between the two tests.

  10. A multi-layer VLC imaging system based on space-time trace-orthogonal coding

    Science.gov (United States)

    Li, Peng-Xu; Yang, Yu-Hong; Zhu, Yi-Jun; Zhang, Yan-Yu

    2017-02-01

    In visible light communication (VLC) imaging systems, different properties of data are usually demanded for transmission with different priorities in terms of reliability and/or validity. For this consideration, a novel transmission scheme called space-time trace-orthogonal coding (STTOC) for VLC is proposed in this paper by taking full advantage of the characteristics of time-domain transmission and space-domain orthogonality. Then, several constellation designs for different priority strategies subject to the total power constraint are presented. One significant advantage of this novel scheme is that the inter-layer interference (ILI) can be eliminated completely and the computation complexity of maximum likelihood (ML) detection is linear. Computer simulations verify the correctness of our theoretical analysis, and demonstrate that both transmission rate and error performance of the proposed scheme greatly outperform the conventional multi-layer transmission system.

  11. Memory characteristics of hysteresis and creep in multi-layer piezoelectric actuators: An experimental analysis

    CERN Document Server

    Biggio, Matteo; Giustiniani, Alessandro; Masi, Alessandro; Storace, Marco

    2014-01-01

    In this paper we provide an experimental characterization of creep and hysteresis in a multi layer piezoelectric actuator (PEA), taking into account their relationships in terms of memory structure. We fit the well-known log-t model to the response of the PEA when driven by piecewise-constant signals, and find that both the instantaneous and the delayed response of the PEA display hysteretic dependence on the voltage level. We investigate experimentally the dependence of the creep coefficient on the input history, by driving the PEA along first order reversal curves and congruent minor loops, and find that it displays peculiar features like strict congruence of the minor loops and discontinuities. We finally explain the observed experimental behaviors in terms of a slow relaxation of the staircase interface line in the Preisach plane.

  12. Thermal analysis of a multi-layer microchannel heat sink for cooling concentrator photovoltaic (CPV) cells

    Science.gov (United States)

    Siyabi, Idris Al; Shanks, Katie; Mallick, Tapas; Sundaram, Senthilarasu

    2017-09-01

    Concentrator Photovoltaic (CPV) technology is increasingly being considered as an alternative option for solar electricity generation. However, increasing the light concentration ratio could decrease the system output power due to the increase in the temperature of the cells. The performance of a multi-layer microchannel heat sink configuration was evaluated using numerical analysis. In this analysis, three dimensional incompressible laminar steady flow model was solved numerically. An electrical and thermal solar cell model was coupled for solar cell temperature and efficiency calculations. Thermal resistance, solar cell temperature and pumping power were used for the system efficiency evaluation. An increase in the number of microchannel layers exhibited the best overall performance in terms of the thermal resistance, solar cell temperature uniformity and pressure drop. The channel height and width has no effect on the solar cell maximum temperature. However, increasing channel height leads to a reduction in the pressure drop and hence less fluid pumping power.

  13. Reference Architecture for Multi-Layer Software Defined Optical Data Center Networks

    Directory of Open Access Journals (Sweden)

    Casimer DeCusatis

    2015-09-01

    Full Text Available As cloud computing data centers grow larger and networking devices proliferate; many complex issues arise in the network management architecture. We propose a framework for multi-layer; multi-vendor optical network management using open standards-based software defined networking (SDN. Experimental results are demonstrated in a test bed consisting of three data centers interconnected by a 125 km metropolitan area network; running OpenStack with KVM and VMW are components. Use cases include inter-data center connectivity via a packet-optical metropolitan area network; intra-data center connectivity using an optical mesh network; and SDN coordination of networking equipment within and between multiple data centers. We create and demonstrate original software to implement virtual network slicing and affinity policy-as-a-service offerings. Enhancements to synchronous storage backup; cloud exchanges; and Fibre Channel over Ethernet topologies are also discussed.

  14. Demonstration of liquid nitrogen wicking using a multi-layer metallic wire cloth laminate

    Science.gov (United States)

    Zhang, Tao; deBock, Peter; Stautner, Ernst Wolfgang; Deng, Tao; Immer, Chris

    2012-04-01

    Cryogenic heat transport devices are the most basic and critical component for the thermal integration between the cryogenic component and its cooling source. In space environments, containment of heat transfer fluid inside a capillary structure is critical due to the absence of gravity. Cryogenic heat pipes using the capillary force for circulation may provide a solution for heat transfer in space applications due to its independence of gravity and transport distance. To achieve a high effective capillary performance, several options of wicking structures have been investigated. An efficient wicking flow of liquid nitrogen is demonstrated with a sintered, multi-layer, porous lamination of metal wire (pore size as low as 5 μm) in an open cryogenic chamber. The test data are presented in this paper. This technology has potential for use in development of improved cryogenic heat transfer devices and containment of cryogenic propellants under micro-gravity environment.

  15. Multi-layer composite structure covered polytetrafluoroethylene for visible-infrared-radar spectral Compatibility

    Science.gov (United States)

    Qi, Dong; Cheng, Yongzhi; Wang, Xian; Wang, Fang; Li, Bowen; Gong, Rongzhou

    2017-12-01

    In this paper, a polytetrafluoroethylene (PTFE) top-covered multi-layer composite structure PTFE/H s/(Ge/ZnS)3 (H s represents the surface layer ZnS with various thicknesses) for spectral compatibility is proposed and investigated theoretically and experimentally. A substantial decline of glossiness from over 200 Gs to 74.2 Gs could be realized, due to high roughness and interface reflection of the 800 nm PTFE protection layer. In addition, similar to the structure of H s/(Ge/ZnS)3, the designed structure with a certain color exhibits ultra-low emissivity of average 0.196 at 8–14 µm and highly transparent performance of 96.45% in the radar frequency range of 2–18 GHz. Our design will provide an important reference for the practical applications of the spectral compatible multilayer films.

  16. An Investigation on Corrosion Behavior of a Multi-layer Modified Aluminum Brazing Sheet

    Directory of Open Access Journals (Sweden)

    Liu Wei

    2016-01-01

    Full Text Available The corrosion behavior of a multi-layer modified aluminum brazing sheet (AA4045/3003Mod./AA7072/AA4045 was investigated. The results shows that, the existence of BDP, which forms at the interface between clad and core layer during brazing, changes the corrosion form of the air side of the material from inter-granular corrosion to local exfoliation corrosion. The addition of anti-corrosion layer makes the corrosion form of the water side from inter-granular corrosion into uniform exfoliation corrosion. Compared to the normal triple-layer brazing sheet at the same thickness, the time to perforation of the modified four-layer brazing sheet is increased by more than 200%.

  17. Highly accurate thickness measurement of multi-layered automotive paints using terahertz technology

    Science.gov (United States)

    Krimi, Soufiene; Klier, Jens; Jonuscheit, Joachim; von Freymann, Georg; Urbansky, Ralph; Beigang, René

    2016-07-01

    In this contribution, we present a highly accurate approach for thickness measurements of multi-layered automotive paints using terahertz time domain spectroscopy in reflection geometry. The proposed method combines the benefits of a model-based material parameters extraction method to calibrate the paint coatings, a generalized Rouard's method to simulate the terahertz radiation behavior within arbitrary thin films, and the robustness of a powerful evolutionary optimization algorithm to increase the sensitivity of the minimum thickness measurement limit. Within the framework of this work, a self-calibration model is introduced, which takes into consideration the real industrial challenges such as the effect of wet-on-wet spray in the painting process.

  18. Accelerating decomposition of light field video for compressive multi-layer display.

    Science.gov (United States)

    Cao, Xuan; Geng, Zheng; Li, Tuotuo; Zhang, Mei; Zhang, Zhaoxing

    2015-12-28

    Compressive light field display based on multi-layer LCDs is becoming a popular solution for 3D display. Decomposing light field into layer images is the most challenging task. Iterative algorithm is an effective solver for this high-dimensional decomposition problem. Existing algorithms, however, iterate from random initial values. As such, significant computation time is required due to the deviation between random initial estimate and target values. Real-time 3D display at video rate is difficult based on existing algorithms. In this paper, we present a new algorithm to provide better initial values and accelerate decomposition of light field video. We utilize internal coherence of single light field frame to transfer the ignorance-to-target to a much lower resolution level. In addition, we explored external coherence for further accelerating light field video and achieved 5.91 times speed improvement. We built a prototype and developed parallel algorithm based on CUDA.

  19. Design of a Multi-layer Lane-Level Map for Vehicle Route Planning

    Directory of Open Access Journals (Sweden)

    Liu Chaoran

    2017-01-01

    Full Text Available With the development of intelligent transportation system, there occurs further demand for high precision localization and route planning, and simultaneously the traditional road-level map fails to meet with this requirement, by which this paper is motivated. In this paper, t he three-layer lane-level map architecture for vehicle path guidance is established, and the mathematical models of road-level layer, intermediate layer and lane-level layer are designed considering efficiency and precision. The geometric model of the lane-level layer of the map is characterized by Cubic Hermite Spline for continuity. A method of generating the lane geometry with fixed and variable control points is proposed, which can effectively ensure the accuracy with limited num ber of control points. In experimental part, a multi-layer map of an intersection is built to validate the map model, and an example of a local map was generated with the lane-level geometry.

  20. Maxwell–Wagner Effect in Multi-Layered Dielectrics: Interfacial Charge Measurement and Modelling

    Directory of Open Access Journals (Sweden)

    Thi Thu Nga Vu

    2017-05-01

    Full Text Available The development of high voltage direct current (HVDC technologies generates new paradigms in research. In particular and contrary to the AC case, investigation of electrical conduction is not only needed for understanding the dielectric breakdown but also to describe the field distribution inside the insulation. Here, we revisit the so-called Maxwell–Wagner effect in multi-layered dielectrics by considering on the one hand a non-linear field dependent model of conductivity and on the other hand by performing space charge measurements giving access to the interfacial charge accumulated between different dielectrics. We show that space charge measurements give access to the amount of interfacial charge built-up by the Maxwell–Wagner effect between two dielectrics of different natures. Measurements also demonstrate that the field distribution undergoes a transition from a capacitive distribution to a resistive one, under long lasting stress.

  1. Recognition of Epileptiform Patterns in the Human Electroencephalogram Using Multi-Layer Perceptron

    Directory of Open Access Journals (Sweden)

    V. Mokran

    1995-06-01

    Full Text Available Automatic detection of epileptiform patterns is highly desirable during continuous monitoring of patients with epilepsy. This paper describes an unconvential system for automatic off-line recognition of epileptic sharp transients in the human electroencephalogram (EEG, based on a standard neural network architecture - multi-layer perceptron (MLP, and implemented on a Silicon Graphics Indigo workstation. The system makes comprehensive use of wide spatial contextual information available on 12 channels of EEG and takes advantage of discrete dyadic wavelet transform (DDWT for efficient parameterisation of EEG data. The EEG database consists of 12 patients, 7 of which are used in the process of training of MLP. The resulting MLP is presented with the testing data set consisting of all data vectors from all 12 patients, and is shown to be capable to recognise a wide variety of epileptic signals.

  2. Field theoretical model of multi-layered Josephson junction and dynamics of Josephson vortices

    CERN Document Server

    Fujimori, Toshiaki; Nitta, Muneto

    2016-01-01

    Multi-layered Josephson junctions are modeled in the context of a field theory, and dynamics of Josephson vortices trapped inside insulators are studied. Starting from a theory consisting of complex and real scalar fields coupled to a U(1) gauge field which admit parallel $N-1$ domain-wall solutions, Josephson couplings are introduced weakly between the complex scalar fields. The $N-1$ domain walls behave as insulators separating $N$ superconductors. We construct the effective Lagrangian on the domain walls, which reduces to a coupled sine-Gordon model for well-separated walls and contains more interactions for walls at short distance. We then construct sine-Gordon solitons emerging in the effective theory that we identify Josephson vortices carrying singly quantized magnetic fluxes. When two neighboring superconductors tend to have the same phase, the ground state does not change with the positions of domain walls. On the other hand, when two neighboring superconductors tend to have the $\\pi$ phase differenc...

  3. Design criteria for multi-layered scintillating fibre arrays with inclined columns

    CERN Document Server

    Achenbach, P; Pochodzalla, J

    2008-01-01

    Multi-layered scintillating fibre arrays read-out are commonly used as high resolution charged particle hodoscopes. Fibres of a column along the geometrical trajectory of incident particles are typically grouped to one pixel of a multi-channel read-out device. In some applications the incident particles will cross the detection plane with large angles w.r.t. the normal to the layers. Then, the packing of the fibres needs to be adapted to the incident particles and the columns need to be inclined. In this paper possible fibre array geometries are shown, relevant design criteria for detectors are discussed, and the effect of diverging particles incident on fibre arrays was studied using a Monte Carlo simulation.

  4. A Multi-layer, Hierarchical Information Management System for the Smart Grid

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Ning; Du, Pengwei; Paulson, Patrick R.; Greitzer, Frank L.; Guo, Xinxin; Hadley, Mark D.

    2011-10-10

    This paper presents the modeling approach, methodologies, and initial results of setting up a multi-layer, hierarchical information management system (IMS) for the smart grid. The IMS allows its users to analyze the data collected by multiple control and communication networks to characterize the states of the smart grid. Abnormal, corrupted, or erroneous measurement data and outliers are detected and analyzed to identify whether they are caused by random equipment failures, unintentional human errors, or deliberate tempering attempts. Data collected from different information networks are crosschecked for data integrity based on redundancy, dependency, correlation, or cross-correlations, which reveal the interdependency between data sets. A hierarchically structured reasoning mechanism is used to rank possible causes of an event to aid the system operators to proactively respond or provide mitigation recommendations to remove or neutralize the threats. The model provides satisfactory performance on identifying the cause of an event and significantly reduces the need of processing myriads of data collected.

  5. Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner.

    Science.gov (United States)

    An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai

    2016-07-20

    There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation.

  6. Non-invasive NMR stratigraphy of a multi-layered artefact: an ancient detached mural painting.

    Science.gov (United States)

    Di Tullio, Valeria; Capitani, Donatella; Presciutti, Federica; Gentile, Gennaro; Brunetti, Brunetto Giovanni; Proietti, Noemi

    2013-10-01

    NMR stratigraphy was used to investigate in situ, non-destructively and non-invasively, the stratigraphy of hydrogen-rich layers of an ancient Nubian detached mural painting. Because of the detachment procedure, a complex multi-layered artefact was obtained, where, besides layers of the original mural painting, also the materials used during the procedure all became constitutive parts of the artefact. NMR measurements in situ enabled monitoring of the state of conservation of the artefact and planning of minimum representative sampling to validate results obtained in situ by solid-state NMR analysis of the samples. This analysis enabled chemical characterization of all organic materials. Use of reference compounds and prepared specimens assisted data interpretation.

  7. Multi-layer coatings for bipolar rechargeable batteries with enhanced terminal voltage

    Science.gov (United States)

    Farmer, Joseph C.; Kaschmitter, James; Pierce, Steve

    2017-06-06

    A method for producing a multi-layer bipolar coated cell according to one embodiment includes applying a first active cathode material above a substrate to form a first cathode; applying a first solid-phase ionically-conductive electrolyte material above the first cathode to form a first electrode separation layer; applying a first active anode material above the first electrode separation layer to form a first anode; applying an electrically conductive barrier layer above the first anode; applying a second active cathode material above the anode material to form a second cathode; applying a second solid-phase ionically-conductive electrolyte material above the second cathode to form a second electrode separation layer; applying a second active anode material above the second electrode separation layer to form a second anode; and applying a metal material above the second anode to form a metal coating section. In another embodiment, the anode is formed prior to the cathode. Cells are also disclosed.

  8. Broadband quasi perfect absorption using chirped multi-layer porous materials

    CERN Document Server

    Jiménez, Noé; Cebrecos, Alejandro; Picó, Rubén; Sánchez-Morcillo, Víctor J; García-Raffi, Lluis M

    2016-01-01

    This work theoretically analyzes the sound absorption properties of a chirped multi-layer porous material including transmission, in particular showing the broadband unidirectional absorption properties of the system. Using the combination of the impedance matching condition and the balance between the leakage and the intrinsic losses as well as the critical coupling condition, the system is designed to have broadband unidirectional and nearly perfect absorption. The transfer and scattering matrix formalism, together with full wave numerical simulations are used to demonstrate the results showing excellent agreement between them. The proposed system allows to construct broadband sound absorbers with improved absorption in the low frequency regime using less than 15 \\% of the complete porous material.

  9. Multi-layered mutation in hedgehog-related genes in Gorlin syndrome may affect the phenotype.

    Directory of Open Access Journals (Sweden)

    Shoko Onodera

    Full Text Available Gorlin syndrome is a genetic disorder of autosomal dominant inheritance that predisposes the affected individual to a variety of disorders that are attributed largely to heterozygous germline patched1 (PTCH1 mutations. PTCH1 is a hedgehog (Hh receptor as well as a repressor, mutation of which leads to constitutive activation of Hh pathway. Hh pathway encompasses a wide variety of cellular signaling cascades, which involve several molecules; however, no associated genotype-phenotype correlations have been reported. Recently, mutations in Suppressor of fused homolog (SUFU or PTCH2 were reported in patients with Gorlin syndrome. These facts suggest that multi-layered mutations in Hh pathway may contribute to the development of Gorlin syndrome. We demonstrated multiple mutations of Hh-related genes in addition to PTCH1, which possibly act in an additive or multiplicative manner and lead to Gorlin syndrome. High-throughput sequencing was performed to analyze exome sequences in four unrelated Gorlin syndrome patient genomes. Mutations in PTCH1 gene were detected in all four patients. Specific nucleotide variations or frameshift variations of PTCH1 were identified along with the inferred amino acid changes in all patients. We further filtered 84 different genes which are closely related to Hh signaling. Fifty three of these had enough coverage of over ×30. The sequencing results were filtered and compared to reduce the number of sequence variants identified in each of the affected individuals. We discovered three genes, PTCH2, BOC, and WNT9b, with mutations with a predicted functional impact assessed by MutationTaster2 or PolyPhen-2 (Polymorphism Phenotyping v2 analysis. It is noticeable that PTCH2 and BOC are Hh receptor molecules. No significant mutations were observed in SUFU. Multi-layered mutations in Hh pathway may change the activation level of the Hh signals, which may explain the wide phenotypic variability of Gorlin syndrome.

  10. Respiratory signal prediction based on adaptive boosting and multi-layer perceptron neural network

    Science.gov (United States)

    Sun, W. Z.; Jiang, M. Y.; Ren, L.; Dang, J.; You, T.; Yin, F.-F.

    2017-09-01

    To improve the prediction accuracy of respiratory signals using adaptive boosting and multi-layer perceptron neural network (ADMLP-NN) for gated treatment of moving target in radiation therapy. The respiratory signals acquired using a real-time position management (RPM) device from 138 previous 4DCT scans were retrospectively used in this study. The ADMLP-NN was composed of several artificial neural networks (ANNs) which were used as weaker predictors to compose a stronger predictor. The respiratory signal was initially smoothed using a Savitzky-Golay finite impulse response smoothing filter (S-G filter). Then, several similar multi-layer perceptron neural networks (MLP-NNs) were configured to estimate future respiratory signal position from its previous positions. Finally, an adaptive boosting (Adaboost) decision algorithm was used to set weights for each MLP-NN based on the sample prediction error of each MLP-NN. Two prediction methods, MLP-NN and ADMLP-NN (MLP-NN plus adaptive boosting), were evaluated by calculating correlation coefficient and root-mean-square-error between true and predicted signals. For predicting 500 ms ahead of prediction, average correlation coefficients were improved from 0.83 (MLP-NN method) to 0.89 (ADMLP-NN method). The average of root-mean-square-error (relative unit) for 500 ms ahead of prediction using ADMLP-NN were reduced by 27.9%, compared to those using MLP-NN. The preliminary results demonstrate that the ADMLP-NN respiratory prediction method is more accurate than the MLP-NN method and can improve the respiration prediction accuracy.

  11. Hydrocarbon accumulation characteristics and enrichment laws of multi-layered reservoirs in the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guang Yang

    2017-03-01

    Full Text Available The Sichuan Basin represents the earliest area where natural gas is explored, developed and comprehensively utilized in China. After over 50 years of oil and gas exploration, oil and gas reservoirs have been discovered in 24 gas-dominant layers in this basin. For the purpose of predicting natural gas exploration direction and target of each layer in the Sichuan Basin, the sedimentary characteristics of marine and continental strata in this basin were summarized and the forms of multi-cycled tectonic movement and their controlling effect on sedimentation, diagenesis and hydrocarbon accumulation were analyzed. Based on the analysis, the following characteristics were identified. First, the Sichuan Basin has experienced the transformation from marine sedimentation to continental sedimentation since the Sinian with the former being dominant. Second, multiple source–reservoir assemblages are formed based on multi-rhythmed deposition, and multi-layered reservoir hydrocarbon accumulation characteristics are vertically presented. And third, multi-cycled tectonic movement appears in many forms and has a significant controlling effect on sedimentation, diagenesis and hydrocarbon accumulation. Then, oil and gas reservoir characteristics and enrichment laws were investigated. It is indicated that the Sichuan Basin is characterized by coexistence of conventional and unconventional oil and gas reservoirs, multi-layered reservoir hydrocarbon supply, multiple reservoir types, multiple trap types, multi-staged hydrocarbon accumulation and multiple hydrocarbon accumulation models. Besides, its natural gas enrichment is affected by hydrocarbon source intensity, large paleo-uplift, favorable sedimentary facies belt, sedimentary–structural discontinuity plane and structural fracture development. Finally, the natural gas exploration and research targets of each layer in the Sichuan Basin were predicted according to the basic petroleum geologic conditions

  12. Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

    Science.gov (United States)

    Huang, Jinsong

    This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C

  13. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Based on Variational Mode Decomposition and Multi-Layer Classifier.

    Science.gov (United States)

    Huang, Nantian; Chen, Huaijin; Cai, Guowei; Fang, Lihua; Wang, Yuqiang

    2016-11-10

    Mechanical fault diagnosis of high-voltage circuit breakers (HVCBs) based on vibration signal analysis is one of the most significant issues in improving the reliability and reducing the outage cost for power systems. The limitation of training samples and types of machine faults in HVCBs causes the existing mechanical fault diagnostic methods to recognize new types of machine faults easily without training samples as either a normal condition or a wrong fault type. A new mechanical fault diagnosis method for HVCBs based on variational mode decomposition (VMD) and multi-layer classifier (MLC) is proposed to improve the accuracy of fault diagnosis. First, HVCB vibration signals during operation are measured using an acceleration sensor. Second, a VMD algorithm is used to decompose the vibration signals into several intrinsic mode functions (IMFs). The IMF matrix is divided into submatrices to compute the local singular values (LSV). The maximum singular values of each submatrix are selected as the feature vectors for fault diagnosis. Finally, a MLC composed of two one-class support vector machines (OCSVMs) and a support vector machine (SVM) is constructed to identify the fault type. Two layers of independent OCSVM are adopted to distinguish normal or fault conditions with known or unknown fault types, respectively. On this basis, SVM recognizes the specific fault type. Real diagnostic experiments are conducted with a real SF₆ HVCB with normal and fault states. Three different faults (i.e., jam fault of the iron core, looseness of the base screw, and poor lubrication of the connecting lever) are simulated in a field experiment on a real HVCB to test the feasibility of the proposed method. Results show that the classification accuracy of the new method is superior to other traditional methods.

  14. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Based on Variational Mode Decomposition and Multi-Layer Classifier

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2016-11-01

    Full Text Available Mechanical fault diagnosis of high-voltage circuit breakers (HVCBs based on vibration signal analysis is one of the most significant issues in improving the reliability and reducing the outage cost for power systems. The limitation of training samples and types of machine faults in HVCBs causes the existing mechanical fault diagnostic methods to recognize new types of machine faults easily without training samples as either a normal condition or a wrong fault type. A new mechanical fault diagnosis method for HVCBs based on variational mode decomposition (VMD and multi-layer classifier (MLC is proposed to improve the accuracy of fault diagnosis. First, HVCB vibration signals during operation are measured using an acceleration sensor. Second, a VMD algorithm is used to decompose the vibration signals into several intrinsic mode functions (IMFs. The IMF matrix is divided into submatrices to compute the local singular values (LSV. The maximum singular values of each submatrix are selected as the feature vectors for fault diagnosis. Finally, a MLC composed of two one-class support vector machines (OCSVMs and a support vector machine (SVM is constructed to identify the fault type. Two layers of independent OCSVM are adopted to distinguish normal or fault conditions with known or unknown fault types, respectively. On this basis, SVM recognizes the specific fault type. Real diagnostic experiments are conducted with a real SF6 HVCB with normal and fault states. Three different faults (i.e., jam fault of the iron core, looseness of the base screw, and poor lubrication of the connecting lever are simulated in a field experiment on a real HVCB to test the feasibility of the proposed method. Results show that the classification accuracy of the new method is superior to other traditional methods.

  15. Representational Learning for Fault Diagnosis of Wind Turbine Equipment: A Multi-Layered Extreme Learning Machines Approach

    Directory of Open Access Journals (Sweden)

    Zhi-Xin Yang

    2016-05-01

    Full Text Available Reliable and quick response fault diagnosis is crucial for the wind turbine generator system (WTGS to avoid unplanned interruption and to reduce the maintenance cost. However, the conditional data generated from WTGS operating in a tough environment is always dynamical and high-dimensional. To address these challenges, we propose a new fault diagnosis scheme which is composed of multiple extreme learning machines (ELM in a hierarchical structure, where a forwarding list of ELM layers is concatenated and each of them is processed independently for its corresponding role. The framework enables both representational feature learning and fault classification. The multi-layered ELM based representational learning covers functions including data preprocessing, feature extraction and dimension reduction. An ELM based autoencoder is trained to generate a hidden layer output weight matrix, which is then used to transform the input dataset into a new feature representation. Compared with the traditional feature extraction methods which may empirically wipe off some “insignificant’ feature information that in fact conveys certain undiscovered important knowledge, the introduced representational learning method could overcome the loss of information content. The computed output weight matrix projects the high dimensional input vector into a compressed and orthogonally weighted distribution. The last single layer of ELM is applied for fault classification. Unlike the greedy layer wise learning method adopted in back propagation based deep learning (DL, the proposed framework does not need iterative fine-tuning of parameters. To evaluate its experimental performance, comparison tests are carried out on a wind turbine generator simulator. The results show that the proposed diagnostic framework achieves the best performance among the compared approaches in terms of accuracy and efficiency in multiple faults detection of wind turbines.

  16. Low-cost fabrication technologies for nanostructures: state-of-the-art and potential

    Science.gov (United States)

    Santos, A.; Deen, M. J.; Marsal, L. F.

    2015-01-01

    In the last decade, some low-cost nanofabrication technologies used in several disciplines of nanotechnology have demonstrated promising results in terms of versatility and scalability for producing innovative nanostructures. While conventional nanofabrication technologies such as photolithography are and will be an important part of nanofabrication, some low-cost nanofabrication technologies have demonstrated outstanding capabilities for large-scale production, providing high throughputs with acceptable resolution and broad versatility. Some of these nanotechnological approaches are reviewed in this article, providing information about the fundamentals, limitations and potential future developments towards nanofabrication processes capable of producing a broad range of nanostructures. Furthermore, in many cases, these low-cost nanofabrication approaches can be combined with traditional nanofabrication technologies. This combination is considered a promising way of generating innovative nanostructures suitable for a broad range of applications such as in opto-electronics, nano-electronics, photonics, sensing, biotechnology or medicine.

  17. Improved process control, lowered costs and reduced risks through the use of non-destructive mobility and sheet carrier density measurements on GaAs and GaN wafers

    Science.gov (United States)

    Nguyen, D.; Hogan, K.; Blew, A.; Cordes, M.

    2004-12-01

    Improved process control, lowered costs and reduced risks can be realized through the use of non-destructive mobility and sheet charge density measurements during the fabrication of GaAs and GaN wafers. The results from this microwave-based technique are shown to agree with destructive van der Pauw Hall testing results to within ±5%. In addition, it has the ability to map wafer uniformity and provide separated 2DEG data for thick cap or multi-layered structures. As a result, this technique provides an efficient and cost-effective alternative to current process control metrology methods, while providing the user with important process control data.

  18. Development of Advanced Technologies to Reduce Design, Fabrication and Construction Costs for Future Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    DiNunzio, Camillo A. [Framatome ANP DE& S, Marlborough, MA (United States); Gupta, Abhinav [Univ. of North Carolina, Raleigh, NC (United States); Golay, Michael [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Luk, Vincent [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turk, Rich [Westinghouse Electric Company Nuclear Systems, Windsor, CT (United States); Morrow, Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jin, Geum-Taek [Korea Power Engineering Company Inc., Yongin-si, Gyeonggi-do (Korea, Republic of)

    2002-11-30

    This report presents a summation of the third and final year of a three-year investigation into methods and technologies for substantially reducing the capital costs and total schedule for future nuclear plants. In addition, this is the final technical report for the three-year period of studies.

  19. SiO2/TiO2 multi-layered thin films with self-cleaning and enhanced ...

    Indian Academy of Sciences (India)

    6 axes robot (ABB, model IRB5400) with a control software. (ABB, IRC5P control system) and a heating ceramic plate. (Ceram, model HP1212M). The glass substrate was initially cleaned by ultra-sonication in alcohol and then dried using compressed air. The multi-layered thin films were obtained by successive deposition ...

  20. Comparison of Homogenous and Multi-layered Berm Breakwaters with Respect to Overtopping and Front Slope Stability

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Skals, K. T.; Burcharth, Hans F.

    2009-01-01

    A model test study was conducted to study overtopping and front slope stability of homogenous and multi-layered berm breakwaters. The two breakwater types are compared and cons and pros are listed. The study shows that the optimum number of stone classes might be significantly lower than what has...

  1. The stability of thiamine in total parenteral nutrition mixtures stored in EVA and multi-layered bags.

    Science.gov (United States)

    Kearney, M C; Allwood, M C; Neale, T; Hardy, G

    1995-10-01

    The compounding of complete total parenteral nutrition (TPN) mixtures into big bags with extended shelf-lives has been made more possible by the introduction of reduced gas permeable bags, using multi-layered plastic laminates. Since this produces a highly reduced chemical environment, the stability of thiamine; which degrades by reduction, may be compromised. It was the purpose of this study to investigate the degradation of thiamine at two different concentrations in TPN mixtures containing different commercial amino acid sources stored for extended periods in EVA or multi-layered bags. Results indicated that thiamine was unstable in mixtures containing Freamine III 8.5%, a metabisulphite-containing amino acid infusion, but was relatively stable in mixtures containing Vamin 14, Aminoplex 12 or Eloamin 15% as the amino acid source. Degradation of thiamine in Freamine III 8.5%-containing mixtures stored in multi-layered bags was more rapid than in EVA bags. Degradation rate was not greatly influenced by thiamine concentration. Results indicate that thiamine is stable in complete TPN mixtures for periods of at least 28 days in multi-layered bags, provided metabisulphite containing amino acid infusions are avoided. The shelf-life of complete mixtures containing Freamine III should be restricted to ensure patient receive minimum acceptable daily thiamine requirements.

  2. Practice-driven evaluation of a multi-layered psychosocial care package for children in areas of armed conflict

    NARCIS (Netherlands)

    Jordans, M.J.D.; Komproe, I.H.; Tol, W.A.; Susanty, D.; Vallipuram, A.; Ntamatumba, P.; Lasuba, A.C.; de Jong, J.T.V.M.

    2010-01-01

    Psychosocial and mental health service delivery frameworks for children in low-income countries are scarce. This paper presents a practice-driven evaluation of a multi-layered community-based care package in Burundi, Indonesia, Sri Lanka and Sudan, through a set of indicators; (a) perceived

  3. Heating of multi-layered samples by a Nd: YAG pulsed laser

    Directory of Open Access Journals (Sweden)

    Diniz Neto, O. O.

    1998-04-01

    Full Text Available In the work we examine the heating of multi-layered samples by a powerful Nd - YAG pulsed láser. The samples are made of two and three layers, conductor-isolator (Al-Al2O3, conductor-conductor (Al-Ag; Al-Au and conductor-conductor-conductor (Al-Au-Ag; Ag-Au-Al. The transient behaviour of the temperature distribution throughout the sample is computed. We carry out three dimensional model calculations for the heating process in which we consider not only the temperature dependence of the sample thermal and optical parameters but also the space and time characteristics of the laser beam as the heating source. We showed the influence of the substrate in the thermal profile, in space and time, and máximum temperature on the multi-layered samples.

    Em nosso trabalho examinamos o aquecimento de amostras compostas de duas e três camadas, condutor- isolante e condutor-condutor, com um pulso potente de láser. O comportamento transiente da distribuição de temperatura através da amostra foi calculado. Em nosso modelo de calculo para o processo de aquecimento levamos em conta a dependência com a temperatura dos parâmetros térmicos (difusividade, capacidade e condutividade térmica, óticos (refletividade e coeficiente de absorção, bem como a dependência das condições de contorno com o tempo e consequentemente com a temperatura. Aplicamos nossa metodología para calcular o aquecimento amostras compostas: Al-Au, Al-Ag, Al-Al2O3, Al-Au-Ag e Ag-Au-Al. Concluimos que o substrato influencia as temperaturas máximas nas superfície exposta ao láser e a forma com que a frente de calor se propaga nas amostras termicamente finas.

  4. Simple and cost-effective fabrication of size-tunable zinc oxide architectures by multiple size reduction technique

    Directory of Open Access Journals (Sweden)

    Hyeong-Ho Park, Xin Zhang, Seon-Yong Hwang, Sang Hyun Jung, Semin Kang, Hyun-Beom Shin, Ho Kwan Kang, Hyung-Ho Park, Ross H Hill and Chul Ki Ko

    2012-01-01

    Full Text Available We present a simple size reduction technique for fabricating 400 nm zinc oxide (ZnO architectures using a silicon master containing only microscale architectures. In this approach, the overall fabrication, from the master to the molds and the final ZnO architectures, features cost-effective UV photolithography, instead of electron beam lithography or deep-UV photolithography. A photosensitive Zn-containing sol–gel precursor was used to imprint architectures by direct UV-assisted nanoimprint lithography (UV-NIL. The resulting Zn-containing architectures were then converted to ZnO architectures with reduced feature sizes by thermal annealing at 400 °C for 1 h. The imprinted and annealed ZnO architectures were also used as new masters for the size reduction technique. ZnO pillars of 400 nm diameter were obtained from a silicon master with pillars of 1000 nm diameter by simply repeating the size reduction technique. The photosensitivity and contrast of the Zn-containing precursor were measured as 6.5 J cm−2 and 16.5, respectively. Interesting complex ZnO patterns, with both microscale pillars and nanoscale holes, were demonstrated by the combination of dose-controlled UV exposure and a two-step UV-NIL.

  5. Fabrication, Structural Characterization and Uniaxial Tensile Properties of Novel Sintered Multi-Layer Wire Mesh Porous Plates

    Directory of Open Access Journals (Sweden)

    Liuyang Duan

    2018-01-01

    Full Text Available There is an increasing interest in developing porous metals or metallic foams for functional and structural applications. The study of the physical and mechanical properties of porous metals is very important and helpful for their application. In this paper, a novel sintered multilayer wire mesh porous plate material (WMPPs with a thickness of 0.5 mm–3 mm and a porosity of 10–35% was prepared by winding, pressing, rolling, and subsequently vacuum sintering them. The pore size and total size distribution in the as-prepared samples were investigated using the bubble point method. The uniaxial tensile behavior of the WMPPs was investigated in terms of the sintering temperature, porosity, wire diameter, and manufacturing technology. The deformation process and the failure mechanism under the tensile press was also discussed based on the appearance of the fractures (SEM figures. The results indicated that the pore size and total size distribution were closely related to the raw material used and the sintering temperature. For the WMPPs prepared by the wire mesh, the pore structures were inerratic and the vast majority of pore size was less than 10 μm. On the other hand, for the WMPPs that were prepared by wire mesh and powder, the pore structures were irregular and the pore size ranged from 0 μm–50 μm. The experimental data showed that the tensile strength of WMPPs is much higher than any other porous metals or metallic foams. Higher sintering temperatures led to coarser joints between wires and resulted in higher tensile strength. The sintering temperature decreased from 1330 °C to 1130 °C and the tensile strength decreased from 296 MPa to 164 MPa. Lower porosity means that there are more metallurgical joints and metallic frameworks resisting deformation per unit volume. Therefore, lower porosities exhibit higher tensile strength. An increase of porosity from 17.14% to 32.5% led to the decrease of the tensile strength by 90 MPa. The coarser wires led to a bigger contact area between the interconnecting wires, resulting in a stronger sintering neck that exhibited higher tensile strength. The wire diameter increased from 81 μm to 122 μm and the tensile strength increased from 296 MPa to 362 MPa. The fracture morphology showed that the wires experience necking deformation and ductile fracture.

  6. Fabrication and performance of a tubular ceria based oxygen transport membrane on a low cost MgO support

    DEFF Research Database (Denmark)

    Kothanda Ramachandran, Dhavanesan; Søgaard, Martin; Clemens, F.

    2015-01-01

    A 30 μm thin-film tubular CGO (Ce0.9Gd0.1O1.95−δ) membrane with catalytic layers on both sides has been prepared by dip-coating on a low cost, porous magnesium oxide (MgO) support. The MgO support was fabricated through a thermoplastic extrusion process. Support, thin membrane and catalytic layers...... were sintered in individual steps at temperatures between 1250 and 1300 °C to achieve a controlled removal of binder and organic additives and to obtain the desired, defect free microstructure. The prepared asymmetric tubular CGO membrane has been tested at elevated temperatures (up to 900 °C) using...

  7. Multi-layered hierarchical nanostructures for transparent monolithic dye-sensitized solar cell architectures

    Science.gov (United States)

    Passoni, Luca; Fumagalli, Francesco; Perego, Andrea; Bellani, Sebastiano; Mazzolini, Piero; Di Fonzo, Fabio

    2017-06-01

    Monolithic dye-sensitized solar cell (DSC) architectures hold great potential for building-integrated photovoltaics applications. They indeed benefit from lower weight and manufacturing costs as they avoid the use of a transparent conductive oxide (TCO)-coated glass counter electrode. In this work, a transparent monolithic DSC comprising a hierarchical 1D nanostructure stack is fabricated by physical vapor deposition techniques. The proof of concept device comprises hyperbranched TiO2 nanostructures, sensitized by the prototypical N719, as photoanode, a hierarchical nanoporous Al2O3 spacer, and a microporous indium tin oxide (ITO) top electrode. An overall 3.12% power conversion efficiency with 60% transmittance outside the dye absorption spectral window is demonstrated. The introduction of a porous TCO layer allows an efficient trade-off between transparency and power conversion. The porous ITO exhibits submicrometer voids and supports annealing temperatures above 400 °C without compromising its optoelectronical properties. After thermal annealing at 500 °C, the resistivity, mobility, and carrier concentration of the 800 nm-thick porous ITO layer are found to be respectively 2.3 × 10-3 Ω cm-1, 11 cm2 V-1 s-1, and 1.62 × 1020 cm-3, resulting in a series resistance in the complete device architecture of 45 Ω. Electrochemical impedance and intensity-modulated photocurrent/photovoltage spectroscopy give insight into the electronic charge dynamic within the hierarchical monolithic DSCs, paving the way for potential device architecture improvements.

  8. Low-Cost and Green Fabrication of Polymer Electronic Devices by Push-Coating of the Polymer Active Layers.

    Science.gov (United States)

    Vohra, Varun; Mróz, Wojciech; Inaba, Shusei; Porzio, William; Giovanella, Umberto; Galeotti, Francesco

    2017-08-02

    Because of both its easy processability and compatibility with roll-to-roll processes, polymer electronics is considered to be the most promising technology for the future generation of low-cost electronic devices such as light-emitting diodes and solar cells. However, the state-of-the-art deposition technique for polymer electronics (spin-coating) generates a high volume of chlorinated solution wastes during the active layer fabrication. Here, we demonstrate that devices with similar or higher performances can be manufactured using the push-coating technique in which a poly(dimethylsiloxane) (PDMS) layer is simply laid over a very small amount of solution (less than 1μL/covered cm(2)), which is then left for drying. Using mm thick PDMS provides a means to control the solvent diffusion kinetics (sorption/retention) and removes the necessity for additional applied pressure to generate the desired active layer thickness. Unlike spin-coating, push-coating is a slow drying process that induces a higher degree of crystallinity in the polymer thin film without the necessity for a post-annealing step. The polymer light-emitting diodes and solar cells prepared by push-coating exhibit slightly higher performances with respect to the reference spin-coated devices, whereas at the same time reduce the amounts of active layer materials and chlorinated solvents by 50 and 20 times, respectively. These increased performances can be correlated to the higher polymer crystallinities obtained without applying a post-annealing treatment. As push-coating is a roll-to-roll compatible method, the results presented here open the path to low-cost and eco-friendly fabrication of a wide range of emerging devices based on conjugated polymer materials.

  9. Low-cost cryo-light microscopy stage fabrication for correlated light/electron microscopy.

    Science.gov (United States)

    Carlson, David B; Evans, James E

    2011-06-05

    The coupling of cryo-light microscopy (cryo-LM) and cryo-electron microscopy (cryo-EM) poses a number of advantages for understanding cellular dynamics and ultrastructure. First, cells can be imaged in a near native environment for both techniques. Second, due to the vitrification process, samples are preserved by rapid physical immobilization rather than slow chemical fixation. Third, imaging the same sample with both cryo-LM and cryo-EM provides correlation of data from a single cell, rather than a comparison of "representative samples". While these benefits are well known from prior studies, the widespread use of correlative cryo-LM and cryo-EM remains limited due to the expense and complexity of buying or building a suitable cryogenic light microscopy stage. Here we demonstrate the assembly, and use of an inexpensive cryogenic stage that can be fabricated in any lab for less than $40 with parts found at local hardware and grocery stores. This cryo-LM stage is designed for use with reflected light microscopes that are fitted with long working distance air objectives. For correlative cryo-LM and cryo-EM studies, we adapt the use of carbon coated standard 3-mm cryo-EM grids as specimen supports. After adsorbing the sample to the grid, previously established protocols for vitrifying the sample and transferring/handling the grid are followed to permit multi-technique imaging. As a result, this setup allows any laboratory with a reflected light microscope to have access to direct correlative imaging of frozen hydrated samples.

  10. Development of a multi-layered psychosocial care system for children in areas of political violence.

    Science.gov (United States)

    Jordans, Mark Jd; Tol, Wietse A; Komproe, Ivan H; Susanty, Dessy; Vallipuram, Anavarathan; Ntamatumba, Prudence; Lasuba, Amin C; de Jong, Joop Tvm

    2010-06-16

    Few psychosocial and mental health care systems have been reported for children affected by political violence in low- and middle income settings and there is a paucity of research-supported recommendations. This paper describes a field tested multi-layered psychosocial care system for children (focus age between 8-14 years), aiming to translate common principles and guidelines into a comprehensive support package. This community-based approach includes different overlapping levels of interventions to address varying needs for support. These levels provide assessment and management of problems that range from the social-pedagogic domain to the psychosocial, the psychological and the psychiatric domains. Specific intervention methodologies and their rationale are described within the context of a four-country program (Burundi, Sri Lanka, Indonesia and Sudan). The paper aims to contribute to bridge the divide in the literature between guidelines, consensus & research and clinical practice in the field of psychosocial and mental health care in low- and middle-income countries.

  11. Peak mooring forces in the horizontal interlaced multi-layered moored floating pipe breakwater

    Directory of Open Access Journals (Sweden)

    Vishwanath Mane

    2011-06-01

    Full Text Available Present study aims to investigate the influence of relative breakwater width W/L (W=width of breakwater, L=wavelength, wave steepness Hi/gT2 (Hi=incident wave height, T=wave period and relative wave height d/W (d=water depth on forces in the moorings of horizontal interlaced multi-layered moored floating pipe breakwater (HIMMFPB model. Studies were conducted on scaled down physical models having three layers of Poly Vinyl Chloride (PVC pipes, wave steepness Hi/gT2 varying from 0.063 to 0.849, relative width W/L varying from 0.4 to 2.65 and relative spacing S/D=2 (S=horizontal centre-to-centre spacing of pipes, D=diameter of pipes. Peak mooring forces were also measured and data collected is analyzed by plotting non-dimensional graphs depicting variation of fs/γW2 (fs=Sea side Mooring force, γ=specific weight of water & fl/γW2 (fl=Lee side Mooring force with Hi/gT2 for d/W varying from 0.082 to 0.276 and also variation of fs/γW2 and fl/γW2 with W/L for Hi/d varying from 0.06 to 0.400.

  12. 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.

  13. Inter-layer synchronization in non-identical multi-layer networks

    Science.gov (United States)

    Leyva, I.; Sevilla-Escoboza, R.; Sendiña-Nadal, I.; Gutiérrez, R.; Buldú, J. M.; Boccaletti, S.

    2017-04-01

    Inter-layer synchronization is a dynamical process occurring in multi-layer networks composed of identical nodes. This process emerges when all layers are synchronized, while nodes in each layer do not necessarily evolve in unison. So far, the study of such inter-layer synchronization has been restricted to the case in which all layers have an identical connectivity structure. When layers are not identical, the inter-layer synchronous state is no longer a stable solution of the system. Nevertheless, when layers differ in just a few links, an approximate treatment is still feasible, and allows one to gather information on whether and how the system may wander around an inter-layer synchronous configuration. We report the details of an approximate analytical treatment for a two-layer multiplex, which results in the introduction of an extra inertial term accounting for structural differences. Numerical validation of the predictions highlights the usefulness of our approach, especially for small or moderate topological differences in the intra-layer coupling. Moreover, we identify a non-trivial relationship connecting the betweenness centrality of the missing links and the intra-layer coupling strength. Finally, by the use of multiplexed layers of electronic circuits, we study the inter-layer synchronization as a function of the removed links.

  14. A Method to have Multi-Layer Thermal Insulation Provide Damage Detection

    Science.gov (United States)

    Woodward, Stanley E.; Taylor, Bryant D.; Jones, Thomas W.; Shams, Qamar A.; Lyons, Frankel; Henderson, Donald

    2007-01-01

    Design and testing of a multi-layer thermal insulation system that also provides debris and micrometeorite damage detection is presented. One layer of the insulation is designed as an array of passive open-circuit electrically conductive spiral trace sensors. The sensors are a new class of sensors that are electrically open-circuits that have no electrical connections thereby eliminating one cause of failure to circuits. The sensors are powered using external oscillating magnetic fields. Once electrically active, they produce their own harmonic magnetic fields. The responding field frequency changes if any sensor is damaged. When the sensors are used together in close proximity, the inductive coupling between sensors provides a means of telemetry. The spiral trace design using reflective electrically conductive material provides sufficient area coverage for the sensor array to serves as a layer of thermal insulation. The other insulation layers are designed to allow the sensor s magnetic field to permeate the insulation layers while having total reflective surface area to reduce thermal energy transfer. Results of characterizing individual sensors and the sensor array s response to punctures are presented. Results of hypervelocity impact testing using projectiles of 1-3.6 millimeter diameter having speeds ranging from 6.7-7.1 kilometers per second are also presented.

  15. Rapid Biogas Production by Compact Multi-Layer Membrane Bioreactor: Efficiency of Synthetic Polymeric Membranes

    Directory of Open Access Journals (Sweden)

    Supansa Youngsukkasem

    2013-11-01

    Full Text Available Entrapment of methane-producing microorganisms between semi-permeable synthetic membranes in a multi-layer membrane bioreactor (MMBR was studied and compared to the digestion capacity of a free-cell digester, using a hydraulic retention time of one day and organic loading rates (OLR of 3.08, 6.16, and 8.16 g COD/L·day. The reactor was designed to retain bacterial cells with uprising plug flow through a narrow tunnel between membrane layers, in order to acquire maximal mass transfer in a compact bioreactor. Membranes of hydrophobic polyamide 46 (PA and hydroxyethylated polyamide 46 (HPA as well as a commercial membrane of polyvinylidene fluoride (PVDF were examined. While the bacteria in the free-cell digester were washed out, the membrane bioreactor succeeded in retaining them. Cross-flow of the liquid through the membrane surface and diffusion of the substrate through the membranes, using no extra driving force, allowed the bacteria to receive nutrients and to produce biogas. However, the choice of membrane type was crucial. Synthesized hydrophobic PA membrane was not effective for this purpose, producing 50–121 mL biogas/day, while developed HPA membrane and the reference PVDF were able to transfer the nutrients and metabolites while retaining the cells, producing 1102–1633 and 1016–1960 mL biogas/day, respectively.

  16. Resolving the cycle skip introduced by the multi-layer static model using a hybrid approach

    Science.gov (United States)

    Tawadros, Emad Ekladios Toma

    Cycle skips (breaks) in seismic data are occasionally irresolvable using conventional static correction programs. Such artificial cycle skips can be misleading for interpreters and introduce false subsurface images. After applying datum static corrections using either the single-layer or multi-layer models, artificial cycle skips might develop in the data. Although conventional residual static correction techniques are occasionally able to solve this problem, they fail in solving many other cases. A new approach is introduced in this study to resolve this problem by forming a static model that is free of these artificial cycle skips, which can be used as a pilot volume for residual statics calculation. The pilot volume is formed by combining the high-frequency static component of the single-layer model which show better static solution at the static problem locations and the low-frequency static component of the two-layer model. This new approach is applied on a 3-D seismic data set from Haba Field of Eastern Saudi Arabia where a major cycle skip was introduced by the multilayer model. Results show a better image of the subsurface structure after application of the new approach.

  17. Preparation of microcapsules with multi-layers structure stabilized by chitosan and sodium dodecyl sulfate.

    Science.gov (United States)

    Chatterjee, Sudipta; Salaün, Fabien; Campagne, Christine; Vaupre, Suzy; Beirão, Alexandre

    2012-10-01

    The microcapsules with oil core and multi-layers shell were developed from poly-cationic chitosan (CS) and anionic SDS in multistep electrostatic layer by layer deposition technique combined with oil in water emulsification process. The net charge of microcapsules determined by zeta potential indicated that microcapsules are highly positive charged because of poly-cationic nature of CS, and charge neutralization of microcapsules occurred after alkali treatment. The granulometry measurement showed increase in average diameter of microcapsules by alkali treatment suggesting swelling or formation of small aggregates. The morphology analysis of microcapsules by optical microscopy corroborated the results of granulometry, and diameter of microcapsules was found to be decreased in multistep process due to tight packing of layers in outer shell of microcapsules. The alkali treatment of microcapsules to solidify outer shell was optimized with 0.02 N NaOH to reduce microcapsules aggregation and gel formation by CS chains as found in optical micrographs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Nitrogen and Phosphorus Removal Performance in the Novel Multi-Layered Biological Tricking Filter

    Directory of Open Access Journals (Sweden)

    CUI Ting-ting

    2014-02-01

    Full Text Available Biological trickling filter is one of the main rural sewage treatment technology, but it still has the shortcomings such as lower re-moval efficiency for nitrogen and phosphorus or lower stability. In order to improve the nitrogen and phosphorus removal efficiency of the de-vice and find out its optimum technological conditions, the study took the novel multi-layered biological tricking filter as the device to test the contribution of filter medium, hydraulic loading, recirculation ratio on the treatment of nitrogen and phosphorus removal. The results showed that when the hydraulic loading of 4 m3·m-2·d-1, the recirculation ratio rate of 2∶1 and slag as filter medium were applied, the best effect could be achieved in the filter. The highest mean efficiency of NH4+-N, TN, TP and COD were 87.08%, 57.37%, 66.04% and 80.78%, respectively.The results also indicated that higher recirculation ratio was one of effective paths to improve nitrogen removal efficiency.

  19. 3D Polygon Mesh Compression with Multi Layer Feed Forward Neural Networks

    Directory of Open Access Journals (Sweden)

    Emmanouil Piperakis

    2003-06-01

    Full Text Available In this paper, an experiment is conducted which proves that multi layer feed forward neural networks are capable of compressing 3D polygon meshes. Our compression method not only preserves the initial accuracy of the represented object but also enhances it. The neural network employed includes the vertex coordinates, the connectivity and normal information in one compact form, converting the discrete and surface polygon representation into an analytic, solid colloquial. Furthermore, the 3D object in its compressed neural form can be directly - without decompression - used for rendering. The neural compression - representation is viable to 3D transformations without the need of any anti-aliasing techniques - transformations do not disrupt the accuracy of the geometry. Our method does not su.er any scaling problem and was tested with objects of 300 to 107 polygons - such as the David of Michelangelo - achieving in all cases an order of O(b3 less bits for the representation than any other commonly known compression method. The simplicity of our algorithm and the established mathematical background of neural networks combined with their aptness for hardware implementation can establish this method as a good solution for polygon compression and if further investigated, a novel approach for 3D collision, animation and morphing.

  20. A multi-layer method to study genome-scale positions of nucleosomes.

    Science.gov (United States)

    Di Gesù, Vito; Lo Bosco, Giosuè; Pinello, Luca; Yuan, Guo-Cheng; Corona, Davide F V

    2009-02-01

    The basic unit of eukaryotic chromatin is the nucleosome, consisting of about 150 bp of DNA wrapped around a protein core made of histone proteins. Nucleosomes position is modulated in vivo to regulate fundamental nuclear processes. To measure nucleosome positions on a genomic scale both theoretical and experimental approaches have been recently reported. We have developed a new method, Multi-Layer Model (MLM), for the analysis of nucleosome position data obtained with microarray-based approach. The MLM is a feature extraction method in which the input data is processed by a classifier to distinguish between several kinds of patterns. We applied our method to simulated-synthetic and experimental nucleosome position data and found that besides a high nucleosome recognition and a strong agreement with standard statistical methods, the MLM can identify distinct classes of nucleosomes, making it an important tool for the genome wide analysis of nucleosome position and function. In conclusion, the MLM allows a better representation of nucleosome position data and a significant reduction in computational time.

  1. Light source distribution and scattering phase function influence light transport in diffuse multi-layered media

    Science.gov (United States)

    Vaudelle, Fabrice; L'Huillier, Jean-Pierre; Askoura, Mohamed Lamine

    2017-06-01

    Red and near-Infrared light is often used as a useful diagnostic and imaging probe for highly scattering media such as biological tissues, fruits and vegetables. Part of diffusively reflected light gives interesting information related to the tissue subsurface, whereas light recorded at further distances may probe deeper into the interrogated turbid tissues. However, modelling diffusive events occurring at short source-detector distances requires to consider both the distribution of the light sources and the scattering phase functions. In this report, a modified Monte Carlo model is used to compute light transport in curved and multi-layered tissue samples which are covered with a thin and highly diffusing tissue layer. Different light source distributions (ballistic, diffuse or Lambertian) are tested with specific scattering phase functions (modified or not modified Henyey-Greenstein, Gegenbauer and Mie) to compute the amount of backscattered and transmitted light in apple and human skin structures. Comparisons between simulation results and experiments carried out with a multispectral imaging setup confirm the soundness of the theoretical strategy and may explain the role of the skin on light transport in whole and half-cut apples. Other computational results show that a Lambertian source distribution combined with a Henyey-Greenstein phase function provides a higher photon density in the stratum corneum than in the upper dermis layer. Furthermore, it is also shown that the scattering phase function may affect the shape and the magnitude of the Bidirectional Reflectance Distribution (BRDF) exhibited at the skin surface.

  2. Multi-Layer 5G Mobile Phone Antenna for Multi-User MIMO Communications

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2015-01-01

    for 5G wireless communications. Two identical linear sub arrays can be simultaneously used at different sides of the mobile-phone printed circuit board (PCB) for operation in diversity or multiple-input multiple-output (MIMO) modes. Each sub array contains eight elements of very compact off......-center dipole antennas with dimensions of 5.4×0.67 mm2. The feature of compact design with good beam-steering function makes them well-suited to integrate into the mobile-phone mock-up. The fundamental properties of the proposed antenna have been investigated. Simulations show that the proposed 5G antenna......In this study, a new design of multi-layer phased array antenna for millimeter-wave (mm-Wave) fifth generation (5G) mobile terminals is proposed. The proposed linear phased array antenna is designed on four layers of the Rogers RT5880 substrates to operate at 28 GHz which is under consideration...

  3. Unified Multi-Layer among Software Defined Multi-Domain Optical Networks (Invited

    Directory of Open Access Journals (Sweden)

    Hui Yang

    2015-06-01

    Full Text Available The software defined networking (SDN enabled by OpenFlow protocol has gained popularity which can enable the network to be programmable and accommodate both fixed and flexible bandwidth services. In this paper, we present a unified multi-layer (UML architecture with multiple controllers and a dynamic orchestra plane (DOP for software defined multi-domain optical networks. The proposed architecture can shield the differences among various optical devices from multi-vendors and the details of connecting heterogeneous networks. The cross-domain services with on-demand bandwidth can be deployed via unified interfaces provided by the dynamic orchestra plane. Additionally, the globalization strategy and practical capture of signal processing are presented based on the architecture. The overall feasibility and efficiency of the proposed architecture is experimentally verified on the control plane of our OpenFlow-based testbed. The performance of globalization strategy under heavy traffic load scenario is also quantitatively evaluated based on UML architecture compared with other strategies in terms of blocking probability, average hops, and average resource consumption.

  4. Artificial vision by multi-layered neural networks: neocognitron and its advances.

    Science.gov (United States)

    Fukushima, Kunihiko

    2013-01-01

    The neocognitron is a neural network model proposed by Fukushima (1980). Its architecture was suggested by neurophysiological findings on the visual systems of mammals. It is a hierarchical multi-layered network. It acquires the ability to robustly recognize visual patterns through learning. Although the neocognitron has a long history, modifications of the network to improve its performance are still going on. For example, a recent neocognitron uses a new learning rule, named add-if-silent, which makes the learning process much simpler and more stable. Nevertheless, a high recognition rate can be kept with a smaller scale of the network. Referring to the history of the neocognitron, this paper discusses recent advances in the neocognitron. We also show that various new functions can be realized by, for example, introducing top-down connections to the neocognitron: mechanism of selective attention, recognition and completion of partly occluded patterns, restoring occluded contours, and so on. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Hypothetical Pattern Recognition Design Using Multi-Layer Perceptorn Neural Network For Supervised Learning

    Directory of Open Access Journals (Sweden)

    Md. Abdullah-al-mamun

    2015-08-01

    Full Text Available Abstract Humans are capable to identifying diverse shape in the different pattern in the real world as effortless fashion due to their intelligence is grow since born with facing several learning process. Same way we can prepared an machine using human like brain called Artificial Neural Network that can be recognize different pattern from the real world object. Although the various techniques is exists to implementation the pattern recognition but recently the artificial neural network approaches have been giving the significant attention. Because the approached of artificial neural network is like a human brain that is learn from different observation and give a decision the previously learning rule. Over the 50 years research now a days pattern recognition for machine learning using artificial neural network got a significant achievement. For this reason many real world problem can be solve by modeling the pattern recognition process. The objective of this paper is to present the theoretical concept for pattern recognition design using Multi-Layer Perceptorn neural networkin the algorithm of artificial Intelligence as the best possible way of utilizing available resources to make a decision that can be a human like performance.

  6. DECIPHERING URBAN LIFE: A MULTI-LAYERED INVESTIGATION OF ST. ENOCH SQUARE, GLASGOW CITY CENTRE

    Directory of Open Access Journals (Sweden)

    Ashraf M. Salama

    2017-07-01

    Full Text Available An urban space is a vital stage for social interaction and city life.  Measuring the city life is always related to social, economic and cultural conditions of an urban context.  Social gathering increases the quality of urban space and improves economic vitality. This paper aims to explore how successful urban spaces could impact the growth and performance of an urban context, not only as a physical urban reality, but also as a generator of social life.  Utilising St. Enoch Square as a case study, a multi-layered methodological approach constituted in a series of tools was implemented, including behavioural mapping, visual preference survey, walking tour assessment, contemplating settings, and observing physical traces and by-product of use in order to interpret various forms of experiences that take place. Findings reveal various attributes of St. Enoch Square while highlighting different qualities that promote and support the overall vibrancy of the city life. Conclusions are drawn to emphasise that the physical and spatial characteristics of an urban space are critical factors for maintaining social interaction while creating essential opportunities that support the human experience in the public realm.

  7. A particle swarm-based algorithm for optimization of multi-layered and graded dental ceramics.

    Science.gov (United States)

    Askari, Ehsan; Flores, Paulo; Silva, Filipe

    2017-10-04

    The thermal residual stresses (TRSs) generated owing to the cooling down from the processing temperature in layered ceramic systems can lead to crack formation as well as influence the bending stress distribution and the strength of the structure. The purpose of this study is to minimize the thermal residual and bending stresses in dental ceramics to enhance their strength as well as to prevent the structure failure. Analytical parametric models are developed to evaluate thermal residual stresses in zirconia-porcelain multi-layered and graded discs and to simulate the piston-on-ring test. To identify optimal designs of zirconia-based dental restorations, a particle swarm optimizer is also developed. The thickness of each interlayer and compositional distribution are referred to as design variables. The effect of layers number constituting the interlayer between two based materials on the performance of graded prosthetic systems is also investigated. The developed methodology is validated against results available in literature and a finite element model constructed in the present study. Three different cases are considered to determine the optimal design of graded prosthesis based on minimizing (a) TRSs; (b) bending stresses; and (c) both TRS and bending stresses. It is demonstrated that each layer thickness and composition profile have important contributions into the resulting stress field and magnitude. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 3D mechanical stratigraphy of a deformed multi-layer: Linking sedimentary architecture and strain partitioning

    Science.gov (United States)

    Cawood, Adam J.; Bond, Clare E.

    2018-01-01

    Stratigraphic influence on structural style and strain distribution in deformed sedimentary sequences is well established, in models of 2D mechanical stratigraphy. In this study we attempt to refine existing models of stratigraphic-structure interaction by examining outcrop scale 3D variations in sedimentary architecture and the effects on subsequent deformation. At Monkstone Point, Pembrokeshire, SW Wales, digital mapping and virtual scanline data from a high resolution virtual outcrop have been combined with field observations, sedimentary logs and thin section analysis. Results show that significant variation in strain partitioning is controlled by changes, at a scale of tens of metres, in sedimentary architecture within Upper Carboniferous fluvio-deltaic deposits. Coupled vs uncoupled deformation of the sequence is defined by the composition and lateral continuity of mechanical units and unit interfaces. Where the sedimentary sequence is characterized by gradational changes in composition and grain size, we find that deformation structures are best characterized by patterns of distributed strain. In contrast, distinct compositional changes vertically and in laterally equivalent deposits results in highly partitioned deformation and strain. The mechanical stratigraphy of the study area is inherently 3D in nature, due to lateral and vertical compositional variability. Consideration should be given to 3D variations in mechanical stratigraphy, such as those outlined here, when predicting subsurface deformation in multi-layers.

  9. Experimental Study of Weepage in Multi-layer Glass Reinforced Piping

    KAUST Repository

    Al Sinan, Hussain

    2014-05-01

    Glass Reinforced Polymer pipes, commonly used in water transport applications, are prone to long term weepage. Weepage is defined as the transfer of fluid through the pipe and is considered a functional failure. An experimental investigation of weepage in multi-layered GRP pipes was carried out in two parts aiming to understand the phenomenon to help enhance the weepage resistance of manufactured pipes. First, liner surface profilometry investigation was carried out to identify microscopic features that might serve in initiating weepage. Second, MRI and x-ray tomography and SEM imaging of pipe samples aged with water and dye penetrant was carried out to capture weepage development through the pipe thickness. Diffusion through liner fiber/resin interface, propagation in the direction of poorly wetted hoop fibers and transverse cracks were found to be the likely causes of accelerating weepage in the samples. Fiber rich zones in the liner were considered weak spots that water can use for fast penetration of the liner. Finally, polyester netting used to hold core layer was found to help in water accumulation and transport through the pipe increasing the chances of failure.

  10. Anisotropy-driven quantum capacitance in multi-layered black phosphorus

    Science.gov (United States)

    Sengupta, Parijat; Rakheja, Shaloo

    2017-10-01

    We report analytic results on quantum capacitance (Cq) measurements and their optical tuning in a dual-gated device with potassium-doped multi-layered black phosphorous (BP) as the channel material. The two-dimensional (2D) layered BP is highly anisotropic with a semi-Dirac dispersion marked by linear and quadratic contributions. The Cq calculations mirror this asymmetric arrangement. A further increase in the asymmetry and consequently Cq is predicted by photon-dressing the BP dispersion. To achieve this and tune Cq in a field-effect transistor (FET), we suggest a configuration wherein a pair of electrostatic (top) and optical (back) gates clamp a BP channel. The back gate shines an optical pulse to rearrange the dispersion of the 2D BP. Analytic calculations are done with Floquet Hamiltonians in the off-resonant regime. The value of such Cq calculations, in addition to its role in adjusting the current drive of an FET, is discussed in the context of metal-insulator and topological phase transitions and enhancements to the thermoelectric figure of merit.

  11. Photocatalytic degradation of methyl orange by a multi-layer rotating disk reactor.

    Science.gov (United States)

    Lin, Chia-Nan; Chang, Chih-Yi; Huang, Hung Ji; Tsai, Din Ping; Wu, Nae-Lih

    2012-11-01

    Solar wastewater treatment based on photocatalytic reactions is a green process that utilizes renewable energy resources and minimizes secondary pollution. Reactor design plays an important role in promoting treatment efficiency and throughput density (based on unit volume of the reactor). A rotating disk reactor that significantly increases the process efficiency has been designed and evaluated for application to photocatalytic decomposition of dye pollutants in aqueous solutions. In this process, a novel multi-layer rotating disk reactor (MLRDR) was presented. Photocatalyst (TiO(2)) particles are immobilized on the surfaces of disks. Within each layer of the reactor, methyl orange aqueous solution is allowed to flow from the center of the disk in a radial direction along the surface of the disk, which is rotating at high speed and is irradiated with UV lamps. The effluent is then directed to the center of another layer that lies underneath. Up to four stacked layers have been tested in this study, and the effects due to the number of the layers and volumetric flow rate on reaction conversion are investigated. The efficiency of this photocatalytic reactor exhibits complex dependence on these parameters. With selected operating conditions, conversions greater than 95% can be achieved within seconds of residence time. Design equations of the reactor have been derived based on fluid dynamics and kinetic models, and the simulation results show promising scale-up potential of the reactor.

  12. High-frequency guided ultrasonic waves for hidden defect detection in multi-layered aircraft structures.

    Science.gov (United States)

    Masserey, Bernard; Raemy, Christian; Fromme, Paul

    2014-09-01

    Aerospace structures often contain multi-layered metallic components where hidden defects such as fatigue cracks and localized disbonds can develop, necessitating non-destructive testing. Employing standard wedge transducers, high frequency guided ultrasonic waves that penetrate through the complete thickness were generated in a model structure consisting of two adhesively bonded aluminium plates. Interference occurs between the wave modes during propagation along the structure, resulting in a frequency dependent variation of the energy through the thickness with distance. The wave propagation along the specimen was measured experimentally using a laser interferometer. Good agreement with theoretical predictions and two-dimensional finite element simulations was found. Significant propagation distance with a strong, non-dispersive main wave pulse was achieved. The interaction of the high frequency guided ultrasonic waves with small notches in the aluminium layer facing the sealant and on the bottom surface of the multilayer structure was investigated. Standard pulse-echo measurements were conducted to verify the detection sensitivity and the influence of the stand-off distance predicted from the finite element simulations. The results demonstrated the potential of high frequency guided waves for hidden defect detection at critical and difficult to access locations in aerospace structures from a stand-off distance. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Examining the impact of multi-layer graphene using cellular and amphibian models

    Science.gov (United States)

    Muzi, Laura; Mouchet, Florence; Cadarsi, Stéphanie; Janowska, Izabela; Russier, Julie; Ménard-Moyon, Cécilia; Risuleo, Gianfranco; Soula, Brigitte; Galibert, Anne-Marie; Flahaut, Emmanuel; Pinelli, Eric; Gauthier, Laury; Bianco, Alberto

    2016-06-01

    In the last few years, graphene has been defined as the revolutionary material showing an incredible expansion in industrial applications. Different graphene forms have been applied in several contexts, spreading from energy technologies and electronics to food and agriculture technologies. Graphene showed promises also in the biomedical field. Hopeful results have been already obtained in diagnostic, drug delivery, tissue regeneration and photothermal cancer ablation. In view of the enormous development of graphene-based technologies, a careful assessment of its impact on health and environment is demanded. It is evident how investigating the graphene toxicity is of fundamental importance in the context of medical purposes. On the other hand, the nanomaterial present in the environment, likely to be generated all along the industrial life-cycle, may have harmful effects on living organisms. In the present work, an important contribution on the impact of multi-layer graphene (MLG) on health and environment is given by using a multifaceted approach. For the first purpose, the effect of the material on two mammalian cell models was assessed. Key cytotoxicity parameters were considered such as cell viability and inflammatory response induction. This was combined with an evaluation of MLG toxicity towards Xenopus laevis, used as both in vivo and environmental model organism.

  14. Achievable Rates of Cognitive Radio Networks Using Multi-Layer Coding with Limited CSI

    KAUST Repository

    Sboui, Lokman

    2016-03-01

    In a Cognitive Radio (CR) framework, the channel state information (CSI) feedback to the secondary transmitter (SU Tx) can be limited or unavailable. Thus, the statistical model is adopted in order to determine the system performance using the outage concept. In this paper, we adopt a new approach using multi-layer-coding (MLC) strategy, i.e., broadcast approach, to enhance spectrum sharing over fading channels. First, we consider a scenario where the secondary transmitter has no CSI of both the link between SU Tx and the primary receiver (cross-link) and its own link. We show that using MLC improves the cognitive rate compared to the rate provided by a singlelayer- coding (SLC). In addition, we observe numerically that 2-Layer coding achieves most of the gain for Rayleigh fading. Second, we analyze a scenario where SU Tx is provided by partial CSI about its link through quantized CSI. We compute its achievable rate adopting the MLC and highlight the improvement over SLC. Finally, we study the case in which the cross-link is perfect, i.e., a cooperative primary user setting, and compare the performance with the previous cases. We present asymptotic analysis at high power regime and show that the cooperation enhances considerably the cognitive rate at high values of the secondary power budget.

  15. A Multi-layered Model for the Shape, Zonal Winds and Gravitational Field of Jupiter

    Science.gov (United States)

    Schubert, G.; Zhang, K.; Kong, D.

    2016-12-01

    We have developed a three-dimensional, finite-element, multi-layered, non-spheroidal model of Jupiter consisting of an inner core, a metallic dynamo region and an outer molecular electrically insulating envelope. Different polytropic equations of state are used in the metallic and molecular regions. The zonal winds are on cylinders parallel to the rotation axis and are confined within the molecular envelope by magnetic braking. The effect of rotational distortion is fully accounted for; it is not treated as simply a small perturbation on a spherically symmetric state. The model determines the density, size and shape of the inner core, the irregular shape of the 1-bar pressure level, and the internal structure of Jupiter. It produces the known mass, the known equatorial and polar radii, and the known zonal gravitational coefficient J2 of Jupiter within their error bars; it also yields the coefficients J4 and J6 with an accuracy of a few percent. The variation of the gravitational field caused solely by the effect of the zonal winds on the rotationally distorted Jupiter is also determined. Different cases, ranging from a deep wind profile to a very shallow profile, are considered. The model enables accurate interpretation of the zonal gravitational coefficients expected from the Juno mission.

  16. Development of a multi-layered psychosocial care system for children in areas of political violence

    Directory of Open Access Journals (Sweden)

    Susanty Dessy

    2010-06-01

    Full Text Available Abstract Few psychosocial and mental health care systems have been reported for children affected by political violence in low- and middle income settings and there is a paucity of research-supported recommendations. This paper describes a field tested multi-layered psychosocial care system for children (focus age between 8-14 years, aiming to translate common principles and guidelines into a comprehensive support package. This community-based approach includes different overlapping levels of interventions to address varying needs for support. These levels provide assessment and management of problems that range from the social-pedagogic domain to the psychosocial, the psychological and the psychiatric domains. Specific intervention methodologies and their rationale are described within the context of a four-country program (Burundi, Sri Lanka, Indonesia and Sudan. The paper aims to contribute to bridge the divide in the literature between guidelines, consensus & research and clinical practice in the field of psychosocial and mental health care in low- and middle-income countries.

  17. 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.

  18. Characterization of multi-layered impact damage in polymer matrix composites using lateral thermography

    Science.gov (United States)

    Whitlow, Travis; Sathish, Shamachary

    2017-02-01

    Polymer matrix composites (PMCs) are increasingly being integrated into aircraft structures. However, these components are susceptible to impact related delamination, which, on aircrafts, can occur due to a number of reasons during aircraft use and maintenance. Quantifying impact damage is an important aspect for life-management of aircraft and requires in-depth knowledge of the damage zone on a ply-by-ply level. Traditionally, immersion ultrasound has provided relative high resolution images of impact damage. Ultrasonic time-of-flight data can be used to determine the front surface delamination depth and an approximation of the delaminated area. However, such inspections require the material to be immersed in water and can be time consuming. The objective of this work is to develop a quick and robust methodology to non-destructively characterize multi-layered impact damage using lateral thermography. Initial results suggest lateral heat flow is sensitive to the depth of impact damage. The anticipated outcome of this project is to estimate the extent of through-thickness impact damage. Initial results are shown and future efforts are discussed.

  19. Mechanical loading regulates human MSC differentiation in a multi-layer hydrogel for osteochondral tissue engineering.

    Science.gov (United States)

    Steinmetz, Neven J; Aisenbrey, Elizabeth A; Westbrook, Kristofer K; Qi, H Jerry; Bryant, Stephanie J

    2015-07-01

    A bioinspired multi-layer hydrogel was developed for the encapsulation of human mesenchymal stem cells (hMSCs) as a platform for osteochondral tissue engineering. The spatial presentation of biochemical cues, via incorporation of extracellular matrix analogs, and mechanical cues, via both hydrogel crosslink density and externally applied mechanical loads, were characterized in each layer. A simple sequential photopolymerization method was employed to form stable poly(ethylene glycol)-based hydrogels with a soft cartilage-like layer of chondroitin sulfate and low RGD concentrations, a stiff bone-like layer with high RGD concentrations, and an intermediate interfacial layer. Under a compressive load, the variation in hydrogel stiffness within each layer produced high strains in the soft cartilage-like layer, low strains in the stiff bone-like layer, and moderate strains in the interfacial layer. When hMSC-laden hydrogels were cultured statically in osteochondral differentiation media, the local biochemical and matrix stiffness cues were not sufficient to spatially guide hMSC differentiation after 21 days. However dynamic mechanical stimulation led to differentially high expression of collagens with collagen II in the cartilage-like layer, collagen X in the interfacial layer and collagen I in the bone-like layer and mineral deposits localized to the bone layer. Overall, these findings point to external mechanical stimulation as a potent regulator of hMSC differentiation toward osteochondral cellular phenotypes. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  20. Multi-layer film flow down an inclined plane: experimental investigation

    KAUST Repository

    Henry, Daniel

    2014-11-19

    We report the results from an experimental study of the flow of a film down an inclined plane where the film itself is comprised of up to three layers of different liquids. By measuring the total film thickness for a broad range of parameters including flow rates and liquid physical properties, we provide a thorough and systematic test of the single-layer approximation for multi-layer films for Reynolds numbers Re = ρQ/μ≈0.03-60. In addition, we also measure the change in film thickness of individual layers as a function of flow rates for a variety of experimental configurations. With the aid of high-speed particle tracking, we derive the velocity fields and free-surface velocities to compare to the single-layer approximation. Furthermore, we provide experimental evidence of small capillary ridge formations close to the point where two layers merge and compare our experimental parameter range for the occurrence of this phenomenon to those previously reported.

  1. MATERIAL DEPENDENCE OF TEMPERATURE DISTRIBUTION IN MULTI-LAYER MULTI-METAL COOKWARE

    Directory of Open Access Journals (Sweden)

    MOHAMMADREZA SEDIGH

    2017-09-01

    Full Text Available Laminated structure is becoming more popular in cookware markets; however, there seems to be a lack of enough scientific studies to evaluate its pros and cons, and to show that how it functions. A numerical model using a finite element method with temperature-dependent material properties has been performed to investigate material and layer dependence of temperature distribution in multi-layer multi-metal plate exposed to irregular heating. Behavior of two parameters including mean temperature value and uniformity on the inner surface of plate under variations of thermal properties and geometrical conditions have been studied. The results indicate that conductive metals used as first layer in bi-layer plates have better thermal performance than those used in the second layer. In addition, since cookware manufacturers increasingly prefer to use all-clad aluminium plate, recently, this structure is analysed in the present study as well. The results show all-clad copper and aluminum plate possesses lower temperature gradient compared with single layer aluminum and all-clad aluminum core plates.

  2. A multi-layered active target for the study of neutron-unbound nuclides at NSCL

    Science.gov (United States)

    Freeman, Jessica; Gueye, Paul; Redpath, Thomas; MoNA Collaboration

    2017-01-01

    The characteristics of neutron-unbound nuclides were investigated using a multi-layered Si/Be active target designed for use with the MoNA/LISA setup at the National Superconducting Cyclotron (NSCL). The setup consists of the MoNA/LISA arrays (for neutron detection) and a superconducting sweeper magnet (for charged separation) to identify products following the decay of neutron unbound states. The segmented target consisted of three 700 mg/cm2 beryllium targets and four 0.14 mm thick 62x62 mm2 silicon detectors. As a commissioning experiment for the target the decay of two-neutron unbound 26O populated in a one-proton removal reaction from a radioactive 27F beam was performed. The 27F secondary radioactive beam from the NSCL's Coupled Cyclotron Facility was produced from the fragmentation of a 140 MeV/u 48Ca beam incident on a thick beryllium target and then cleanly selected by the A1900 fragment separator. The energy loss and position spectra of the incoming beam and reaction products were used to calibrate the Silicon detectors to within 1.5% in both energy and position. A dedicated Geant4 model of the target was developed to simulate the energy loss within the target. A description of the experimental setup, simulation work, and energy and position calibration will be presented. DoE/NNSA - DE-NA0000979.

  3. Multi-layered multi-pattern CPG for adaptive locomotion of humanoid robots.

    Science.gov (United States)

    Nassour, John; Hénaff, Patrick; Benouezdou, Fethi; Cheng, Gordon

    2014-06-01

    In this paper, we present an extended mathematical model of the central pattern generator (CPG) in the spinal cord. The proposed CPG model is used as the underlying low-level controller of a humanoid robot to generate various walking patterns. Such biological mechanisms have been demonstrated to be robust in locomotion of animal. Our model is supported by two neurophysiological studies. The first study identified a neural circuitry consisting of a two-layered CPG, in which pattern formation and rhythm generation are produced at different levels. The second study focused on a specific neural model that can generate different patterns, including oscillation. This neural model was employed in the pattern generation layer of our CPG, which enables it to produce different motion patterns-rhythmic as well as non-rhythmic motions. Due to the pattern-formation layer, the CPG is able to produce behaviors related to the dominating rhythm (extension/flexion) and rhythm deletion without rhythm resetting. The proposed multi-layered multi-pattern CPG model (MLMP-CPG) has been deployed in a 3D humanoid robot (NAO) while it performs locomotion tasks. The effectiveness of our model is demonstrated in simulations and through experimental results.

  4. A multi-layer description of Reynolds stresses in canonical wall bounded flows

    Science.gov (United States)

    Chen, Xi; Hussain, Fazle; She, Zhen-Su

    2015-11-01

    A complete description of the Reynolds stress tensor is obtained for all three canonical wall turbulence (channel, pipe and turbulent boundary layer - TBL). The result builds on a multi-layer description of length (order) functions and their ratios, including viscous sublayer, buffer layer, meso-layer for the near wall (inner) region, and bulk flow or a central core (absent in TBL) for the outer region. It is shown that the streamwise mean kinetic-energy profile is quantified with high accuracy over the entire flow domain. The model contains only three Re-dependent parameters for Reynolds number (Re) covering nearly three decades. Furthermore, the inner peak location is predicted to be invariant at y+ = 15, while its magnitude shows notable Re and geometry effects, predicted to be .9.2 for high Re's pipe flows. A mechanism is proposed for the emergence of outer peak in pipes, whose magnitude is predicted to scale as .Reτ0. 05 beyond a critical Reτ about 104(). The recently reported logarithmic dependence in the bulk is recovered, but with an alternative explanation. The result is successfully extended to TBL flows by a fractional total stress and an absence of core. Equally accurate descriptions of vertical and spanwise kinetic-energy are also presented for the three flows. The result has been used to modify turbulent engineering models (i.e. k- ω model) with significant improvement.

  5. MLDS: Multi-Layer Defense System for Preventing Advanced Persistent Threats

    Directory of Open Access Journals (Sweden)

    Daesung Moon

    2014-12-01

    Full Text Available Here we report on the issue of Advanced Persistent Threats (APT, which use malware for the purpose of leaking the data of large corporations and government agencies. APT attacks target systems continuously by utilizing intelligent and complex technologies. To overthrow the elaborate security network of target systems, it conducts an attack after undergoing a pre-reconnaissance phase. An APT attack causes financial loss, information leakage, etc. They can easily bypass the antivirus system of a target system. In this paper, we propose a Multi-Layer Defense System (MLDS that can defend against APT. This system applies a reinforced defense system by collecting and analyzing log information and various information from devices, by installing the agent on the network appliance, server and end-user. It also discusses how to detect an APT attack when one cannot block the initial intrusion while continuing to conduct other activities. Thus, this system is able to minimize the possibility of initial intrusion and damages of the system by promptly responding through rapid detection of an attack when the target system is attacked.

  6. Structural and optical studies of nanostructured TiO{sub 2}–Ge multi-layer thin films

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Abdul Faheem, E-mail: faheem_khan_1977@yahoo.com [UM Power Energy Dedicated Advanced Centre (UMPEDAC), Level 4, Wisma R and D UM, University of Malaya, Jalan Pantai Baharu, 59990 Kuala Lumpur (Malaysia); Department of Materials Science and Engineering, Institute of Space Technology, P.O. Box 2750, Islamabad 44000 (Pakistan); Mehmood, Mazhar [National Centre for Nanotechnology and Department of Metallurgy and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad 45650 (Pakistan); Ali, Turab [Accelerator Lab, National Center for Physics, Islamabad (Pakistan); Fayaz, H. [UM Power Energy Dedicated Advanced Centre (UMPEDAC), Level 4, Wisma R and D UM, University of Malaya, Jalan Pantai Baharu, 59990 Kuala Lumpur (Malaysia)

    2013-06-01

    This paper reports the effects of annealing on structural and optical properties of nanostructured multi-layer TiO{sub 2}–Ge thin films. These films were characterized using different techniques such as X-ray diffraction, X-ray reflectivity, Rutherford backscattering (RBS), and Fourier Transform Infrared spectroscopy. Annealing was responsible for pronounced changes in structural and optical properties of these films, as associated with changes in their structures, stoichiometry and stress-state. Three sets of TiO{sub 2}–Ge multi-layer films were deposited by electron beam evaporation and resistive heating with different Ge layer thickness (5, 10 and 15 nm), and TiO{sub 2} layer thickness was fixed to 20 nm. The films were annealed in air up to 500 °C for 2 h. RBS studies showed that the layer structure of TiO{sub 2}–Ge multi-layer films had been formed. The absorption spectra and band gap energy showed a blue shift with decrease in Ge layer thickness. The absorption spectra of these films suggest quantum confinement that increases with annealing temperature before the complete oxidation of Ge. Apparently complete oxidation results in sudden or sharp rise in band gap energy that matches with that of TiO{sub 2}. RBS study reveals that layered structure of TiO{sub 2}–Ge multi-layer films is not destroyed by annealing, which may be due to non-wetting behavior of Ge and its oxide with TiO{sub 2}. These results imply that nanostructured TiO{sub 2}–Ge multi-layer thin films may be employed as heterojunctions (with tunable band gap energy) based on quantum confinement effects for use in photovoltaics. - Highlights: • Nanostructured multi-layer TiO{sub 2}–Ge films were deposited by electron beam evaporation. • The layered structure of the films was not destroyed by annealing. • The band gap energy showed a blue shift with Germanium (Ge) layer thickness. • The absorption spectra of these films suggest quantum confinement. • The films with lower Ge

  7. ESTIMATING FATE AND TRANSPORT OF MULTIPLE CONTAMINANTS IN THE VADOSE ZONE USING A MULTI-LAYERED SOIL COLUMN AND THREE-PHASE EQUILIBRIUM PARTITIONING MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Rucker, G

    2007-05-01

    Soils at waste sites must be evaluated for the potential of residual soil contamination to leach and migrate to the groundwater beneath the disposal area. If migration to the aquifer occurs, contaminants can travel vast distances and contaminate drinking water wells, thus exposing human receptors to harmful levels of toxins and carcinogens. To prevent groundwater contamination, a contaminant fate and transport analysis is necessary to assess the migration potential of residual soil contaminates. This type of migration analysis is usually performed using a vadose zone model to account for complex geotechnical and chemical variables including: contaminant decay, infiltration rate, soil properties, vadose zone thickness, and chemical behavior. The distinct advantage of using a complex model is that less restrictive, but still protective, soil threshold levels may be determined avoiding the unnecessary and costly remediation of marginally contaminated soils. However, the disadvantage of such modeling is the additional cost for data collection and labor required to apply these models. In order to allay these higher costs and to achieve a less restrictive but still protective clean-up level, a multiple contaminant and multi layered soil column equilibrium partitioning model was developed which is faster, simpler and less expensive to use.

  8. MOD Buffer/YBCO Approach to Fabricate Low-Cost Second Generation HTS Wires

    Energy Technology Data Exchange (ETDEWEB)

    Paranthaman, Mariappan Parans [ORNL; Sathyamurthy, Srivatsan [ORNL; Bhuiyan, Md S [ORNL; Martin, Patrick M [ORNL; Aytug, Tolga [ORNL; Kim, Kyunghoon [ORNL; Fayek, Mostafa [ORNL; Leonard, Keith J [ORNL; Li, Jing [ORNL; Zhang, W. [American Superconductor Corporation, Westborough, MA; Rupich, Marty [American Superconductor Corporation, Westborough, MA

    2007-01-01

    The metal organic deposition (MOD) of buffer layers on RABiTS substrates is considered a potential, low-cost approach to manufacturing high performance Second Generation (2G) high temperature superconducting (HTS) wires. The typical architecture used by American Superconductor in their 2G HTS wire consists of a Ni-W (5 at.%) substrate with a reactively sputtered Y2O3 seed layer, YSZ barrier layer and a CeO2 cap layer. This architecture supports critical currents of over 300 A/cm-width (77 K, self-field) with 0.8 mum YBCO films deposited by the TFA-MOD process. The main challenge in the development of the MOD buffers is to match or exceed the performance of the standard vacuum deposited buffer architecture. We have recently shown that the texture and properties of MOD - La2Zr2Ogamma (LZO) barrier layers can be improved by inserting a thin sputtered Y2O3 seed layer and prepared MOD deposited LZO layers followed by MOD or RF sputtered CeO2 cap layers that support MOD-YBCO films with Ic's of 200 and 255 A/cm-width, respectively. Detailed X-ray and microstructural characterizations indicated that MOD - CeO2 cap reacted completely with MOD YBCO to form BaCeOs. However, sputtered CeO2 cap/MOD YBCO interface remains clean. By further optimizing the coating conditions and reducing the heat-treatment temperatures, we have demonstrated an Ic of 336 A/cm with improved LZO layers and sputtered CeO2 cap and exceeded the performance of that of standard vacuum deposited buffers.

  9. Low Cost Rapid Response Spacecraft, (LCRRS): A Research Project in Low Cost Spacecraft Design and Fabrication in a Rapid Prototyping Environment

    Science.gov (United States)

    Spremo, Stevan; Bregman, Jesse; Dallara, Christopher D.; Ghassemieh, Shakib M.; Hanratty, James; Jackson, Evan; Kitts, Christopher; Klupar, Pete; Lindsay, Michael; Ignacio, Mas; hide

    2009-01-01

    The Low Cost Rapid Response Spacecraft (LCRRS) is an ongoing research development project at NASA Ames Research Center (ARC), Moffett Field, California. The prototype spacecraft, called Cost Optimized Test for Spacecraft Avionics and Technologies (COTSAT) is the first of what could potentially be a series of rapidly produced low-cost satellites. COTSAT has a target launch date of March 2009 on a SpaceX Falcon 9 launch vehicle. The LCRRS research system design incorporates use of COTS (Commercial Off The Shelf), MOTS (Modified Off The Shelf), and GOTS (Government Off The Shelf) hardware for a remote sensing satellite. The design concept was baselined to support a 0.5 meter Ritchey-Chretien telescope payload. This telescope and camera system is expected to achieve 1.5 meter/pixel resolution. The COTSAT team is investigating the possibility of building a fully functional spacecraft for $500,000 parts and $2,000,000 labor. Cost is dramatically reduced by using a sealed container, housing the bus and payload subsystems. Some electrical and RF designs were improved/upgraded from GeneSat-1 heritage systems. The project began in January 2007 and has yielded two functional test platforms. It is expected that a flight-qualified unit will be finished in December 2008. Flight quality controls are in place on the parts and materials used in this development with the aim of using them to finish a proto-flight satellite. For LEO missions the team is targeting a mission class requiring a minimum of six months lifetime or more. The system architecture incorporates several design features required by high reliability missions. This allows for a true skunk works environment to rapidly progress toward a flight design. Engineering and fabrication is primarily done in-house at NASA Ames with flight certifications on materials. The team currently employs seven Full Time Equivalent employees. The success of COTSATs small team in this effort can be attributed to highly cross trained

  10. Low-Cost and Rapid Fabrication of Metallic Nanostructures for Sensitive Biosensors Using Hot-Embossing and Dielectric-Heating Nanoimprint Methods

    Directory of Open Access Journals (Sweden)

    Kuang-Li Lee

    2017-07-01

    Full Text Available We propose two approaches—hot-embossing and dielectric-heating nanoimprinting methods—for low-cost and rapid fabrication of periodic nanostructures. Each nanofabrication process for the imprinted plastic nanostructures is completed within several seconds without the use of release agents and epoxy. Low-cost, large-area, and highly sensitive aluminum nanostructures on A4 size plastic films are fabricated by evaporating aluminum film on hot-embossing nanostructures. The narrowest bandwidth of the Fano resonance is only 2.7 nm in the visible light region. The periodic aluminum nanostructure achieves a figure of merit of 150, and an intensity sensitivity of 29,345%/RIU (refractive index unit. The rapid fabrication is also achieved by using radio-frequency (RF sensitive plastic films and a commercial RF welding machine. The dielectric-heating, using RF power, takes advantage of the rapid heating/cooling process and lower electric power consumption. The fabricated capped aluminum nanoslit array has a 5 nm Fano linewidth and 490.46 nm/RIU wavelength sensitivity. The biosensing capabilities of the metallic nanostructures are further verified by measuring antigen–antibody interactions using bovine serum albumin (BSA and anti-BSA. These rapid and high-throughput fabrication methods can benefit low-cost, highly sensitive biosensors and other sensing applications.

  11. Fabric circuits and method of manufacturing fabric circuits

    Science.gov (United States)

    Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Scully, Robert C. (Inventor); Trevino, Robert C. (Inventor); Lin, Greg Y. (Inventor); Fink, Patrick W. (Inventor)

    2011-01-01

    A flexible, fabric-based circuit comprises a non-conductive flexible layer of fabric and a conductive flexible layer of fabric adjacent thereto. A non-conductive thread, an adhesive, and/or other means may be used for attaching the conductive layer to the non-conductive layer. In some embodiments, the layers are attached by a computer-driven embroidery machine at pre-determined portions or locations in accordance with a pre-determined attachment layout before automated cutting. In some other embodiments, an automated milling machine or a computer-driven laser using a pre-designed circuit trace as a template cuts the conductive layer so as to separate an undesired portion of the conductive layer from a desired portion of the conductive layer. Additional layers of conductive fabric may be attached in some embodiments to form a multi-layer construct.

  12. The Tribological Properties of Multi-Layered Graphene as Additives of PAO2 Oil in Steel–Steel Contacts

    Directory of Open Access Journals (Sweden)

    Yan-Bao Guo

    2016-08-01

    Full Text Available Multi-layered graphene was prepared by supercritical CO2 exfoliation of graphite. As the additives of polyalphaolefin-2 (PAO2 oil, its tribological properties were investigated using four-ball test method. The friction reduction and anti-wear ability of pure lubricant was improved by the addition of graphene. With a favorable concentration, the graphene was dispersive. The PAO2 oil with 0.05 wt % graphene showed better tribological properties than that for the other concentration of graphene additives. It could be used as a good lubricant additive for its excellent tribological characteristics, and the multi-layered graphene can bear the load of the steel ball and prevent direct contact of the mating metal surfaces. However, a higher concentration would cause the agglomeration of graphene and weaken the improvement of tribological properties.

  13. MHD pressure drop characteristics in a three-surface-multi-layered channel under a strong magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi, M., E-mail: mao@karma.qse.tohoku.ac.jp [Department of Quantum Science and Energy Engineering, School of Engineering, Tohoku University, 6-6-01-2 Aramaki-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Ito, S.; Hashizume, H. [Department of Quantum Science and Energy Engineering, School of Engineering, Tohoku University, 6-6-01-2 Aramaki-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Muroga, T. [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)

    2010-12-15

    A three-surface-multi-layered channel is one of the possible methods for reducing the magnetohydrodynamic (MHD) pressure drop in a Li/V blanket. In this study, experimental and numerical evaluations of the liquid metal MHD flow in a three-surface-multi-layered channel were conducted to confirm the extent of MHD pressure reduction in the channel. The MHD flow was tested using a Bi-Sn eutectic alloy (MHD liquid) and an open annular channel under up to 5 T magnetic field. Experimentally determined pressure drops differed from those predicted by numerical analysis. This may be as a result of an increase in the friction force caused by an oxide appearing on the liquid free surface and a decrease in the electromagnetic force owing to the formation of a contact resistance between the Bi-Sn alloy and the bottom wall of the stainless steel channel.

  14. Analytical modeling of multi-layered printed circuit board using multi-stacked via clusters as component heat spreader

    Directory of Open Access Journals (Sweden)

    Monier-Vinard Eric

    2016-01-01

    Full Text Available In order to help the electronic designer to early determine the limits of the power dissipation of electronic component, an analytical model was established to allow a fast insight of relevant design parameters of a multi-layered electronic board constitution. The proposed steady-state approach based on Fourier series method promotes a practical solution to quickly investigate the potential gain of multi-layered thermal via clusters. Generally, it has been shown a good agreement between the results obtained by the proposed analytical model and those given by electronics cooling software widely used in industry. Some results highlight the fact that the conventional practices for Printed Circuit Board modeling can be dramatically underestimate source temperatures, in particular with smaller sources. Moreover, the analytic solution could be applied to optimize the heat spreading in the board structure with a local modification of the effective thermal conductivity layers.

  15. Sensitivity analysis of multi-layered C-axis inclined zigzag zinc oxide thin-film resonators as viscosity sensors.

    Science.gov (United States)

    Zhang, Haifeng; Bao, Yuanye

    2014-03-01

    This paper presents a theoretical analysis of a new zigzag C-axis inclined multi-layer ZnO thin-film bulk acoustic wave resonator (FBAR) as a viscosity sensor to monitor the lubrication performance of engine oil and other liquids. Free vibration and forced vibration for the FBAR loaded with liquids are analyzed. Equations necessary to calculate the sensitivity are derived. The numerical analysis shows that as the number of layers increases, the absolute sensitivity increases as well. The influences on the sensitivity of C-axis inclined angle, Q-factor, and thickness are also investigated. The results provide a foundation for further design of multi-layer FBAR viscosity sensors.

  16. Detection of defects in multi-layered aramid composites by ultrasonic IR thermography

    Science.gov (United States)

    Pracht, Monika; Swiderski, Waldemar

    2017-10-01

    thermography in inspecting multi-layered aramide composite materials will be presented.

  17. A Physics-Based Approach for Power Integrity in Multi-Layered PCBs

    Science.gov (United States)

    Zhao, Biyao

    Developing a power distribution network (PDN) for ASICs and ICs to achieve the low-voltage ripple specifications for current digital designs is challenging with the high-speed and low-voltage ICs. Present methods are typically guided by best engineering practices for low impedance looking into the PDN from the IC. A pre-layout design methodology for power integrity in multi-layered PCB PDN geometry is proposed in the thesis. The PCB PDN geometry is segmented into four parts and every part is modelled using different methods based on the geometry details of the part. Physics-based circuit models are built for every part and the four parts are re-assembled into one model. The influence of geometry details is clearly revealed in this methodology. Based on the physics-based circuit mode, the procedures of using the pre-layout design methodology as a guideline during the PDN design is illustrated. Some common used geometries are used to build design space, and the design curves with the geometry details are provided to be a look up library for engineering use. The pre-layout methodology is based on the resonant cavity model of parallel planes for the cavity structures, and parallel-plane PEEC (PPP) for the irregular shaped plane inductance, and PEEC for the decoupling capacitor connection above the top most or bottom most power-return planes. PCB PDN is analyzed based on the input impedance looking into the PCB from the IC. The pre-layout design methodology can be used to obtain the best possible PCB PDN design. With the switching current profile, the target impedance can be selected to evaluate the PDN performance, and the frequency domain PDN input impedance can be used to obtain the voltage ripple in the time domain to give intuitive insight of the geometry impact on the voltage ripple.

  18. Spectral imaging using clinical megavoltage beams and a novel multi-layer imager

    Science.gov (United States)

    Myronakis, Marios; Fueglistaller, Rony; Rottmann, Joerg; Hu, Yue-Houng; Wang, Adam; Baturin, Paul; Huber, Pascal; Morf, Daniel; Star-Lack, Josh; Berbeco, Ross

    2017-12-01

    We assess the feasibility of clinical megavoltage (MV) spectral imaging for material and bone separation with a novel multi-layer imager (MLI) prototype. The MLI provides higher detective quantum efficiency and lower noise than conventional electronic portal imagers. Simulated experiments were performed using a validated Monte Carlo model of the MLI to estimate energy absorption and energy separation between the MLI components. Material separation was evaluated experimentally using solid water and aluminum (Al), copper (Cu) and gold (Au) for 2.5 MV, 6 MV and 6 MV flattening filter free (FFF) clinical photon beams. An anthropomorphic phantom with implanted gold fiducials was utilized to further demonstrate bone/gold separation. Weighted subtraction imaging was employed for material and bone separation. The weighting factor (w) was iteratively estimated, with the optimal w value determined by minimization of the relative signal difference (Δ {{S}R} ) and signal-difference-to-noise ratio (SDNR) between material (or bone) and the background. Energy separation between layers of the MLI was mainly the result of beam hardening between components with an average energy separation between 34 and 47 keV depending on the x-ray beam energy. The minimum average energy of the detected spectrum in the phosphor layer was 123 keV in the top layer of the MLI with the 2.5 MV beam. The w values that minimized Δ {{S}R} and SDNR for Al, Cu and Au were 0.89, 0.76 and 0.64 for 2.5 MV; for 6 MV FFF, w was 0.98, 0.93 and 0.77 respectively. Bone suppression in the anthropomorphic phantom resulted in improved visibility of the gold fiducials with the 2.5 MV beam. Optimization of the MLI design is required to achieve optimal separation at clinical MV beam energies.

  19. An Automated MR Image Segmentation System Using Multi-layer Perceptron Neural Network

    Directory of Open Access Journals (Sweden)

    Amiri S

    2013-12-01

    Full Text Available Background: Brain tissue segmentation for delineation of 3D anatomical structures from magnetic resonance (MR images can be used for neuro-degenerative disorders, characterizing morphological differences between subjects based on volumetric analysis of gray matter (GM, white matter (WM and cerebrospinal fluid (CSF, but only if the obtained segmentation results are correct. Due to image artifacts such as noise, low contrast and intensity non-uniformity, there are some classifcation errors in the results of image segmentation. Objective: An automated algorithm based on multi-layer perceptron neural networks (MLPNN is presented for segmenting MR images. The system is to identify two tissues of WM and GM in human brain 2D structural MR images. A given 2D image is processed to enhance image intensity and to remove extra cerebral tissue. Thereafter, each pixel of the image under study is represented using 13 features (8 statistical and 5 non- statistical features and is classifed using a MLPNN into one of the three classes WM and GM or unknown. Results: The developed MR image segmentation algorithm was evaluated using 20 real images. Training using only one image, the system showed robust performance when tested using the remaining 19 images. The average Jaccard similarity index and Dice similarity metric for the GM and WM tissues were estimated to be 75.7 %, 86.0% for GM, and 67.8% and 80.7%for WM, respectively. Conclusion: The obtained performances are encouraging and show that the presented method may assist with segmentation of 2D MR images especially where categorizing WM and GM is of interest.

  20. Characterization of Multi-layered Tissue Engineered Human Alveolar Bone and Gingival Mucosa.

    Science.gov (United States)

    Almela, Thafar; Al-Sahaf, Sarmad; Bolt, Robert; Brook, Ian; Moharamzadeh, K

    2017-11-01

    Advances in tissue engineering have permitted assembly of multi-layered composite tissue constructs for potential applications in the treatment of combined hard and soft tissue defects and as an alternative in vitro test model to animal experimental systems. The aim of this study was to develop and characterize a novel three-dimensional combined human alveolar bone and gingival mucosal model based on primary cells isolated from the oral tissues. Bone component of the model was engineered by seeding primary human alveolar osteoblasts (HAOBs) into a hydroxyapatite/tricalcium phosphate (HA/TCP) scaffold and culturing in a spinner bioreactor. The engineered bone was then laminated, using an adhesive tissue sealant, with tissue engineered gingival mucosa consisting of air/liquid interface-cultured normal human gingival keratinocytes on oral fibroblast-populated collagen gel scaffold. Histological characterization revealed a structure consisting of established epithelial, connective tissue, and bone layers closely comparable to normal oral tissue architecture. The mucosal component demonstrated a mature epithelium undergoing terminal differentiation similar to that characteristic of native buccal mucosa, as confirmed using cytokeratin 13 (CK13) and cytokeratin 14 (CK14) immunohistochemistry. Ultrastructural analysis confirmed the presence of desmosomes and hemi-desmosomes in the epithelial layer, a continuous basement membrane and newly synthesized collagen in the connective tissue layer. Quantitative PCR (qPCR) assessment of osteogenesis-related gene expression showed a higher expression of genes encoded Collagen I (COL1) and Osteonectin (ON) compared with Osteocalcin (OC), Osteopontin (OPN), and Alkaline phosphatase (ALP). ELISA quantification of COL1, ON, and OC confirmed a pattern of secretion which paralleled the model's gene expression profile. We demonstrate here that replicating the anatomical setting between oral mucosa and the underlying alveolar bone is

  1. A Multi-Layer Fusion-Based Facial Expression Recognition Approach with Optimal Weighted AUs

    Directory of Open Access Journals (Sweden)

    Xibin Jia

    2017-01-01

    Full Text Available Affective computing is an increasingly important outgrowth of Artificial Intelligence, which is intended to deal with rich and subjective human communication. In view of the complexity of affective expression, discriminative feature extraction and corresponding high-performance classifier selection are still a big challenge. Specific features/classifiers display different performance in different datasets. There has currently been no consensus in the literature that any expression feature or classifier is always good in all cases. Although the recently updated deep learning algorithm, which uses learning deep feature instead of manual construction, appears in the expression recognition research, the limitation of training samples is still an obstacle of practical application. In this paper, we aim to find an effective solution based on a fusion and association learning strategy with typical manual features and classifiers. Taking these typical features and classifiers in facial expression area as a basis, we fully analyse their fusion performance. Meanwhile, to emphasize the major attributions of affective computing, we select facial expression relative Action Units (AUs as basic components. In addition, we employ association rules to mine the relationships between AUs and facial expressions. Based on a comprehensive analysis from different perspectives, we propose a novel facial expression recognition approach that uses multiple features and multiple classifiers embedded into a stacking framework based on AUs. Extensive experiments on two public datasets show that our proposed multi-layer fusion system based on optimal AUs weighting has gained dramatic improvements on facial expression recognition in comparison to an individual feature/classifier and some state-of-the-art methods, including the recent deep learning based expression recognition one.

  2. A Fully Self-consistent Multi-layered Model of Jupiter

    Science.gov (United States)

    Kong, Dali; Zhang, Keke; Schubert, Gerald

    2016-08-01

    We construct a three-dimensional, fully self-consistent, multi-layered, non-spheroidal model of Jupiter consisting of an inner core, a metallic electrically conducting dynamo region, and an outer molecular electrically insulating envelope. We assume that the Jovian zonal winds are on cylinders parallel to the rotation axis but, due to the effect of magnetic braking, are confined within the outer molecular envelope. We also assume that the location of the molecular-metallic interface is characterized by its equatorial radius {{HR}}e, where R e is the equatorial radius of Jupiter at the 1 bar pressure level and H is treated as a parameter of the model. We solve the relevant mathematical problem via a perturbation approach. The leading-order problem determines the density, size, and shape of the inner core, the irregular shape of the 1 bar pressure level, and the internal structure of Jupiter that accounts for the full effect of rotational distortion, but without the influence of the zonal winds; the next-order problem determines the variation of the gravitational field solely caused by the effect of the zonal winds on the rotationally distorted non-spheroidal Jupiter. The leading-order solution produces the known mass, the known equatorial and polar radii, and the known zonal gravitational coefficient J 2 of Jupiter within their error bars; it also yields the coefficients J 4 and J 6 within about 5% accuracy, the core equatorial radius 0.09{R}e and the core density {ρ }c=2.0× {10}4 {{kg}} {{{m}}}-3 corresponding to 3.73 Earth masses; the next-order solution yields the wind-induced variation of the zonal gravitational coefficients of Jupiter.

  3. Electrochemical behavior of hydroxyapatite/TiN multi-layer coatings on Ti alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Ju [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Jeong, Yong-Hoon [Biomechanics and Tissue Engineering Laboratory, Division of Orthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States); Choe, Han-Cheol, E-mail: hcchoe@chosun.ac.kr [Department of Dental Materials, Research Center of Nano-Interface Activation for Biomaterials, School of Dentistry, Chosun University (Korea, Republic of); Brantley, William A. [Division of Restorative Science and Prosthodontics, College of Dentistry, The Ohio State University, Columbus, OH (United States)

    2014-12-01

    The electrochemical behavior of hydroxyapatite (HA) and titanium nitride (TiN) multi-layer coatings on Ti–Nb–Zr alloys was investigated by a variety of surface analytical methods. The HA/TiN layers were deposited using a magnetron sputtering system. The HA target was made of human tooth-ash sintered at 1300 °C for 1 h and had an average Ca/P ratio of 1.9. From X-ray diffraction patterns, the Ti–29Nb–5Zr alloy was composed entirely of equiaxed β-phase exhibiting the principal (110) reflection, and the coating exhibited the (111) and (200) reflections for TiN and the (112) and (202) reflections for HA. At the coating surface the HA films consisted of granular particles, and the surface roughness was 4.22 nm. The thickness of the coating layers increased in the order of HA/TiN (lowest), TiN, and HA (highest). Potentiodynamic polarization measurements revealed that the corrosion current density was the lowest, and the corrosion potential and polarization resistance the highest, when the Ti–29Nb–5Zr surface was covered by the HA/TiN film, compared to solely HA or TiN films. - Highlights: • HA/TiN films were deposited by magnetron sputtering on a Ti–29Nb–5Zr biomedical alloy. • The corrosion current density for the HA/TiN films was lower than that of the non-coated alloy. • The polarization resistance of the HA/TiN films was higher than that of the non-coated alloy.

  4. Acoustical characteristic predictions of a multi-layer system of a submerged vehicle hull mounted sonar simplified to an infinite planar model

    Directory of Open Access Journals (Sweden)

    Sung-Hee Kim

    2012-06-01

    Full Text Available Hull Mounted Sonar (HMS is a long range submerged vehicle's hull-mounted passive sonar system which detects low-frequency noise caused by machineries of enemy ships or submerged vehicles. The HMS needs a sound absorption /insulation multi-layer structure to shut out the self-noise from own machineries and to amplify signals from outside. Therefore, acoustic analysis of the multi-layer system should be performed when the HMS is designed. This paper simplified the HMS multi-layer system to be an infinite planar multi-layer model. Also, main excitations that influence the HMS were classified into mechanical, plane wave and turbulent flow excitation, and the investigations for each excitation were performed for various models. Stiffened multi-layer analysis for mechanical excitation and general multi-layer analysis for turbulent flow excitation were developed. The infinite planar multi-layer analysis was expected to be more useful for preliminary design stage of HMS system than the infinite cylindrical model because of short analysis time and easiness of parameter study.

  5. Extended Traffic Crash Modelling through Precision and Response Time Using Fuzzy Clustering Algorithms Compared with Multi-layer Perceptron

    Directory of Open Access Journals (Sweden)

    Iman Aghayan

    2012-11-01

    Full Text Available This paper compares two fuzzy clustering algorithms – fuzzy subtractive clustering and fuzzy C-means clustering – to a multi-layer perceptron neural network for their ability to predict the severity of crash injuries and to estimate the response time on the traffic crash data. Four clustering algorithms – hierarchical, K-means, subtractive clustering, and fuzzy C-means clustering – were used to obtain the optimum number of clusters based on the mean silhouette coefficient and R-value before applying the fuzzy clustering algorithms. The best-fit algorithms were selected according to two criteria: precision (root mean square, R-value, mean absolute errors, and sum of square error and response time (t. The highest R-value was obtained for the multi-layer perceptron (0.89, demonstrating that the multi-layer perceptron had a high precision in traffic crash prediction among the prediction models, and that it was stable even in the presence of outliers and overlapping data. Meanwhile, in comparison with other prediction models, fuzzy subtractive clustering provided the lowest value for response time (0.284 second, 9.28 times faster than the time of multi-layer perceptron, meaning that it could lead to developing an on-line system for processing data from detectors and/or a real-time traffic database. The model can be extended through improvements based on additional data through induction procedure.

  6. Design of Circular, Square, Single, and Multi-layer Induction Coils for Electromagnetic Priming Using Inductance Estimates

    Science.gov (United States)

    Fritzsch, Robert; Kennedy, Mark W.; Aune, Ragnhild E.

    2018-02-01

    Special induction coils used for electro magnetic priming of ceramic foam filters in liquid metal filtration have been designed using a combination of analytical and finite element modeling. Relatively simple empirical equations published by Wheeler in 1928 and 1982 have been used during the design process. The equations were found to accurately predict the z-component of the magnetic flux densities of both single- and multi-layer coils as verified both experimentally and by using COMSOL® 5.1 multiphysics simulations.

  7. Development of a Multi-layer Anti-reflective Coating for Gallium Arsenide/Aluminum Gallium Arsenide Solar Cells

    Science.gov (United States)

    2015-07-01

    Aluminum Gallium Arsenide Solar Cells by Kimberley A Olver Approved for public release; distribution unlimited...Development of a Multi-layer Anti-reflective Coating for Gallium Arsenide/Aluminum Gallium Arsenide Solar Cells by Kimberley A Olver...Aluminum Gallium Arsenide (AlGaAs) Solar Cells 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Kimberley A Olver

  8. Influence of cross-anisotropy material behavior on back-calculation analysis of multi-layered systems

    CSIR Research Space (South Africa)

    Maina, JW

    2008-07-01

    Full Text Available 2008 27 INFLUENCE OF CROSS-ANISOTROPY MATERIAL BEHAVIOR ON BACK-CALCULATION ANALYSIS OF MULTI-LAYERED SYSTEMS Yoshiaki OZAWA Department of Civil and Environmental Engineering, Tokyo Denki University Ishizaka, Hatoyama Town, Hiki-gun, Saitama... and Environmental Engineering, Tokyo Denki University Ishizaka, Hatoyama Town, Hiki-gun, Saitama 350-0394, Japan matsui@g.dendai.ac.jp ABSTRACT Each layer in a pavement structure is compacted during construction. Moreover, since the compaction process...

  9. Microwave energy harvesting based on metamaterial absorbers with multi-layered square split rings for wireless communications

    Science.gov (United States)

    Karaaslan, Muharrem; Bağmancı, Mehmet; Ünal, Emin; Akgol, Oguzhan; Sabah, Cumali

    2017-06-01

    We propose the design of a multiband absorber based on multi-layered square split ring (MSSR) structure. The multi-layered metamaterial structure is designed to be used in the frequency bands such as WIMAX, WLAN and satellite communication region. The absorption levels of the proposed structure are higher than 90% for all resonance frequencies. In addition, the incident angle and polarization dependence of the multi-layered metamaterial absorber and harvester is also investigated and it is observed that the structure has polarization angle independent frequency response with good absorption characteristics in the entire working frequency band. The energy harvesting ratios of the structure is investigated especially for the resonance frequencies at which the maximum absorption occurs. The energy harvesting potential of the proposed MSSRs is as good as those of the structures given in the literature. Therefore, the suggested design having good absorption, polarization and angle independent characteristics with a wide bandwidth is a potential candidate for future energy harvesting applications in commonly used wireless communication bands, namely WIMAX, WLAN and satellite communication bands.

  10. Broadband nonlinear optical response in multi-layer black phosphorus: an emerging infrared and mid-infrared optical material.

    Science.gov (United States)

    Lu, S B; Miao, L L; Guo, Z N; Qi, X; Zhao, C J; Zhang, H; Wen, S C; Tang, D Y; Fan, D Y

    2015-05-04

    Black phosphorous (BP), the most thermodynamically stable allotrope of phosphorus, is a high-mobility layered semiconductor with direct band-gap determined by the number of layers from 0.3 eV (bulk) to 2.0 eV (single layer). Therefore, BP is considered as a natural candidate for broadband optical applications, particularly in the infrared (IR) and mid-IR part of the spectrum. The strong light-matter interaction, narrow direct band-gap, and wide range of tunable optical response make BP as a promising nonlinear optical material, particularly with great potentials for infrared and mid-infrared opto-electronics. Herein, we experimentally verified its broadband and enhanced saturable absorption of multi-layer BP (with a thickness of ~10 nm) by wide-band Z-scan measurement technique, and anticipated that multi-layer BPs could be developed as another new type of two-dimensional saturable absorber with operation bandwidth ranging from the visible (400 nm) towards mid-IR (at least 1930 nm). Our results might suggest that ultra-thin multi-layer BP films could be potentially developed as broadband ultra-fast photonics devices, such as passive Q-switcher, mode-locker, optical switcher etc.

  11. Geant4 Simulation of A Multi-layered target for the Study of Neutron-Unbound Nuclei

    Science.gov (United States)

    Gueye, Paul; Freeman, Jessica; Frank, Nathan; Thoennessen, Michael; MONA Collaboration

    2013-10-01

    The MoNA/LISA setup at the National Superconducting Cyclotron Laboratory at Michigan State University has provided an avenue to study the nuclear structure of unbound states/nuclei at and beyond the neutron dripline for the past decade using secondary beams from the Coupled Cyclotron Facility. A new multi-layered Si/Be active target is being designed to specifically study neutron-unbound nuclei. In these experiments the decay energy is reconstructed from fragment-neutron coincidence measurements that are typically low in count rate. The multi-layered target will allow the use of thicker targets to increase the reaction rates, thus enabling to study currently out of reach nuclei such as 21C, 23C and 24N. The Geant4 Monte Carlo toolkit is currently used to model these physics processes within the multi-layered target and expected invariant mass distributions. A description of the experimental setup and simulation work will be discussed. This work is supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0000979.

  12. Formulation of root water uptake in a multi-layer soil-plant model: does van den Honert's equation hold?

    Directory of Open Access Journals (Sweden)

    J.-P. Lhomme

    1998-01-01

    Full Text Available The withdrawal of water from soil by vegetation, which in steady state conditions is equivalent to the transpiration rate, can be written in terms of water potential in the form of an Ohm's law analogy, known as van den Honert's equation: The difference between an effective soil water potential and the bulk canopy water potential is divided by an effective soil-plant resistance. This equation is commonly used, but little is known about the precise definition of its parameters. The issue of this paper is to bridge the gap between the bulk approach and a multi-layer description of soil-plant water transfer by interpreting the bulk parameters in terms of the characteristics of the multi-layer approach. Water flow through an elementary path within the soil or the root is assumed to follow an Ohm's law analogy, and the soil and root characterisics are allowed to vary with depth. Starting from the basic equations of the multi-layer approach, it is proved that the total rate of transpiration can also be expressed in the form of an Ohm's law analogy. This means that van den Honert's equation holds at canopy scale, insofar as the assumptions made on the physics of root water uptake hold. In the bulk formulation derived, the effective soil-plant resistance appears as a combination of the elementary resistances making up the multi-layer model; and the effective soil water potential is a weighted mean of the water potentials in each soil layer, the weighting system involving the complete set of elementary resistances. Simpler representations of soil-plant interaction leading to Ohm's law type formulations are also examined: a simplified multi-layer model, in which xylem (root axial resistance is neglected, and a bulk approach, in which soil-root interaction is represented by only one layer. Numerical simulations performed in different standard conditions show that these simpler representations do not provide accurate estimates of the transpiration rate

  13. Adsorption and photocatalytic activity of electron-irradiated polystyrene nanosphere multi-layer film

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sung Oh; Yoo, Seung Hwa; Kim, Jea Joon; Kum, Jong Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    photocatalytic activities for H{sub 2} production from water, after the first report of poly(p-phenylene) (PPP) in 1990. Both of these work shows enhanced activity by incorporating a co-catalyst. However, to date, there is no reported literature about single material organic photocatalyst for removal of organic pollutant from water. In this paper, we present a novel low-cost, metal-free organic photocatalyst that consists of only carbon and hydrogen fabricated by electron-beam irradiation on polymer nanospheres. Characterization results and adsorption-photocatalytic activities are shown of electron-irradiated polystyrene (PS) nanospheres

  14. A simple and cost-effective method for fabrication of integrated electronic-microfluidic devices using a laser-patterned PDMS layer

    KAUST Repository

    Li, Ming

    2011-12-03

    We report a simple and cost-effective method for fabricating integrated electronic-microfluidic devices with multilayer configurations. A CO 2 laser plotter was employed to directly write patterns on a transferred polydimethylsiloxane (PDMS) layer, which served as both a bonding and a working layer. The integration of electronics in microfluidic devices was achieved by an alignment bonding of top and bottom electrode-patterned substrates fabricated with conventional lithography, sputtering and lift-off techniques. Processes of the developed fabrication method were illustrated. Major issues associated with this method as PDMS surface treatment and characterization, thickness-control of the transferred PDMS layer, and laser parameters optimization were discussed, along with the examination and testing of bonding with two representative materials (glass and silicon). The capability of this method was further demonstrated by fabricating a microfluidic chip with sputter-coated electrodes on the top and bottom substrates. The device functioning as a microparticle focusing and trapping chip was experimentally verified. It is confirmed that the proposed method has many advantages, including simple and fast fabrication process, low cost, easy integration of electronics, strong bonding strength, chemical and biological compatibility, etc. © Springer-Verlag 2011.

  15. Net-Immobilization of β-glucosidase on Nonwoven Fabrics to Lower the Cost of "Cellulosic Ethanol" and Increase Cellulose Conversions.

    Science.gov (United States)

    Zhu, Xing; He, Bin; Zhao, Changwen; Fan, Rong; Zhang, Lihua; Wang, Guan; Ma, Yuhong; Yang, Wantai

    2016-03-24

    The main limitation preventing the use of enzymatic cellulosic ethanol in industrial production is its higher cost which is mainly due to the elevated price of β-glucosidase (BG). Herein, we report on a simple strategy for the in-situ encapsulation of BG for repeated cellulosic ethanol production. In this strategy, BG was net-immobilized into a poly(ethylene glycol) (PEG) net-cloth layer on a PP nonwoven fabric by way of the visible light-induced surface controlled/living graft cross-linking polymerization. The visible light and mild reaction conditions could ensure the activity retention of BG during immobilization, while the non-swelling uniform net-mesh formed by living cross-linking polymerization could prevent the leakage of BG effectively (at the immobilization rate of more than 98.6% and the leakage rate of only 0.4%). When the BG-loaded fabric was used in combination with free cellulase (CEL), the results of the catalytic reaction demonstrated that these BG-loaded fabrics could not only give a 40% increase in cellulose conversions but also be reused for more than fifteen batches without losing the activity. These BG-loaded fabrics with characteristics including easy separation, excellent operation stability, a low cost of the polymeric matrix and a simple fabrication process are particularly interesting for a future bio-fuel production strategy.

  16. Net-Immobilization of β-glucosidase on Nonwoven Fabrics to Lower the Cost of “Cellulosic Ethanol” and Increase Cellulose Conversions

    Science.gov (United States)

    Zhu, Xing; He, Bin; Zhao, Changwen; Fan, Rong; Zhang, Lihua; Wang, Guan; Ma, Yuhong; Yang, Wantai

    2016-03-01

    The main limitation preventing the use of enzymatic cellulosic ethanol in industrial production is its higher cost which is mainly due to the elevated price of β-glucosidase (BG). Herein, we report on a simple strategy for the in-situ encapsulation of BG for repeated cellulosic ethanol production. In this strategy, BG was net-immobilized into a poly(ethylene glycol) (PEG) net-cloth layer on a PP nonwoven fabric by way of the visible light-induced surface controlled/living graft cross-linking polymerization. The visible light and mild reaction conditions could ensure the activity retention of BG during immobilization, while the non-swelling uniform net-mesh formed by living cross-linking polymerization could prevent the leakage of BG effectively (at the immobilization rate of more than 98.6% and the leakage rate of only 0.4%). When the BG-loaded fabric was used in combination with free cellulase (CEL), the results of the catalytic reaction demonstrated that these BG-loaded fabrics could not only give a 40% increase in cellulose conversions but also be reused for more than fifteen batches without losing the activity. These BG-loaded fabrics with characteristics including easy separation, excellent operation stability, a low cost of the polymeric matrix and a simple fabrication process are particularly interesting for a future bio-fuel production strategy.

  17. Tidal synchronization of an anelastic multi-layered body: Titan's synchronous rotation

    Science.gov (United States)

    Folonier, Hugo A.; Ferraz-Mello, Sylvio

    2017-12-01

    Tidal torque drives the rotational and orbital evolution of planet-satellite and star-exoplanet systems. This paper presents one analytical tidal theory for a viscoelastic multi-layered body with an arbitrary number of homogeneous layers. Starting with the static equilibrium figure, modified to include tide and differential rotation, and using the Newtonian creep approach, we find the dynamical equilibrium figure of the deformed body, which allows us to calculate the tidal potential and the forces acting on the tide generating body, as well as the rotation and orbital elements variations. In the particular case of the two-layer model, we study the tidal synchronization when the gravitational coupling and the friction in the interface between the layers is added. For high relaxation factors (low viscosity), the stationary solution of each layer is synchronous with the orbital mean motion ( n) when the orbit is circular, but the rotational frequencies increase if the orbital eccentricity increases. This behavior is characteristic in the classical Darwinian theories and in the homogeneous case of the creep tide theory. For low relaxation factors (high viscosity), as in planetary satellites, if friction remains low, each layer can be trapped in different spin-orbit resonances with frequencies n/2,n,3n/2,2n,\\ldots . When the friction increases, attractors with differential rotations are destroyed, surviving only commensurabilities in which core and shell have the same velocity of rotation. We apply the theory to Titan. The main results are: (i) the rotational constraint does not allow us to confirm or reject the existence of a subsurface ocean in Titan; and (ii) the crust-atmosphere exchange of angular momentum can be neglected. Using the rotation estimate based on Cassini's observation (Meriggiola et al. in Icarus 275:183-192, 2016), we limit the possible value of the shell relaxation factor, when a deep subsurface ocean is assumed, to γ _s≲ 10^{-9} s^{-1}, which

  18. Micro-Satellite Impact Tests to Investigate Multi-Layer Insulation Fragments

    Science.gov (United States)

    Liou, J.C.; Murakami, Junko; Hanaha, Toshiya

    2009-01-01

    This paper summarizes two satellite impact experiments completed in 2008. The objective of the experiments is to investigate the physical properties of satellite fragments, including those originated from Multi-Layer Insulation (MLI) and solar panels. The ultimate goal is to use the results to improve the NASA Standard Breakup Model. The targets were two cubic micro-satellites, 20 cm by 20 cm by 20 cm in size, and approximately 1,500 g in mass. The main structure of each micro-satellite was composed of five layers; the top and bottom layers and three internal layers parallel to the top and bottom layers, plus four side panels. The top layer was equipped with solar cells that was mounted to an aluminum honeycomb sandwich panel with CFRP face sheets. The four side panels and the bottom layer are all covered with MLI. The two satellite impact experiments were conducted using the two-stage light gas gun at the Kyushu Institute of Technology in Kitakyusyu, Japan. For the first experiment (labeled Shot F), the satellite was oriented in such a way that the solar panel was facing the incoming projectile, a 39.3 g aluminum alloy solid sphere. For the second experiment (labeled Shot R), the satellite was oriented so that the solar panel was on the opposite side of the impact surface. The projectile used in the second shot was a 39.2 g aluminum alloy solid sphere. The impact speeds of Shot F and Shot R were 1.74 km/s and 1.78 km/s, respectively. The ratio of the impact kinetic energy to satellite mass for the two experiments was about 40 J/g. Both target satellites were completely fragmented, although there were noticeable differences in the characteristics of the fragments. Approximately 1,800 fragments were collected from Shot F but only 1,000 fragments were collected from Shot R. This difference primarily comes from the number of needle-like CFRP and MLI fragments. The difference in CFRP pieces depends on how the CFRP panels were fragmented. Regarding the MLI pieces, a

  19. Prediction of gas hydrate saturation throughout the seismic section in Krishna Godavari basin using multivariate linear regression and multi-layer feed forward neural network approach

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, Y.; Nair, R.R.; Singh, H.; Datta, P.; Jaiswal, P.; Dewangan, P.; Ramprasad, T.

    Stepwise linear regression, multi-layer feed forward neural (MLFN) network method was used to predict the 2D distribution of P-wave velocity, resistivity, porosity, and gas hydrate saturation throughout seismic section NGHP-01 in the Krishna...

  20. Urban Conservation Policies and Plans for a World Heritage Site Case: Antique Pergamon City and its Multi-Layered Cultural Landscape

    Science.gov (United States)

    Tunçer, Mehmet

    2017-10-01

    Izmir’s Pergamon (Bergama) Antique City and Its Multi-Layered Cultural Landscape entered the UNESCO World Heritage List with the participation of 21 countries in the 38th World Heritage Committee Meeting held in Doha, Qatar’s capital in between 15 - 25 June 2014. Bergama became the 999th WORLD HERITAGE. Bergama, which has been in operation since 2010, has entered the list as a Multi-layered Cultural Landscape Area. The main purpose of this paper will explain and summarize of urban and archaeological conservation efforts for Pergamon since 1992 to 2014. In the paper also aimed to give the conservation policies of public administrations which mainly central /Ministry of Culture and Tourism, Ministry of Environment/ and local /Bergama Municipality, Gen. Directorate of Vakiflar. Turkey is one of the 10 original member states to establish UNESCO. 9 cities in Turkey are included in the UNESCO List of World Heritage Sites. Further, 23 sites have been nominated and are included in the tentative list. The activities aimed to include the district of Bergama in the UNESCO World Heritage List are ongoing in the years 2009-2014. All the efforts have been made carry this unique antique city to the UNESCO Heritage List at 2014. As an Urban Conservation Planner, I had a change of preparing the FIRST Conservation Aimed Plans and urban designs for Urban and Archaeological Sites of Pergamon together with my team, in the years between 1992-94. We prepared conservation aimed plans for all of the areas of Acropolis, Middle City and Ottoman period urban conservation areas. Urban and archaeological sites of Pergamon the ancient city today, which is over two thousand years old, where scientists, archaeologists, architects, art historians, urban planners, sculptors and similar arts and culture, men talk about admiration, write about and write praises, face to face some deterioration and destruction. As a conservation planner working on Pergamon since 1992, I’ will concentrate the

  1. Design, installation, and performance of a multi-layered permeable reactive barrier, Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kaszuba, J. P. (John P.); Longmire, P. A. (Patrick A.); Strietelmeier, E. A. (Elizabeth A.); Taylor, T. P. (Tammy P.); Den-Baars, P. S. (Peter S.)

    2004-01-01

    A multi-layered permeable reactive barrier (PRB) has been installed in Mortandad Canyon, on the Pajarito Plateau in the north-central part of LANL, to demonstrate in-situ treatment of a suite of contaminants with dissimilar geochemical properties. The PRB will also mitigate possible vulnerabilities from downgradient contaminant movement within alluvial and deeper perched groundwater. Mortandad Canyon was selected as the location for this demonstration project because the flow of alluvial groundwater is constrained by the geology of the canyon, a large network of monitoring wells already were installed along the canyon reach, and the hydrochemistry and contaminant history of the canyon is well-documented. The PRB uses a funnel-and-gate system with a series of four reactive media cells to immobilize or destroy contaminants present in alluvial groundwater, including strontium-90, plutonium-238,239,240, americium-241, perchlorate, and nitrate. The four cells, ordered by sequence of contact with the groundwater, consist of gravel-sized scoria (for colloid removal); phosphate rock containing apatite (for metals and radionuclides); pecan shells and cotton seed admixed with gravel (bio-barrier, to deplete dissolved oxygen and destroy potential RCRA organic compounds, nitrate and perchlorate); and limestone (pH buffering and anion adsorption). Design elements of the PRB are based on laboratory-scale treatability studies and on a field investigation of hydrologic, geochemical, and geotechnical parameters. The PRB was designed with the following criteria: 1-day residence time within the biobarrier, 10-year lifetime, minimization of surface water infiltration and erosion, optimization of hydraulic capture, and minimization of excavated material requiring disposal. Each layer has been equipped with monitoring wells or ports to allow sampling of groundwater and reactive media, and monitor wells are located immediately adjacent to the up- and down-gradient perimeter of the

  2. Fabric Weave Pattern and Yarn Color Recognition and Classification Using a Deep ELM Network

    Directory of Open Access Journals (Sweden)

    Babar Khan

    2017-10-01

    Full Text Available Usually, a fabric weave pattern is recognized using methods which identify the warp floats and weft floats. Although these methods perform well for uniform or repetitive weave patterns, in the case of complex weave patterns, these methods become computationally complex and the classification error rates are comparatively higher. Furthermore, the fault-tolerance (invariance and stability (selectivity of the existing methods are still to be enhanced. We present a novel biologically-inspired method to invariantly recognize the fabric weave pattern (fabric texture and yarn color from the color image input. We proposed a model in which the fabric weave pattern descriptor is based on the HMAX model for computer vision inspired by the hierarchy in the visual cortex, the color descriptor is based on the opponent color channel inspired by the classical opponent color theory of human vision, and the classification stage is composed of a multi-layer (deep extreme learning machine. Since the weave pattern descriptor, yarn color descriptor, and the classification stage are all biologically inspired, we propose a method which is completely biologically plausible. The classification performance of the proposed algorithm indicates that the biologically-inspired computer-aided-vision models might provide accurate, fast, reliable and cost-effective solution to industrial automation.

  3. Structural, optical and compositional stability of MoS2 multi-layer flakes under high dose electron beam irradiation

    Science.gov (United States)

    Rotunno, E.; Fabbri, F.; Cinquanta, E.; Kaplan, D.; Longo, M.; Lazzarini, L.; Molle, A.; Swaminathan, V.; Salviati, G.

    2016-06-01

    MoS2 multi-layer flakes, exfoliated from geological molybdenite, have been exposed to high dose electron irradiation showing clear evidence of crystal lattice and stoichiometry modifications. A massive surface sulfur depletion is induced together with the consequent formation of molybdenum nanoislands. It is found that a nanometric amorphous carbon layer, unwillingly deposited during the transmission electron microscope experiments, prevents the formation of the nanoislands. In the absence of the carbon layer, the formation of molybdenum grains proceeds both on the top and bottom surfaces of the flake. If carbon is present on both the surfaces then the formation of Mo grains is completely prevented.

  4. Roughness Influence On Macro- And Micro-Tribology Of Multi-Layered Hard Coatings On Carbon Fibre Polymer Composite

    Directory of Open Access Journals (Sweden)

    Lackner J.M.

    2015-09-01

    Full Text Available Goal of this work is the investigation of roughness influences on the abrasive wear behaviour of magnetron sputtered multi-layered, low-friction coatings on carbon-fibre reinforced polymers (CFRP. Higher coating roughness at similar CFRP quality was realized by higher deposition rates, leading to increased heat flux to the substrates during deposition. Thermal expansion of the epoxy matrix on the micro scale results in a wavy, wrinkled surface topography. Both in scratch and reciprocal sliding testing against alumina, the friction coefficients are lower for the smooth coatings, but their wear rate is higher due to low-cycle fatigue caused abrasion.

  5. A preliminary study on puncture resistances of top and bottom layers of multi-layered needlepunched nonwoven geotextiles

    Science.gov (United States)

    Alan, G.; Tercan, M.

    2017-10-01

    Needlepunched nonwoven textiles are commonly used as geotextiles for various applications. Considering both environmental and economical benefits, utilization of recycled fibres in nonwoven geotextiles has become an attractive issue. Within this scope, the aim of this study is to evaluate the puncture resistance performances of top and bottom layers of multi-layered needle punched nonwovens made of recycled fibres to be used as membrane protective geotextiles by comparing them with those of made from polypropylene and polyester fibres. Puncture resistance results indicated that nonwovens made of recycled fibres demonstrated good performances at this preliminary stage.

  6. Product Development and Cost Analysis of Fabricating the Prototype of Roller Clamp in Intravenous (I.V) Tubing Medical Devices using Fused Deposition Modeling (FDM) Technology

    Science.gov (United States)

    Way, Yusoff

    2018-01-01

    The main aim of this research is to develop a new prototype and to conduct cost analysis of the existing roller clamp which is one of parts attached to Intravenous (I.V) Tubing used in Intravenous therapy medical device. Before proceed with the process to manufacture the final product using Fused Deposition Modeling (FDM) Technology, the data collected from survey were analyzed using Product Design Specifications approach. Selected concept has been proven to have better quality, functions and criteria compared to the existing roller clamp and the cost analysis of fabricating the roller clamp prototype was calculated.

  7. Multi-layered, chemically bonded lithium-ion and lithium/air batteries

    Science.gov (United States)

    Narula, Chaitanya Kumar; Nanda, Jagjit; Bischoff, Brian L; Bhave, Ramesh R

    2014-05-13

    Disclosed are multilayer, porous, thin-layered lithium-ion batteries that include an inorganic separator as a thin layer that is chemically bonded to surfaces of positive and negative electrode layers. Thus, in such disclosed lithium-ion batteries, the electrodes and separator are made to form non-discrete (i.e., integral) thin layers. Also disclosed are methods of fabricating integrally connected, thin, multilayer lithium batteries including lithium-ion and lithium/air batteries.

  8. Comparison of different forms of the Multi-layer Feed-Forward Neural Network method used for river flow forecasting

    Directory of Open Access Journals (Sweden)

    A. Y. Shamseldin

    2002-01-01

    Full Text Available The Multi-Layer Feed-Forward Neural Network (MLFFNN is applied in the context of river flow forecast combination, where a number of rainfall-runoff models are used simultaneously to produce an overall combined river flow forecast. The operation of the MLFFNN depends not only on its neuron configuration but also on the choice of neuron transfer function adopted, which is non-linear for the hidden and output layers. These models, each having a different structure to simulate the perceived mechanisms of the runoff process, utilise the information carrying capacity of the model calibration data in different ways. Hence, in a discharge forecast combination procedure, the discharge forecasts of each model provide a source of information different from that of the other models used in the combination. In the present work, the significance of the choice of the transfer function type in the overall performance of the MLFFNN, when used in the river flow forecast combination context, is investigated critically. Five neuron transfer functions are used in this investigation, namely, the logistic function, the bipolar function, the hyperbolic tangent function, the arctan function and the scaled arctan function. The results indicate that the logistic function yields the best model forecast combination performance. Keywords: River flow forecast combination, multi-layer feed-forward neural network, neuron transfer functions, rainfall-runoff models

  9. NDT response of spectral analysis of surface wave method to multi-layer thin high-strength concrete structures.

    Science.gov (United States)

    Cho, Young S

    2002-05-01

    This study presents the results of the non-destructive testing using spectral analysis of surface waves (SASW) based on high-strength concrete materials. This SASW method was used to evaluate the compressive strength of single-layer high-strength concrete slabs through a correlation with the surface wave velocities. This paper also presents the relationship between the theoretical and experimental compact dispersion curves when the SASW test is applied to multi-layer thin high-strength concrete slab systems with a finite thickness. The test results show that the surface wave velocity profile obtained from the theoretical dispersion curve has lower values than the profile obtained from the experimental compact dispersion curve under the condition of a finite thickness due to different boundary conditions and reflections from the boundaries. Based on the measured response, an experimental study was conducted to examine if the dispersive characteristics of Rayleigh wave exist in the multi-layer high-strength concrete slab systems. This study can be utilized in examining structural elements of high-strength concrete structures and can also be applied in the integrity analysis of high-strength concrete structures with a finite thickness.

  10. Evaluation of the feasibility for detecting hidden corrosion damage in multi-layer gusset plates using multiple inspection techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, Adam C.; Duffer, Charles E.; Light, Glenn M. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166 (United States)

    2014-02-18

    Gusset plates are used to connect the members in truss bridges and they are usually inspected using calipers or conventional thickness measurement ultrasonic testing (UT) devices. The damage mechanism of particular concern in gusset plates is corrosion and the regions most susceptible to corrosion damage are on the gusset interior surface where it intersects the chord, diagonal, and vertical members from water collecting at the interfaces. For heavily loaded gusset plates, one or more shingle plates are used to reinforce the gusset plate, creating a multi-layer structure. While the areas with corrosion damage remain near the members on the gusset plate, the shingle plates cover the gusset plate and greatly limit the surface access to the gusset plate, making UT thickness measurement impractical. Because of the critical nature of the gussets, a viable inspection strategy for multi-layer gusset assemblies must be developed. The premise of this research and development effort was to develop viable, field-deployable inspection approaches for this problem area. This paper presents three separate inspection approaches: two ultrasonic-based techniques and one radiographic approach. Each of these techniques was evaluated on a mock-up specimen provided by the Federal Highway Administration (FHWA) that is representative of gusseted connection from a truss bridge.

  11. Evaluation of multi-layered hardness in ion-irradiated stainless steel by nano-indentation technique

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Hiroshi, E-mail: hiroshi_oka@eng.hokudai.ac.jp; Sato, Yutaka; Hashimoto, Naoyuki; Ohnuki, Somei

    2015-07-15

    Depth dependence of hardness in ion-irradiated 316 stainless steel was evaluated by the sectioning of damaged region and subsequent nano-indentation. The range of plastically deformed region by the nano-indentation was supplementarily investigated by transmission electron microscopy. When the indentation depth was the critical indentation depth, h{sub c}, which was derived from the Nix–Gao plot, the dislocation structure was observed from the specimen surface to right below the bottom of the ion-irradiated region. To verify the depth dependence of hardness, the “multi-layer model” was introduced in this study. The multi-layer model is based on the following assumptions; (1) the ion-irradiated region can be divided into sub-layers having their own local hardness, H{sub L}; (2) the hardness can be the product of f and H{sub L} in each sub-layer where f is the volume fraction of a deformation zone; and (3) the deformation zone can be a hemisphere. Eventually, through the sectioning and following nano-indentation, H{sub L} in each sub-layer was experimentally evaluated. Further the correlation between the displacement damage and the irradiation hardening ΔH in this study agreed with that of neutron irradiation experiments.

  12. Guided ultrasonic waves for the monitoring of hidden fatigue crack growth in multi-layer aerospace structures

    Science.gov (United States)

    Najarre, I.; Kostson, E.; Fromme, P.

    2014-03-01

    Varying loading conditions of aircraft structures result in stress concentration at fastener holes, where multi-layered components are connected, possibly leading to the development of fatigue cracks. The potential of guided ultrasonic waves, propagating along large plate-like structures, for the Structural Health Monitoring (SHM) of aerospace structures has been identified. However, the sensitivity for the detection of small, potentially hidden, defects has to be ascertained. This contribution presents a study of the application of guided ultrasonic waves in multi-layered tensile specimens for the monitoring of fatigue crack growth at fastener holes in the 2nd (bottom) layer of such structures. Fatigue crack growth was monitored optically and the changes in the ultrasonic signal caused by the crack development were quantified. It was shown that hidden fatigue crack detection and monitoring using the low frequency guided waves is possible. The sensitivity and repeatability of the measurements were ascertained, having the potential for fatigue crack growth monitoring at critical and difficult to access fastener locations from a stand-off distance. The robustness of the methodology for practical in-situ ultrasonic monitoring of fatigue crack growth was discussed.

  13. Spectral collocation method with a flexible angular discretization scheme for radiative transfer in multi-layer graded index medium

    Science.gov (United States)

    Wei, Linyang; Qi, Hong; Sun, Jianping; Ren, Yatao; Ruan, Liming

    2017-05-01

    The spectral collocation method (SCM) is employed to solve the radiative transfer in multi-layer semitransparent medium with graded index. A new flexible angular discretization scheme is employed to discretize the solid angle domain freely to overcome the limit of the number of discrete radiative direction when adopting traditional SN discrete ordinate scheme. Three radial basis function interpolation approaches, named as multi-quadric (MQ), inverse multi-quadric (IMQ) and inverse quadratic (IQ) interpolation, are employed to couple the radiative intensity at the interface between two adjacent layers and numerical experiments show that MQ interpolation has the highest accuracy and best stability. Variable radiative transfer problems in double-layer semitransparent media with different thermophysical properties are investigated and the influence of these thermophysical properties on the radiative transfer procedure in double-layer semitransparent media is also analyzed. All the simulated results show that the present SCM with the new angular discretization scheme can predict the radiative transfer in multi-layer semitransparent medium with graded index efficiently and accurately.

  14. Root profile in Multi-layered Dehesas: an approach to plant-to-plant Interaction

    Science.gov (United States)

    Rolo, V.; Moreno, G.

    2009-04-01

    Assessing plant-to-plant relationship is a key issue in agroforestry systems. Due to the sessile feature of plants most of these interactions take place within a restricted space, so characterizing the zone where the plant alters its environment is important to find overlapping areas where the facilitation or competition could occur. Main part of plan-to-plant interactions in the dehesa are located at belowground level, thus the main limited resources in Mediterranean ecosystems are soil nutrient and water. Hence a better knowledge of rooting plant profile can be useful to understand the functioning of the dehesa. The Iberian dehesa has always been considered as a silvopastoral system where, at least, two strata of vegetation coexist: native grasses and trees. However the dehesa is also a diverse system where cropland and encroached territories have been systematically combined, more or less periodically, with native pasture in order to obtain agricultural, pastoral and forestry outputs. These multipurpose mosaic-type systems generate several scenarios where the plant influence zone may be overlapped and the interaction, competition or facilitation, between plants can play an important role in the ecosystem functioning in terms of productivity and stability. In the present study our aim was to characterize the rooting profile of multi-layered dehesas in order to understand the competitive, and/or facilitative, relationships within the different plant strata. The root profile of Quercus ilex subsp. ballota, Cistus ladanifer, Retama spaherocarpa and natural grasses was studied. So 48 trenches, up to 2 meters deep, were excavated in 4 different environments: (i) grass; (ii) tree-grass; (iii) tree-shrub and (iv) tree-shrub-grass (12 trenches in each environment). The study was carried out in 4 dehesas, 2 encroached with C. ladanifer and 2 with R. spaherocarpa. In every trench soil samples were taken each 20 cm. Subsequently, all samples were sieved using different mesh

  15. Multi-layered Security Approaches for a Modular Open Network Architecture-based Satellite

    OpenAIRE

    Shirley, Brandon; Young, Quinn; Wegner, Peter; Christensen, Jacob; Janicik, Jeffrey

    2014-01-01

    A growing trend in satellite development includes shortening the development lifecycle for hardware and software, cost reduction, and promoting reuse for future missions. Department of Defense (DoD) acquisition policies mandate system providers use Open Systems Architecture (OSA) where feasible. Modular Open Network Architecture (MONA) is a subset of OSA and paves the way to achieve cost reduction and reuse during a reduced development lifecycle. MONA approaches provide opportunities to enhan...

  16. Design and Test of Advanced Multi-Layer Dielectric Gratings for High Energy Petawatt

    Energy Technology Data Exchange (ETDEWEB)

    Molander, W; Komashko, A; Britten, J; Jones, L; Brown, C; Caird, J; Jovanovic, I; Wattellier, B; Nielsen, N; Pennington, D; Barty, C P J

    2003-09-05

    In this paper we discuss recent work on the development of high damage threshold, high efficiency MLD (multilayer dielectric) diffraction gratings for use in high energy, petawatt laser systems. This effort involves a close integration between modeling, fabrication, and testing. The modeling work is used to identify grating designs that satisfy the constraints of high efficiency (>94%) and low field enhancement which is a necessary condition for high damage threshold. Subscale MLD gratings for test are being fabricated in an advanced ion-etch machine we have recently built. The testing effort is being conducted in a dedicated laboratory. The laser beam used to test the samples is based on an OPCPA (optical parametric chirped-pulse amplifier) and a compressor that can provide pulse energies up to 50mJ with pulse lengths variable from 0.3-20 ps. This test station is equipped with diagnostics to fully characterize both the spatial and temporal characteristics of the test beam at the plane of the sample. Initial results have demonstrated a dependence of damage threshold on incident angle that is in good agreement with the field enhancement calculations. We have demonstrated a grating design with a damage threshold of 3J/cm{sup 2} and are investigating manufacturability and reproducibility issues as well.

  17. Spatial tuning of negative and positive Poisson's ratio in a multi-layer scaffold.

    Science.gov (United States)

    Soman, Pranav; Lee, Jin Woo; Phadke, Ameya; Varghese, Shyni; Chen, Shaochen

    2012-07-01

    While elastic modulus is tunable in tissue engineering scaffolds, it is substantially more challenging to tune the Poisson's ratio of scaffolds. In certain biological applications, scaffolds with a tunable Poisson's ratio may be more suitable for emulating the behavior of native tissue mechanics. Here, we design and fabricate a scaffold, which exhibits simultaneous negative and positive Poisson's ratio behavior. Custom-made digital micro-mirror device stereolithography was used to fabricate single- and multiple-layer scaffolds using polyethylene glycol-based biomaterial. These scaffolds are composed of pore structures having special geometries, and deformation mechanisms, which can be tuned to exhibit both negative Poisson's ratio (NPR) and positive Poisson's ratio (PPR) behavior in a side-to-side or top-to-bottom configuration. Strain measurement results demonstrate that analytical deformation models and simulations accurately predict the Poisson's ratios of both the NPR and PPR regions. This hybrid Poisson's ratio property can be imparted to any photocurable material, and potentially be applicable in a variety of biomedical applications. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  18. Simple and cost-effective fabrication of solid biodegradable polymer microneedle arrays with adjustable aspect ratio for transdermal drug delivery using acupuncture microneedles

    Science.gov (United States)

    Cha, Kyoung Je; Kim, Taewan; Jea Park, Sung; Kim, Dong Sung

    2014-11-01

    Polymer microneedle arrays (MNAs) have received much attention for their use in transdermal drug delivery and microneedle therapy systems due to the advantages they offer, such as low cost, good mechanical properties, and a versatile choice of materials. Here, we present a simple and cost-effective method for the fabrication of a biodegradable polymer MNA in which the aspect ratio of each microneedle is adjustable using commercially available acupuncture microneedles. In our process, a master template with acupuncture microneedles, whose shape will be the final MNA, was carefully prepared by fixing them onto a plastic substrate with selectively drilled holes which, in turn, determine the aspect ratios of the microneedles. A polylactic acid (PLA; a biodegradable polymer) MNA was fabricated by a micromolding process with a polydimethylsiloxane (PDMS) mold containing the cavity of the microneedles, which was obtained by the PDMS replica molding against the master template. The mechanical force and degradation behavior of the replicated PLA MNA were characterized with the help of a compression test and an accelerated degradation test, respectively. Finally, the transdermal drug delivery performance of the PLA MNA was successfully simulated by two different methods of penetration and staining, using the skin of a pig cadaver. These results indicated that the proposed method can be effectively used for the fabrication of polymer MNAs which can be used in various microneedle applications.

  19. Melt-and-mold fabrication (MnM-Fab) of reconfigurable low-cost devices for use in resource-limited settings.

    Science.gov (United States)

    Li, Zhi; Tevis, Ian D; Oyola-Reynoso, Stephanie; Newcomb, Lucas B; Halbertsma-Black, Julian; Bloch, Jean-Francis; Thuo, Martin

    2015-12-01

    Interest in low-cost analytical devices (especially for diagnostics) has recently increased; however, concomitant translation to the field has been slow, in part due to personnel and supply-chain challenges in resource-limited settings. Overcoming some of these challenges require the development of a method that takes advantage of locally available resources and/or skills. We report a Melt-and-mold fabrication (MnM Fab) approach to low-cost and simple devices that has the potential to be adapted locally since it requires a single material that is recyclable and simple skills to access multiple devices. We demonstrated this potential by fabricating entry level bio-analytical devices using an affordable low-melting metal alloy, Field's metal, with molds produced from known materials such as plastic (acrylonitrile-butadiene-styrene (ABS)), glass, and paper. We fabricated optical gratings then 4×4 well plates using the same recycled piece of metal. We then reconfigured the well plates into rapid prototype microfluidic devices with which we demonstrated laminar flow, droplet generation, and bubble formation from T-shaped channels. We conclude that this MnM-Fab method is capable of addressing some challenges typically encountered with device translation, such as technical know-how or material supply, and that it can be applied to other devices, as needed in the field, using a single moldable material. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. The Effect of Degree of Substitution of Cationic Starch on Multi-layer Formation of Ionic Starches in Recycled Fibers

    Directory of Open Access Journals (Sweden)

    hamidreza rudi

    2012-12-01

    Full Text Available Layer-by-layer self-assembly technique is a novel method in nanotechnology for modifcation of the surface properties of solid materials. Among these materials cellulosic fbers can undergo surface changes by formation of polyelectrolyte multi-layers (PEM using layer-by-layer method. In this study, the effect of degree of substitution of cationic starch on multi-layer build up of cationic and anionic starches and on the bonding ability of the waste corrugated container (OCC recycled fber with layer-by-layer  technique was  investigated. Experiments were  conducted  at pH≈7.5 and 750 rpm stirring rate in a dynamic drainage jar (DDJ for 10 min deposition time to  construct 1  to 8  consecutive  layers. The handsheets  at 60 g/m2 on weight basis were made with untreated and  layer-by-layer  treated fbers and  their strengths have been evaluated. The results showed that the interbonding ability indices of fbers such as  tensile  index and  internal bonding  improved signifcantly with multi-layering of cationic starch. However, there was no meaningful change in quality of the specimens formed. Compared to the untreated fbers, the tensile index of cationic starch increased by 129% at 7th layer with DS≈0.045 and internal bonding increased by 400% at the 5th  layer. Moreover, with  regard  to  different  degrees  of  substitution  of  starch,  the increasing  trend  in properties was observed;  in which DS≈0.018  for  lower number of layers and DS≈0.045 for higher number of layers. In the frst case, more starch of lower DS was needed to neutralize the charge of the fber surface but in the second case greater charge balance of two polymers resulted in further adsorption and greater stability of cationic starch layer, and consequently higher strength has been achieved for the obtained paper.

  1. Sensitivity study of multi-layer active magnetic regenerators using first order magnetocaloric material La(Fe,Mn,Si)13Hy

    Science.gov (United States)

    Lei, Tian; Nielsen, Kaspar K.; Engelbrecht, Kurt; Bahl, Christian R. H.; Neves Bez, Henrique; Veje, Christian T.

    2015-07-01

    We present simulation results of multi-layer active magnetic regenerators using the solid-state refrigerant La(Fe,Mn,Si)13Hy. This material presents a large, however quite sharp, isothermal entropy change that requires a careful choice of number of layers and working temperature for multi-layer regenerators. The impact of the number of layers and the sensitivity to the working temperature as well as the temperature span are quantified using a one dimensional numerical model. A study of the sensitivity of variation in Curie temperature through a uniform and normal distribution is also presented. The results show that the nominal cooling power is very sensitive to the Curie temperature variation in the multi-layer regenerators. A standard deviation of the Curie temperature variation for a normal distribution less than 0.6 K is suggested in order to achieve sufficient performance of a 15-layer regenerator with Curie temperature spacing of 2 K.

  2. Measurements of Multi-Layer Insulation at High Boundary Temperature, using a Simple Non-Calorimetric Method

    CERN Document Server

    Mazzone, L; Rieubland, Jean Michel; Vandoni, Giovanna

    2002-01-01

    In spite of abundant literature, the thermal performance of Multi-Layer Insulation (MLI) still deserves dedicated investigation for specific applications, as the achievable insulation strongly depends on installation details. Furthermore, less accurate information is available for warm than for cold boundaries, since errors due to edge effects in small test benches increase strongly with warm boundary temperature. We establish here the thermal performance of MLI between 300 K and 77 K or 4 K, without bringing calorimetric methods into play, through the accurate measurement of a temperature profile. A cylinder in thin copper, wrapped with MLI, is cooled at one extremity while suspended under vacuum inside a sheath at room temperature. For known thermal conductivity and thickness of the tube, the heat flux can be inferred from the temperature profile. In-situ measurement of the thermal conductivity is obtained by applying a know heat flow at the warm extremity of the cylinder. Results, cross-checked with a cali...

  3. Numerical study of the MHD flow characteristics in a three-surface-multi-layered channel with different inlet conditions

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi, Mitsuhiro, E-mail: mao@karma.qse.tohoku.ac.jp; Ito, Satoshi; Hashizume, Hidetoshi

    2014-10-15

    A 3D MHD flow simulation was conducted to clarify the effects of the inlet flow conditions on the results of the validation experiment carried out previously and on the design window of the first wall using a three-surface-multi-layered channel. MHD pressure drop was largely influenced by the inlet condition. The numerical model with turbulent velocity profile showed qualitatively good agreement with the experimental result. The first wall temperature and pressure distributions obtained by the 3D simulation corresponded well to those obtained by the 2D simulation assuming fully developed flow. This suggested that complicated three-dimensional inlet flow condition generated in the L-shape elbow would not affects the existing design window.

  4. An integral test of FLUKA nuclear models with 160 MeV proton beams in multi-layer Faraday cups

    CERN Document Server

    Rinaldi, I; Parodi, K; Ferrari, A; Sala, P; Mairani, A

    2011-01-01

    Monte Carlo (MC) codes are useful tools to simulate the complex processes of proton beam interactions with matter. In proton therapy, nuclear reactions influence the dose distribution. Therefore, the validation of nuclear models adopted in MC codes is a critical requisite for their use in this field. A simple integral test can be performed using a multi-layer Faraday cup (MLFC). This method allows separation of the nuclear and atomic interaction processes, which are responsible for secondary particle emission and the finite primary proton range, respectively. In this work, the propagation of 160 MeV protons stopping in two MLFCs made of polyethylene and copper has been simulated by the FLUKA MC code. The calculations have been performed with and without secondary electron emission and transport, as well as charge sharing in the dielectric layers. Previous results with other codes neglected those two effects. The impact of this approximation has been investigated and found to be relevant only in the proximity ...

  5. Brain tumor detection using scalp eeg with modified Wavelet-ICA and multi layer feed forward neural network.

    Science.gov (United States)

    Selvam, V Salai; Shenbagadevi, S

    2011-01-01

    Use of scalp EEG for the diagnosis of various cerebral disorders is progressively increasing. Though the advanced neuroimaging techniques such as MRI and CT-SCAN still stay as principal confirmative methods for detecting and localizing brain tumors, the development of automated systems for the detection of brain tumors using the scalp EEG has started attracting the researchers all over the world notably since 2000. This is because of two important facts: (i) cheapness and easiness of methods of recording and analyzing the scalp EEG and (ii) lower risk and possible early detection. This paper presents a method of detecting the brain tumor using the first, second and third order statistics of the scalp EEG with a Modified Wavelet-Independent Component Analysis (MwICA) technique and a multi-layer feed-forward neural network.

  6. Study of multi-layer active magnetic regenerators using magnetocaloric materials with first and second order phase transition

    DEFF Research Database (Denmark)

    Lei, Tian; Engelbrecht, Kurt; Nielsen, Kaspar Kirstein

    2016-01-01

    Magnetocaloric materials (MCM) with a first order phase transition (FOPT) usually exhibit a large, although sharp, isothermal entropy change near their Curie temperature, compared to materials with a second order phase transition (SOPT). Experimental results of applying FOPT materials in recent...... magnetocaloric refrigerators (MCR) demonstrated the great potential for these materials, but a thorough study on the impact of the moderate adiabatic temperature change and strong temperature dependence of the magnetocaloric effect (MCE) is lacking. Besides, comparing active magnetic regenerators (AMR) using...... FOPT and SOPT materials is also of fundamental interest. We present modeling results of multi-layer AMRs using FOPT and SOPT materials based on a 1D numerical model. First the impact of isothermal entropy change, adiabatic temperature change and shape factor describing the temperature dependence...

  7. Estimation of long-term aqueous phase changes in a multi-layer cover using generic soil properties

    Science.gov (United States)

    Jacques, D.; Mallants, D.; Schneider, S.

    2009-04-01

    To protect near surface disposal facilities from infiltrating rainfall a multi-layer cover is installed consisting of different materials including soil (usually sand- or loam-based) and clay. The function of such layers is to divert infiltrating rainwater and hence minimize water drainage from the cover in the underlying disposal facility. However, the soil and clay materials will change the composition of the infiltrating water due to biogeochemical processes. A methodology is developed to assess changes in water composition as the rain water percolates through the soil and clay layers of a vegetated multi-layer cover. The method is based on a steady-state mass balance approach and uses generic soil physical and chemical properties. The approach considers weathering of the soil and clay minerals estimated from a pedotransfer function and accounts for the average temperature, the textural class and the depth of the profile. Soil microbiological activity is taken into account by imposing the soil partial pressure of CO2. The latter value is estimated from an empirical model based on the actual evapotranspiration. Eight scenarios were developed that resulted in eight different solution compositions of the drainage water. This approach resulted in a realistic pH range between 3.4 and 4.4 for the scenarios that consider either absence of all soil and clay layers (thus representing rain composition) or presence of a single soil layer only. Scenarios that considered both soil and clay layers to be present produced rather high pH values (around 9.5), probably due to too high estimates of the base cation weathering rates generated with the pedotransfer functions. Alternative methods for dealing with weathering of the clay layer are proposed. These types of water compositions were used to simulate the chemical degradation process of concrete as to produce a lower and upper bound to the durability of concrete engineered barriers.

  8. Effect of MAP and Multi-layer Flexible Films on the Growth of Anaerobic Bacteria of Fresh Ostrich Meat

    Directory of Open Access Journals (Sweden)

    Nazanin Zand

    2016-11-01

    Full Text Available The usage of different concentrations of two gas mixture (Carbon dioxide, Nitrogen, and also vacuum conditions and the effect of flexible multi-layer pouches has been studied on the growth of anaerobic bacteria in fresh ostrich meat at refrigerator (T=4 0C. Ordinary condition as a control packaging was compared with three types of modified atmosphere packaging: {(N270% + CO230%, (N230% + CO270%} and vacuum conditions in this project. Ostrich fresh meat were packaged into 3 kinds of polymeric flexible pouch” 4-layers with thickness 131μ, {PET (12 / AL (7 / PET (12 / LLD (100}, 3-layer with thickness 124μ {PET (12 / AL (12 / LLD (100 and 3- layer with thickness 119 μ {PET (12 / AL (7 / LLD (100}. Samples were performed microbial tests (Total count of anaerobic bacteria, in different times with 12 treatment ,3 run, statistical analysis and comparison of data, were done by software SAS (Ver:9/1 and Duncan’s new multiple range test, with confidence level of 95% (P <0.05. The usage of MAP was not adequate for controlling spoilage, but the spoilage process was delayed. Anaerobic bacteria population of ostrich meat under (% 30 CO2 +% 70 N2 and also vacuum conditions in this container were more than 104 (not acceptable.However, the best condition belonged to ( N2 30% + CO2 70% ,and was acceptable till15 days. Maximum anaerobic bacteria s which were grown in these meat samples was related to % 30 CO2 conditions in 3-layer Al(7 μ, and the lowest growth belonged to treatment under % 70 CO2 in 4-layer. The Characteristic of this multi-layer flexible pouch (4-layers with less water vapor and oxygen permeability and also increasing more percentage of CO2 due to antibacterial properties of carbon dioxide gas, caused to control microbial growth in samples, so could be extended shelf life of fresh ostrich meat.

  9. High frequency guided ultrasonic waves for hidden fatigue crack growth monitoring in multi-layer model aerospace structures

    Science.gov (United States)

    Chan, Henry; Masserey, Bernard; Fromme, Paul

    2015-02-01

    Especially for ageing aircraft the development of fatigue cracks at fastener holes due to stress concentration and varying loading conditions constitutes a significant maintenance problem. High frequency guided waves offer a potential compromise between the capabilities of local bulk ultrasonic measurements with proven defect detection sensitivity and the large area coverage of lower frequency guided ultrasonic waves. High frequency guided waves have energy distributed through all layers of the specimen thickness, allowing in principle hidden (2nd layer) fatigue damage monitoring. For the integration into structural health monitoring systems the sensitivity for the detection of hidden fatigue damage in inaccessible locations of the multi-layered components from a stand-off distance has to be ascertained. The multi-layered model structure investigated consists of two aluminium plate-strips with an epoxy sealant layer. During cyclic loading fatigue crack growth at a fastener hole was monitored. Specific guided wave modes (combination of fundamental A0 and S0 Lamb modes) were selectively excited above the cut-off frequencies of higher modes using a standard ultrasonic wedge transducer. Non-contact laser measurements close to the defect were performed to qualify the influence of a fatigue crack in one aluminium layer on the guided wave scattering. Fatigue crack growth monitoring using laser interferometry showed good sensitivity and repeatability for the reliable detection of small, quarter-elliptical cracks. Standard ultrasonic pulse-echo equipment was employed to monitor hidden fatigue damage from a stand-off distance without access to the damaged specimen layer. Sufficient sensitivity for the detection of fatigue cracks located in the inaccessible aluminium layer was verified, allowing in principle practical in situ ultrasonic monitoring of fatigue crack growth.

  10. Shape, zonal winds and gravitational field of Jupiter: a fully self-consistent, multi-layered model

    Science.gov (United States)

    Schubert, Gerald; Kong, Dali; Zhang, Keke

    2016-10-01

    We construct a three-dimensional, finite-element, fully self-consistent, multi-layered,non-spheroidal model of Jupiter consisting of an inner core, a metallic electrically conducting dynamo region and an outer molecular electrically insulating envelope. We assume that the Jovian zonal winds are on cylinders parallel to the rotation axis but, due to the effect of magnetic braking, are confined within the outer molecular envelope. Two related calculations are carried out. The first provides an accurate description of the shape and internal density profile of Jupiter; the effect of rotational distortion is not treated as a small perturbation on a spherically symmetric state. This calculation determines the density, size and shape of the inner core, the irregular shape of the 1-bar pressure level, and the internal structure of Jupiter; the full effect of rotational distortion, without the influence of the zonal winds, is accounted for. Our multi-layered model is able to produce the known mass, the known equatorial and polar radii, and the known zonal gravitational coefficient J2 of Jupiter within their error bars; it also yields the coefficients J4 and J6 within about 5% accuracy, and the core equatorial radius 0.09RJ containing 3.73 Earth masses.The second calculation determines the variation of the gravitational field caused solely by the effect of the zonal winds on the rotationally distorted non-spheroidal Jupiter. Four different cases, ranging from a deep wind profile to a very shallow profile, are considered and implications for accurate interpretation of the zonal gravitational coefficients expected from the Juno mission are discussed.

  11. Direct synthesis of multi-layer graphene film on various substrates by microwave plasma at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Jae [Plasma Technology Research Center, 814-2 Osickdo-dong (SGFEZ), Gunsan, Jeollabuk-do 573-540 (Korea, Republic of); Ahn, Byung Wook; Kim, Tae Yoo; Lee, Jung Woo [School of Advanced Materials Science and Engineering, Advanced Materials and Process Research Center (AMPRC), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Jung, Yong Ho; Choi, Yong Sup [Plasma Technology Research Center, 814-2 Osickdo-dong (SGFEZ), Gunsan, Jeollabuk-do 573-540 (Korea, Republic of); Song, Young Il, E-mail: physein01@skku.edu [School of Advanced Materials Science and Engineering, Advanced Materials and Process Research Center (AMPRC), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Suh, Su Jeong, E-mail: suhsj@skku.edu [School of Advanced Materials Science and Engineering, Advanced Materials and Process Research Center (AMPRC), Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2015-07-31

    We introduce a possible route for vertically standing multi-layer graphene films (VMGs) on various substrates at low temperature by electron cyclone resonance microwave plasma. VMG films on various substrates, including copper sheet, glass and silicon oxide wafer, were analyzed by studying their structural, electrical, and optical properties. The density and temperature of plasma were measured using Cylindrical Langmuir probe analysis. The morphologies and microstructures of multi-layer graphene were characterized using field emission scattering electron microscope, high resolution transmission electron microscope, and Raman spectra measurement. The VMGs on different substrates at the same experimental conditions synthesized the wrinkled VMGs with different heights. In addition, the transmittance and electrical resistance were measured using ultra-violet visible near-infrared spectroscopy and 4 probe point surface resistance measurement. The VMGs on glass substrate obtained a transmittance of 68.8% and sheet resistance of 796 Ω/square, whereas the VMGs on SiO{sub 2} wafer substrate showed good sheet resistance of 395 Ω/square and 278 Ω/square. The results presented herein demonstrate a simple method of synthesizing of VMGs on various substrates at low temperature for mass production, in which the VMGs can be used in a wide range of application fields for energy storage, catalysis, and field emission due to their unique orientation. - Highlights: • We present for synthesis method of graphene at low temperature on various substrates. • We grow the graphene films at low temperature under of 432 °C. • Structural information of graphene films were studied upon Raman spectroscopy. • Inter-layer spacing of vertically standing graphene relies on synthesis time. • We measured a transmittance and a resistance for graphene films on difference substrate.

  12. Critical factors in manufacturing multi-layer tablets--assessing material attributes, in-process controls, manufacturing process and product performance.

    Science.gov (United States)

    Vaithiyalingam, Sivakumar R; Sayeed, Vilayat A

    2010-10-15

    Advancement in the fields of material science, analytical methodologies, instrumentation, automation, continuous monitoring, feed forward/feed back control and comprehensive data collection have led to continual improvement of pharmaceutical tablet manufacturing technology, notably the multi-layer tablets. This review highlights the material attributes, formulation design, process parameters that impact the performance, and manufacturability of the multi-layer tablets. It also highlights on critical-to-quality elements that needs to be addressed in the regulatory submission. Published by Elsevier B.V.

  13. Fabrication of low-cost beta-type Ti-Mn alloys for biomedical applications by metal injection molding process and their mechanical properties.

    Science.gov (United States)

    Santos, Pedro Fernandes; Niinomi, Mitsuo; Liu, Huihong; Cho, Ken; Nakai, Masaaki; Itoh, Yoshinori; Narushima, Takayuki; Ikeda, Masahiko

    2016-06-01

    Titanium and its alloys are suitable for biomedical applications owing to their good mechanical properties and biocompatibility. Beta-type Ti-Mn alloys (8-17 mass% Mn) were fabricated by metal injection molding (MIM) as a potential low cost material for use in biomedical applications. The microstructures and mechanical properties of the alloys were evaluated. For up to 13 mass% Mn, the tensile strength (1162-938MPa) and hardness (308-294HV) of the MIM fabricated alloys are comparable to those of Ti-Mn alloys fabricated by cold crucible levitation melting. Ti-9Mn exhibits the best balance of ultimate tensile strength (1046MPa) and elongation (4.7%) among the tested alloys, and has a Young's modulus of 89GPa. The observed low elongation of the alloys is attributed to the combined effects of high oxygen content, with the presence of interconnected pores and titanium carbides, the formation of which is due to carbon pickup during the debinding process. The elongation and tensile strength of the alloys decrease with increasing Mn content. The Ti-Mn alloys show good compressive properties, with Ti-17Mn showing a compressive 0.2% proof stress of 1034MPa, and a compressive strain of 50%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Single- and multi-layered all-dielectric ENG, MNG, and DNG material parameter extraction by use of the S-parameter method

    DEFF Research Database (Denmark)

    Wu, Yunqiu; Arslanagic, Samel

    2016-01-01

    The multi-layer two-dimensional(2-D) epsilon-negative (ENG), mu-negative (MNG) and double-negative (DNG) materials are investigated in this work. The unit cells consist of infinite dielectric cylinders of which the size and permittivity are chosen to excite the dominant electric and magnetic dipo...

  15. Sensitivity study of multi-layer active magnetic regenerators using first order magnetocaloric material La(Fe,Mn,Si)13Hy

    DEFF Research Database (Denmark)

    Lei, Tian; Nielsen, Kaspar Kirstein; Engelbrecht, Kurt

    2015-01-01

    We present simulation results of multi-layer active magnetic regenerators using the solid-state refrigerant La(Fe,Mn,Si)13Hy. This material presents a large, however quite sharp, isothermal entropy change that requires a careful choice of number of layers and working temperature for multi...

  16. Tactile Evaluation Feedback System for Multi-Layered Structure Inspired by Human Tactile Perception Mechanism

    Science.gov (United States)

    Mohamad Hashim, Iza Husna; Kumamoto, Shogo; Takemura, Kenjiro; Maeno, Takashi; Okuda, Shin; Mori, Yukio

    2017-01-01

    Tactile sensation is one type of valuable feedback in evaluating a product. Conventionally, sensory evaluation is used to get direct subjective responses from the consumers, in order to improve the product’s quality. However, this method is a time-consuming and costly process. Therefore, this paper proposes a novel tactile evaluation system that can give tactile feedback from a sensor’s output. The main concept of this system is hierarchically layering the tactile sensation, which is inspired by the flow of human perception. The tactile sensation is classified from low-order of tactile sensation (LTS) to high-order of tactile sensation (HTS), and also to preference. Here, LTS will be correlated with physical measures. Furthermore, the physical measures that are used to correlate with LTS are selected based on four main aspects of haptic information (roughness, compliance, coldness, and slipperiness), which are perceived through human tactile sensors. By using statistical analysis, the correlation between each hierarchy was obtained, and the preference was derived in terms of physical measures. A verification test was conducted by using unknown samples to determine the reliability of the system. The results showed that the system developed was capable of estimating preference with an accuracy of approximately 80%. PMID:29137128

  17. Tactile Evaluation Feedback System for Multi-Layered Structure Inspired by Human Tactile Perception Mechanism

    Directory of Open Access Journals (Sweden)

    Iza Husna Mohamad Hashim

    2017-11-01

    Full Text Available Tactile sensation is one type of valuable feedback in evaluating a product. Conventionally, sensory evaluation is used to get direct subjective responses from the consumers, in order to improve the product’s quality. However, this method is a time-consuming and costly process. Therefore, this paper proposes a novel tactile evaluation system that can give tactile feedback from a sensor’s output. The main concept of this system is hierarchically layering the tactile sensation, which is inspired by the flow of human perception. The tactile sensation is classified from low-order of tactile sensation (LTS to high-order of tactile sensation (HTS, and also to preference. Here, LTS will be correlated with physical measures. Furthermore, the physical measures that are used to correlate with LTS are selected based on four main aspects of haptic information (roughness, compliance, coldness, and slipperiness, which are perceived through human tactile sensors. By using statistical analysis, the correlation between each hierarchy was obtained, and the preference was derived in terms of physical measures. A verification test was conducted by using unknown samples to determine the reliability of the system. The results showed that the system developed was capable of estimating preference with an accuracy of approximately 80%.

  18. SU-F-E-09: Respiratory Signal Prediction Based On Multi-Layer Perceptron Neural Network Using Adjustable Training Samples

    Energy Technology Data Exchange (ETDEWEB)

    Sun, W; Jiang, M; Yin, F [Duke University Medical Center, Durham, NC (United States)

    2016-06-15

    Purpose: Dynamic tracking of moving organs, such as lung and liver tumors, under radiation therapy requires prediction of organ motions prior to delivery. The shift of moving organ may change a lot due to huge transform of respiration at different periods. This study aims to reduce the influence of that changes using adjustable training signals and multi-layer perceptron neural network (ASMLP). Methods: Respiratory signals obtained using a Real-time Position Management(RPM) device were used for this study. The ASMLP uses two multi-layer perceptron neural networks(MLPs) to infer respiration position alternately and the training sample will be updated with time. Firstly, a Savitzky-Golay finite impulse response smoothing filter was established to smooth the respiratory signal. Secondly, two same MLPs were developed to estimate respiratory position from its previous positions separately. Weights and thresholds were updated to minimize network errors according to Leverberg-Marquart optimization algorithm through backward propagation method. Finally, MLP 1 was used to predict 120∼150s respiration position using 0∼120s training signals. At the same time, MLP 2 was trained using 30∼150s training signals. Then MLP is used to predict 150∼180s training signals according to 30∼150s training signals. The respiration position is predicted as this way until it was finished. Results: In this experiment, the two methods were used to predict 2.5 minute respiratory signals. For predicting 1s ahead of response time, correlation coefficient was improved from 0.8250(MLP method) to 0.8856(ASMLP method). Besides, a 30% improvement of mean absolute error between MLP(0.1798 on average) and ASMLP(0.1267 on average) was achieved. For predicting 2s ahead of response time, correlation coefficient was improved from 0.61415 to 0.7098.Mean absolute error of MLP method(0.3111 on average) was reduced by 35% using ASMLP method(0.2020 on average). Conclusion: The preliminary results

  19. Optimal Composite Material for Low Cost Fabrication of Large Composite Aerospace Structures using NASA Resins or POSS Nanoparticle Modifications

    Science.gov (United States)

    Lamontia, Mark A.; Gruber, Mark B.; Jensen, Brian J.

    2006-01-01

    Thermoplastic laminates in situ consolidated via tape or tow placement require full mechanical properties. Realizing full properties requires resin crystallinity to be controlled - partial crystallinity leads to unacceptably low laminate compression properties. There are two approaches: utilize an amorphous matrix resin; or place material made from a semi-crystalline resin featuring kinetics faster than the process. In this paper, a matrix resin evaluation and trade study was completed with commercial and NASA amorphous polyimides on the one hand, and with PEKK mixed with POSS nanoparticles for accelerated crystallinity growth on the other. A new thermoplastic impregnated material, 6 mm wide (0.25-in) AS-4 carbon/LaRC(TradeMark)8515 dry polyimide tow, was fabricated. Since LaRC(TradeMark)8515 is fully amorphous, it attains full properties following in situ consolidation, with no post processing required to build crystallinity. The tow in situ processing was demonstrated via in situ thermoplastic filament winding it into rings.

  20. Low-cost and facile fabrication of a paper-based capillary electrophoresis microdevice for pathogen detection.

    Science.gov (United States)

    Lee, Jee Won; Lee, Dohwan; Kim, Yong Tae; Lee, Eun Yeol; Kim, Do Hyun; Seo, Tae Seok

    2017-05-15

    This paper describes the development of a novel paper-based capillary electrophoresis (pCE) microdevice using mineral paper, which is durable, oil and tear resistant, and waterproof. The pCE device is inexpensive (~$1.6 per device for materials), simple to fabricate, lightweight, and disposable, so it is more adequate for point-of-care (POC) pathogen diagnostics than a conventional CE device made of glass, quartz, silicon or polymer. In addition, the entire fabrication process can be completed within 1h without using expensive clean room facilities and cumbersome photolithography procedures. A simple cross-designed pCE device was patterned on the mineral paper by using a plotter, and assembled with an OHP film via a double-sided adhesive film. After filling the microchannel with polyacrylamide gel, the injection, backbiasing, and separation steps were sequentially operated to differentiate single-stranded DNA (ssDNA) with 4 bp resolution in a 2.9cm-long CE separation channel. Furthermore, we successfully demonstrated the identification of the PCR amplicons of two target genes of Escherichia coli O157:H7 (rrsH gene, 121 bp) and Staphylococcus aureus (glnA gene, 225 bp). For accurate assignment of the peaks in the electropherogram, two bracket ladders (80 bp for the shortest and 326 bp for the longest) were employed, so the two amplicons of the pathogens were precisely identified on a pCE chip within 3min using the relative migration time ratio without effect of the CE environments. Thus, we believe that the pCE microdevice could be very useful for the separation of nucleic acids, amino acids, and ions as an analytical tool for use in the medical applications in the resource-limited environments as well as fundamental research fields. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Fabrication of conducting composite sheets using cost-effective graphite flakes and amorphous styrene acrylonitrile for enhanced thermistor, dielectric, and electromagnetic interference shielding properties

    Energy Technology Data Exchange (ETDEWEB)

    Panwar, Varij, E-mail: varijpanwarcertain@gmail.com [Electronics and Communication Engineering, Graphic Era University, Dehradun, Uttarakhand (India); Gill, Fateh Singh; Rathi, Vikas; Tewari, V.K. [Electronics and Communication Engineering, Graphic Era University, Dehradun, Uttarakhand (India); Mehra, R.M. [Sharda University, Greater Noida (India); Park, Jong-Oh, E-mail: jop@jnu.ac.kr [School of Mechanical Engineering, Chonnam National University, Gwangju (Korea, Republic of); Park, Sukho, E-mail: shpark12@dgist.ac.kr [Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)

    2017-06-01

    The fabrication of strong conducting composite sheets (CCSs) using a simple technique with cost-effective materials is desirable for capacitor, decoupling capacitor, and electromagnetic interference (EMI) shielding applications. Here, we used cost-effective graphite flakes (GFs) as a conducting filler and amorphous poly (styrene-co-acrylonitrile) (PSAN) as an insulating polymer to fabricate a CCS via a simple mechanical mixing and hot compression molding process in 2.5 h, with the aim to save time and avoid the use of toxic reagents, which are generally used in chemical methods. In the present method, the GFs are connected in diffusively adhere polymer matrix, controlled by temperature and pressure that generate the conduction in the CCSs. The resulting PSAN/GF CCSs were characterized by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and hardness tests. The GFs penetrated the interfacial region of PSAN, thus improving the thermistor and dielectric properties (dielectric constant, AC conductivity, and dissipation factor) of the PSAN/GF CCSs. Furthermore, the PSAN/GF CCSs showed enhanced hardness and EMI shielding effectiveness (SE) properties in the X-band frequency range (8.5–12.5 GHz). The percolation theory was implemented to DC and AC conductivity. To detect the transition of the dielectric properties, the dielectric constant of the CCSs was analyzed with increasing volume fraction of GFs in the radio frequency region. The improved dielectric constant, AC conductivity, and dissipation factor of the PSAN/GF CCS, indicated a significant improvement in their EMI shielding properties in the X-band frequency range, which were measured using the waveguide method. The ac conductivity of PSAN/GF CCS shows stable behavior in the higher frequency ranges. The EMISE of PSAN/GF CCS were found to increase with increasing GF content due to the absorbance mechanism. - Highlights: • Enhanced hardness and

  2. Comparison of different forms of the Multi-layer Feed-Forward Neural Network method used for river flow forecasting

    Science.gov (United States)

    Shamseldin, A. Y.; Nasr, A. E.; O'Connor, K. M.

    The Multi-Layer Feed-Forward Neural Network (MLFFNN) is applied in the context of river flow forecast combination, where a number of rainfall-runoff models are used simultaneously to produce an overall combined river flow forecast. The operation of the MLFFNN depends not only on its neuron configuration but also on the choice of neuron transfer function adopted, which is non-linear for the hidden and output layers. These models, each having a different structure to simulate the perceived mechanisms of the runoff process, utilise the information carrying capacity of the model calibration data in different ways. Hence, in a discharge forecast combination procedure, the discharge forecasts of each model provide a source of information different from that of the other models used in the combination. In the present work, the significance of the choice of the transfer function type in the overall performance of the MLFFNN, when used in the river flow forecast combination context, is investigated critically. Five neuron transfer functions are used in this investigation, namely, the logistic function, the bipolar function, the hyperbolic tangent function, the arctan function and the scaled arctan function. The results indicate that the logistic function yields the best model forecast combination performance.

  3. Experimental Investigation of Multi-layer Insulation Effect on Damage of Stuffed Shield by High-velocity Impact

    Directory of Open Access Journals (Sweden)

    GUAN Gong-shun

    2016-09-01

    Full Text Available The stuffed shield with multi-layer insulation(MLI was designed by improving on Al Whipple shield, and a series of high-velocity impact tests were practiced with a two-stage light gas gun facility at vacuum environment. The damage model of the stuffed shield with different MLI location by Al-sphere projectile impacting was obtained. The effect of MLI on damage of the stuffed shield by high-velocity impact was studied. The results indicate when the MLI is located at front side of the first Al-plate, the protection performance of the stuffed shield is improved with the larger perforation diameter of the first Al-plate and more impact kinetic energy dissipation of the projectile. When MLI is arranged at back side of the first Al-plate, the expansion of the secondary debris cloud from projectile impacting the first Al-plate is restrained, it is not good to improve the protection performance of the stuffed shield. When MLI is arranged at front side of the stuffed wall, the perforation size of the stuffed wall increases; when MLI is arranged at front side of the rear wall, the distribution range of crater on the rear wall decreases.

  4. Targeted kinetic strategy for improving the thermal conductivity of epoxy composite containing percolating multi-layer graphene oxide chains

    Directory of Open Access Journals (Sweden)

    T. Zhou

    2015-07-01

    Full Text Available By adding 2 wt% multi-layer graphene oxide (MGO to an epoxy resin, the thermal conductivity of the composite reached a maximum, 2.03 times that of the epoxy. The presence of 2 wt%MGO percolating chains leads to an unprecedentedly sharp rise in energy barrier at final curing stage, but an increased epoxy curing degree (αIR is observed; however, this αIR difference nearly disappears after aging or thermal annealing. These results suggest that the steep concentration gradient of –OH, originated from the 2 wt%MGO percolating chains, exerts the vital driving force on the residual isolated/trapped epoxy to conquer barrier for epoxy-MGO reaction. A modified Shrinking Core Model customized for the special layered-structure of MGO sheet was proposed to understand the resistance variation during the intercalative epoxy-MGO reaction. It shows that the promoted intercalative crosslinking is highly desirable for further improving the thermal conductivity of the composite, but it meets with increased resistance. Guided by the kinetic studies, targeted optimization on the cure processing strategy was accordingly proposed to promote the intercalative crosslinking, a thermal conductivity, 2.96 times that of the epoxy, was got with only a small amount (30°C increase of the post-heating temperature.

  5. In situ nanomechanical characterization of multi-layer MoS2 membranes: from intraplanar to interplanar fracture.

    Science.gov (United States)

    Li, Peifeng; Jiang, Chenchen; Xu, Shang; Zhuang, Yu; Gao, Libo; Hu, Alice; Wang, Hongtao; Lu, Yang

    2017-07-06

    Layered molybdenum disulfide (MoS2) exhibits rich electronic and optical properties and possesses vastly differing characteristic dimensions. A multi-layer MoS2 membrane represents the critical hierarchical structure which bridges the length-scale of monolayer and bulk material architectures. In this study, the in-plane mechanical properties of MoS2 membranes were investigated by in situ SEM tensile testing. Under the uniaxial tensile loading, brittle fracture caused failure in a highly localized region of the MoS2 membranes and their mechanical properties showed a thickness effect: the strengths of the relatively thicker MoS2 membranes (thickness around hundreds of nanometers) distribute from ∼100 to ∼250 MPa, while the corresponding values of the MoS2 nanosheets (thickness around tens of nanometers) increase significantly to more than 1 GPa. Upon molecular dynamics (MD) simulations on the fractures of MoS2 with various thicknesses/layers, the thicker MoS2 membranes show interplanar fracture, and the typical MoS2 nanosheets demonstrate the transition from interplanar to intraplanar fractures, while monolayer and few-layer MoS2 are dominated by intraplanar fracture. Our study provides some critical insights into the mechanical properties and fracture behavior of layered MoS2 2D materials, which could be of value for their flexible electronic, optoelectronic and nano-electro-mechanical system (NEMS) applications.

  6. Rural Sewage Treatment by using Combined Process of Multi-layer Bio-filter and Constructed Wetland

    Science.gov (United States)

    Li, Xudong; Paul, Etienne; Qiu, Jiangping; Roustan, Michel; Wisniewski, Christelle; Mauviot, Patrice

    2010-11-01

    A combined process of multi-layer bio-filter and constructed wetland has been used to treat the rural sewage in eastern China. The capacity of the system was 60 m3/d, the hydraulic loading rate (HLR) of the bio-filter and the constructed wetland was 4.0 m3/(m3ṡd) and 0.50 m3/(m3ṡd), respectively. The system has been operated automatically for 2 years. The results showed that the average concentrations of COD, NH4+-N, TN and TP in the effluent were 58.2, 8.1, 12.1 and 0.9 mg/L with the removal efficiency of 79.2%, 62.8%, 55.1% and 77.1% respectively, which could meet the first grade of Chinese national pollutants discharge standard for municipal wastewater treatment plant (GB 18918-2002). The track studies showed that the organic pollutants were mainly removed in the first 4 layers and the ammonia was mainly removed in the 4th˜6th layers of the filter. It was observed that the COD removal efficiency in the whole system decreased from 84.6% to 73.3% following the sequences of summer, autumn, spring and winter. Comparing with traditional techniques, the combined process could provide a higher nitrogen and phosphorus removal capacity.

  7. Daily global solar radiation modelling using multi-layer perceptron neural networks in semi-arid region

    Directory of Open Access Journals (Sweden)

    Mawloud GUERMOUI

    2016-07-01

    Full Text Available Accurate estimation of Daily Global Solar Radiation (DGSR has been a major goal for solar energy application. However, solar radiation measurements are not a simple task for several reasons. In the cases where data are not available, it is very common the use of computational models to estimate the missing data, which are based mainly of the search for relationships between weather variables, such as temperature, humidity, sunshine duration, etc. In this respect, the present study focuses on the development of artificial neural network (ANN model for estimation of daily global solar radiation on horizontal surface in Ghardaia city (South Algeria. In this analysis back-propagation algorithm is applied. Daily mean air temperature, relative humidity and sunshine duration was used as climatic inputs parameters, while the daily global solar radiation (DGSR was the only output of the ANN. We have evaluated Multi-Layer Perceptron (MLP models to estimate DGSR using three year of measurement (2005-2008. It was found that MLP-model based on sunshine duration and mean air temperature give accurate results in term of Mean Absolute Bias Error, Root Mean Square Error, Relative Square Error and Correlation Coefficient. The obtained values of these indicators are 0.67 MJ/m², 1.28 MJ/m², 6.12%and 98.18%, respectively which shows that MLP is highly qualified for DGSR estimation in semi-arid climates.

  8. DIFFUSION OF THE PULSED ELECTROMAGNETIC FIELD INTO THE MULTI-LAYER CORE OF INDUCTOR AT PULSED DEVICES

    Directory of Open Access Journals (Sweden)

    Volodymyr T. Chemerys

    2008-02-01

    Full Text Available  The problem of the pulsed magnetic field distribution in the cross section of the inductor core at the induction accelerator of electron beam is under consideration in this paper. Owing to multi-layer structure of the core package it has the magnetic and electric anisotropy with different speed of the field diffusion along the sheets of magnetic and across the sheets. At the pulse duration less than one microsecond the essential non-uniformity of the field along both axes of the core cross section can be found. This effect reduces the efficiency of the ferromagnetic material using with corresponding loss of the accelerator efficiency. The main conclusion of the paper consists of the necessity to check the field diffusion characteristics in the process of inductor design to be sure that the pulsed field is able to fill the cross section of the core during the pulse switching. The magnetic characteristics of the anisotropic core have been investigated in the paper by one-dimensional and two-dimensional simulation in the quasi-stationary approximation using the traditional equation of the field diffusion.

  9. Multi-layered nanoparticles for penetrating the endosome and nuclear membrane via a step-wise membrane fusion process.

    Science.gov (United States)

    Akita, Hidetaka; Kudo, Asako; Minoura, Arisa; Yamaguti, Masaya; Khalil, Ikramy A; Moriguchi, Rumiko; Masuda, Tomoya; Danev, Radostin; Nagayama, Kuniaki; Kogure, Kentaro; Harashima, Hideyoshi

    2009-05-01

    Efficient targeting of DNA to the nucleus is a prerequisite for effective gene therapy. The gene-delivery vehicle must penetrate through the plasma membrane, and the DNA-impermeable double-membraned nuclear envelope, and deposit its DNA cargo in a form ready for transcription. Here we introduce a concept for overcoming intracellular membrane barriers that involves step-wise membrane fusion. To achieve this, a nanotechnology was developed that creates a multi-layered nanoparticle, which we refer to as a Tetra-lamellar Multi-functional Envelope-type Nano Device (T-MEND). The critical structural elements of the T-MEND are a DNA-polycation condensed core coated with two nuclear membrane-fusogenic inner envelopes and two endosome-fusogenic outer envelopes, which are shed in stepwise fashion. A double-lamellar membrane structure is required for nuclear delivery via the stepwise fusion of double layered nuclear membrane structure. Intracellular membrane fusions to endosomes and nuclear membranes were verified by spectral imaging of fluorescence resonance energy transfer (FRET) between donor and acceptor fluorophores that had been dually labeled on the liposome surface. Coating the core with the minimum number of nucleus-fusogenic lipid envelopes (i.e., 2) is essential to facilitate transcription. As a result, the T-MEND achieves dramatic levels of transgene expression in non-dividing cells.

  10. The multi-layered ring under parabolic distribution of radial stresses combined with uniform internal and external pressure

    Directory of Open Access Journals (Sweden)

    Christos F. Markides

    2017-04-01

    Full Text Available A recently introduced solution for the stress- and displacement-fields, developed in a multi-layered circular ring, composed of a finite number of linearly elastic concentric layers, subjected to a parabolic distribution of ra-dial stresses, is here extended to encompass a more general loading scheme, closer to actual conditions. The loading scheme includes, besides the para¬-bolic radial stresses, a combination of uniform pressures acting along the outer- and inner- most boundaries of the layered ring. The analytic solution of the problem is achieved by adopting Savin’s pioneering approach for an infinite plate with a hole strengthened by rings. Taking advantage of the results provided by the ana¬lytic solution, a numerical model, simulating the configuration of a three-layered ring (quite commonly encountered in practic¬al applications is validated. The numerical model is then used for a parametric analysis enlightening some crucial aspects of the overall response of the ring.

  11. Time series modeling with pruned multi-layer perceptron and 2-stage damped least-squares method

    Science.gov (United States)

    Voyant, Cyril; Tamas, Wani; Paoli, Christophe; Balu, Aurélia; Muselli, Marc; Nivet, Marie-Laure; Notton, Gilles

    2014-03-01

    A Multi-Layer Perceptron (MLP) defines a family of artificial neural networks often used in TS modeling and forecasting. Because of its "black box" aspect, many researchers refuse to use it. Moreover, the optimization (often based on the exhaustive approach where "all" configurations are tested) and learning phases of this artificial intelligence tool (often based on the Levenberg-Marquardt algorithm; LMA) are weaknesses of this approach (exhaustively and local minima). These two tasks must be repeated depending on the knowledge of each new problem studied, making the process, long, laborious and not systematically robust. In this paper a pruning process is proposed. This method allows, during the training phase, to carry out an inputs selecting method activating (or not) inter-nodes connections in order to verify if forecasting is improved. We propose to use iteratively the popular damped least-squares method to activate inputs and neurons. A first pass is applied to 10% of the learning sample to determine weights significantly different from 0 and delete other. Then a classical batch process based on LMA is used with the new MLP. The validation is done using 25 measured meteorological TS and cross-comparing the prediction results of the classical LMA and the 2-stage LMA.

  12. Powering an implantable minipump with a multi-layered printed circuit coil for drug infusion applications in rodents.

    Science.gov (United States)

    Givrad, Tina K; Maarek, Jean-Michel I; Moore, William H; Holschneider, Daniel P

    2010-03-01

    We report the use of a multi-layer printed coil circuit for powering (36-94 mW) an implantable microbolus infusion pump (MIP) that can be activated remotely for use in drug infusion in nontethered, freely moving small animals. This implantable device provides a unique experimental tool with applications in the fields of animal behavior, pharmacology, physiology, and functional brain imaging. Two different designs are described: a battery-less pump usable when the animal is inside a home-cage surrounded by a primary inductive coil and a pump powered by a rechargeable battery that can be used for studies outside the home-cage. The use of printed coils for powering of small devices by inductive power transfer presents significant advantages over similar approaches using hand-wound coils in terms of ease of manufacturing and uniformity of design. The high efficiency of a class-E oscillator allowed powering of the minipumps without the need for close physical contact of the primary and secondary coils, as is currently the case for most devices powered by inductive power transfer.

  13. Natural Regeneration in a Multi-Layered Pinus sylvestris-Picea abies Forest after Target Diameter Harvest and Soil Scarification

    Directory of Open Access Journals (Sweden)

    Lars Drössler

    2017-01-01

    Full Text Available Forest management in Sweden can be characterized by even-aged silviculture heavily relying on three established harvest regimes: clearcutting, the seed-tree method, and the shelterwood system. Less intense, small-scale retention harvest systems such as single tree and group selection harvest are rarely used. In addition, natural regeneration dynamics without enrichment planting have barely been studied. Consequently, this study examined natural regeneration establishment in a multi-layered Pinus sylvestris-Picea abies forest stand in southwest Sweden after target diameter harvesting and soil scarification. The creation of forest canopy gaps had a positive effect on total seedling density five years after harvest, mainly due to a significantly higher number of Betula pendula individuals. Seedling density of more desirable tree species suitable for continuous cover forestry such as Fagus sylvatica, Quercus petraea and Picea abies also increased substantially in gaps when compared to pre-harvest conditions or the unharvested plots. In contrast, soil scarification did not increase the number of seedlings of desired tree species due to a significant decrease in Picea abies abundance. Soil moisture and gap size significantly improved Betula pendula seedling establishment while a larger number of Quercus petraea seedlings were observed in Vaccinium myrtillus patches. We conclude that canopy gaps are beneficial under the encountered stand conditions to initiate forest regeneration, and that soil scarification without the timely occurrence of a mast year of desired tree species is not effective in the type of forest studied.

  14. Multi-layer plastic scintillation detector for intermediate- and high-energy neutrons with n- γ discrimination capability

    Science.gov (United States)

    Yu, L.; Terashima, S.; Ong, H. J.; Chan, P. Y.; Tanihata, I.; Iwamoto, C.; Tran, D. T.; Tamii, A.; Aoi, N.; Fujioka, H.; Gey, G.; Sakaguchi, H.; Sakaue, A.; Sun, B. H.; Tang, T. L.; Wang, T. F.; Watanabe, Y. N.; Zhang, G. X.

    2017-09-01

    A new type of neutron detector, named Stack Structure Solid organic Scintillator (S4), consisting of multi-layer plastic scintillators with capability to suppress low-energy γ rays under high-counting rate has been constructed and tested. To achieve n- γ discrimination, we exploit the difference in the ranges of the secondary charged particles produced by the interactions of neutrons and γ rays in the scintillator material. The thickness of a plastic scintillator layer was determined based on the results of Monte Carlo simulations using the Geant4 toolkit. With layer thicknesses of 5 mm, we have achieved a good separation between neutrons and γ rays at 5 MeVee threshold setting. We have also determined the detection efficiencies using monoenergetic neutrons at two energies produced by the d + d → n+3He reaction. The results agree well with the Geant4 simulations implementing the Li e ̀ge Intranuclear Cascade hadronic model (INCL++) and the high-precision model of low-energy neutron interactions (NeutronHP).

  15. The Multi-Layer Variable Absorbers in NGC 1365 Revealed by XMM-Newton and NuSTAR

    Science.gov (United States)

    Rivers, E.; Risaliti, G.; Walton, D. J.; Harrison, F.; Arevalo, P.; Baur, F. E.; Boggs, S. E.; Brenneman, L. W.; Brightman, M.; Zhang, W. W.

    2015-01-01

    Between 2012 July and 2013 February, NuSTAR and XMM-Newton performed four long-look joint observations of the type 1.8 Seyfert, NGC 1365. We have analyzed the variable absorption seen in these observations in order to characterize the geometry of the absorbing material. Two of the observations caught NGC 1365 in an unusually low absorption state, revealing complexity in the multi-layer absorber that had previously been hidden. We find the need for three distinct zones of neutral absorption in addition to the two zones of ionized absorption and the Compton-thick torus previously seen in this source. The most prominent absorber is likely associated with broad-line region clouds with column densities of around approximately 10 (sup 23) per square centimeter and a highly clumpy nature as evidenced by an occultation event in 2013 February. We also find evidence of a patchy absorber with a variable column around approximately 10 (sup 22) per square centimeter and a line-of-sight covering fraction of 0.3-0.9, which responds directly to the intrinsic source flux, possibly due to a wind geometry. A full-covering, constant absorber with a low column density of approximately 1 by 10 (sup 22) per square centimeter is also present, though the location of this low density haze is unknown.

  16. Multi-Layered Stratification in the Baltic Sea: Insight from a Modeling Study with Reference to Environmental Conditions

    Directory of Open Access Journals (Sweden)

    Bijan Dargahi

    2017-01-01

    Full Text Available The hydrodynamic and transport characteristics of the Baltic Sea in the period 2000–2009 were studied using a fully calibrated and validated 3D hydrodynamic model with a horizontal resolution of 4.8 km. This study provided new insight into the type and dynamics of vertical structure in the Baltic Sea, not considered in previous studies. Thermal and salinity stratification are both addressed, with a focus on the structural properties of the layers. The detection of cooler regions (dicothermal within the layer structure is an important finding. The detailed investigation of thermal stratification for a 10-year period (i.e., 2000–2009 revealed some new features. A multilayered structure that contains several thermocline and dicothermal layers was identified from this study. Statistical analysis of the simulation results made it possible to derive the mean thermal stratification properties, expressed as mean temperatures and the normalized layer thicknesses. The three-layered model proposed by previous investigators appears to be valid only during the winter periods; for other periods, a multi-layered structure with more than five layers has been identified during this investigation. This study provides detailed insight into thermal and salinity stratification in the Baltic Sea during a recent decade that can be used as a basis for diverse environmental assessments. It extends previous studies on stratification in the Baltic Sea regarding both the extent and the nature of stratification.

  17. Study of multi-layer active magnetic regenerators using magnetocaloric materials with first and second order phase transition

    Science.gov (United States)

    Lei, T.; Engelbrecht, K.; Nielsen, K. K.; Neves Bez, H.; Bahl, C. R. H.

    2016-09-01

    Magnetocaloric materials (MCM) with a first order phase transition (FOPT) usually exhibit a large, although sharp, isothermal entropy change near their Curie temperature, compared to materials with a second order phase transition (SOPT). Experimental results of applying FOPT materials in recent magnetocaloric refrigerators (MCR) demonstrated the great potential for these materials, but a thorough study on the impact of the moderate adiabatic temperature change and strong temperature dependence of the magnetocaloric effect (MCE) is lacking. Besides, comparing active magnetic regenerators (AMR) using FOPT and SOPT materials is also of fundamental interest. We present modeling results of multi-layer AMRs using FOPT and SOPT materials based on a 1D numerical model. First the impact of isothermal entropy change, adiabatic temperature change and shape factor describing the temperature dependence of the MCE are quantified and analyzed by using artificially built magnetocaloric properties. Then, based on measured magnetocaloric properties of La(Fe,Mn,Si)13H y and Gd, an investigation on how to layer typical FOPT and SOPT materials with different temperature spans is carried out. Moreover, the sensitivity of variation in Curie temperature distribution for both groups of AMRs is investigated. Finally, a concept of mixing FOPT and SOPT materials is studied for improving the stability of layered AMRs with existing materials.

  18. High-frequency guided ultrasonic waves for the detection of hidden defects in multi-layer aerospace structures

    Science.gov (United States)

    Masserey, B.; Raemy, C.; Fromme, P.

    2012-04-01

    High-frequency guided ultrasonic waves allow for the non-destructive testing of aerospace structures. This type of structure often contains multi-layer components subjected to cyclic loading conditions, where fatigue cracks and localized disbonds can develop. Using standard ultrasonic transducers, high frequency guided wave modes were generated in a model structure consisting of two adhesively bonded aluminum plates. This type of waves propagates along the structure and penetrates through the complete thickness. The wave propagation along the specimen was measured experimentally using a laser interferometer. Good agreement with 2D finite element simulations was found. Two types of hidden defects were considered: localized lacks of sealant and small defects in the aluminum layer facing the sealant. The interaction of the high frequency guided waves with the hidden defects was investigated. Standard pulseecho measurements were conducted to verify the detection sensitivity and the influence of the stand-off distance predicted from the finite element simulation results. The high frequency guided waves have the potential for fatigue crack growth monitoring at critical and difficult to access fastener locations in aerospace structures from a stand-off distance.

  19. On the applicability of the Natori formula to realistic multi-layer quantum well III-V FETs

    Science.gov (United States)

    Gili, A.; Xanthakis, J. P.

    2017-10-01

    We investigated the validity of the Natori formalism for realistic multi-layer quantum well FETs. We show that the assumption of a single layer (the channel) carrying all of the current density is far from reality in the sub-threshold region, where in fact most of the current density resides below the channel. Our analysis is based on comparing results of Natori calculations with experimental ones and on comparing with other first-principles calculations. If the Natori calculations are employed in the subthreshold region then a misleadingly small subthreshold slope would be obtained. We propose a way to remedy this inefficiency of this formulation so that it can be applicable to realistic many-layer devices. In particular we show that if the 1-dimensional quantum well of the Natori method enclosing the electron gas is expanded to include the supply layer-usually below the channel- and a proper ab initio potential is used to obtain its eigenvalues, then the Natori formula regains its validity.

  20. Development of SiPM-based scintillator tile detectors for a multi-layer fast neutron tracker

    Directory of Open Access Journals (Sweden)

    Jakubek J.

    2012-10-01

    Full Text Available We are developing thin tile scintillator detectors with silicon photomultiplier (SiPM readout for use in a multi-layer fast-neutron tracker. The tracker is based on interleaved Timepix and plastic scintillator layers. The thin 15 × 15 × 2 mm plastic scintillators require suitable optical readout in order to detect and measure the energy lost by energetic protons that have been recoiled by fast neutrons. Our first prototype used dual SiPMs, coupled to opposite edges of the scintillator tile using light-guides. An alternative readout geometry was designed in an effort to increase the fraction of scintillation light detected by the SiPMs. The new prototype uses a larger SiPM array to cover the entire top face of the tile. This paper details the comparative performance of the two prototype designs. A deuterium-tritium (DT fast-neutron source was used to compare the relative light collection efficiency of the two designs. A collimated UV light source was scanned across the detector face to map the uniformity. The new prototype was found to have 9.5 times better light collection efficiency over the original design. Both prototypes exhibit spatial non-uniformity in their response. Methods of correcting this non-uniformity are discussed.

  1. Study on the groundwater sustainable problem by numerical simulation in a multi-layered coastal aquifer system of Zhanjiang, China

    Science.gov (United States)

    Zhou, Pengpeng; Li, Ming; Lu, Yaodong

    2017-10-01

    Assessing sustainability of coastal groundwater is significant for groundwater management as coastal groundwater is vulnerable to over-exploitation and contamination. To address the issues of serious groundwater level drawdown and potential seawater intrusion risk of a multi-layered coastal aquifer system in Zhanjiang, China, this paper presents a numerical modelling study to research groundwater sustainability of this aquifer system. The transient modelling results show that the groundwater budget was negative (-3826× 104 to -4502× 10^{4 } m3/a) during the years 2008-2011, revealing that this aquifer system was over-exploited. Meanwhile, the groundwater sustainability was assessed by evaluating the negative hydraulic pressure area (NHPA) of the unconfined aquifer and the groundwater level dynamic and flow velocity of the offshore boundaries of the confined aquifers. The results demonstrate that the Nansan Island is most influenced by NHPA and that the local groundwater should not be exploited. The results also suggest that, with the current groundwater exploitation scheme, the sustainable yield should be 1.784× 108 m3/a (i.e., decreased by 20% from the current exploitation amount). To satisfy public water demands, the 20% decrease of the exploitation amount can be offset by the groundwater sourced from the Taiping groundwater resource field. These results provide valuable guidance for groundwater management of Zhanjiang.

  2. Improved transport property of proton-conducting solid oxide fuel cell with multi-layered electrolyte structure

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Sumi, Hirofumi; Nomura, Katsuhiro; Yamaguchi, Yuki; Fujishiro, Yoshinobu

    2017-10-01

    A multi-layered electrolyte structure is proposed for proton-conducting solid oxide fuel cells (SOFCs) to achieve higher power density and higher open-circuit voltage (OCV). Although recent proton-conducting SOFCs have demonstrated high power density, their OCVs have been lower than that of conventional SOFCs with stabilized zirconia because proton-conducting oxides intrinsically have electron-hole conduction. The proposed electrolyte structure has a porous BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) layer deposited on a dense BZCYYb layer. This structure effectively improves both cathode polarization and ionic transport property, resulting in higher power density with higher OCV. Also, discussion based on an equivalent circuit model of proton-conducting SOFCs clearly reveals a mechanism that determines OCV, namely, higher ohmic resistance and lower electrode polarization resistance lead to higher OCV. Our results suggest that higher electrode performance is essential for proton-conducting SOFCs to achieve higher OCV, particularly in the case of anode-supported configurations with thin electrolyte.

  3. A Multi-layer, Data-driven Advanced Reasoning Tool for Intelligent Data Mining and Analysis for Smart Grids

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Ning; Du, Pengwei; Greitzer, Frank L.; Guo, Xinxin; Hohimer, Ryan E.; Pomiak, Yekaterina G.

    2012-12-31

    This paper presents the multi-layer, data-driven advanced reasoning tool (M-DART), a proof-of-principle decision support tool for improved power system operation. M-DART will cross-correlate and examine different data sources to assess anomalies, infer root causes, and anneal data into actionable information. By performing higher-level reasoning “triage” of diverse data sources, M-DART focuses on early detection of emerging power system events and identifies highest priority actions for the human decision maker. M-DART represents a significant advancement over today’s grid monitoring technologies that apply offline analyses to derive model-based guidelines for online real-time operations and use isolated data processing mechanisms focusing on individual data domains. The development of the M-DART will bridge these gaps by reasoning about results obtained from multiple data sources that are enabled by the smart grid infrastructure. This hybrid approach integrates a knowledge base that is trained offline but tuned online to capture model-based relationships while revealing complex causal relationships among data from different domains.

  4. Non-stationary axially symmetric goal of thermo-elasticity for a fixed rigid circular multi-layer plate

    Directory of Open Access Journals (Sweden)

    Shlyakhin Dmitry

    2017-01-01

    Full Text Available This paper considers axially symmetric goal of thermos–elasticity for a fixed rigid circular multi-layer isotropic plate with non–stationary heat flows on its front faces. The mathematical model is presented in the form of a not self–adjoint system that includes differential motion equations and a linear equation of the thermal-elastic state in a three-dimensional model. A new closed solution in an unconnected setting is built by the method of finite integral transformation. At the same time, a standardization procedure is conducted at each stage of the solution, which allows to implement an appropriate conversion algorithm. The calculated ratios provide an opportunity to perform a qualitative and quantitative analysis of the associated temperature and mechanical fields and also to examine stress–strain behaviour of the multi–layer systems both under the local thermal shock, which is observed, for example, in the interaction with the laser beam and in the case of uneven unsteady surface heating, which is frequent during the operation of protective construction structures.

  5. A simple and low-cost approach to fabricate TiO{sub 2}-NO{sub 2} hollow spheres with excellent simulated sunlight photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kexin; Liu, Shufen; Yi, Shaoting; Yan, Liushui, E-mail: yanliushui@hotmail.com; Guo, Huiqin; Dai, Yuhua; Luo, Xubiao; Luo, Shenglian, E-mail: sllou@hnu.edu.cn

    2016-09-15

    Nitryl surface functionalized TiO{sub 2} hollow spheres (TiO{sub 2}-NO{sub 2} HSs) composite material was successfully fabricated by a simple sol-gel combined with solvothermal and concentrated HNO{sub 3} treatment strategy using carbon microspheres obtained from hydrothermal carbonization of waste Camellia oleifera shells as a template. The microstructure, surface property, compositional and structural information, and optical and electronic property of as-prepared TiO{sub 2}-NO{sub 2} HSs were well characterized. Compare with conventional g-C{sub 3}N{sub 4} and TiO{sub 2} photocatalysts, the as-prepared TiO{sub 2}-NO{sub 2} HSs exhibited excellent simulated sunlight photocatalytic activity toward aqueous organic pollutants degradation and hydrogen evolution from water-splitting, which can be attributed to their unique hollow spherical microstructure and the introduction of -NO{sub 2} groups. - Highlights: • TiO{sub 2}-NO{sub 2} HSs were successfully fabricated by a simple and low-cost method. • Their morphology, composition, and optoelectronic property were well characterized. • TiO{sub 2}-NO{sub 2} HSs exhibit considerably high activity under simulated sunlight irradiation. • High activity is attributed to hollow spherical structure and introduced -NO{sub 2} groups.

  6. TiO2 Photocatalyst Nanoparticle Separation: Flocculation in Different Matrices and Use of Powdered Activated Carbon as a Precoat in Low-Cost Fabric Filtration

    Directory of Open Access Journals (Sweden)

    Carlos F. Liriano-Jorge

    2014-01-01

    Full Text Available Separation of photocatalyst nanoparticles is a problem impeding widespread application of photocatalytic oxidation. As sedimentation of photocatalyst particles is facilitated by their flocculation, the influence of common constituents of biologically pretreated wastewaters (NaCl, NaHCO3, and their combination with humic acid sodium salt on flocculation was tested by the pipet method. Results showed that the impact of these substances on TiO2 nanoparticle flocculation is rather complex and strongly affected by pH. When humic acid was present, TiO2 particles did not show efficient flocculation in the neutral and slightly basic pH range. As an alternative to photocatalyst separation by sedimentation, precoat vacuum filtration with powdered activated carbon (PAC over low-cost spunbond polypropylene fabrics was tested in the presence of two PAC types in aqueous NaCl and NaHCO3 solutions as well as in biologically treated greywater and in secondary municipal effluent. PAC concentrations of ≥2 g/L were required in order to achieve a retention of nearly 95% of the TiO2 nanoparticles on the fabric filter when TiO2 concentration was 1 g/L. Composition of the aqueous matrix and PAC type had a slight impact on precoat filtration. PAC precoat filtration represents a potential pretreatment for photocatalyst removal by micro- or ultrafiltration.

  7. Low-cost fabrication of highly sensitive room temperature hydrogen sensor based on ordered mesoporous Co-doped TiO2 structure

    Science.gov (United States)

    Li, Zhong; Haidry, Azhar Ali; Wang, Tao; Yao, Zheng Jun

    2017-07-01

    The development of cost-effective gas sensors with improved sensing properties and minimum power consumption for room temperature hydrogen leakage monitoring is in increasing demand. In this context, this report focus on the facile fabrication of ordered mesoporous TiO2 via evaporation-induced self-assembly route. With the controlled doping threshold (3%Co-TiO2), the output resistance change to 1000 ppm H2 is ˜4.1 × 103 with the response time of 66 s. The sensor response exhibits power law dependence with an increase in the hydrogen concentration, where the power law coefficient was found not only specific to the kind of target gas but also related to temperature. Further, the effect of structure integrity with doping level and humidity on sensing characteristics is interpreted in terms of variation in surface potential eVS and depletion region w caused by the adsorption of molecular oxygen O2-.

  8. CONTAINER MATERIALS, FABRICATION AND ROBUSTNESS

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, K.; Louthan, M.; Rawls, G.; Sindelar, R.; Zapp, P.; Mcclard, J.

    2009-11-10

    The multi-barrier 3013 container used to package plutonium-bearing materials is robust and thereby highly resistant to identified degradation modes that might cause failure. The only viable degradation mechanisms identified by a panel of technical experts were pressurization within and corrosion of the containers. Evaluations of the container materials and the fabrication processes and resulting residual stresses suggest that the multi-layered containers will mitigate the potential for degradation of the outer container and prevent the release of the container contents to the environment. Additionally, the ongoing surveillance programs and laboratory studies should detect any incipient degradation of containers in the 3013 storage inventory before an outer container is compromised.

  9. Design and Fabrication of a Dual-Photoelectrode Fuel Cell towards Cost-Effective Electricity Production from Biomass.

    Science.gov (United States)

    Zhang, Bingqing; Fan, Wenjun; Yao, Tingting; Liao, Shichao; Li, Ailong; Li, Deng; Liu, Mingyao; Shi, Jingying; Liao, Shijun; Li, Can

    2017-01-10

    A photo fuel cell (PFC) offers an attractive way to simultaneously convert solar and biomass energy into electricity. Photocatalytic biomass oxidation on a semiconductor photoanode combined with dark electrochemical reduction of oxygen molecules on a metal cathode (usually Pt) in separated compartments is the common configuration for a PFC. Herein, we report a membrane-free PFC based on a dual electrode, including a W-doped BiVO4 photoanode and polyterthiophene photocathode for solar-stimulated biomass-to-electricity conversion. Air- and water-soluble biomass derivatives can be directly used as reagents. The optimal device yields an open-circuit voltage (VOC ) of 0.62 V, a short-circuit current density (JSC ) of 775 μA cm(-2) , and a maximum power density (Pmax ) of 82 μW cm(-2) with glucose as the feedstock under tandem illumination, which outperforms dual-photoelectrode PFCs previously reported. Neither costly separating membranes nor Pt-based catalysts are required in the proposed PFC architecture. Our work may inspire rational device designs for cost-effective electricity generation from renewable resources. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Fabrication of large-volume, low-cost ceramic lanthanum halide scintillators for gamma ray detection : final report for DHS/DNDO/TRDD project TA-01-SL01.

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, Timothy J.; Ottley, Leigh Anna M.; Yang, Pin; Chen, Ching-Fong; Sanchez, Margaret R.; Bell, Nelson Simmons

    2008-10-01

    This project uses advanced ceramic processes to fabricate large, optical-quality, polycrystalline lanthanum halide scintillators to replace small single crystals produced by the conventional Bridgman growth method. The new approach not only removes the size constraint imposed by the growth method, but also offers the potential advantages of both reducing manufacturing cost and increasing production rate. The project goal is to fabricate dense lanthanum halide ceramics with a preferred crystal orientation by applying texture engineering and solid-state conversion to reduce the thermal mechanical stress in the ceramic and minimize scintillation light scattering at grain boundaries. Ultimately, this method could deliver the sought-after high sensitivity and <3% energy resolution at 662 keV of lanthanum halide scintillators and unleash their full potential for advanced gamma ray detection, enabling rapid identification of radioactive materials in a variety of practical applications. This report documents processing details from powder synthesis, seed particle growth, to final densification and texture development of cerium doped lanthanum bromide (LaBr{sub 3}:Ce{sup +3}) ceramics. This investigation demonstrated that: (1) A rapid, flexible, cost efficient synthesis method of anhydrous lanthanum halides and their solid solutions was developed. Several batches of ultrafine LaBr{sub 3}:Ce{sup +3} powder, free of oxyhalide, were produced by a rigorously controlled process. (2) Micron size ({approx} 5 {micro}m), platelet shape LaBr{sub 3} seed particles of high purity can be synthesized by a vapor phase transport process. (3) High aspect-ratio seed particles can be effectively aligned in the shear direction in the ceramic matrix, using a rotational shear-forming process. (4) Small size, highly translucent LaBr{sub 3} (0.25-inch diameter, 0.08-inch thick) samples were successfully fabricated by the equal channel angular consolidation process. (5) Large size, high density

  11. A study of an influence of a fiber arrangement of a laminate ply on the distribution and values of stresses in the multi-layered composite material

    Directory of Open Access Journals (Sweden)

    Herbuś Krzysztof

    2017-01-01

    Full Text Available In the work are presented studies related with the influence of a fiber arrangement of a laminate ply on the distribution and values of stresses in the multi-layered composite material. For this purpose, the characteristics of the three-point bending test, according to the standard PN-EN ISO 7438, of specimens made from the composite material, where a single ply is a composition of epoxy resin and glass fibres, was mapped. The modelling process of the multi-layered composite material and its strength verification was performed in the PLM Siemens NX system. Based on the results of performed numerical studies, the relation between the value of the main angle of an arrangement of fibers in each plies of the laminate, and the distribution and values of stresses, occurring in the examined specimens has been determined.

  12. Multi-layer scintillation detector for the MOON double beta decay experiment: Scintillation photon responses studied by a prototype detector MOON-1

    CERN Document Server

    Nakamura, H; Ejiri, H; Elliott, S R; Engel, J; Finger, Miroslav H; Fushimi, K; Gehman, V; Gorin, A; Greenfield, M; Hai, V H; Hazama, R; Higa, K; Higashiguchi, T; Ichihara, K; Ikegami, Y; Imoto, J; Ishii, H; Itahashi, T; Kaneko, H; Kavitov, P; Kawasuso, H; Kekelidze, V D; Matsuoka, K; Mizuhashi, T; Noda, D; Nomachi, M; Ogama, T; Onishi, K; Para, A; Robertson, R G H; Sakamoto, M; Sakiuchi, T; Samejima, Y; Shichijo, Y; Shima, T; Shimada, Y; Shirkov, G; Sissakian, A N; Slunecka, M; Sugaya, Y; Titov, A; Uenoyama, M; Umehara, S; Urano, A; Vatulin, V; Voronov, V; Wilkerson, J F; Will, D I; Yasuda, K; Yoshida, S; Yoshihuku, M

    2006-01-01

    An ensemble of multi-layer scintillators is discussed as an option of the high-sensitivity detector Mo Observatory Of Neutrinos (MOON) for spectroscopic measurements of neutrino-less double beta decays. A prototype detector MOON-1, which consists of 6 layer plastic-scintillator plates, was built to study the sensitivity of the MOON-type detector. The scintillation photon collection and the energy resolution, which are key elements for the high-sensitivity experiments, are found to be 1835+/-30 photo-electrons for 976 keV electrons and sigma = 2.9+/-0.1% (dE/E = 6.8+/-0.3 % in FWHM) at the Qbb ~ 3 MeV region, respectively. The multi-layer plastic-scintillator structure with good energy resolution as well as good background suppression of beta-gamma rays is crucial for the MOON-type detector to achieve the inverted hierarchy neutrino mass sensitivity.

  13. Application of GPU-based, highly parallelized algorithms for the estimation of electromagnetic multi-layer interactions

    Science.gov (United States)

    Torner, François M.; Karatas, Abdullah; Eifler, Matthias; Raid, Indek; Seewig, Jörg

    2017-06-01

    In nowadays industry, complex surfaces with material contrasts or surface coatings are present and represent a challenge for optical topography measuring instruments. The reason is that varying optical properties lead to phase jumps and to topography deviations when the surface height is evaluated. Thus, Ellipso-Height-Topometry as a measurement technique which can measure both topography and material properties of technical surfaces was proposed in order to achieve a correction of the occurring topographic artefacts. The height correction value can be obtained for the compensation of material-induced height deviations and the thickness of surface layers can be evaluated. Currently, it is possible to calculate the surface characteristics from ellipsometric parameters for at most two layers. However, the described height corrections are only possible when well-defined and realistic models of surface layers can be utilized, e.g. a given set of homogeneous oxide layers. Oxidation effects however describe statistical processes which can be predicted with underlying material distribution models. This leads to an uncertainty in ellipsometry, which is considered with a new approach that will be discussed in this publication. Therefore, an extended multi-layer approach which is capable of handling additional layers based on a parallelized algorithm using graphic processing units and the commonly known CUDA technology is proposed. This algorithm can also be used to consider material proportions which result from oxidation effects in z direction. The new approach for the Ellipso-Height-topometry measurement technique is compared with the current procedures which often neglect the existence of an oxide layer for the basic material. To experimentally verify the approach and according algorithm, it is applied for the evaluation of actual surfaces with multiple plane layers and different materials. Test samples with different materials are used in order to evaluate the complex

  14. Identifying the origin of groundwater samples in a multi-layer aquifer system with Random Forest classification

    Science.gov (United States)

    Baudron, Paul; Alonso-Sarría, Francisco; García-Aróstegui, José Luís; Cánovas-García, Fulgencio; Martínez-Vicente, David; Moreno-Brotóns, Jesús

    2013-08-01

    Accurate identification of the origin of groundwater samples is not always possible in complex multilayered aquifers. This poses a major difficulty for a reliable interpretation of geochemical results. The problem is especially severe when the information on the tubewells design is hard to obtain. This paper shows a supervised classification method based on the Random Forest (RF) machine learning technique to identify the layer from where groundwater samples were extracted. The classification rules were based on the major ion composition of the samples. We applied this method to the Campo de Cartagena multi-layer aquifer system, in southeastern Spain. A large amount of hydrogeochemical data was available, but only a limited fraction of the sampled tubewells included a reliable determination of the borehole design and, consequently, of the aquifer layer being exploited. Added difficulty was the very similar compositions of water samples extracted from different aquifer layers. Moreover, not all groundwater samples included the same geochemical variables. Despite of the difficulty of such a background, the Random Forest classification reached accuracies over 90%. These results were much better than the Linear Discriminant Analysis (LDA) and Decision Trees (CART) supervised classification methods. From a total of 1549 samples, 805 proceeded from one unique identified aquifer, 409 proceeded from a possible blend of waters from several aquifers and 335 were of unknown origin. Only 468 of the 805 unique-aquifer samples included all the chemical variables needed to calibrate and validate the models. Finally, 107 of the groundwater samples of unknown origin could be classified. Most unclassified samples did not feature a complete dataset. The uncertainty on the identification of training samples was taken in account to enhance the model. Most of the samples that could not be identified had an incomplete dataset.

  15. Influence of MAP and Multi-layer Flexible Pouches on Clostridium Count of Smoked Kutum Fish (Rutilus frisii kutum

    Directory of Open Access Journals (Sweden)

    Nazanin Zand

    2016-11-01

    Full Text Available In this study the effect of different concentrations of three gas mixture (carbon dioxide, nitrogen, oxygen, and also vacuum conditions and flexible multi-layer films were evaluated on Clostridium count of smoked kutum fish (Rutilus frisii kutum at ambient condition (T= 25 0C. Ordinary condition as control packaging were compared with four types of modified atmosphere packaging: (N270%+ CO230%, (N230% + CO270%, (45%CO2+ 45%N2+10%O2 and vacuum conditions, in this project. Smoked kutum fish were packaged into 3 kinds of flexible pouches {3- layers(PET(12/AL(12/LLD(100, 4-layers (PET(12/AL(7/ PET(12/LLD(100, and 3-layer (PET(12/AL(7/LLD(100}. Packed samples were performed microbial tests (Clostridium count, in different times during 60 days, with 15 treatment ,3 run, statistical analysis and comparison of data, were done by software SAS (Ver:9/1 and Duncan’s new multiple range test, with confidence level of 95% (P <0.05 . The shelf life of Samples (according to Clostridium count were reported in 4-layers , under conditions 1,2,3 and vacuum conditions, 60,58,45,40 days, in 3-layers (AL:12, under conditions 1,2,3 were 55,50,40 days and in vacuum conditions were about 35 days, with 3- layers(AL:7, under conditions 1,2,3 and vacuum conditions 45,40,35, 30 days. Clostridium count showed that increasing CO2 concentration prolonged shelf life. During the period of this experiment Clostridium count of samples in various conditions, had significant level. According to these results could be concluded the best condition belonged to treatment under modified atmosphere CO2 70% and also 4- layer container due to the thickness (131 μ, low permeability of water vapor in this 4-layer container and anti-microbial effect of more percentage of CO2.

  16. Synchronous Chaos and Broad Band Gamma Rhythm in a Minimal Multi-Layer Model of Primary Visual Cortex

    Science.gov (United States)

    Battaglia, Demian; Hansel, David

    2011-01-01

    Visually induced neuronal activity in V1 displays a marked gamma-band component which is modulated by stimulus properties. It has been argued that synchronized oscillations contribute to these gamma-band activity. However, analysis of Local Field Potentials (LFPs) across different experiments reveals considerable diversity in the degree of oscillatory behavior of this induced activity. Contrast-dependent power enhancements can indeed occur over a broad band in the gamma frequency range and spectral peaks may not arise at all. Furthermore, even when oscillations are observed, they undergo temporal decorrelation over very few cycles. This is not easily accounted for in previous network modeling of gamma oscillations. We argue here that interactions between cortical layers can be responsible for this fast decorrelation. We study a model of a V1 hypercolumn, embedding a simplified description of the multi-layered structure of the cortex. When the stimulus contrast is low, the induced activity is only weakly synchronous and the network resonates transiently without developing collective oscillations. When the contrast is high, on the other hand, the induced activity undergoes synchronous oscillations with an irregular spatiotemporal structure expressing a synchronous chaotic state. As a consequence the population activity undergoes fast temporal decorrelation, with concomitant rapid damping of the oscillations in LFPs autocorrelograms and peak broadening in LFPs power spectra. We show that the strength of the inter-layer coupling crucially affects this spatiotemporal structure. We predict that layer VI inactivation should induce global changes in the spectral properties of induced LFPs, reflecting their slower temporal decorrelation in the absence of inter-layer feedback. Finally, we argue that the mechanism underlying the emergence of synchronous chaos in our model is in fact very general. It stems from the fact that gamma oscillations induced by local delayed

  17. Phase segregation of sulfonate groups in Nafion interface lamellae, quantified via neutron reflectometry fitting techniques for multi-layered structures.

    Science.gov (United States)

    DeCaluwe, Steven C; Kienzle, Paul A; Bhargava, Pavan; Baker, Andrew M; Dura, Joseph A

    2014-08-21

    Neutron reflectometry analysis methods for under-determined, multi-layered structures are developed and used to determine the composition depth profile in cases where the structure is not known a priori. These methods, including statistical methods, sophisticated fitting routines, and coupling multiple data sets, are applied to hydrated and dehydrated Nafion nano-scaled films with thicknesses comparable to those found coating electrode particles in fuel cell catalyst layers. These results confirm the lamellar structure previously observed on hydrophilic substrates, and demonstrate that for hydrated films they can accurately be described as layers rich in both water and sulfonate groups alternating with water-poor layers containing an excess of fluorocarbon groups. The thickness of these layers increases slightly and the amplitude of the water volume fraction oscillation exponentially decreases away from the hydrophilic interface. For dehydrated films, the composition oscillations die out more rapidly. The Nafion-SiO2 substrate interface contains a partial monolayer of sulfonate groups bonded to the substrate and a large excess of water compared to that expected by the water-to-sulfonate ratio, λ, observed throughout the rest of the film. Films that were made thin enough to truncate this lamellar region showed a depth profile nearly identical to thicker films, indicating that there are no confinement or surface effects altering the structure. Comparing the SLD profile measured for films dried at 60 °C to modeled composition profiles derived by removing water from the hydrated lamellae suggests incomplete re-mixing of the polymer groups upon dehydration, indicated limited polymer mobility in these Nafion thin films.

  18. A comprehensive study of the long pulse Nd:YAG laser drilling of multi-layer carbon fibre composites

    Science.gov (United States)

    Rodden, W. S. O.; Kudesia, S. S.; Hand, D. P.; Jones, J. D. C.

    2002-09-01

    The results of an extensive experimental study of the free running Nd:YAG laser drilling of a multi-layer carbon fibre composite, where adjacent layers have differently orientated fibres, are reported. For holes drilled with the laser operating in fixed-Q mode at 1064 nm, parallel sections of blind holes illustrating discontinuities in the hole size along a given section direction will be shown to occur at the interface between adjacent layers. An explanation for this effect is proposed. Detailed single pulse drilling characteristics will be presented illustrating the exit hole diameter as a function of pulse energy and material thickness. These characteristics illustrate a `stable' drilling regime in which the exit hole diameters are least sensitive to changes in pulse energy or material thickness and a less `stable' regime in which they are more strongly dependent on these parameters. Drilling characteristics will be given for two different beam qualities, illustrating the greater drilling depth and reduced hole size achievable with an improved beam quality. Finally holes drilled through a 2 mm thick sample of material with multiple pulses are considered. Size distribution curves for entrance and exit holes will be presented. The total energy required (number of pulses × pulse energy) to drill through 2 mm thick material will be reported as a function of pulse energy in stationary air and argon atmospheres and in a partial vacuum, illustrating a threshold energy which is dependent upon the drilling atmosphere. The threshold energies will be discussed with reference to plasma formation and the reactivity of the drilling atmosphere.

  19. Synchronous chaos and broad band gamma rhythm in a minimal multi-layer model of primary visual cortex.

    Directory of Open Access Journals (Sweden)

    Demian Battaglia

    2011-10-01

    Full Text Available Visually induced neuronal activity in V1 displays a marked gamma-band component which is modulated by stimulus properties. It has been argued that synchronized oscillations contribute to these gamma-band activity. However, analysis of Local Field Potentials (LFPs across different experiments reveals considerable diversity in the degree of oscillatory behavior of this induced activity. Contrast-dependent power enhancements can indeed occur over a broad band in the gamma frequency range and spectral peaks may not arise at all. Furthermore, even when oscillations are observed, they undergo temporal decorrelation over very few cycles. This is not easily accounted for in previous network modeling of gamma oscillations. We argue here that interactions between cortical layers can be responsible for this fast decorrelation. We study a model of a V1 hypercolumn, embedding a simplified description of the multi-layered structure of the cortex. When the stimulus contrast is low, the induced activity is only weakly synchronous and the network resonates transiently without developing collective oscillations. When the contrast is high, on the other hand, the induced activity undergoes synchronous oscillations with an irregular spatiotemporal structure expressing a synchronous chaotic state. As a consequence the population activity undergoes fast temporal decorrelation, with concomitant rapid damping of the oscillations in LFPs autocorrelograms and peak broadening in LFPs power spectra. We show that the strength of the inter-layer coupling crucially affects this spatiotemporal structure. We predict that layer VI inactivation should induce global changes in the spectral properties of induced LFPs, reflecting their slower temporal decorrelation in the absence of inter-layer feedback. Finally, we argue that the mechanism underlying the emergence of synchronous chaos in our model is in fact very general. It stems from the fact that gamma oscillations induced by

  20. In situ characterization of delamination and crack growth of a CGO–LSM multi-layer ceramic sample investigated by X-ray tomographic microscopy

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Esposito, Vincenzo; Lauridsen, Erik Mejdal

    2014-01-01

    The densification, delamination and crack growth behavior in a Ce0.9Gd0.1O1.95 (CGO) and (La0.85Sr0.15)0.9MnO3 (LSM) multi-layer ceramic sample was studied using in situ X-ray tomographic microscopy (microtomography) to investigate the critical dynamics of crack propagation and delamination...... and delamination only accelerates when sintering occurs....

  1. Oxidation of PtNi nanoparticles studied by a scanning X-ray fluorescence microscope with multi-layer Laue lenses.

    Science.gov (United States)

    Kang, Hyon Chol; Yan, Hanfei; Chu, Yong S; Lee, Su Yong; Kim, Jungdae; Nazaretski, Evgeny; Kim, Chan; Seo, Okkyun; Noh, Do Young; Macrander, Albert T; Stephenson, G Brian; Maser, Jörg

    2013-08-21

    We report a study of the oxidation process of individual PtNi nanoparticles (NPs) conducted with a novel scanning multi-layer Laue lens X-ray microscope. The elemental maps reveal that alloyed PtNi NPs were transformed into Pt/NiO core-shell NPs by thermal oxidation. The observations furthermore indicate that a coalescence of Pt/NiO core-shell NPs occurred during oxidation.

  2. Design of Multi-Layer Optical Fibers with Ring Refractive Index to Reduce Dispersion and Increase Bandwidth in Broadband Optical Networks

    Directory of Open Access Journals (Sweden)

    M. Seifouri

    2012-06-01

    Full Text Available The main goal in this paper is to design single-mode optical fibers for DWDM networks, which are used today in rapid communications. These networks require low dispersion in a wide range of wavelengths. So, in this paper, multi-layer optical fibers with low dispersion value and flat dispersion slope in wavelength range of (1.5-1.6µm are designed, using optimization algorithms.

  3. Beamforming and Reconfiguration of a Structurally Embedded Vascular Antenna Array (SEVA2) in Both Multi-Layer and Complex Curved Composites (Preprint)

    Science.gov (United States)

    2017-10-20

    summarizes the potential of designing complex SEVA structure. Pressure driven flow of EGaIn (liquid metal ) can be used to attain frequency reconfigurable...AND COMPLEX CURVED COMPOSITES (PREPRINT) Darren J. Hartl UTC Jeffery W. Baur AFRL/RX Geoffrey J. Frank, Robyn Bradford, David Phillips...SEVA2) IN BOTH MULTI-LAYER AND COMPLEX CURVED COMPOSITES (PREPRINT) 5a. CONTRACT NUMBER FA8650-11-D-5800-0012 5b. GRANT NUMBER 5c. PROGRAM

  4. Fabrication and Testing of Low Cost 2D Carbon-Carbon Nozzle Extensions at NASA/MSFC

    Science.gov (United States)

    Greene, Sandra Elam; Shigley, John K.; George, Russ; Roberts, Robert

    2015-01-01

    Subscale liquid engine tests were conducted at NASA/MSFC using a 1.2 Klbf engine with liquid oxygen (LOX) and gaseous hydrogen. Testing was performed for main-stage durations ranging from 10 to 160 seconds at a chamber pressure of 550 psia and a mixture ratio of 5.7. Operating the engine in this manner demonstrated a new and affordable test capability for evaluating subscale nozzles by exposing them to long duration tests. A series of 2D C-C nozzle extensions were manufactured, oxidation protection applied and then tested on a liquid engine test facility at NASA/MSFC. The C-C nozzle extensions had oxidation protection applied using three very distinct methods with a wide range of costs and process times: SiC via Polymer Impregnation & Pyrolysis (PIP), Air Plasma Spray (APS) and Melt Infiltration. The tested extensions were about 6" long with an exit plane ID of about 6.6". The test results, material properties and performance of the 2D C-C extensions and attachment features will be discussed.

  5. Investigation of solar cells fabricated on low-cost silicon sheet materials using 1 MeV electron irradiation

    Science.gov (United States)

    Kachare, A. H.; Hyland, S. L.; Garlick, G. F. J.

    1981-01-01

    The use of high energy electron irradiation is investigated as a controlled means to study in more detail the junction depletion layer processes of solar cells made on various low-cost silicon sheet materials. Results show that solar cells made on Czochralski grown silicon exhibit enhancement of spectral response in the shorter wavelength region when irradiated with high energy electrons. The base region damage can be reduced by subsequent annealing at 450 C which restores the degraded longer wavelength response, although the shorter wavelength enhancement persists. The second diode component of the cell dark forward bias current is also reduced by electron irradiation, while thermal annealing at 450 C without electron irradiation can also produce these same effects. Electron irradiation produces small changes in the shorter wavelength spectral responses and junction improvements in solar cells made on WEB, EFG, and HEM silicon. It is concluded that these beneficial effects on cell characteristics are due to the reduction of oxygen associated deep level recombination centers in the N(+) diffused layer and in the junction.

  6. 3D Defect Localization on Exothermic Faults within Multi-Layered Structures Using Lock-In Thermography: An Experimental and Numerical Approach

    Directory of Open Access Journals (Sweden)

    Ji Yong Bae

    2017-10-01

    Full Text Available Micro-electronic devices are increasingly incorporating miniature multi-layered integrated architectures. However, the localization of faults in three-dimensional structure remains challenging. This study involved the experimental and numerical estimation of the depth of a thermally active heating source buried in multi-layered silicon wafer architecture by using both phase information from an infrared microscopy and finite element simulation. Infrared images were acquired and real-time processed by a lock-in method. It is well known that the lock-in method can increasingly improve detection performance by enhancing the spatial and thermal resolution of measurements. Operational principle of the lock-in method is discussed, and it is represented that phase shift of the thermal emission from a silicon wafer stacked heat source chip (SSHSC specimen can provide good metrics for the depth of the heat source buried in SSHSCs. Depth was also estimated by analyzing the transient thermal responses using the coupled electro-thermal simulations. Furthermore, the effects of the volumetric heat source configuration mimicking the 3D through silicon via integration package were investigated. Both the infrared microscopic imaging with the lock-in method and FE simulation were potentially useful for 3D isolation of exothermic faults and their depth estimation for multi-layered structures, especially in packaged semiconductors.

  7. A hydrogen curing effect on surface plasmon resonance fiber optic hydrogen sensors using an annealed Au/Ta₂O₅/Pd multi-layers film.

    Science.gov (United States)

    Hosoki, Ai; Nishiyama, Michiko; Igawa, Hirotaka; Seki, Atsushi; Watanabe, Kazuhiro

    2014-07-28

    In this paper, a response time of the surface plasmon resonance fiber optic hydrogen sensor has successfully improved with keeping sensor sensitivity high by means of hydrogen curing (immersing) process of annealed Au/Ta2O5/ Pd multi-layers film. The hydrogen curing effect on the response time and sensitivity has been experimentally revealed by changing the annealing temperatures of 400, 600, 800°C and through observing the optical loss change in the H2 curing process. When the 25-nm Au/60-nm Ta2O5/10-nm Pd multi-layers film annealed at 600°C is cured with 4% H2/N2 mixture, it is found that a lot of nano-sized cracks were produced on the Pd surface. After H2 curing process, the response time is improved to be 8 s, which is two times faster than previous reported one in the case of the 25-nm Au/60-nm Ta2O5/3-nm Pd multi-layers film with keeping the sensor sensitivity of 0.27 dB for 4% hydrogen adding. Discussions most likely responsible for this effect are given by introducing the α-β transition Pd structure in the H2 curing process.

  8. Tribological Behavior of Multi-layered WC-Co/MoS2-Ni Self-lubricating Coating Fabricated by Detonation Gun Spraying

    Directory of Open Access Journals (Sweden)

    WANG Tie-gang

    2017-03-01

    Full Text Available The multilayered composite WC-Co/MoS2-Ni self-lubricating coatings were prepared by detonation gun spraying technology. The coating microstructure, element distribution, adhesive strength, and tribological properties were studied systematically. The results show that a little of MoS2 is oxidized and decomposed into gas of SO2 during the high-temperature spraying process. The SO2 left in the coating and can form into the micro porosities. The friction coefficient of the WC-Co coating first increases rapidly in the initial running-in phase, and then gradually increases slightly after entering into the steady-state phase; whereas the friction coefficient of multilayer composite coating steps in the steady-state phase soon and starts to decline gradually when the top WC-Co coating became perforated. By comparison, the coating cohesion declines slightly after adding the self-lubricating layer MoS2-Ni, but the friction coefficient decreases by about 40%, and the wear resistance is also improved slightly.

  9. Fabrication and characterization of multi-layer InAs/InGaAs quantum dot p-i-n GaAs solar cells grown on silicon substrates

    Science.gov (United States)

    Omri, M.; Sayari, A.; Sfaxi, L.

    2018-01-01

    This paper reports on InAs/InGaAs quantum dot solar cells (QDSCs) deposited by molecular beam epitaxy (MBE) on (001) n-type silicon ( n-Si) substrates. In-situ RHEED measurements show that InAs/InGaAs QDs SC has a high crystalline structure. The dislocation density in the active layer of the InAs/InGaAs QDSC and the lattice mismatch in the GaAs layer can be reduced by using an Si rough surface buffer layer (RSi). To show the effect of the QD layers, a reference SC with the same p-i-n structure as the InAs/InGaAs QDSC, but without InAs QDs, is also grown. The two SCs were studied by sepectroscopic ellipsometry (SE), in the 1-6 eV photon energy range, photoluminescence and photocurrent measurements. The optical constants of the two devices are determined in the photon energy range 1-6 eV from the SE data. The dominant features in the dielectric function spectra at 3 and 4.5 eV are attributed, respectively, to the E 1 and E 2 critical point structures of GaAs and InAs. The low-temperature photoluminescence spectrum of the InAs/InGaAs QDSC shows ground-state emissions, respectively, from the relatively small QDs near 1081 nm and from the large QDs near 1126 nm. Photocurrent measurements confirm the improved absorption performance (up to 1200 nm) of the InAs QDs SC which is ascribed to the optical absorption from the InAs/InGaAs QDs and the Si substrate as demonstrated by SE and photoluminescence measurements.

  10. Radiative budget in the presence of multi-layered aerosol structures in the framework of AMMA SOP-0

    Directory of Open Access Journals (Sweden)

    J.-C. Raut

    2008-11-01

    Full Text Available This paper presents radiative transfer calculations performed over Niamey in the UV-Visible range over the period 26th January–1st February 2006 during the African Multidisciplinary Monsoon Analysis (AMMA international program. Climatic effects of aerosols along the vertical column have required an accurate determination of their optical properties, which are presented here for a variety of instrumented platforms: Ultralight aircraft, Facility for Airborne Atmospheric Measurements (FAAM research aircraft, AERONET station. Measurements highlighted the presence of a multi-layered structure of mineral dust located below and biomass-burning particles in the more elevated layers. Radiative forcing was affected by both the scattering and absorption effects governed by the aerosol complex refractive index (ACRI. The best agreement between our results and AERONET optical thicknesses, ground-based extinction measurements and NO2 photolysis rate coefficient was found using the synergy between all the instrumented platforms. The corresponding averaged ACRI at 355 nm were 1.53 (±0.04 −0.047i (±0.006 and 1.52 (±0.04 −0.008i (±0.001 for biomass-burning and mineral dust aerosols, respectively. Biomass-burning aerosols were characterized by single-scattering albedo ranging from 0.78 to 0.82 and asymmetry parameter ranging from 0.71 to 0.73. For dust aerosols, single-scattering albedo (asymmetry parameter ranged from 0.9 to 0.92 (0.73 to 0.75. The solar energy depletion at the surface is shown to be ~−21.2 (±1.7 W/m2 as a daily average. At the TOA, the radiative forcing appeared slightly negative but very close to zero (~−1.4 W/m2. The corresponding atmospheric radiative forcing was found to be ~19.8 (±2.3 W/m2. Mineral dust located below a more absorbing layer act as an increase in surface reflectivity of ~3–4%. The radiative forcing is also shown to be highly sensitive to the optical features of the

  11. Leveraging multi-layer imager detector design to improve low-dose performance for megavoltage cone-beam computed tomography

    Science.gov (United States)

    Hu, Yue-Houng; Rottmann, Joerg; Fueglistaller, Rony; Myronakis, Marios; Wang, Adam; Huber, Pascal; Shedlock, Daniel; Morf, Daniel; Baturin, Paul; Star-Lack, Josh; Berbeco, Ross

    2018-02-01

    While megavoltage cone-beam computed tomography (CBCT) using an electronic portal imaging device (EPID) provides many advantages over kilovoltage (kV) CBCT, clinical adoption is limited by its high doses. Multi-layer imager (MLI) EPIDs increase DQE(0) while maintaining high resolution. However, even well-designed, high-performance MLIs suffer from increased electronic noise from each readout, degrading low-dose image quality. To improve low-dose performance, shift-and-bin addition (ShiBA) imaging is proposed, leveraging the unique architecture of the MLI. ShiBA combines hardware readout-binning and super-resolution concepts, reducing electronic noise while maintaining native image sampling. The imaging performance of full-resolution (FR); standard, aligned binned (BIN); and ShiBA images in terms of noise power spectrum (NPS), electronic NPS, modulation transfer function (MTF), and the ideal observer signal-to-noise ratio (SNR)—the detectability index (d‧)—are compared. The FR 4-layer readout of the prototype MLI exhibits an electronic NPS magnitude 6-times higher than a state-of-the-art single layer (SLI) EPID. Although the MLI is built on the same readout platform as the SLI, with each layer exhibiting equivalent electronic noise, the multi-stage readout of the MLI results in electronic noise 50% higher than simple summation. Electronic noise is mitigated in both BIN and ShiBA imaging, reducing its total by ~12 times. ShiBA further reduces the NPS, effectively upsampling the image, resulting in a multiplication by a sinc2 function. Normalized NPS show that neither ShiBA nor BIN otherwise affects image noise. The LSF shows that ShiBA removes the pixilation artifact of BIN images and mitigates the effect of detector shift, but does not quantifiably improve the MTF. ShiBA provides a pre-sampled representation of the images, mitigating phase dependence. Hardware binning strategies lower the quantum noise floor, with 2  ×  2 implementation reducing the

  12. Improving daily streamflow forecasts in mountainous Upper Euphrates basin by multi-layer perceptron model with satellite snow products

    Science.gov (United States)

    Uysal, Gökçen; Şensoy, Aynur; Şorman, A. Arda

    2016-12-01

    This paper investigates the contribution of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Snow Cover Area (SCA) product and in-situ snow depth measurements to Artificial Neural Network model (ANN) based daily streamflow forecasting in a mountainous river basin. In order to represent non-linear structure of the snowmelt process, Multi-Layer Perceptron (MLP) Feed-Forward Backpropagation (FFBP) architecture is developed and applied in Upper Euphrates River Basin (10,275 km2) of Turkey where snowmelt constitutes approximately 2/3 of total annual volume of runoff during spring and early summer months. Snowmelt season is evaluated between March and July; 7 years (2002-2008) seasonal daily data are used during training while 3 years (2009-2011) seasonal daily data are split for forecasting. One of the fastest ANN training algorithms, the Levenberg-Marquardt, is used for optimization of the network weights and biases. The consistency of the network is checked with four performance criteria: coefficient of determination (R2), Nash-Sutcliffe model efficiency (ME), root mean square error (RMSE) and mean absolute error (MAE). According to the results, SCA observations provide useful information for developing of a neural network model to predict snowmelt runoff, whereas snow depth data alone are not sufficient. The highest performance is experienced when total daily precipitation, average air temperature data are combined with satellite snow cover data. The data preprocessing technique of Discrete Wavelet Analysis (DWA) is coupled with MLP modeling to further improve the runoff peak estimates. As a result, Nash-Sutcliffe model efficiency is increased from 0.52 to 0.81 for training and from 0.51 to 0.75 for forecasting. Moreover, the results are compared with that of a conceptual model, Snowmelt Runoff Model (SRM), application using SCA as an input. The importance and the main contribution of this study is to use of satellite snow products and data

  13. Finding palaeowaters in a multi-layered aquifer system in the Lom depression of Danubian Plain in Bulgaria

    Science.gov (United States)

    Túri, Marianna; Palcsu, László; Molnár, Mihály; Futó, István; Orehova, Tatiana; Toteva, Aglaida; Hristov, Vladimir; Benderev, Aleksey

    2017-04-01

    This work is an environmental isotope investigation of groundwater samples from a multi-layered aquifer system in the Lom depression of Danubian Plain in Bulgaria. Our previous studies in the Carpathian-Pannonian Region had been convinced through groundwater researches using noble gas temperatures that the recharge temperature difference between the Holocene and the late Pleistocene recharged waters is 9.13±0.89°C. The aim of this research in Bulgaria is to observe this phenomenon at the outside of the Carpathian-Pannonian Region. The purpose of the sampling campaign was to find out that one of the aquifers of the Lom depression could be a potential site for late Pleistocene, and Holocene paleoclimate reconstruction. There are water samples from the Dacian-Romanian complex, Upper-Pontian aquifer, Meotian-Lower Pontian aquitard and the Sarmatian aquifer as well. The collected water samples were examined for water chemistry, stable carbon, oxygen and hydrogen isotopes, and for noble gas concentrations, and besides them for radiocarbon and tritium. The radiocarbon content of the water samples are in the range from 15.9 pMC to 98.6 pMC. Based on the obtained radiocarbon values it can be stated that tree aquifers of four could be contain such waters which recharged during the early Holocene late Pleistocene (Pontian, Dacian, Sarmatian). There are two wells in the Pontian aquifer (Dolni Tsibar, 20.8 pMC; Agroinvest, 23.8 pMC) with lower radiocarbon content. Based on the stable oxygen composition of the Agroinvest well, which is with -14.2 ‰ more negative than the others so it can be late Pleistocene recharged water. In the Dacian aquifer might be one well, the Valchedram which can be late Pleistocene recharged with 23.7 pMC. In the Sarmatian aquifer can be find the oldest water sample from all with 15.9 pMC of Smirnenski. The obtained noble gas temperatures and tritium values might be stated this hypothesis as well. All measurements were carried out in Hertelendi

  14. Final Closeout report for grant FG36-08GO18018, titled: Functional Multi-Layer Solution Processable Polymer Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Adam J. Moule

    2012-05-01

    The original objectives were: (1) Develop a method to deposit multiple conjugated polymer film layers and avoid the problem of dissolution from mutually solubility; (2) Use this deposition method to develop multi-layer polymer based solar cells with layers that are function specific; (3) characterize these layers and devices; (4) develop electrical and optical models that describe and predict the properties of the multi-layers; and (5) Ultimate efficiency goals are {approx}6.75% with J{sub sc} = 12 mA/cm{sup 2}, FF = 0.75, and V{sub oc} = 0.75. The question of whether photovoltaic (PV) cells will ever be able to replace fossil fuels as the main provider of electrical power is not just a question of device efficiency; it is a question of how much power can be provided for what price. It has been well documented that PV devices at 10% power efficiency can provide for all of the world's power needs without covering too much of the earth's surface. Assuming desert like cloud coverage, an area equivalent to the land area of Texas would have to be covered. However, it has also been shown that using the current state-of-the-art silicon devices, the price-per-Watt will never be low enough to be economically feasible for large-scale development. Solution-processable PV devices based on polymers are a very attractive alternative to traditional Silicon PV because this technology is much lower in materials cost and in environmentally toxic waste production. Solution-based polymers can be rapidly deposited using printing technologies and are compatible with light-weight flexible substrates that can increase the range of available PV applications. In the past ten years, the efficiency of polymer based PV devices has increased from {approx}1% to over 10%. The highest efficiency organic solar cells are based upon a single layer than consists of a mixture of donor and acceptor moieties. This one layer has multiple optical and electrical functions, so the design of a

  15. Fabrication of Cost-Effective Dye-Sensitized Solar Cells Using Sheet-Like CoS2 Films and Phthaloylchitosan-Based Gel-Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    Saradh Prasad

    2018-01-01

    Full Text Available Platinum-free counter electrodes (CE were developed for use in efficient and cost-effective energy conversion devices, such as dye-sensitized solar cells (DSSCs. Electrochemical deposition of CoS2 on fluorine-doped tin oxide (FTO formed a hierarchical sheet-like structured CoS2 thin film. This film was engaged as a cost-effective platinum-free and high-efficiency CE for DSSCs. High stability was achieved using a phthaloychitosan-based gel-polymer electrolyte as the redox electrolyte. The electrocatalytic performance of the sheet-like CoS2 film was analyzed by electrochemical impedance spectroscopy and cyclic voltammetry. The film displayed improved electrocatalytic behavior that can be credited to a low charge-transfer resistance at the CE/electrolyte boundary and improved exchange between triiodide and iodide ions. The fabricated DSSCs with a phthaloychitosan-based gel-polymer electrolyte and sheet-like CoS2 CE had a power conversion efficiency (PCE, η of 7.29% with a fill factor (FF of 0.64, Jsc of 17.51 mA/cm2, and a Voc of 0.65 V, which was analogous to that of Pt CE (η = 7.82%. The high PCE of the sheet-like CoS2 CE arises from the enhanced FF and Jsc, which can be attributed to the abundant active electrocatalytic sites and enhanced interfacial charge-transfer by the well-organized surface structure.

  16. Low-cost fabrication and polar-dependent switching uniformity of memory devices using alumina interfacial layer and Ag nanoparticle monolayer

    Science.gov (United States)

    Xia, Peng; Li, Luman; Wang, Pengfei; Gan, Ying; Xu, Wei

    2017-11-01

    A facile and low-cost process was developed for fabricating write-once-read-many-times (WORM) Cu/Ag NPs/Alumina/Al memory devices, where the alumina passivation layer formed naturally in air at room temperature, whereas the Ag nanoparticle monolayer was in situ prepared through thermal annealing of a 4.5 nm Ag film in air at 150°C. The devices exhibit irreversible transition from initial high resistance (OFF) state to low resistance (ON) state, with ON/OFF ratio of 107, indicating the introduction of Ag nanoparticle monolayer greatly improves ON/OFF ratio by four orders of magnitude. The uniformity of threshold voltages exhibits a polar-dependent behavior, and a narrow range of threshold voltages of 0.40 V among individual devices was achieved upon the forward voltage. The memory device can be regarded as two switching units connected in series. The uniform alumina interfacial layer and the non-uniform distribution of local electric fields originated from Ag nanoparticles might be responsible for excellent switching uniformity. Since silver ions in active layer can act as fast ion conductor, a plausible mechanism relating to the formation of filaments sequentially among the two switching units connected in series is suggested for the polar-dependent switching behavior. Furthermore, we demonstrate both alumina layer and Ag NPs monolayer play essential roles in improving switching parameters based on comparative experiments.

  17. Fabrication process for a gradient index x-ray lens

    Science.gov (United States)

    Bionta, Richard M.; Makowiecki, Daniel M.; Skulina, Kenneth M.

    1995-01-01

    A process for fabricating high efficiency x-ray lenses that operate in the 0.5-4.0 keV region suitable for use in biological imaging, surface science, and x-ray lithography of integrated circuits. The gradient index x-ray optics fabrication process broadly involves co-sputtering multi-layers of film on a wire, followed by slicing and mounting on block, and then ion beam thinning to a thickness determined by periodic testing for efficiency. The process enables the fabrication of transmissive gradient index x-ray optics for the 0.5-4.0 keV energy range. This process allows the fabrication of optical elements for the next generation of imaging and x-ray lithography instruments m the soft x-ray region.

  18. YASEIS: Yet Another computer program to calculate synthetic SEISmograms for a spherically multi-layered Earth model

    Science.gov (United States)

    Ma, Yanlu

    2013-04-01

    Although most researches focus on the lateral heterogeneity of 3D Earth nowadays, a spherically multi-layered model where the parameters depend only on depth still represents a good first order approximation of real Earth. Such 1D models could be used as starting models for seismic tomographic inversion or as background model where the source mechanisms are inverted. The problem of wave propagation in a spherically layered model had been solved theoretically long time ago (Takeuchi and Saito, 1972). The existing computer programs such as Mineos (developed by G. Master, J. Woodhouse and F. Gilbert), Gemini (Friederich and Dalkolmo 1995), DSM (Kawai et. al. 2006) and QSSP (Wang 1999) tackled the computational aspects of the problem. A new simple and fast program for computing the Green's function of a stack of spherical dissipative layers is presented here. The analytical solutions within each homogeneous spherical layer are joined through the continuous boundary conditions and propagated from the center of model up to the level of source depth. Another solution is built by propagating downwardly from the free surface of model to the source level. The final solution is then constructed in frequency domain from the previous two solutions to satisfy the discontinuities of displacements and stresses at the source level which are required by the focal mechanism. The numerical instability in the propagator approach is solved by complementing the matrix propagating with an orthonormalization procedure (Wang 1999). Another unstable difficulty due to the high attenuation in the upper mantle low velocity zone is overcome by switching the bases of solutions from the spherical Bessel functions to the spherical Hankel functions when necessary. We compared the synthetic seismograms obtained from the new program YASEIS with those computed by Gemini and QSSP. In the range of near distances, the synthetics by a reflectivity code for the horizontally layers are also compared with

  19. The fictitious force method for efficient calculation of vibration from a tunnel embedded in a multi-layered half-space

    Science.gov (United States)

    Hussein, M. F. M.; François, S.; Schevenels, M.; Hunt, H. E. M.; Talbot, J. P.; Degrande, G.

    2014-12-01

    This paper presents an extension of the Pipe-in-Pipe (PiP) model for calculating vibrations from underground railways that allows for the incorporation of a multi-layered half-space geometry. The model is based on the assumption that the tunnel displacement is not influenced by the existence of a free surface or ground layers. The displacement at the tunnel-soil interface is calculated using a model of a tunnel embedded in a full space with soil properties corresponding to the soil in contact with the tunnel. Next, a full space model is used to determine the equivalent loads that produce the same displacements at the tunnel-soil interface. The soil displacements are calculated by multiplying these equivalent loads by Green's functions for a layered half-space. The results and the computation time of the proposed model are compared with those of an alternative coupled finite element-boundary element model that accounts for a tunnel embedded in a multi-layered half-space. While the overall response of the multi-layered half-space is well predicted, spatial shifts in the interference patterns are observed that result from the superposition of direct waves and waves reflected on the free surface and layer interfaces. The proposed model is much faster and can be run on a personal computer with much less use of memory. Therefore, it is a promising design tool to predict vibration from underground tunnels and to assess the performance of vibration countermeasures in an early design stage.

  20. New Technology Demonstration Program - Results of an Attempted Field Test of Multi-Layer Light Polarizing Panels in an Office Space

    Energy Technology Data Exchange (ETDEWEB)

    Richman, Eric E.

    2001-06-14

    An assessment of the potential energy savings associated with the use of multi-layer light polarizing panels in an office space was initiated as part of the Department of Energy's (DOE) Federal Energy Management Program (FEMP) New Technology Demonstration Program (NTDP) in 1997. This project was intended to provide information on the effectiveness and application of this technology that could help federal energy managers and other interested individuals determine whether this technology had benefits for their occupied spaces. The use of an actual working office area provided the capability of evaluating the technology's effectiveness in the real world.

  1. Analysis of multi-layered films. [determining dye densities by applying a regression analysis to the spectral response of the composite transparency

    Science.gov (United States)

    Scarpace, F. L.; Voss, A. W.

    1973-01-01

    Dye densities of multi-layered films are determined by applying a regression analysis to the spectral response of the composite transparency. The amount of dye in each layer is determined by fitting the sum of the individual dye layer densities to the measured dye densities. From this, dye content constants are calculated. Methods of calculating equivalent exposures are discussed. Equivalent exposures are a constant amount of energy over a limited band-width that will give the same dye content constants as the real incident energy. Methods of using these equivalent exposures for analysis of photographic data are presented.

  2. Simulating vertical and horizontal inhibition with short-term dynamics in a multi-column multi-layer model of neocortex.

    Science.gov (United States)

    Strack, Beata; Jacobs, Kimberle M; Cios, Krzysztof J

    2014-08-01

    The paper introduces a multi-layer multi-column model of the cortex that uses four different neuron types and short-term plasticity dynamics. It was designed with details of neuronal connectivity available in the literature and meets these conditions: (1) biologically accurate laminar and columnar flows of activity, (2) normal function of low-threshold spiking and fast spiking neurons, and (3) ability to generate different stages of epileptiform activity. With these characteristics the model allows for modeling lesioned or malformed cortex, i.e. examine properties of developmentally malformed cortex in which the balance between inhibitory neuron subtypes is disturbed.

  3. Method for obtaining a high-barrier multi-layer film, film, material and use thereof in packaging, tissue engineering and in a bio-polyester

    OpenAIRE

    Lagarón Cabello, José María; Martínez Sanz, Marta; López Rubio, Amparo

    2011-01-01

    [EN] The invention relates to a method for obtaining a high-barrier multi-layer film that includes a) an inner layer that includes a polar substance and b) at least one coating that includes a substance that is hydrophobic and/or suitable as a barrier to water, characterized in that said method includes coating the inner layer a) with at least one coating b), using a spinning technique. The polar substance of the inner layer a) is preferably a substance suitable as a barrier to gases and/or v...

  4. Hybrid integration of modified uni-traveling carrier photodiodes on a multi-layer silicon nitride platform using total reflection mirrors.

    Science.gov (United States)

    Shen, Yang; Feng, Shaoqi; Xie, Xiaojun; Zang, Jizhao; Li, Siwei; Su, Tiehui; Shang, Kuanping; Lai, Weicheng; Liu, Guangyao; Ben Yoo, S J; Campbell, Joe C

    2017-05-01

    We demonstrate hybrid integration of modified uni-traveling carrier photodiodes on a multi-layer silicon nitride platform using total reflection mirrors etched by focused ion beam. The hybrid photodetectors show external responsivity of 0.15 A/W and bandwidth of 3.5 GHz for devices with a diameter of 80 µm. The insertion loss of the waveguide is 3 dB and the coupling efficiency of the total reflection mirror is -3 dB. The highest RF output power is -0.5 dBm measured at 3 GHz with 9 mA photocurrent and -9 V bias.

  5. Dynamic study of a sliding interface wear process of TiAlN and CrN multi-layers by X-ray absorption

    DEFF Research Database (Denmark)

    Rasmussen, Inge Lise; Guibert, M.; Belin, M.

    indicates the marker layer is worn off and thus the wear process finished. The measurements of the wear during the sliding interface wear experiments were performed in-situ, with a special portable tribo-meter designed and build at Laboratory of Tribologi and System Dynamics, Ecole Centrale de Lyon...... in France. The contact under investigation (TiAlN/CrN/TiAlN (2000nm/1000nm/2000nm) multi-layer system) was exposed to a reciprocating sliding motion under a normal load. Simultaneously, the contact zone was submitted to a direct, focused and monochromatic SR photon beam. In this way we have studied...

  6. 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.

  7. Effect of Short-Term Water Exposure on the Mechanical Properties of Halloysite Nanotube-Multi Layer Graphene Reinforced Polyester Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mohd Shahneel Saharudin

    2017-01-01

    Full Text Available The influence of short-term water absorption on the mechanical properties of halloysite nanotubes-multi layer graphene reinforced polyester hybrid nanocomposites has been investigated. The addition of nano-fillers significantly increased the flexural strength, tensile strength, and impact strength in dry and wet conditions. After short-term water exposure, the maximum microhardness, tensile, flexural and impact toughness values were observed at 0.1 wt % multi-layer graphene (MLG. The microhardness increased up to 50.3%, tensile strength increased up to 40% and flexural strength increased up to 44%. Compared to dry samples, the fracture toughness and surface roughness of all types of produced nanocomposites were increased that may be attributed to the plasticization effect. Scanning electron microscopy revealed that the main failure mechanism is caused by the weakening of the nano-filler-matrix interface induced by water absorption. It was further observed that synergistic effects were not effective at a concentration of 0.1 wt % to produce considerable improvement in the mechanical properties of the produced hybrid nanocomposites.

  8. Numerical and experimental investigation into the subsequent thermal cycling during selective laser melting of multi-layer 316L stainless steel

    Science.gov (United States)

    Liu, Yang; Zhang, Jian; Pang, Zhicong

    2018-01-01

    Subsequent thermal cycling (STC), as the unique thermal behavior during the multi-layer manufacturing process of selective laser melting (SLM), brings about unique microstructure of the as-produced parts. A multi-layer finite element (FE) model was proposed to study the STC along with a contrast experiment. The FE simulational results show that as layer increases, the maximum temperature, dimensions and liquid lifetime of the molten pool increase, while the heating and cooling rates decrease. The maximum temperature point shifts into the molten pool, and central of molten pool shifts backward. The neighborly underlying layer can be remelted thoroughly when laser irradiates a powder layer, thus forming an excellent bonding between neighbor layers. The contrast experimental results between the single-layer and triple-layer samples show that grains in of latter become coarsen and tabular along the height direction compared with those of the former. Moreover, this effect become more serious in 2nd and 1st layers in the triple-layer sample. All the above illustrate that the STC has an significant influence on the thermal behavior during SLM process, and thus affects the microstructure of SLMed parts.

  9. Effect of Amount of Carbon on the Reduction Efficiency of Iron Ore-Coal Composite Pellets in Multi-layer Bed Rotary Hearth Furnace (RHF)

    Science.gov (United States)

    Mishra, Srinibash; Roy, Gour Gopal

    2016-08-01

    The effect of carbon-to-hematite molar ratio has been studied on the reduction efficiency of iron ore-coal composite pellet reduced at 1523 K (1250 °C) for 20 minutes in a laboratory scale multi-layer bed rotary hearth furnace (RHF). Reduced pellets have been characterized through weight loss measurement, estimation of porosity, shrinkage, qualitative and quantitative phase analysis by XRD. Performance parameters such as the degree of reduction, metallization, carbon efficiency, productivity, and compressive strength have been calculated to compare the process efficacy at different carbon levels in the pellets. Pellets with optimum carbon-to-hematite ratio (C/Fe2O3 molar ratio = 1.66) that is much below the stoichiometric carbon required for direct reduction of hematite yielded maximum reduction, better carbon utilization, and productivity for all three layers. Top layer exhibited maximum reduction at comparatively lower carbon level (C/Fe2O3 molar ratio 2.33). Correlation between degree of reduction and metallization indicated non-isothermal kinetics influenced by heat and mass transfer in multi-layer bed RHF. Compressive strength of the partially reduced pellet with optimum carbon content (C/Fe2O3 molar ratio = 1.66) showed that they could be potentially used as an alternate feed in a blast furnace or any other smelting reactor.

  10. Correlation of radioactive waste treatment costs and the environmental impact of waste effluents in the nuclear fuel cycle: fabrication of high-temperature gas-cooled reactor fuel containing uranium-233 and thorium

    Energy Technology Data Exchange (ETDEWEB)

    Roddy, J.W.; Blanco, R.E.; Hill, G.S.; Moore, R.E.; Seagren, R.D.; Witherspoon, J.P.

    1976-06-01

    A cost/benefit study was made to determine the cost and effectiveness of various radioactive waste (radwaste) treatment systems for decreasing the release of radioactive materials from model High-Temperature Gas-Cooled (HTGR) fuel fabrication plants and to determine the radiological impact (dose commitment) of the released materials on the environment. The study is designed to assist in defining the term ''as low as reasonably achievable'' as it applies to these nuclear facilities. The base cases of the two model plants, a fresh fuel fabrication plant and a refabrication plant, are representative of current proposed commercial designs or are based on technology that is being developed to fabricate uranium, thorium, and graphite into fuel elements. The annual capacities of the fresh fuel plant and the refabrication plant are 450 and 245 metric tons of heavy metal (where heavy metal is uranium plus thorium), as charged to about fifty 1000-MW(e) HTGRs. Additional radwaste treatment systems are added to the base case plants in a series of case studies to decrease the amounts of radioactive materials released and to reduce the radiological dose commitment to the population in the surrounding area. The capital and annual costs for the added waste treatment operations and the corresponding reductions in dose commitments are calculated for each case. In the final analysis, the cost/benefit of each case, calculated as additional cost of radwaste system divided by the reduction in dose commitment, is tabulated or the dose commitment is plotted with cost as the variable. The status of each of the radwaste treatment methods is discussed. 48 figures, 74 tables.

  11. Fabrication Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — The Fabrication Facilities are a direct result of years of testing support. Through years of experience, the three fabrication facilities (Fort Hood, Fort Lewis, and...

  12. Single and multi-layered core-shell structures based on ZnO nanorods obtained by aerosol assisted chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sáenz-Trevizo, A.; Amézaga-Madrid, P.; Pizá-Ruiz, P.; Antúnez-Flores, W.; Ornelas-Gutiérrez, C.; Miki-Yoshida, M., E-mail: mario.miki@cimav.edu.mx

    2015-07-15

    Core–shell nanorod structures were prepared by a sequential synthesis using an aerosol assisted chemical vapor deposition technique. Several samples consisting of ZnO nanorods were initially grown over TiO{sub 2} film-coated borosilicate glass substrates, following the synthesis conditions reported elsewhere. Later on, a uniform layer consisting of individual Al, Ni, Ti or Fe oxides was grown onto ZnO nanorod samples forming the so-called single MO{sub x}/ZnO nanorod core–shell structures, where MO{sub x} was the metal oxide shell. Additionally, a three-layer core–shell sample was developed by growing Fe, Ti and Fe oxides alternately, onto the ZnO nanorods. The microstructure of the core–shell materials was characterized by grazing incidence X-ray diffraction, scanning and transmission electron microscopy. Energy dispersive X-ray spectroscopy was employed to corroborate the formation of different metal oxides. X-ray diffraction outcomes for single core–shell structures showed solely the presence of ZnO as wurtzite and TiO{sub 2} as anatase. For the multi-layered shell sample, the existence of Fe{sub 2}O{sub 3} as hematite was also detected. Morphological observations suggested the existence of an outer material grown onto the nanorods and further microstructural analysis by HR-STEM confirmed the development of core–shell structures in all cases. These studies also showed that the individual Al, Fe, Ni and Ti oxide layers are amorphous; an observation that matched with X-ray diffraction analysis where no apparent extra oxides were detected. For the multi-layered sample, the development of a shell consisting of three different oxide layers onto the nanorods was found. Overall results showed that no alteration in the primary ZnO core was produced during the growth of the shells, indicating that the deposition technique used herein was and it is suitable for the synthesis of homogeneous and complex nanomaterials high in quality and purity. In addition

  13. A NOVEL LOW THERMAL BUDGET THIN-FILM POLYSILICON FABRICATION PROCESS FOR LARGE-AREA, HIGH-THROUGHPUT SOLAR CELL PRODUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Yue Kuo

    2010-08-15

    A novel thin-film poly-Si fabrication process has been demonstrated. This low thermal budget process transforms the single- and multi-layer amorphous silicon thin films into a poly-Si structure in one simple step over a pulsed rapid thermal annealing process with the enhancement of an ultrathin Ni layer. The complete poly-Si solar cell was fabricated in a short period of time without deteriorating the underneath glass substrate. The unique vertical crystallization process including the mechanism is discussed. Influences of the dopant type and process parameters on crystal structure will be revealed. The poly-Si film structure has been proved using TEM, XRD, Raman, and XPS methods. The poly-Si solar cell structure and the performance have been examined. In principle, the new process is potentially applicable to produce large-area thin-film poly-Si solar cells at a high throughput and low cost. A critical issue in this process is to prevent the excessive dopant diffusion during crystallization. Process parameters and the cell structure have to be optimized to achieve the production goal.

  14. Icon of the Holy Mandylion and representation of multi-layered visual identity of Božidar Vuković

    Directory of Open Access Journals (Sweden)

    Borozan Igor

    2015-01-01

    Full Text Available It was in the monastery of Saint Francis in Venice in the year 1520 when Božidar Vuković purchased the icon of the Holy Mandylion. By that particular acquisition, this prominent publisher originating from Zeta has visualized his new position in the sixteenth century Venice. The multi-layered identity of Božidar Vuković was manifested by the subsequent inclusion of the noble coat of arms of the House of Vuković on the back of the icon. By the use of verbal and visual language the artificial initiation of Božidar Vuković within the distinguished members of Venetian society has been confirmed. [Projekat Ministarstva nauke Republike Srbije, br. 177001: Predstave identiteta u verbalno-vizuelnoj kulturi novog doba

  15. A Novel 3D Thermal Impedance Model for High Power Modules Considering Multi-layer Thermal Coupling and Different Heating/Cooling Conditions

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2015-01-01

    accurate temperature estimation either vertically or horizontally inside the power devices is still hard to identify. This paper investigates the thermal behavior of high power module in various operating conditions by means of Finite Element Method (FEM). A novel 3D thermal impedance network considering......Thermal management of power electronic devices is essential for reliable performance especially at high power levels. One of the most important activities in the thermal management and reliability improvement is acquiring the temperature information in critical points of the power module. However...... the multi-layer thermal coupling among chips is proposed. The impacts to the thermal impedance by various cooling and heating conditions are also studied. It is concluded that the heating and cooling conditions will have influence on the junction to case thermal impedances and need to be carefully...

  16. Effect of Initial Stress on the Dynamic Response of a Multi-Layered Plate-Strip Subjected to an Arbitrary Inclined Time-Harmonic Force

    Science.gov (United States)

    Daşdemir, A.

    2017-08-01

    The forced vibration of a multi-layered plate-strip with initial stress under the action of an arbitrary inclined time-harmonic force resting on a rigid foundation is considered. Within the framework of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic waves in initially stressed bodies (TLTEWISB), a mathematical modelling is presented in plane strain state. It is assumed that there exists the complete contact interaction at the interface between the layers and the materials of the layer are linearly elastic, homogeneous and isotropic. The governing system of the partial differential equations of motion for the considered problem is solved approximately by employing the Finite Element Method (FEM). Further, the influence of the initial stress parameter on the dynamic response of the plate-strip is presented.

  17. Ni nanoparticles prepared by simple chemical method for the synthesis of Ni/NiO-multi-layered graphene by chemical vapor deposition

    Science.gov (United States)

    Ali, Mokhtar; Remalli, Nagarjuna; Gedela, Venkataramana; Padya, Balaji; Jain, Pawan Kumar; Al-Fatesh, Ahmed; Rana, Usman Ali; Srikanth, Vadali V. S. S.

    2017-02-01

    A new chemical method was used to obtain a high yield of nickel nanoparticles (Ni-NPs). The effect of solvent (distilled water, ethylene glycol, and ethanol) and surfactant (oleic acid and polyvinyl pyrrolidinone) on the morphology and crystallinity of the synthesized Ni-NPs has been investigated. The experimental results revealed that among the solvents mentioned above, ethanol gives the best results in terms of complete reduction, controlled morphology and size distribution of Ni-NPs. The surfactants played an important role in impeding the agglomeration and surface oxidation of Ni-NPs. The surfactants also affected the morphology of the Ni-NPs. The synthesized Ni-NPs are found to be quite stable in air. The best of the synthesized Ni-NPs were effectively used as catalysts for the synthesis of Ni/NiO-multi-layered graphene using catalytic chemical vapor deposition technique.

  18. On an analytical evaluation of the flux and dominant eigenvalue problem for the steady state multi-group multi-layer neutron diffusion equation

    Energy Technology Data Exchange (ETDEWEB)

    Ceolin, Celina; Schramm, Marcelo; Bodmann, Bardo Ernst Josef; Vilhena, Marco Tullio Mena Barreto de [Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Bogado Leite, Sergio de Queiroz [Comissao Nacional de Energia Nuclear, Rio de Janeiro (Brazil)

    2014-11-15

    In this work the authors solved the steady state neutron diffusion equation for a multi-layer slab assuming the multi-group energy model. The method to solve the equation system is based on an expansion in Taylor Series resulting in an analytical expression. The results obtained can be used as initial condition for neutron space kinetics problems. The neutron scalar flux was expanded in a power series, and the coefficients were found by using the ordinary differential equation and the boundary and interface conditions. The effective multiplication factor k was evaluated using the power method. We divided the domain into several slabs to guarantee the convergence with a low truncation order. We present the formalism together with some numerical simulations.

  19. Hydro-geochemical paths of multi-layer groundwater system in coal mining regions - Using multivariate statistics and geochemical modeling approaches.

    Science.gov (United States)

    Liu, Pu; Hoth, Nils; Drebenstedt, Carsten; Sun, Yajun; Xu, Zhimin

    2017-12-01

    Groundwater is an important drinking water resource that requires protection in North China. Coal mining industry in the area may influence the water quality evolution. To provide primary characterization of the hydrogeochemical processes and paths that control the water quality evolution, a complex multi-layer groundwater system in a coal mining area is investigated. Multivariate statistical methods involving hierarchical cluster analysis (HCA) and principal component analysis (PCA) are applied, 6 zones and 3 new principal components are classified as major reaction zones and reaction factors. By integrating HCA and PCA with hydrogeochemical correlations analysis, potential phases, reactions and connections between various zones are presented. Carbonates minerals, gypsum, clay minerals as well as atmosphere gases - CO 2 , H 2 O and NH 3 are recognized as major reactants. Mixtures, evaporation, dissolution/precipitation of minerals and cation exchange are potential reactions. Inverse modeling is finally used, and it verifies the detailed processes and diverse paths. Consequently, 4 major paths are found controlling the variations of groundwater chemical properties. Shallow and deep groundwater is connected primarily by the flow of deep groundwater up through fractures and faults into the shallow aquifers. Mining does not impact the underlying aquifers that represent the most critical groundwater resource. But controls should be taken to block the mixing processes from highly polluted mine water. The paper highlights the complex hydrogeochemical evolution of a multi-layer groundwater system under mining impact, which could be applied to further groundwater quality management in the study area, as well as most of the other coalfields in North China. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Classification of Atrial Septal Defect and Ventricular Septal Defect with Documented Hemodynamic Parameters via Cardiac Catheterization by Genetic Algorithms and Multi-Layered Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Mustafa Yıldız

    2012-08-01

    Full Text Available Introduction: We aimed to develop a classification method to discriminate ventricular septal defect and atrial septal defect by using severalhemodynamic parameters.Patients and Methods: Forty three patients (30 atrial septal defect, 13 ventricular septal defect; 26 female, 17 male with documentedhemodynamic parameters via cardiac catheterization are included to study. Such parameters as blood pressure values of different areas,gender, age and Qp/Qs ratios are used for classification. Parameters, we used in classification are determined by divergence analysismethod. Those parameters are; i pulmonary artery diastolic pressure, ii Qp/Qs ratio, iii right atrium pressure, iv age, v pulmonary arterysystolic pressure, vi left ventricular sistolic pressure, vii aorta mean pressure, viii left ventricular diastolic pressure, ix aorta diastolicpressure, x aorta systolic pressure. Those parameters detected from our study population, are uploaded to multi-layered artificial neuralnetwork and the network was trained by genetic algorithm.Results: Trained cluster consists of 14 factors (7 atrial septal defect and 7 ventricular septal defect. Overall success ratio is 79.2%, andwith a proper instruction of artificial neural network this ratio increases up to 89%.Conclusion: Parameters, belonging to artificial neural network, which are needed to be detected by the investigator in classical methods,can easily be detected with the help of genetic algorithms. During the instruction of artificial neural network by genetic algorithms, boththe topology of network and factors of network can be determined. During the test stage, elements, not included in instruction cluster, areassumed as in test cluster, and as a result of this study, we observed that multi-layered artificial neural network can be instructed properly,and neural network is a successful method for aimed classification.

  1. Net-Immobilization of [beta]-glucosidase on Nonwoven Fabrics to Lower the Cost of "Cellulosic Ethanol" and Increase Cellulose Conversions

    National Research Council Canada - National Science Library

    Xing Zhu; Bin He; Changwen Zhao; Rong Fan; Lihua Zhang; Guan Wang; Yuhong Ma; Wantai Yang

    2016-01-01

    .... In this strategy, BG was net-immobilized into a poly(ethylene glycol) (PEG) net-cloth layer on a PP nonwoven fabric by way of the visible light-induced surface controlled/living graft cross-linking polymerization...

  2. Nuclear Fabrication Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Levesque, Stephen [EWI, Columbus, OH (United States)

    2013-04-05

    This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. Supporting industry in helping to create a larger qualified nuclear supplier network. Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium

  3. Cost-Effective Fabrication Routes for the Production of Quantum Well Structures and Recovery of Waste Heat from Heavy Duty Trucks

    Energy Technology Data Exchange (ETDEWEB)

    Willigan, Rhonda

    2009-09-30

    The primary objectives of Phase I were: (a) carry out cost, performance and system level models, (b) quantify the cost benefits of cathodic arc and heterogeneous nanocomposites over sputtered material, (c) evaluate the expected power output of the proposed thermoelectric materials and predict the efficiency and power output of an integrated TE module, (d) define market acceptance criteria by engaging Caterpillar's truck OEMs, potential customers and dealers and identify high-level criteria for a waste heat thermoelectric generator (TEG), (e) identify potential TEG concepts, and (f) establish cost/kWatt targets as well as a breakdown of subsystem component cost targets for the commercially viable TEG.

  4. A low-cost mullite-titania composite ceramic hollow fiber microfiltration membrane for highly efficient separation of oil-in-water emulsion.

    Science.gov (United States)

    Zhu, Li; Chen, Mingliang; Dong, Yingchao; Tang, Chuyang Y; Huang, Aisheng; Li, Lingling

    2016-03-01

    Oil-in-water (O/W) emulsion is considered to be difficult to treat. In this work, a low-cost multi-layer-structured mullite-titania composite ceramic hollow fiber microfiltration membrane was fabricated and utilized to efficiently remove fine oil droplets from (O/W) emulsion. In order to reduce membrane cost, coal fly ash was effectively recycled for the first time to fabricate mullite hollow fiber with finger-like and sponge-like structures, on which a much more hydrophilic TiO2 layer was further deposited. The morphology, crystalline phase, mechanical and surface properties were characterized in details. The filtration capability of the final composite membrane was assessed by the separation of a 200 mg·L(-1) synthetic (O/W) emulsion. Even with this microfiltration membrane, a TOC removal efficiency of 97% was achieved. Dilute NaOH solution backwashing was used to effectively accomplish membrane regeneration (∼96% flux recovery efficiency). This study is expected to guide an effective way to recycle waste coal fly ash not only to solve its environmental problems but also to produce a high-valued mullite hollow fiber membrane for highly efficient separation application of O/W emulsion with potential simultaneous functions of pure water production and oil resource recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Evaluating the performance of land surface model ORCHIDEE-CAN v1.0 on water and energy flux estimation with a single-and multi-layer energy budget scheme

    NARCIS (Netherlands)

    Chen, Yiying; Ryder, James; Bastrikov, Vladislav; McGrath, Matthew J.; Naudts, Kim; Otto, Juliane; Ottlé, Catherine; Peylin, Philippe; Polcher, Jan; Valade, Aude; Black, Andrew; Elbers, Jan A.; Moors, Eddy; Foken, Thomas; Gorsel, Van Eva; Haverd, Vanessa; Heinesch, Bernard; Tiedemann, Frank; Knohl, Alexander; Launiainen, Samuli; Loustau, Denis; Ogeé, Jérôme; Vessala, Timo; Luyssaert, Sebastiaan

    2016-01-01

    Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions, as it determines the energy and scalar exchanges between the land surface and the overlying air mass. In this study we evaluated the performance of a newly developed multi-layer energy

  6. Coastal groundwater salinization: Focus on the vertical variability in a multi-layered aquifer through a multi-isotope fingerprinting (Roussillon Basin, France)

    Energy Technology Data Exchange (ETDEWEB)

    Petelet-Giraud, Emmanuelle, E-mail: e.petelet@brgm.fr [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France); Négrel, Philippe [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France); Aunay, Bertrand [BRGM, Réunion Agency, 5, rue Sainte-Anne, CS 51016, 97404 Saint Denis Cedex (France); Ladouche, Bernard; Bailly-Comte, Vincent [BRGM Montpellier Agency, 1039, rue de Pinville, 34000 Montpellier (France); Guerrot, Catherine; Flehoc, Christine [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France); Pezard, Philippe; Lofi, Johanna [Géosciences Montpellier, UMR 5243, Université de Montpellier, cc069, Place Eugène Bataillon, 34095 Montpellier Cedex 05 (France); Dörfliger, Nathalie [BRGM, Avenue C. Guillemin, BP 36009, 45060 Orléans Cedex 02 (France)

    2016-10-01

    The Roussillon sedimentary Basin (South France) is a complex multi-layered aquifer, close to the Mediterranean Sea facing seasonally increases of water abstraction and salinization issues. We report geochemical and isotopic vertical variability in this aquifer using groundwater sampled with a Westbay System® at two coastal monitoring sites: Barcarès and Canet. The Westbay sampling allows pointing out and explaining the variation of water quality along vertical profiles, both in productive layers and in the less permeable ones where most of the chemical processes are susceptible to take place. The aquifer layers are not equally impacted by salinization, with electrical conductivity ranging from 460 to 43,000 μS·cm{sup −1}. The δ{sup 2}H–δ{sup 18}O signatures show mixing between seawater and freshwater components with long water residence time as evidenced by the lack of contribution from modern water using {sup 3}H, {sup 14}C and CFCs/SF6. S(SO{sub 4}) isotopes also evidence seawater contribution but some signatures can be related to oxidation of pyrite and/or organically bounded S. In the upper layers {sup 87}Sr/{sup 86}Sr ratios are close to that of seawater and then increase with depth, reflecting water–rock interaction with argillaceous formations while punctual low values reflect interaction with carbonate. Boron isotopes highlight secondary processes such as adsorption/desorption onto clays in addition to mixings. At the Barcarès site (120 m deep), the high salinity in some layers appear to be related neither to present day seawater intrusion, nor to Salses-Leucate lagoonwater intrusion. Groundwater chemical composition thus highlights binary mixing between fresh groundwater and inherited salty water together with cation exchange processes, water–rock interactions and, locally, sedimentary organic matter mineralisation probably enhanced by pyrite oxidation. Finally, combining the results of this study and those of Caballero and Ladouche (2015

  7. SU-G-TeP2-13: Patient-Specific Reduction of Range Uncertainties in Proton Therapy by Proton Radiography with a Multi-Layer Ionization Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Deffet, S; Macq, B [Universite catholique de Louvain, Louvain-la-Neuve (Belgium); Farace, P; Righetto, R [Trento Hospital / APSS, Trento (Italy); Vander Stappen, F [Ion Beam Applications (IBA), Louvain-la-Neuve (Belgium)

    2016-06-15

    Purpose: The conversion from Hounsfield units (HU) to stopping powers is a major source of range uncertainty in proton therapy (PT). Our contribution shows how proton radiographs (PR) acquired with a multi-layer ionization chamber in a PT center can be used for accurate patient positioning and subsequently for patient-specific optimization of the conversion from HU to stopping powers. Methods: A multi-layer ionization chamber was used to measure the integral depth-dose (IDD) of 220 MeV pencil beam spots passing through several anthropomorphic phantoms. The whole area of interest was imaged by repositioning the couch and by acquiring a 45×45 mm{sup 2} frame for each position. A rigid registration algorithm was implemented to correct the positioning error between the proton radiographs and the planning CT. After registration, the stopping power map obtained from the planning CT with the calibration curve of the treatment planning system was used together with the water equivalent thickness gained from two proton radiographs to generate a phantom-specific stopping power map. Results: Our results show that it is possible to make a registration with submillimeter accuracy from proton radiography obtained by sending beamlets separated by more than 1 mm. This was made possible by the complex shape of the IDD due to the presence of lateral heterogeneities along the path of the beam. Submillimeter positioning was still possible with a 5 mm spot spacing. Phantom specific stopping power maps obtained by minimizing the range error were cross-verified by the acquisition of an additional proton radiography where the phantom was positioned in a random but known manner. Conclusion: Our results indicate that a CT-PR registration algorithm together with range-error based optimization can be used to produce a patient-specific stopping power map. Sylvain Deffet reports financial funding of its PhD thesis by Ion Beam Applications (IBA) during the confines of the study and outside the

  8. Fabrication of nanowires and nanostructures

    DEFF Research Database (Denmark)

    Mátéfi-Tempfli, Stefan; Mátéfi-Tempfli, M.; Piraux, L.

    2009-01-01

    We report on different approaches that we have adopted and developed for the fabrication of nanowires and nanostructures. Methods based on template synthesis and on self organization seem to be the most promising for the fabrication of nanomaterials and nanostructures due to their easiness and low...... cost. The development of a supported nanoporous alumina template and the possibility of using this template to combine electrochemical synthesis with lithographic methods open new ways for the fabrication of complex nanostructures. The numerous advantages of the supported template and its compatibility...... with microelectronic processes make it an ideal candidate for further integration into large-scale fabrication of various nanowire-based devices....

  9. Cost analysis of roll-to-roll fabricated ITO free single and tandem organic solar modules based on data from manufacture

    DEFF Research Database (Denmark)

    Machui, Florian; Hösel, Markus; Li, Ning

    2014-01-01

    We present a cost analysis based on state of the art printing and coating processes to fully encapsulated, flexible ITO- and vacuum-free polymer solar cell modules. Manufacturing data for both single junctions and tandem junctions are presented and analyzed. Within this calculation the most...... costs drop below 10 € per m2 which proves that OPV is a competitive alternative to established power generation technologies....

  10. Temperature dependent fabrication of cost-effective and nontoxic Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films for solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Digraskar, Renuka, E-mail: renukad120@gmail.com; Sathe, Bhaskar, E-mail: bhaskarsathe@gmail.com [Department of Chemistry, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 43100, (M.S) India (India); Gattu, Ketan; Ghule, Anil; Sharma, Ramphal [Department of Nanotechnology, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 43100, (M.S) India (India)

    2016-05-06

    In the present work, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been fabricated onto the glass substrate by simple and economic chemical bath deposition technique{sup 1}, and the effect of deposition temperature is reported. The deposition temperatures used were 50°C and 60°C for a deposition time of 60 min, which are significantly lower than earlier reports. These CZTS thin films were characterized for optical, electrical, morphological and elemental properties using, UV-Vis spectrophotometer, I-V system for photosensitivity, two probe resistivity system for resistivity, scanning electron microscopy, energy dispersive spectroscopy and Raman spectroscopy.

  11. Digital fabrication

    CERN Document Server

    2012-01-01

    The Winter 2012 (vol. 14 no. 3) issue of the Nexus Network Journal features seven original papers dedicated to the theme “Digital Fabrication”. Digital fabrication is changing architecture in fundamental ways in every phase, from concept to artifact. Projects growing out of research in digital fabrication are dependent on software that is entirely surface-oriented in its underlying mathematics. Decisions made during design, prototyping, fabrication and assembly rely on codes, scripts, parameters, operating systems and software, creating the need for teams with multidisciplinary expertise and different skills, from IT to architecture, design, material engineering, and mathematics, among others The papers grew out of a Lisbon symposium hosted by the ISCTE-Instituto Universitario de Lisboa entitled “Digital Fabrication – A State of the Art”. The issue is completed with four other research papers which address different mathematical instruments applied to architecture, including geometric tracing system...

  12. Design and Fabrication of Low Cost Thick Film pH Sensor using Silver Chlorinated Reference Electrodes with Integrated Temperature Sensor

    Directory of Open Access Journals (Sweden)

    Wiranto Goib

    2016-01-01

    Full Text Available This paper describes the design and fabrication of thick film pH sensor, in which the reference electrode has been formed by chlorination of Ag using FeCl3. The process was aimed to replace Ag/AgCl paste commonly used as reference electrodes. Fabricated using thick film screen printing technology on Al2O3 substrate, the pH sensor showed a measured sensitivity of -52.97, -53.17 and -53.68 mV/pH at 25°C, 45°C, and 65°C, respectively. The measured values were close to the theoretical Nernstian slope of -59 mV/pH 25°C.The sensor was also designed with an integrated Ruthenium based temperature sensor for future temperature compensation. The measured resistance temperature characteristics showed a linear reasponse over the range of 25 – 80°C. This miniaturised planar sensor should find wide application, especially in field water quality monitoring, replacing their glass type counterparts.

  13. Complex-plane generalization of scalar Levin transforms: A robust, rapidly convergent method to compute potentials and fields in multi-layered media

    Energy Technology Data Exchange (ETDEWEB)

    Sainath, Kamalesh, E-mail: sainath.1@osu.edu [The Ohio State University, Electroscience Laboratory, 1330 Kinnear Road, Columbus, OH 43212 (United States); Teixeira, Fernando L., E-mail: teixeira@ece.osu.edu [The Ohio State University, Electroscience Laboratory, 1330 Kinnear Road, Columbus, OH 43212 (United States); Donderici, Burkay, E-mail: Burkay.Donderici@Halliburton.com [Halliburton, Sensor Physics and Technology, 3000 N. Sam Houston Pkwy E, Houston, TX 77032 (United States)

    2014-07-15

    We propose the complex-plane generalization of a powerful algebraic sequence acceleration algorithm, the method of weighted averages (MWA), to guarantee exponential-cum-algebraic convergence of Fourier and Fourier–Hankel (F–H) integral transforms. This “complex-plane” MWA, effected via a linear-path detour in the complex plane, results in rapid, absolute convergence of field and potential solutions in multi-layered environments regardless of the source-observer geometry and anisotropy/loss of the media present. In this work, we first introduce a new integration path used to evaluate the field contribution arising from the radiation spectra. Subsequently, we (1) exhibit the foundational relations behind the complex-plane extension to a general Levin-type sequence convergence accelerator, (2) specialize this analysis to one member of the Levin transform family (the MWA), (3) address and circumvent restrictions, arising for two-dimensional integrals associated with wave dynamics problems, through minimal complex-plane detour restrictions and a novel partition of the integration domain, (4) develop and compare two formulations based on standard/real-axis MWA variants, and (5) present validation results and convergence characteristics for one of these two formulations.

  14. Effects of different boundary conditions on the simulation of groundwater flow in a multi-layered coastal aquifer system (Taranto Gulf, southern Italy)

    Science.gov (United States)

    De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio L.

    2017-11-01

    The evaluation of the accuracy or reasonableness of numerical models of groundwater flow is a complex task, due to the uncertainties in hydrodynamic properties and boundary conditions and the scarcity of good-quality field data. To assess model reliability, different calibration techniques are joined to evaluate the effects of different kinds of boundary conditions on the groundwater flow in a coastal multi-layered aquifer in southern Italy. In particular, both direct and indirect approaches for inverse modeling were joined through the calibration of one of the most uncertain parameters, namely the hydraulic conductivity of the karst deep hydrostratigraphic unit. The methodology proposed here, and applied to a real case study, confirmed that the selection of boundary conditions is among the most critical and difficult aspects of the characterization of a groundwater system for conceptual analysis or numerical simulation. The practical tests conducted in this study show that incorrect specification of boundary conditions prevents an acceptable match between the model response to the hydraulic stresses and the behavior of the natural system. Such effects have a negative impact on the applicability of numerical modeling to simulate groundwater dynamics in complex hydrogeological situations. This is particularly important for management of the aquifer system investigated in this work, which represents the only available freshwater resource of the study area, and is threatened by overexploitation and saltwater intrusion.

  15. Effects of different boundary conditions on the simulation of groundwater flow in a multi-layered coastal aquifer system (Taranto Gulf, southern Italy)

    Science.gov (United States)

    De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio L.

    2017-05-01

    The evaluation of the accuracy or reasonableness of numerical models of groundwater flow is a complex task, due to the uncertainties in hydrodynamic properties and boundary conditions and the scarcity of good-quality field data. To assess model reliability, different calibration techniques are joined to evaluate the effects of different kinds of boundary conditions on the groundwater flow in a coastal multi-layered aquifer in southern Italy. In particular, both direct and indirect approaches for inverse modeling were joined through the calibration of one of the most uncertain parameters, namely the hydraulic conductivity of the karst deep hydrostratigraphic unit. The methodology proposed here, and applied to a real case study, confirmed that the selection of boundary conditions is among the most critical and difficult aspects of the characterization of a groundwater system for conceptual analysis or numerical simulation. The practical tests conducted in this study show that incorrect specification of boundary conditions prevents an acceptable match between the model response to the hydraulic stresses and the behavior of the natural system. Such effects have a negative impact on the applicability of numerical modeling to simulate groundwater dynamics in complex hydrogeological situations. This is particularly important for management of the aquifer system investigated in this work, which represents the only available freshwater resource of the study area, and is threatened by overexploitation and saltwater intrusion.

  16. Observation of the Gap Distribution on Multi-layered Cuprate Superconductor Ba2Ca4Cu5O10(O1-x, Fx)2 by STM/STS

    Science.gov (United States)

    Sugimoto, Akira; Ekino, Toshikazu; Tanaka, Katsuhiro; Mineta, Kyohei; Tanabe, Kenji; Tokiwa, Kazuyasu

    The nano-scale spatial gap distributions on apical-fluorine multi-layered cuprate superconductors Ba2Ca4Cu5O10(O1-x, Fx) (F0245, Tc = 70 K) are investigated by scanning tunneling microscopy/spectroscopy (STM/STS). The STM image shows randomly-distributed bright spot structures, which are assigned to the non-replaced apical oxygen. The dI/dV tunnel spectra show the coexistence of two kinds of the gap structures. The magnitudes of these gaps at 4.9 K are about ΔS ∼25 meV and ΔL ∼78 meV, respectively. The ΔL map shows the inhomogeneous distribution with the characteristic length of ∼1 nm. The smaller ΔL gap regions tend to locate at the bright-spot positions, indicating that the apical oxygen causes reduction of ΔL. These results are consistent with the well known relation between the carrier doping level and macroscopically observed gap size.

  17. An ultracold neutron (UCN) detector with Ti/ sup 6 LiF multi-layer converter and sup 5 sup 8 Ni reflector

    CERN Document Server

    Maier-Komor, P; Bergmaier, A; Dollinger, G; Paul, S; Petzoldt, G; Schott, W

    2002-01-01

    High efficient detectors for ultracold neutrons (UCN) must be developed for the new high flux neutron source Forschungsreaktor Muenchen II (FRM II). On silicon PIN diodes 76 mu g/cm sup 2 sup 5 sup 8 Ni was deposited as a UCN reflector. On this 100 double layers of sup n sup a sup t Ti (4.7 mu g/cm sup 2) and sup 6 LiF (1.8 mu g/cm sup 2) were deposited to function as a UCN converter. On top of this, 33 double layers of sup n sup a sup t Ti (3.4 mu g/cm sup 2) and sup 6 LiF (0.92 mu g/cm sup 2) were condensed in addition to provide sensitivity to very low-energy UCN. Finally, 6.0 mu g/cm sup 2 sup n sup a sup t V was deposited to protect the multi-layers. Vanadium has nearly zero optical potential for UCN and thus should not hinder their transmission. Since no expensive isotopes were involved, a source to substrate distance of 24 cm could be chosen, leading to excellent uniformity. The setup designed for deposition under ultrahigh vacuum conditions and the evaporation procedures are described.

  18. Reliable recovery of the optical properties of multi-layer turbid media by iteratively using a layered diffusion model at multiple source-detector separations.

    Science.gov (United States)

    Liao, Yu-Kai; Tseng, Sheng-Hao

    2014-03-01

    Accurately determining the optical properties of multi-layer turbid media using a layered diffusion model is often a difficult task and could be an ill-posed problem. In this study, an iterative algorithm was proposed for solving such problems. This algorithm employed a layered diffusion model to calculate the optical properties of a layered sample at several source-detector separations (SDSs). The optical properties determined at various SDSs were mutually referenced to complete one round of iteration and the optical properties were gradually revised in further iterations until a set of stable optical properties was obtained. We evaluated the performance of the proposed method using frequency domain Monte Carlo simulations and found that the method could robustly recover the layered sample properties with various layer thickness and optical property settings. It is expected that this algorithm can work with photon transport models in frequency and time domain for various applications, such as determination of subcutaneous fat or muscle optical properties and monitoring the hemodynamics of muscle.

  19. Parallelisation and application of a multi-layer atmospheric transport model to quantify dispersion and deposition of ammonia over the British Isles.

    Science.gov (United States)

    Fournier, N; Pais, V A; Sutton, M A; Weston, K J; Dragosits, U; Tang, S Y; Aherne, J

    2002-01-01

    An atmospheric transport model, FRAME (Fine Resolution AMmonia Exchange), has been used to model the spatial pattern of ammonia concentrations and deposition over the British Isles for the first time. The model uses a multi-layer approach with diffusion through 33 layers to describe vertical concentration profiles in the atmosphere explicitly. Together with the necessary description of atmospheric reactions with sulphur and oxidised nitrogen, this imposes a major computational requirement, with the model having a run-time of 8.5 days on a mid-range workstation. Improvement in the model run-time was sought by developing a parallel implementation coded in a data-parallel approach using High Performance Fortran. Running the code on a Cray T3E with 128 processors provided a speedup by a factor of 69. The code's portability, its validation with measurements and new maps of its application to the British Isles, are presented. Good agreement is found with measured NH3 concentrations, while wet de-position is underestimated. In addition to model uncertainties, this may be due to an underestimation of the NH3 emissions input data.

  20. Core/Shell Structure of Ni/NiO Encapsulated in Carbon Nanosphere Coated with Few- and Multi-Layered Graphene: Synthesis, Mechanism and Application

    Directory of Open Access Journals (Sweden)

    Ferial Ghaemi

    2016-11-01

    Full Text Available This paper focuses on the synthesis and mechanism of carbon nanospheres (CNS coated with few- and multi-layered graphene (FLG, MLG. The graphitic carbon encapsulates the core/shell structure of the Ni/NiO nanoparticles via the chemical vapor deposition (CVD method. The application of the resulting CNS and hybrids of CNS-FLG and CNS-MLG as reinforcement nanofillers in a polypropylene (PP matrix were studied from the aspects of mechanical and thermal characteristics. In this research, to synthesize carbon nanostructures, nickel nitrate hexahydrate (Ni(NO32·6H2O and acetylene (C2H2 were used as the catalyst source and carbon source, respectively. Besides, the morphology, structure and graphitization of the resulting carbon nanostructures were investigated. On the other hand, the mechanisms of CNS growth and the synthesis of graphene sheets on the CNS surface were studied. Finally, the mechanical and thermal properties of the CNS/PP, CNS-FLG/PP, and CNS-MLG/PP composites were analyzed by applying tensile test and thermogravimetric analysis (TGA, respectively.

  1. Design of modified structure multi-layer perceptron networks based on decision trees for the prediction of flow parameters in 90° open-channel bends

    Directory of Open Access Journals (Sweden)

    Azadeh Gholami

    2016-01-01

    Full Text Available A modified multi-layer perceptron (MLP model based on decision trees (DT-MLP is presented to predict velocity and water free-surface profiles in a 90° open-channel bend. The ability of the new hybrid model to predict the velocity and flow depth in a 90° sharp bend is investigated and compared with the abilities of MLP and multiple-linear regression (MLR models. The MLP and DT-MLP networks are trained and tested using 520 and 506 experimental data measured for velocity and flow depth, respectively, at five different discharge rates of 5, 7.8, 13.6, 19.1 and 25.3 l/s. The MLP and DT-MLP comparison results against MLR reveal that the two artificial neural networks (ANNs are 84% and 16% more accurate than the MLR model in predicting the velocity and flow depth variables, respectively. According to the results, the root mean square error (RMSE value of the DT-MLP model decreases by 9% and 7.5% in predicting velocity and flow depth, respectively, compared with the MLP model. It was found that the hybrid decision-tree-based method can significantly improve MLP neural network performance in forecasting velocity and free-surface profiles in a 90° open-channel bend.

  2. On the effect of thermodynamic equilibrium on the assembly efficiency of complex multi-layered virus-like particles (VLP: the case of rotavirus VLP.

    Directory of Open Access Journals (Sweden)

    António Roldão

    Full Text Available Previous studies have reported the production of malformed virus-like-particles (VLP in recombinant host systems. Here we computationally investigate the case of a large triple-layered rotavirus VLP (RLP. In vitro assembly, disassembly and reassembly data provides strong evidence of microscopic reversibility of RLP assembly. Light scattering experimental data also evidences a slow and reversible assembly untypical of kinetic traps, thus further strengthening the fidelity of a thermodynamically controlled assembly. In silico analysis further reveals that under favourable conditions particles distribution is dominated by structural subunits and completely built icosahedra, while other intermediates are present only at residual concentrations. Except for harshly unfavourable conditions, assembly yield is maximised when proteins are provided in the same VLP protein mass composition. The assembly yield decreases abruptly due to thermodynamic equilibrium when the VLP protein mass composition is not obeyed. The latter effect is more pronounced the higher the Gibbs free energy of subunit association is and the more complex the particle is. Overall this study shows that the correct formation of complex multi-layered VLPs is restricted to a narrow range of association energies and protein concentrations, thus the choice of the host system is critical for successful assembly. Likewise, the dynamic control of intracellular protein expression rates becomes very important to minimize wasted proteins.

  3. Adaptive Multi-Layer LMS Controller Design and Application to Active Vibration Suppression on a Truss and Proposed Impact Analysis Technique

    Science.gov (United States)

    Barney, Timothy A.; Shin, Y. S.; Agrawal, B. N.

    2001-01-01

    This research develops an adaptive controller that actively suppresses a single frequency disturbance source at a remote position and tests the system on the NPS Space Truss. The experimental results are then compared to those predicted by an ANSYS finite element model. The NPS space truss is a 3.7-meter long truss that simulates a space-borne appendage with sensitive equipment mounted at its extremities. One of two installed piezoelectric actuators and an Adaptive Multi-Layer LMS control law were used to effectively eliminate an axial component of the vibrations induced by a linear proof mass actuator mounted at one end of the truss. Experimental and analytical results both demonstrate reductions to the level of system noise. Vibration reductions in excess of 50dB were obtained through experimentation and over 100dB using ANSYS, demonstrating the ability to model this system with a finite element model. This report also proposes a method to use distributed quartz accelerometers to evaluate the location, direction, and energy of impacts on the NPS space truss using the dSPACE data acquisition and processing system to capture the structural response and compare it to known reference Signals.

  4. Multi-Layer Phase Analysis: Quantifying the Elastic Properties of Soft Tissues and Live Cells with Ultra-High Frequency Scanning Acoustic Microscopy

    Science.gov (United States)

    Zhao, Xuegen; Akhtar, Riaz; Nijenhuis, Nadja; Wilkinson, Steven J.; Murphy, Lilli; Ballestrem, Christoph; Sherratt, Michael. J.; Watson, Rachel E.B.; Derby, Brian

    2012-01-01

    Scanning acoustic microscopy is potentially a powerful tool for characterising the elastic properties of soft biological tissues and cells. In this paper, we present a method, Multi-Layer Phase Analysis (MLPA), which can be used to extract local speed of sound values, for both thin tissue sections mounted on glass slides and cultured cells grown on cell culture plastic, with a resolution close to 1 μm. The method exploits the phase information that is preserved in the interference between the acoustic wave reflected from the substrate surface and internal reflections from the acoustic lens. In practice, a stack of acoustic images are captured beginning with the acoustic focal point 4 μm above the substrate surface and moving down in 0.1 μm increments. Scanning parameters, such as acoustic wave frequency and gate position, were adjusted to obtain optimal phase and lateral resolution. The data were processed offline to extract the phase information with the contribution of any inclination in the substrate removed prior to the calculation of sound speed. Here, we apply this approach to both skin sections and fibroblast cells, and compare our data with the V(f) (voltage vs frequency) method that has previously been used for characterisation of soft tissues and cells. Compared with the V(f) method, the MPLA method not only reduces signal noise but can be implemented without making a priori assumptions with regards to tissue or cell parameters. PMID:22547273

  5. Modeling Urban Expansion in Bangkok Metropolitan Region Using Demographic–Economic Data through Cellular Automata-Markov Chain and Multi-Layer Perceptron-Markov Chain Models

    Directory of Open Access Journals (Sweden)

    Chudech Losiri

    2016-07-01

    Full Text Available Urban expansion is considered as one of the most important problems in several developing countries. Bangkok Metropolitan Region (BMR is the urbanized and agglomerated area of Bangkok Metropolis (BM and its vicinity, which confronts the expansion problem from the center of the city. Landsat images of 1988, 1993, 1998, 2003, 2008, and 2011 were used to detect the land use and land cover (LULC changes. The demographic and economic data together with corresponding maps were used to determine the driving factors for land conversions. This study applied Cellular Automata-Markov Chain (CA-MC and Multi-Layer Perceptron-Markov Chain (MLP-MC to model LULC and urban expansions. The performance of the CA-MC and MLP-MC yielded more than 90% overall accuracy to predict the LULC, especially the MLP-MC method. Further, the annual population and economic growth rates were considered to produce the land demand for the LULC in 2014 and 2035 using the statistical extrapolation and system dynamics (SD. It was evident that the simulated map in 2014 resulting from the SD yielded the highest accuracy. Therefore, this study applied the SD method to generate the land demand for simulating LULC in 2035. The outcome showed that urban occupied the land around a half of the BMR.

  6. Multi-layered control of Galectin-8 mediated autophagy during adenovirus cell entry through a conserved PPxY motif in the viral capsid.

    Directory of Open Access Journals (Sweden)

    Charlotte Montespan

    2017-02-01

    Full Text Available Cells employ active measures to restrict infection by pathogens, even prior to responses from the innate and humoral immune defenses. In this context selective autophagy is activated upon pathogen induced membrane rupture to sequester and deliver membrane fragments and their pathogen contents for lysosomal degradation. Adenoviruses, which breach the endosome upon entry, escape this fate by penetrating into the cytosol prior to autophagosome sequestration of the ruptured endosome. We show that virus induced membrane damage is recognized through Galectin-8 and sequesters the autophagy receptors NDP52 and p62. We further show that a conserved PPxY motif in the viral membrane lytic protein VI is critical for efficient viral evasion of autophagic sequestration after endosomal lysis. Comparing the wildtype with a PPxY-mutant virus we show that depletion of Galectin-8 or suppression of autophagy in ATG5-/- MEFs rescues infectivity of the PPxY-mutant virus while depletion of the autophagy receptors NDP52, p62 has only minor effects. Furthermore we show that wildtype viruses exploit the autophagic machinery for efficient nuclear genome delivery and control autophagosome formation via the cellular ubiquitin ligase Nedd4.2 resulting in reduced antigenic presentation. Our data thus demonstrate that a short PPxY-peptide motif in the adenoviral capsid permits multi-layered viral control of autophagic processes during entry.

  7. Manufacturing Cost Analysis of Novel Steel/Concrete Composite Vessel for Stationary Storage of High-Pressure Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhili [ORNL; Zhang, Wei [ORNL; Wang, Jy-An John [ORNL; Ren, Fei [ORNL

    2012-09-01

    A novel, low-cost, high-pressure, steel/concrete composite vessel (SCCV) technology for stationary storage of compressed gaseous hydrogen (CGH2) is currently under development at Oak Ridge National Laboratory (ORNL) sponsored by DOE s Fuel Cell Technologies (FCT) Program. The SCCV technology uses commodity materials including structural steels and concretes for achieving cost, durability and safety requirements. In particular, the hydrogen embrittlement of high-strength low-alloy steels, a major safety and durability issue for current industry-standard pressure vessel technology, is mitigated through the use of a unique layered steel shell structure. This report presents the cost analysis results of the novel SCCV technology. A high-fidelity cost analysis tool is developed, based on a detailed, bottom-up approach which takes into account the material and labor costs involved in each of the vessel manufacturing steps. A thorough cost study is performed to understand the SCCV cost as a function of the key vessel design parameters, including hydrogen pressure, vessel dimensions, and load-carrying ratio. The major conclusions include: The SCCV technology can meet the technical/cost targets set forth by DOE s FCT Program for FY2015 and FY2020 for all three pressure levels (i.e., 160, 430 and 860 bar) relevant to the hydrogen production and delivery infrastructure. Further vessel cost reduction can benefit from the development of advanced vessel fabrication technologies such as the highly automated friction stir welding (FSW). The ORNL-patented multi-layer, multi-pass FSW can not only reduce the amount of labor needed for assembling and welding the layered steel vessel, but also make it possible to use even higher strength steels for further cost reductions and improvement of vessel structural integrity. It is noted the cost analysis results demonstrate the significant cost advantage attainable by the SCCV technology for different pressure levels when compared to the

  8. Photonic devices on planar and curved substrates and methods for fabrication thereof

    Energy Technology Data Exchange (ETDEWEB)

    Bartl, Michael H.; Barhoum, Moussa; Riassetto, David

    2016-08-02

    A versatile and rapid sol-gel technique for the fabrication of high quality one-dimensional photonic bandgap materials. For example, silica/titania multi-layer materials may be fabricated by a sol-gel chemistry route combined with dip-coating onto planar or curved substrate. A shock-cooling step immediately following the thin film heat-treatment process is introduced. This step was found important in the prevention of film crack formation--especially in silica/titania alternating stack materials with a high number of layers. The versatility of this sol-gel method is demonstrated by the fabrication of various Bragg stack-type materials with fine-tuned optical properties by tailoring the number and sequence of alternating layers, the film thickness and the effective refractive index of the deposited thin films. Measured optical properties show good agreement with theoretical simulations confirming the high quality of these sol-gel fabricated optical materials.

  9. Multi-Layer Traffic Steering

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Gimenez, Lucas Chavarria

    2013-01-01

    This paper investigates the potentials of traffic steering in the Radio Resource Control (RRC) Idle state by evaluating the Absolute Priorities (AP) framework in a multilayer Long Term Evolution (LTE) macrocell scenario. Frequency priorities are broadcast on the system information and RRC Idle...... signaling. The priority adjustment is based on both the Composite Available Capacity (CAC) and the radio conditions of the candidate layers. Compared to broadcast AP, the proposed scheme achieves better load balancing performance and improves network capacity, given that the User Equipment (UE) inactivity...

  10. A new multi-layer approach for progressive damage simulation in composite laminates based on isogeometric analysis and Kirchhoff-Love shells. Part II: impact modeling

    Science.gov (United States)

    Pigazzini, M. S.; Bazilevs, Y.; Ellison, A.; Kim, H.

    2017-11-01

    In this two-part paper we introduce a new formulation for modeling progressive damage in laminated composite structures. We adopt a multi-layer modeling approach, based on isogeometric analysis, where each ply or lamina is represented by a spline surface, and modeled as a Kirchhoff-Love thin shell. Continuum damage mechanics is used to model intralaminar damage, and a new zero-thickness cohesive-interface formulation is introduced to model delamination as well as permitting laminate-level transverse shear compliance. In Part I of this series we focus on the presentation of the modeling framework, validation of the framework using standard Mode I and Mode II delamination tests, and assessment of its suitability for modeling thick laminates. In Part II of this series we focus on the application of the proposed framework to modeling and simulation of damage in composite laminates resulting from impact. The proposed approach has significant accuracy and efficiency advantages over existing methods for modeling impact damage. These stem from the use of IGA-based Kirchhoff-Love shells to represent the individual plies of the composite laminate, while the compliant cohesive interfaces enable transverse shear deformation of the laminate. Kirchhoff-Love shells give a faithful representation of the ply deformation behavior, and, unlike solids or traditional shear-deformable shells, do not suffer from transverse-shear locking in the limit of vanishing thickness. This, in combination with higher-order accurate and smooth representation of the shell midsurface displacement field, allows us to adopt relatively coarse in-plane discretizations without sacrificing solution accuracy. Furthermore, the thin-shell formulation employed does not use rotational degrees of freedom, which gives additional efficiency benefits relative to more standard shell formulations.

  11. Water equivalent thickness of immobilization devices in proton therapy planning - Modelling at treatment planning and validation by measurements with a multi-layer ionization chamber.

    Science.gov (United States)

    Fellin, Francesco; Righetto, Roberto; Fava, Giovanni; Trevisan, Diego; Amelio, Dante; Farace, Paolo

    2017-03-01

    To investigate the range errors made in treatment planning due to the presence of the immobilization devices along the proton beam path. The measured water equivalent thickness (WET) of selected devices was measured by a high-energy spot and a multi-layer ionization chamber and compared with that predicted by treatment planning system (TPS). Two treatment couches, two thermoplastic masks (both un-stretched and stretched) and one headrest were selected. At TPS, every immobilization device was modelled as being part of the patient. The following parameters were assessed: CT acquisition protocol, dose-calculation grid-sizes (1.5 and 3.0mm) and beam-entrance with respect to the devices (coplanar and non-coplanar). Finally, the potential errors produced by a wrong manual separation between treatment couch and the CT table (not present during treatment) were investigated. In the thermoplastic mask, there was a clear effect due to beam entrance, a moderate effect due to the CT protocols and almost no effect due to TPS grid-size, with 1mm errors observed only when thick un-stretched portions were crossed by non-coplanar beams. In the treatment couches the WET errors were negligible (0.5mm with a 3.0mm grid-size. In the headrest, WET errors were negligible (0.2mm). With only one exception (un-stretched mask, non-coplanar beams), the WET of all the immobilization devices was properly modelled by the TPS. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  12. SU-F-J-41: Experimental Validation of a Cascaded Linear System Model for MVCBCT with a Multi-Layer EPID

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Y; Rottmann, J; Myronakis, M; Berbeco, R [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana Farber Cancer Institute and Harvard Medical School, Boston, MA. (United States); Fueglistaller, R; Morf, D [Varian Medical Systems, Dattwil, Aargau (Switzerland); Wang, A; Shedlock, D; Star-Lack, J [Varian Medical Systems, Palo Alto, CA (United States)

    2016-06-15

    Purpose: The purpose of this study was to validate the use of a cascaded linear system model for MV cone-beam CT (CBCT) using a multi-layer (MLI) electronic portal imaging device (EPID) and provide experimental insight into image formation. A validated 3D model provides insight into salient factors affecting reconstructed image quality, allowing potential for optimizing detector design for CBCT applications. Methods: A cascaded linear system model was developed to investigate the potential improvement in reconstructed image quality for MV CBCT using an MLI EPID. Inputs to the three-dimensional (3D) model include projection space MTF and NPS. Experimental validation was performed on a prototype MLI detector installed on the portal imaging arm of a Varian TrueBeam radiotherapy system. CBCT scans of up to 898 projections over 360 degrees were acquired at exposures of 16 and 64 MU. Image volumes were reconstructed using a Feldkamp-type (FDK) filtered backprojection (FBP) algorithm. Flat field images and scans of a Catphan model 604 phantom were acquired. The effect of 2×2 and 4×4 detector binning was also examined. Results: Using projection flat fields as an input, examination of the modeled and measured NPS in the axial plane exhibits good agreement. Binning projection images was shown to improve axial slice SDNR by a factor of approximately 1.4. This improvement is largely driven by a decrease in image noise of roughly 20%. However, this effect is accompanied by a subsequent loss in image resolution. Conclusion: The measured axial NPS shows good agreement with the theoretical calculation using a linear system model. Binning of projection images improves SNR of large objects on the Catphan phantom by decreasing noise. Specific imaging tasks will dictate the implementation image binning to two-dimensional projection images. The project was partially supported by a grant from Varian Medical Systems, Inc. and grant No. R01CA188446-01 from the National Cancer Institute.

  13. Multi-Variable, Multi-Layer Graphical Knowledge Unit for Storing and Representing Density Clusters of Multi-Dimensional Big Data

    Directory of Open Access Journals (Sweden)

    K. K. L. B. Adikaram

    2016-04-01

    Full Text Available A multi-variable visualization technique on a 2D bitmap for big data is introduced. If A and B are two data points that are represented using two similar shapes with m pixels, where each shape is colored with RGB color of (0, 0, k, when A ∩ B ≠ ɸ, adding the color of A ∩ B gives higher color as (0, 0, 2k and the highlight as a high density cluster, where RGB stands for Red, Green, Blue and k is the blue color. This is the hypothesis behind the single variable graphical knowledge unit (GKU, which uses the entire bit range of a pixel for a single variable. Instead, the available bit range of a pixel is split, and a pixel can be used for representing multiple variables (multi-variables. However, this will limit the bit block for single variables and limit the amount of overlapping. Using the same size k (>1 bitmaps (multi-layers will increase the number of bits per variable (BPV, where each (x, y of an individual layer represents the same data point. Then, one pixel in a four-layer GKU is capable of showing more than four billion overlapping ones when BPV = 8 bits (2(BPV × number of layers Then, the 32-bit pixel format allows the representation of a maximum of up to four dependent variables against one independent variable. Then, a four-layer GKU of w width and h height has the capacity of representing a maximum of (2(BPV × number of layers × m × w × h overlapping occurrences.

  14. Fast and low-cost method to fabricate large-area superhydrophobic surface on steel substrate with anticorrosion and anti-icing properties

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Wei; Liu, Hongtao, E-mail: liuht100@126.com; Sun, Qinghe; Zhu, Wei [College of Materials Science and Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Chen, Tianchi [College of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China)

    2016-07-15

    A facile and quick fabrication method was proposed to prepare superhydrophobic surfaces on iron substrate by chemical immersion and subsequent stearic acid modification. The association between wettability and surface morphology was studied through altering the copper ion concentration and immersion time. Surface tension instrument, scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and electrochemical workstation were used to characterize the wettability, physical morphology, chemical composition, and corrosion resistance ability of the prepared film. Results showed that both the rough micro/nanostructures and low surface energy material play critical roles in surface wettability. The superhydrophobic film achieved a better anticorrosion property compared to barrier iron by analysis of open circuit potential, potentiodynamic polarization curves, and Nyquist plots. In addition, the superhydrophobic surface showed excellent performance of acid and alkali resistance, anti-icing, and self-cleaning through a series of environmental tests. This study provides a valid method for quick-preparation of the stable superhydrophobic surfaces, which has a promising application in steel buildings and facilities.

  15. Enhanced power production of a membrane electrode assembly microbial fuel cell (MFC) using a cost effective poly [2,5-benzimidazole] (ABPBI) impregnated non-woven fabric filter.

    Science.gov (United States)

    Choi, Soojung; Kim, Jung Rae; Cha, Jaehwan; Kim, Yejin; Premier, Giuliano C; Kim, Changwon

    2013-01-01

    A membrane electrode assembly (MEA) microbial fuel cell (MFC) with a non-woven paper fabric filter (NWF) was investigated as an alternative to a proton exchange membrane (PEM) separator. The MFC with a NWF generated a cell voltage of 545 mV and a maximum power density of 1027 mW/m(3), which was comparable to that obtained from MFCs with a PEM (551 mV, 609 mW/m(3)). The MFC with a NWF showed stable cell performance (550 mV) over 300 days, whereas, the MFC with PEM performance decreased significantly from 551 mV to 415 mV due to biofilm formation and chemical precipitation on the membrane surface. Poly [2,5-benzimidazole] (ABPBI) was evaluated with respect to its capacity to increased proton conductivity and contact between separator and electrodes. The overall performance of the MFC with ABPBI was improved by enhancing the ion conductivity and steric contact, producing 766 mW/m(3) at optimum loading of 50 mg ABPBI/cm(2). Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Multi-layered water resources, management, and uses under the impacts of global changes in a southern coastal metropolis: When will it be already too late? Crossed analysis in Recife, NE Brazil.

    Science.gov (United States)

    Petelet-Giraud, Emmanuelle; Cary, Lise; Cary, Paul; Bertrand, Guillaume; Giglio-Jacquemot, Armelle; Hirata, Ricardo; Aquilina, Luc; Alves, Lincoln Muniz; Martins, Veridiana; Melo, Ana Maria; Montenegro, Suzana; Chatton, Eliot; Franzen, Melissa; Aurouet, Axel

    2018-03-15

    Coastal water resources are a worldwide key socio-environmental issue considering the increasing concentration of population in these areas. Here, we propose an integrative transdisciplinary approach of water resource, water management and water access in Recife (NE Brazil). The present-day water situation is conceptualized as an imbricated multi-layered system: a multi-layered water resource, managed by a multi-layered governance system and used by a multi-layered social population. This allows identifying processes of quantitative, qualitative, and sanitary conflicts between governance and population strategies regarding water supply, as well as the institutional and individual denials of these conflicts. Based on this model, we anticipate future water-related problematic fates. Concerning the water resource system, the rapid groundwater level decrease due to unsustainable water predatory strategies, and the very low recharge rate have drastically modified the aquifer system functioning, inducing hydraulic connection between shallow groundwater (contaminated and locally salty) and deep ones (mostly fresh, with local inherited salinity), threatening the deep strategic water resource. Concerning the water governance system, the investments to increase the capacity storage of surface water, the water regulation agencies and the public/private partnership should shortly improve the water supply and wastewater issue. Nevertheless, the water situation will remain highly fragile due to the expected water demand increase, the precipitation decrease and the sea-level increase. Concerning the water access system, the population variably perceives these current and further effects and the possible mitigation policies, and develops alternative individual strategies. Authorities, policymakers and water managers will have to implement a well-balanced water governance, taking into account the specificities of the PPP, public and private groundwater users, and with a strong

  17. Effectiveness of a multi-layer foam dressing in preventing sacral pressure ulcers for the early acute care of patients with a traumatic spinal cord injury: comparison with the use of a gel mattress.

    Science.gov (United States)

    Richard-Denis, Andréane; Thompson, Cynthia; Mac-Thiong, Jean-Marc

    2017-10-01

    Individuals with spinal cord injury are at risk of sacral pressure ulcers due to, among other reasons, prolonged immobilisation. The effectiveness of a multi-layer foam dressing installed pre-operatively in reducing sacral pressure ulcer occurrence in spinal cord injured patients was compared to that of using a gel mattress, and stratified analyses were performed on patients with complete tetraplegia and paraplegia. Socio-demographic and clinical data were collected from 315 patients admitted in a level-I trauma centre following a spinal cord injury between April 2010 and March 2016. Upon arrival to the emergency room and until surgery, patients were transferred on a foam stretcher pad with a viscoelastic polymer gel mattress (before 1 October 2014) or received a multi-layer foam dressing applied to their sacral-coccygeal area (after 1 October 2014). The occurrence of sacral pressure ulcer during acute hospitalisation was similar irrespective of whether patients received the dressing or the gel mattress. It was found that 82% of patients with complete tetraplegia receiving the preventive dressing developed sacral ulcers as compared to only 36% of patients using the gel mattress. Although multi-layer dressings were suggested to improve skin protection and decrease pressure ulcer occurrence in critically ill patients, such preventive dressings are not superior to gel mattresses in spinal cord injured patients and should be used with precaution, especially in complete tetraplegia. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  18. Fabricating Copper Nanotubes by Electrodeposition

    Science.gov (United States)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  19. Low cost fabrication of sheet structure using a new beta titanium alloy, Ti-15V-3Cr-3Al-3Sn

    Science.gov (United States)

    Kaneko, R. S.; Davis, G. W.; Woods, C. A.; Royster, D. M.

    1982-01-01

    Development efforts have been undertaken to improve the processing and structural efficiencies of advanced cold-formable beta Ti alloys, using the standard, hot-formed and rivetted construction of Ti-6Al-4V sheet structures as a basis for comparison. Ti-15V-3Cr-3Al-3Sn (Ti-15-3) beta alloy is formable, brazable and weldable in the solution-treated condition, and after aging displays mechanical properties suitable for postulated service in the -65 to 600 F temperature range. A novel methodology using cold-formed Ti-15-3 stringers and Ti-6Al-4V face sheets that are joined by means of an out-of-furnace isothermal brazing process, followed by low temperature aging, can reduce production costs by as much as 28 per cent. Structural efficiency has been demonstrated in room and elevated temperature crippling tests of small skin-stringer assemblies.

  20. Evaluating the performance of land surface model ORCHIDEE-CAN v1.0 on water and energy flux estimation with a single- and multi-layer energy budget scheme

    Science.gov (United States)

    Chen, Yiying; Ryder, James; Bastrikov, Vladislav; McGrath, Matthew J.; Naudts, Kim; Otto, Juliane; Ottlé, Catherine; Peylin, Philippe; Polcher, Jan; Valade, Aude; Black, Andrew; Elbers, Jan A.; Moors, Eddy; Foken, Thomas; van Gorsel, Eva; Haverd, Vanessa; Heinesch, Bernard; Tiedemann, Frank; Knohl, Alexander; Launiainen, Samuli; Loustau, Denis; Ogée, Jérôme; Vessala, Timo; Luyssaert, Sebastiaan

    2016-09-01

    Canopy structure is one of the most important vegetation characteristics for land-atmosphere interactions, as it determines the energy and scalar exchanges between the land surface and the overlying air mass. In this study we evaluated the performance of a newly developed multi-layer energy budget in the ORCHIDEE-CAN v1.0 land surface model (Organising Carbon and Hydrology In Dynamic Ecosystems - CANopy), which simulates canopy structure and can be coupled to an atmospheric model using an implicit coupling procedure. We aim to provide a set of acceptable parameter values for a range of forest types. Top-canopy and sub-canopy flux observations from eight sites were collected in order to conduct this evaluation. The sites crossed climate zones from temperate to boreal and the vegetation types included deciduous, evergreen broad-leaved and evergreen needle-leaved forest with a maximum leaf area index (LAI; all-sided) ranging from 3.5 to 7.0. The parametrization approach proposed in this study was based on three selected physical processes - namely the diffusion, advection, and turbulent mixing within the canopy. Short-term sub-canopy observations and long-term surface fluxes were used to calibrate the parameters in the sub-canopy radiation, turbulence, and resistance modules with an automatic tuning process. The multi-layer model was found to capture the dynamics of sub-canopy turbulence, temperature, and energy fluxes. The performance of the new multi-layer model was further compared against the existing single-layer model. Although the multi-layer model simulation results showed few or no improvements to both the nighttime energy balance and energy partitioning during winter compared with a single-layer model simulation, the increased model complexity does provide a more detailed description of the canopy micrometeorology of various forest types. The multi-layer model links to potential future environmental and ecological studies such as the assessment of in