WorldWideScience

Sample records for nonplanar arrays formed

  1. EM design and analysis of dipole arrays on non-planar dielectric substrate

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents a simple and systematic description of EM design of antenna arrays. Printed dipole antennas are known to be simple yet more efficient than wire antennas. The dielectric substrate and the presence of ground plane affect the antenna performance and the resonant frequency is shifted. This book includes the EM design and performance analysis of printed dipole arrays on planar and cylindrical substrates. The antenna element is taken as half-wave centre-fed dipole. The substrate is taken as low-loss dielectric. The effect of substrate material, ground plane, and the curvature effect is discussed. Results are presented for both the linear and planar dipole arrays. The performance of dipole array is analyzed in terms of input impedance, return loss, and radiation pattern for different configurations. The effect of curved platform (substrate and ground plane) on the radiation behaviour of dipole array is analyzed. The book explains fundamentals of EM design and analysis of dipole antenna array throu...

  2. Fabrication method for small-scale structures with non-planar features

    Energy Technology Data Exchange (ETDEWEB)

    Burckel, David Bruce; Ten Eyck, Gregory A.

    2016-09-20

    The fabrication of small-scale structures is disclosed. A unit-cell of a small-scale structure with non-planar features is fabricated by forming a membrane on a suitable material. A pattern is formed in the membrane and a portion of the substrate underneath the membrane is removed to form a cavity. Resonators are then directionally deposited on the wall or sides of the cavity. The cavity may be rotated during deposition to form closed-loop resonators. The resonators may be non-planar. The unit-cells can be formed in a layer that includes an array of unit-cells.

  3. Manifestations of non-planar adsorption geometries of lead pyrenocyanine at the liquid-solid interface.

    Science.gov (United States)

    Mali, Kunal S; Zöphel, Lukas; Ivasenko, Oleksandr; Müllen, Klaus; De Feyter, Steven

    2013-10-01

    In this work, we provide evidence for multiple non-planar adsorption geometries of a novel pyrenocyanine derivative at the liquid-solid interface under ambient conditions. When adsorbed at the organic liquid-solid interface, lead pyrenocyanine forms well-ordered monolayers that exhibit peculiar non-periodic contrast variation. The different contrast of the adsorbed molecules is attributed to dissimilar adsorption geometries which arise from the non-planar conformation of the molecules. The non-planarity of the molecular backbone in turn arises due to a combination of the angularly extended pyrene subunits and the presence of the large lead ion, which is too big to fit inside the central cavity and thus is located out of the aromatic plane. The two possible locations of the lead atom, namely below and above the aromatic plane, could be identified as depression and protrusion in the central cavity, respectively. The manifestation of such multiple adsorption geometries on the structure of the resultant monolayer is discussed in detail. The packing density of these 2D arrays of molecules could be tuned by heating of the sample wherein the molecular packing changes from a low-density, pseudo six-fold symmetric to a high-density, two-fold symmetric arrangement. Finally, a well-ordered two-component system could be constructed by incorporating C60 molecules in the adlayer of lead pyrenocyanine at the liquid-solid interface.

  4. Evidence for a Nonplanar Amplituhedron

    CERN Document Server

    Bern, Zvi; Litsey, Sean; Stankowicz, James; Trnka, Jaroslav

    2015-01-01

    The scattering amplitudes of planar N = 4 super-Yang-Mills exhibit a number of remarkable analytic structures, including dual conformal symmetry and logarithmic singularities of integrands. The amplituhedron is a geometric construction of the integrand that incorporates these structures. This geometric construction further implies the amplitude is fully specified by constraining it to vanish on spurious residues. By writing the amplitude in a dlog basis, we provide nontrivial evidence that these analytic properties and "zero conditions" carry over into the nonplanar sector. This suggests that the concept of the amplituhedron can be extended to the the nonplanar sector of N = 4 super-Yang-Mills theory.

  5. Evidence for a nonplanar amplituhedron

    Science.gov (United States)

    Bern, Zvi; Herrmann, Enrico; Litsey, Sean; Stankowicz, James; Trnka, Jaroslav

    2016-06-01

    The scattering amplitudes of planar mathcal{N} = 4 super-Yang-Mills exhibit a number of remarkable analytic structures, including dual conformal symmetry and logarithmic singularities of integrands. The amplituhedron is a geometric construction of the integrand that incorporates these structures. This geometric construction further implies the amplitude is fully specified by constraining it to vanish on spurious residues. By writing the amplitude in a dlog basis, we provide nontrivial evidence that these analytic properties and "zero conditions" carry over into the nonplanar sector. This suggests that the concept of the amplituhedron can be extended to the nonplanar sector of mathcal{N} = 4 super-Yang-Mills theory.

  6. Beam-Forming Concentrating Solar Thermal Array Power Systems

    Science.gov (United States)

    Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

    2016-01-01

    The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

  7. Hydrogel-Forming Microneedle Arrays for Enhanced Transdermal Drug Delivery

    OpenAIRE

    Donnelly, Ryan F.; Singh, Thakur Raghu Raj; Garland, Martin J.; Migalska, Katarzyna; Majithiya, Rita; McCrudden, Cian M; Kole, Prashant Laxman; Mahmood, Tuan Mazlelaa Tuan; McCarthy, Helen O; Woolfson, A. David

    2012-01-01

    Unique microneedle arrays prepared from crosslinked polymers, which contain no drug themselves, are described. They rapidly take up skin interstitial fluid upon skin insertion to form continuous, unblockable, hydrogel conduits from attached patch-type drug reservoirs to the dermal microcirculation. Importantly, such microneedles, which can be fabricated in a wide range of patch sizes and microneedle geometries, can be easily sterilized, resist hole closure while in place, and are removed comp...

  8. Forming lipid bilayer membrane arrays on micropatterned polyelectrolyte film surfaces.

    Science.gov (United States)

    Zhang, Ying; Wang, Lei; Wang, Xuejing; Qi, Guodong; Han, Xiaojun

    2013-07-01

    A novel method of forming lipid bilayer membrane arrays on micropatterned polyelectrolyte film surfaces is introduced. Polyelectrolyte films were fabricated by the layer-by-layer technique on a silicon oxide surface modified with a 3-aminopropyltriethoxysilane (APTES) monolayer. The surface pK(a) value of the APTES monolayer was determined by cyclic voltammetry to be approximately 5.61, on the basis of which a pH value of 2.0 was chosen for layer-by-layer assembly. Micropatterned polyelectrolyte films were obtained by deep-UV (254 nm) photolysis though a mask. Absorbed fluorescent latex beads were used to visualize the patterned surfaces. Lipid bilayer arrays were fabricated on the micropatterned surfaces by immersing the patterned substrates into a solution containing egg phosphatidylcholine vesicles. Fluorescence recovery after photobleaching studies yielded a lateral diffusion coefficient for probe molecules of 1.31±0.17 μm(2) s(-1) in the bilayer region, and migration of the lipid NBD PE in bilayer lipid membrane arrays was observed in an electric field.

  9. Hydrogel-Forming Microneedle Arrays for Enhanced Transdermal Drug Delivery.

    Science.gov (United States)

    Donnelly, Ryan F; Singh, Thakur Raghu Raj; Garland, Martin J; Migalska, Katarzyna; Majithiya, Rita; McCrudden, Cian M; Kole, Prashant Laxman; Mahmood, Tuan Mazlelaa Tuan; McCarthy, Helen O; Woolfson, A David

    2012-12-05

    Unique microneedle arrays prepared from crosslinked polymers, which contain no drug themselves, are described. They rapidly take up skin interstitial fluid upon skin insertion to form continuous, unblockable, hydrogel conduits from attached patch-type drug reservoirs to the dermal microcirculation. Importantly, such microneedles, which can be fabricated in a wide range of patch sizes and microneedle geometries, can be easily sterilized, resist hole closure while in place, and are removed completely intact from the skin. Delivery of macromolecules is no longer limited to what can be loaded into the microneedles themselves and transdermal drug delivery is now controlled by the crosslink density of the hydrogel system rather than the stratum corneum, while electrically modulated delivery is also a unique feature. This technology has the potential to overcome the limitations of conventional microneedle designs and greatly increase the range of the type of drug that is deliverable transdermally, with ensuing benefits for industry, healthcare providers and, ultimately, patients.

  10. Polymeric microlens array formed directly on glass plate

    Science.gov (United States)

    Zhou, Zuowei; Ren, Hongwen

    2017-01-01

    We prepared a polymeric microlens array (MLA) using ultraviolet (UV) light to cure photosensitive monomers through a photomask. After a short-time UV exposure, the uncured monomers experience a process of partial wetting and self-development on the surface of cured monomers. As a result, a geometric relief with a lens character is generated. Depending on the pattern of the photomask, either a convex or concave MLA can be fabricated. The mechanism of forming the MLA is explained and the concept is proved experimentally. Owing to the merits of simple fabrication, good flexibility, and high optical performance, the MLA has potential applications in light diffusers, fiber/organic light-emitting diode couplers, biomedical imaging, and displays.

  11. Dynamics of rotationally fissioned asteroids: non-planar case

    Science.gov (United States)

    Boldrin, L. A. G.; Scheeres, D. J.; Winter, O. C.

    2016-10-01

    The rotational fission of asteroids has been studied previously with simplified models restricted to planar motion. However, the observed physical configuration of contact binaries leads one to conclude that most of them are not in a planar configuration and hence would not be restricted to planar motion once they undergo rotational fission. This motivated a study of the evolution of initially non-planar binaries created by fission. Using a two-ellipsoid model, we performed simulations taking only gravitational interactions between components into account. We simulate 91 different initial inclinations of the equator of the secondary body for 19 different mass ratios. After disruption, the binary system dynamics are chaotic, as predicted from theory. Starting the system in a non-planar configuration leads to a larger energy and enhanced coupling between the rotation state of the smaller fissioned body and the evolving orbital system, and enables re-impact to occur. This leads to differences with previous planar studies, with collisions and secondary spin fission occurring for all mass ratios with inclinations θ0 ≥ 40o, and mimics a Lidov-Kozai mechanism. Out of 1729 studied cases, we found that ˜14 per cent result in secondary fission, ˜25 per cent result in collisions and ˜6 per cent have lifetimes longer than 200 yr. In Jacobson & Scheeres stable binaries only formed in cases with mass ratios q system should start in a non-planar configuration.

  12. Discrete differential geometry: the nonplanar quadrilateral mesh.

    Science.gov (United States)

    Twining, Carole J; Marsland, Stephen

    2012-06-01

    We consider the problem of constructing a discrete differential geometry defined on nonplanar quadrilateral meshes. Physical models on discrete nonflat spaces are of inherent interest, as well as being used in applications such as computation for electromagnetism, fluid mechanics, and image analysis. However, the majority of analysis has focused on triangulated meshes. We consider two approaches: discretizing the tensor calculus, and a discrete mesh version of differential forms. While these two approaches are equivalent in the continuum, we show that this is not true in the discrete case. Nevertheless, we show that it is possible to construct mesh versions of the Levi-Civita connection (and hence the tensorial covariant derivative and the associated covariant exterior derivative), the torsion, and the curvature. We show how discrete analogs of the usual vector integral theorems are constructed in such a way that the appropriate conservation laws hold exactly on the mesh, rather than only as approximations to the continuum limit. We demonstrate the success of our method by constructing a mesh version of classical electromagnetism and discuss how our formalism could be used to deal with other physical models, such as fluids.

  13. Effect of nonplanar geometry on ion acoustic solitary waves in presence of ionization in collisional dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Samiran [College of Textile Technology, Berhampore 742101, Murshidabad, West Bengal (India)]. E-mail: sran_g@yahoo.com

    2005-04-11

    It has been found that the dust ion acoustic solitary wave (DIASW) is governed by a modified form of Korteweg-de Vries (KdV) equation modified by the effects of ionization, particle collisions and bounded nonplanar geometry. Approximate analytical time evolution solution and also the numerical solution of modified form of KdV equation reveal that the wave amplitude grows exponentially with time due to ionization, whereas the bounded nonplanar geometry and collision reduce the instability growth rate.

  14. Eigenpolarization theory of monolithic nonplanar ring oscillators

    Science.gov (United States)

    Nilsson, Alan C.; Gustafson, Eric K.; Byer, Robert L.

    1989-01-01

    Diode-laser-pumped monolithic nonplanar ring oscillators (NPROs) in an applied magnetic field can operate as unidirectional traveling-wave lasers. The diode laser pumping, monolithic construction, and unidirectional oscillation lead to narrow linewidth radiation. Here, a comprehensive theory of the eigenpolarizations of a monolithic NPRO is presented. It is shown how the properties of the integral optical diode that forces unidirectional operation depend on the choice of the gain medium, the applied magnetic field, the output coupler, and the geometry of the nonplanar ring light path. Using optical equivalence theorems to gain insight into the polarization characteristics of the NPRO, a strategy for designing NPROs with low thresholds and large loss nonreciprocities is given. An analysis of the eigenpolarizations for one such NPRO is presented, alternative optimization approaches are considered, and the prospects for further reducing the linewidths of these lasers are briefly discussed.

  15. Structural mechanisms of nonplanar hemes in proteins

    Energy Technology Data Exchange (ETDEWEB)

    Shelnutt, J.A.

    1997-05-01

    The objective is to assess the occurrence of nonplanar distortions of hemes and other tetrapyrroles in proteins and to determine the biological function of these distortions. Recently, these distortions were found by us to be conserved among proteins belonging to a functional class. Conservation of the conformation of the heme indicates a possible functional role. Researchers have suggested possible mechanisms by which heme distortions might influence biological properties; however, no heme distortion has yet been shown conclusively to participate in a structural mechanism of hemoprotein function. The specific aims of the proposed work are: (1) to characterize and quantify the distortions of the hemes in all of the more than 300 hemoprotein X-ray crystal structures in terms of displacements along the lowest-frequency normal coordinates, (2) to determine the structural features of the protein component that generate and control these nonplanar distortions by using spectroscopic studies and molecular-mechanics calculations for the native proteins, their mutants and heme-peptide fragments, and model porphyrins, (3) to determine spectroscopic markers for the various types of distortion, and, finally, (4) to discover the functional significance of the nonplanar distortions by correlating function with porphyrin conformation for proteins and model porphyrins.

  16. nf2 contributions to fermionic four-loop form factors

    Science.gov (United States)

    Lee, Roman N.; Smirnov, Alexander V.; Smirnov, Vladimir A.; Steinhauser, Matthias

    2017-07-01

    We compute the four-loop contributions to the photon quark and Higgs quark form factors involving two closed fermion loops. We present analytical results for all nonplanar master integrals of the two nonplanar integral families which enter our calculation.

  17. Synchronization and beam forming in an array of repulsively coupled oscillators.

    Science.gov (United States)

    Rulkov, N F; Tsimring, L; Larsen, M L; Gabbay, M

    2006-11-01

    We study the dynamics of an array of Stuart-Landau oscillators with repulsive coupling. Autonomous network with global repulsive coupling settles on one from a continuum of synchronized regimes characterized by zero mean field. Driving this array by an external oscillatory signal produces a nonzero mean field that follows the driving signal even when the oscillators are not locked to the external signal. At sufficiently large amplitude the external signal synchronizes the oscillators and locks the phases of the array oscillations. Application of this system as a beam-forming element of a phase array antenna is considered. The phase dynamics of the oscillator array synchronization is used to reshape the phases of signals received from the phase array antenna and improve its beam pattern characteristics.

  18. Arrays of optical vortices formed by "fork" holograms

    CERN Document Server

    Bekshaev, A Ya; Mohammed, K A

    2014-01-01

    Singular light beams with optical vortices (OV) are often generated by means of thin binary gratings with groove bifurcation ("fork holograms") that produce a set of diffracted beams with different OV charges. Usually, only single separate beams are used and investigated; here we consider the whole set of diffracted OV beams that, at certain conditions, are involved in efficient mutual interference to form a characteristic pattern where the ring-like structure of separate OV beams is replaced by series of bright and dark lines between adjacent diffraction orders. This pattern, well developed for high diffraction orders, reflects the main spatial properties of the diffracted beams as well as of the fork grating used for their generation. In particular, it confirms the theoretical model for the diffracted beams (Kummer beam model) and enables to determine the sign and the absolute value of the phase singularity embedded in the hologram.

  19. Development of a Marine Propeller With Nonplanar Lifting Surfaces

    DEFF Research Database (Denmark)

    Andersen, Poul; Friesch, Jürgen; Kappel, Jens J.

    2005-01-01

    The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or winglet at the wingtip has been developed for aircraft, the application of the nonplanar principle to marine propellers, dealt...

  20. System Realization of Broad Band Digital Beam Forming for Digital Array Radar

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2013-09-01

    Full Text Available Broad band Digital Beam Forming (DBF is the key technique for the realization of Digital Array Radar (DAR. We propose the method of combination realization of the channel equalization and DBF time delay filter function by using adaptive Sample Matrix Inversion algorithm. The broad band DBF function is realized on a new DBF module based on parallel fiber optic engines and Field Program Gate Array (FPGA. Good performance is achieved when it is used to some radar products.

  1. Numerical Investigation of Pulsatile Blood Flow in a Bifurcation Model with a Non-Planar Branch: The Effect of Different Bifurcation Angles and Non-Planar Branch

    Directory of Open Access Journals (Sweden)

    Omid Arjmandi-Tash

    2012-12-01

    Full Text Available Introduction: Atherosclerosis is a focal disease that susceptibly forms near bifurcations, anastomotic joints, side branches, and curved vessels along the arterial tree. In this study, pulsatile blood flow in a bifurcation model with a non-planar branch is investigated. Methods: Wall shear stress (WSS distributions along generating lines on vessels for different bifurcation angles are calculated during the pulse cycle. Results: The WSS at the outer side of the bifurcation plane vanishes especially for higher bifurcation angles but by increasing the bifurcation angle low WSS region squeezes. At the systolic phase there is a high possibility of formation of a separation region at the outer side of bifurcation plane for all the cases. WSS peaks exist on the inner side of bifurcation plane near the entry section of daughter vessels and these peaks drop as bifurcation angle is increased. Conclusion: It was found that non-planarity of the daughter vessel lowers the minimum WSS at the outer side of the bifurcation and increases the maximum WSS at the inner side. So it seems that the formation of atherosclerotic plaques at bifurcation region in direction of non-planar daughter vessel is more risky.

  2. Non-planar microfabricated gas chromatography column

    Science.gov (United States)

    Lewis, Patrick R.; Wheeler, David R.

    2007-09-25

    A non-planar microfabricated gas chromatography column comprises a planar substrate having a plurality of through holes, a top lid and a bottom lid bonded to opposite surfaces of the planar substrate, and inlet and outlet ports for injection of a sample gas and elution of separated analytes. A plurality of such planar substrates can be aligned and stacked to provide a longer column length having a small footprint. Furthermore, two or more separate channels can enable multi-channel or multi-dimensional gas chromatography. The through holes preferably have a circular cross section and can be coated with a stationary phase material or packed with a porous packing material. Importantly, uniform stationary phase coatings can be obtained and band broadening can be minimized with the circular channels. A heating or cooling element can be disposed on at least one of the lids to enable temperature programming of the column.

  3. Higher Loop Nonplanar Anomalous Dimensions from Symmetry

    CERN Document Server

    Koch, Robert de Mello; Messamah, Ilies

    2013-01-01

    In this article we study the action of the one loop dilatation operator on operators with a classical dimension of order N. These operators belong to the su(2) sector and are constructed using two complex fields Y and Z. For these operators non-planar diagrams contribute already at the leading order in N and the planar and large N limits are distinct. The action of the one loop and the two loop dilatation operator reduces to a set of decoupled oscillators and factorizes into an action on the Z fields and an action on the Y fields. Direct computation has shown that the action on the Y fields is the same at one and two loops. In this article, using the su(2) symmetry algebra as well as structural features of field theory, we give compelling evidence that the factor in the dilatation operator that acts on the Ys is given by the one loop expression, at any loop order.

  4. Method for making conductors for ferrite memory arrays. [from pre-formed metal conductors

    Science.gov (United States)

    Heckler, C. H.; Baba, P. D.; Bhiwandker, N. C. (Inventor)

    1974-01-01

    The ferrite memory arrays are made from pre-formed metal conductors for the ferrite arrays. The conductors are made by forming a thin sheet of a metallizing paste of metal alloy powder, drying the paste layer, bisque firing the dried sheet at a first temperature, and then punching the conductors from the fired sheet. During the bisque firing, the conductor sheet shrinks to 58 percent of its pre-fired volume and the alloy particles sinter together. The conductors are embedded in ferrite sheet material and finally fired at a second higher temperature during which firing the conductors shrink approximately the same degree as the ferrite material.

  5. Optically anisotropic microlens array film directly formed on a single substrate.

    Science.gov (United States)

    Ren, Hongwen; Xu, Su; Liu, Yifan; Wu, Shin-Tson

    2013-12-02

    An optically anisotropic microlens array film directly formed on a single substrate is demonstrated. UV curable diacrylate monomers are coated as a film on the substrate. Under the action of fringing field, not only the film surface is flattened by the generated dielectric force but also the monomers are reoriented to form a gradient refractive index (GRIN) distribution in the film. Via UV exposure, the GRIN distribution is fixed and the polymeric film behaves as a microlens array. The fabrication process is simple and the film offers a switchable focus through controlling the polarization direction of the incident light. Integrating with a 90° twisted-nematic liquid crystal cell, our polymeric microlens array film shows great potential for switchable 2D/3D autostereoscopic displays.

  6. Design of a ring resonator-based optical beam forming network for phased array receive antennas

    NARCIS (Netherlands)

    Klooster, van 't J.W.; Roeloffzen, C.G.H.; Meijerink, A.; Zhuang, L.; Marpaung, D.A.I.; Etten, van W.C.; Heideman, R.G.; Leinse, A.; Schippers, H.; Verpoorte, J.; Wintels, M.

    2008-01-01

    A novel squint-free ring resonator-based optical beam forming network (OBFN) for phased array antennas (PAA) is proposed. It is intended to provide broadband connectivity to airborne platforms via geostationary satellites. In this paper, we present the design of the OBFN and its control system. Our

  7. Non-planar vibrations of a string in the presence of a boundary obstacle

    Science.gov (United States)

    Singh, Harkirat; Wahi, Pankaj

    2017-02-01

    We analyze planar and non-planar motions of a string vibrating against a unilateral curved obstacle. Our model incorporates the change in tension due to stretching of the string, which introduces nonlinear coupling between motions in mutually perpendicular directions, as well as the wrapping nonlinearity due to the presence of the obstacle. The system of equations has been discretized by assuming functional form of the displacements which satisfies all the geometrical boundary conditions. This discretized system is then used to investigate the various motions possible both in the absence as well as the presence of the obstacle. In the absence of the obstacle, there are infinitely many planar and two non-planar motions viz. a circular trajectory and a precessing elliptical trajectory for a fixed magnitude of the disturbance. In contrast, the string has only one planar motion when the obstacle is present and two non-planar motions, either an oscillating orbit or a whirling orbit depending on the magnitude of the initial disturbance. To obtain the transition from oscillating to whirling orbits, we perform a stability analysis of the planar motion using Floquet theory. This analysis reveals that there exists a critical amplitude below which the planar motion is neutrally stable and the typical trajectories are ellipses with major and minor radii changing both in magnitude and direction. Beyond the critical amplitude, the planar motion is unstable and we get whirling trajectories which are precessing ellipses again with varying major and minor radii. We further study the effect of changing obstacle parameters on the critical amplitude, and obtain the stability boundaries in the space spanned by the obstacle parameters and the amplitude of the planar vibration. We obtain some interesting values of the obstacle parameters for which small and large amplitude planar motions are stable resulting in oscillating ellipses while motions with intermediate amplitudes are unstable

  8. Precision molding of advanced glass optics: innovative production technology for lens arrays and free form optics

    Science.gov (United States)

    Pongs, Guido; Bresseler, Bernd; Bergs, Thomas; Menke, Gert

    2012-10-01

    Today isothermal precision molding of imaging glass optics has become a widely applied and integrated production technology in the optical industry. Especially in consumer electronics (e.g. digital cameras, mobile phones, Blu-ray) a lot of optical systems contain rotationally symmetrical aspherical lenses produced by precision glass molding. But due to higher demands on complexity and miniaturization of optical elements the established process chain for precision glass molding is not sufficient enough. Wafer based molding processes for glass optics manufacturing become more and more interesting for mobile phone applications. Also cylindrical lens arrays can be used in high power laser systems. The usage of unsymmetrical free-form optics allows an increase of efficiency in optical laser systems. Aixtooling is working on different aspects in the fields of mold manufacturing technologies and molding processes for extremely high complex optical components. In terms of array molding technologies, Aixtooling has developed a manufacturing technology for the ultra-precision machining of carbide molds together with European partners. The development covers the machining of multi lens arrays as well as cylindrical lens arrays. The biggest challenge is the molding of complex free-form optics having no symmetrical axis. A comprehensive CAD/CAM data management along the entire process chain is essential to reach high accuracies on the molded lenses. Within a national funded project Aixtooling is working on a consistent data handling procedure in the process chain for precision molding of free-form optics.

  9. Analysis of thick, non-planar boundaries using the discontinuity analyser

    Directory of Open Access Journals (Sweden)

    M. W. Dunlop

    Full Text Available The advent of missions comprised of phased arrays of spacecraft, with separation distances ranging down to at least mesoscales, provides the scientific community with an opportunity to accurately analyse the spatial and temporal dependencies of structures in space plasmas. Exploitation of the multi-point data sets, giving vastly more information than in previous missions, thereby allows unique study of their small-scale physics. It remains an outstanding problem, however, to understand in what way comparative information across spacecraft is best built into any analysis of the combined data. Different investigations appear to demand different methods of data co-ordination. Of the various multi-spacecraft data analysis techniques developed to affect this exploitation, the discontinuity analyser has been designed to investigate the macroscopic properties (topology and motion of boundaries, revealed by multi-spacecraft magnetometer data, where the possibility of at least mesoscale structure is considered. It has been found that the analysis of planar structures is more straightforward than the analysis of non-planar boundaries, where the effects of topology and motion become interwoven in the data, and we argue here that it becomes necessary to customise the analysis for non-planar events to the type of structure at hand. One issue central to the discontinuity analyser, for instance, is the calculation of normal vectors to the structure. In the case of planar and `thin' non-planar structures, the method of normal determination is well-defined, although subject to uncertainties arising from unwanted signatures. In the case of `thick', non-planar structures, however, the method of determination becomes particularly sensitive to the type of physical sampling that is present. It is the purpose of this article to firstly review the discontinuity analyser technique and secondly, to discuss the analysis of the normals to thick non-planar

  10. Hydrogel-forming microneedle arrays: Potential for use in minimally-invasive lithium monitoring.

    Science.gov (United States)

    Eltayib, Eyman; Brady, Aaron J; Caffarel-Salvador, Ester; Gonzalez-Vazquez, Patricia; Zaid Alkilani, Ahlam; McCarthy, Helen O; McElnay, James C; Donnelly, Ryan F

    2016-05-01

    We describe, for the first time, hydrogel-forming microneedle (s) (MN) arrays for minimally-invasive extraction and quantification of lithium in vitro and in vivo. MN arrays, prepared from aqueous blends of hydrolysed poly(methyl-vinylether-co-maleic anhydride) and crosslinked by poly(ethyleneglycol), imbibed interstitial fluid (ISF) upon skin insertion. Such MN were always removed intact. In vitro, mean detected lithium concentrations showed no significant difference following 30min MN application to excised neonatal porcine skin for lithium citrate concentrations of 0.9 and 2mmol/l. However, after 1h application, the mean lithium concentrations extracted were significantly different, being appropriately concentration-dependent. In vivo, rats were orally dosed with lithium citrate equivalent to 15mg/kg and 30mg/kg lithium carbonate, respectively. MN arrays were applied 1h after dosing and removed 1h later. The two groups, having received different doses, showed no significant difference between lithium concentrations in serum or MN. However, the higher dosed rats demonstrated a lithium concentration extracted from MN arrays equivalent to a mean increase of 22.5% compared to rats which received the lower dose. Hydrogel-forming MN clearly have potential as a minimally-invasive tool for lithium monitoring in outpatient settings. We will now focus on correlation between serum and MN lithium concentrations.

  11. BEAM-FORMING ERRORS IN MURCHISON WIDEFIELD ARRAY PHASED ARRAY ANTENNAS AND THEIR EFFECTS ON EPOCH OF REIONIZATION SCIENCE

    Energy Technology Data Exchange (ETDEWEB)

    Neben, Abraham R.; Hewitt, Jacqueline N.; Dillon, Joshua S.; Goeke, R.; Morgan, E. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Bradley, Richard F. [Dept. of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, 22904 (United States); Bernardi, G. [Square Kilometre Array South Africa (SKA SA), Cape Town 7405 (South Africa); Bowman, J. D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Briggs, F. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Cappallo, R. J.; Corey, B. E.; Lonsdale, C. J.; McWhirter, S. R. [MIT Haystack Observatory, Westford, MA 01886 (United States); Deshpande, A. A. [Raman Research Institute, Bangalore 560080 (India); Greenhill, L. J. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Hazelton, B. J.; Morales, M. F. [Department of Physics, University of Washington, Seattle, WA 98195 (United States); Johnston-Hollitt, M. [School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Kaplan, D. L. [Department of Physics, University of Wisconsin–Milwaukee, Milwaukee, WI 53201 (United States); Mitchell, D. A. [CSIRO Astronomy and Space Science (CASS), P.O. Box 76, Epping, NSW 1710 (Australia); and others

    2016-03-20

    Accurate antenna beam models are critical for radio observations aiming to isolate the redshifted 21 cm spectral line emission from the Dark Ages and the Epoch of Reionization (EOR) and unlock the scientific potential of 21 cm cosmology. Past work has focused on characterizing mean antenna beam models using either satellite signals or astronomical sources as calibrators, but antenna-to-antenna variation due to imperfect instrumentation has remained unexplored. We characterize this variation for the Murchison Widefield Array (MWA) through laboratory measurements and simulations, finding typical deviations of the order of ±10%–20% near the edges of the main lobe and in the sidelobes. We consider the ramifications of these results for image- and power spectrum-based science. In particular, we simulate visibilities measured by a 100 m baseline and find that using an otherwise perfect foreground model, unmodeled beam-forming errors severely limit foreground subtraction accuracy within the region of Fourier space contaminated by foreground emission (the “wedge”). This region likely contains much of the cosmological signal, and accessing it will require measurement of per-antenna beam patterns. However, unmodeled beam-forming errors do not contaminate the Fourier space region expected to be free of foreground contamination (the “EOR window”), showing that foreground avoidance remains a viable strategy.

  12. Design of crossed-mirror array to form floating 3D LED signs

    Science.gov (United States)

    Yamamoto, Hirotsugu; Bando, Hiroki; Kujime, Ryousuke; Suyama, Shiro

    2012-03-01

    3D representation of digital signage improves its significance and rapid notification of important points. Our goal is to realize floating 3D LED signs. The problem is there is no sufficient device to form floating 3D images from LEDs. LED lamp size is around 1 cm including wiring and substrates. Such large pitch increases display size and sometimes spoils image quality. The purpose of this paper is to develop optical device to meet the three requirements and to demonstrate floating 3D arrays of LEDs. We analytically investigate image formation by a crossed mirror structure with aerial aperture, called CMA (crossed-mirror array). CMA contains dihedral corner reflectors at each aperture. After double reflection, light rays emitted from an LED will converge into the corresponding image point. We have fabricated CMA for 3D array of LEDs. One CMA unit contains 20 x 20 apertures that are located diagonally. Floating image of LEDs was formed in wide range of incident angle. The image size of focused beam agreed to the apparent aperture size. When LEDs were located three-dimensionally (LEDs in three depths), the focused distances were the same as the distance between the real LED and the CMA.

  13. Design and Implementation of a Beam Forming Network for a Phased Array Antenna

    Directory of Open Access Journals (Sweden)

    S. Devimeena

    2015-03-01

    Full Text Available This dissertation presents a beam forming network (BFN for phased array antenna-based on coherently radiating periodic structure (CORPS. The elements of CORPS are selected in such a way to obtain broad band characteristics, good return loss and good isolation between the radiating elements. These elements were arranged in such a way that the BFN naturally produces Gaussian amplitude. This methodology reduces the complexity of the conventional phased array design making it more flexible and minimizing the loss of energy inside the structure. A phase shifter design is proposed for the CORPS. The entire BFN’s sub-blocks have been designed for the frequency band of 5.925 GHz to 6.425 GHz, which find applications in communication satellite, fixed wireless systems.Defence Science Journal, Vol. 65, No. 1, January 2015, pp.46-52, DOI:http://dx.doi.org/10.14429/dsj.65.6940

  14. Conformal growth of anodic nanotubes for dye-sensitized solar cells: part II. Nonplanar electrode.

    Science.gov (United States)

    Sun, Lidong; Zhang, Sam; Wang, Qing

    2014-02-01

    Anodic titania nanotube array features highly ordered alignment as well as porous nature, and exhibits intriguing properties when employed in a variety of applications. All these profit from the continuous efforts on controlling the nanotube configurations. Recently, nonplanar electrodes have also been used to grow the nanotubes besides the conventional planar counterparts. As such, it is of great interest and significance to complete a picture to link the nanotubes grown on planar and various nonplanar electrodes for a comprehensive understanding of nanotube growing manners, in an attempt to boost their future applications. In the first part of this review, planar electrodes are focused with regard to nanotube growth and application in dye-sensitized solar cells. In this part, the nanotubes grown on patterned or curved surfaces are discussed first with reference to a similar structure of alumina nanopores, which are subsequently used to mirror the growth of nanotubes on cylindrical electrodes (i.e., titanium wires or meshes). The last section focuses on titanium tubular electrodes which are attractive for thermal fluids in view of the drastically reduced thermal conductivity in the presence of anodic nanotubes. As a recent hot topic, wire-shaped dye-sensitized solar cells are deliberated in terms of cell structure, efficiency calculation, merits, challenges and outlook.

  15. Nanopatterning planar and non-planar mold surfaces for a polymer replication

    DEFF Research Database (Denmark)

    Cech, Jiri; Pranov, Henrik; Kofod, Guggi;

    2013-01-01

    , freestanding nickel foil with a reversed pattern. This foil is then used either as a direct master for polymer replication or as a master for an extremely high pressure embossing of such master onto a metallic injection mold cavity surface coated with special coating, which, when cured, forms robust and hard......, glass-like material. We have demonstrated nanopattern transfer on both planar and non-planar geometries and our nanopatterned mold coating can sustain more than 10.000 injection molding cycles. We can coat our nanopatterned mold surfaces with a monolayer of perfluorosilane to further reduce surface...

  16. Direct Closed-Form Design of Finite Alphabet Constant Envelope Waveforms for Planar Array Beampatterns

    KAUST Repository

    Bouchoucha, Taha

    2015-05-01

    Multiple Input Multiple Output (MIMO) radar systems has attracted lately a lot of attention thanks to its advantage over the classical phased array radar systems. We site among these advantages the improvement of parametric identifiability, achievement of higher spatial resolution and design of complex beampatterns. In colocated multiple-input multiple-output radar systems, it is usually desirable to steer transmitted power in the region-of-interest in order to increase the Signal to Noise Ratio (SNR) and reduce any undesired signal and thus improve the detection process. This problem is also known as transmit beampattern design. To achieve this goal, conventional methods optimize the waveform covariance matrix, R, for the desired beampattern, which is then used to generate the actual transmitted waveforms. Both steps require constrained optimization. Most of the existing methods use iterative algorithms to solve these problems, therefore their computational complexity is very high which makes them hard to use in practice especially for real time radar applications. In this paper, we provide a closed-form solution to design the covariance matrix for a given beampattern in the three dimensional space using planar arrays, which is then used to derive a novel closed-form algorithm to directly design the finite-alphabet constant-envelope waveforms. The proposed algorithm exploits the two-dimensional discrete Fourier transform which is implemented using fast Fourier transform algorithm. Consequently, the computational complexity of the proposed beampattern solution is very low allowing it to be used for large arrays to change the beampattern in real time. We also show that the number of required snapshots in each waveform depends on the beampattern and that it is less than the total number of transmit antennas. In addition, we show that the proposed waveform design method can be used with non symmetric beampatterns. The performance of our proposed algorithm compares

  17. Nonplanar loops leave the Veneziano model photon massless

    NARCIS (Netherlands)

    Foda, O.

    1987-01-01

    The absence of a pole at p2=0 in the orientable nonplanar one-loop photon self-energy in the Veneziano model is verified. Thus the photon remains massless, and spontaneous symmetry breaking - at least as reported in this context in the literature - is not found.

  18. Nonplanar loops leave the Veneziano model photon massless

    NARCIS (Netherlands)

    Foda, O.

    1987-01-01

    The absence of a pole at p2=0 in the orientable nonplanar one-loop photon self-energy in the Veneziano model is verified. Thus the photon remains massless, and spontaneous symmetry breaking - at least as reported in this context in the literature - is not found.

  19. Nonplanar loops leave the Veneziano model photon massless

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O.

    1987-04-16

    The absence of a pole at p/sup 2/=0 in the orientable nonplanar one-loop photon self-energy in the Veneziano model is verified. Thus the photon remains massless, and spontaneous symmetry breaking - at least as reported in this context in the literature - is not found.

  20. Closed-form Solution to Directly Design FACE Waveforms for Beampatterns Using Planar Array

    KAUST Repository

    Bouchoucha, Taha

    2015-04-19

    In multiple-input multiple-output radar systems, it is usually desirable to steer transmitted power in the region-of-interest. To do this, conventional methods optimize the waveform covariance matrix, R, for the desired beampattern, which is then used to generate actual transmitted waveforms. Both steps require constrained optimization, therefore, use iterative algorithms. The main challenges encountered in the existing approaches are the computational complexity and the design of waveforms to use in practice. In this paper, we provide a closed-form solution to design covariance matrix for the given beampattern using the planar array, which is then used to derive a novel closed-form algorithm to directly design the finite-alphabet constant-envelope (FACE) waveforms. The proposed algorithm exploits the two-dimensional fast-Fourier-transform. The performance of our proposed algorithm is compared with existing methods that are based on semi-definite quadratic programming with the advantage of a considerably reduced complexity.

  1. Nonlinear chiro-optical amplification by plasmonic nanolens arrays formed via directed assembly of gold nanoparticles.

    Science.gov (United States)

    Biswas, Sushmita; Liu, Xiaoying; Jarrett, Jeremy W; Brown, Dean; Pustovit, Vitaliy; Urbas, Augustine; Knappenberger, Kenneth L; Nealey, Paul F; Vaia, Richard A

    2015-03-11

    Metal nanoparticle assemblies are promising materials for nanophotonic applications due to novel linear and nonlinear optical properties arising from their plasmon modes. However, scalable fabrication approaches that provide both precision nano- and macroarchitectures, and performance commensurate with design and model predictions, have been limiting. Herein, we demonstrate controlled and efficient nanofocusing of the fundamental and second harmonic frequencies of incident linearly and circularly polarized light using reduced symmetry gold nanoparticle dimers formed by surface-directed assembly of colloidal nanoparticles. Large ordered arrays (>100) of these C∞v heterodimers (ratio of radii R1/R2 = 150 nm/50 nm = 3; gap distance l = 1 ± 0.5 nm) exhibit second harmonic generation and structure-dependent chiro-optic activity with the circular dichroism ratio of individual heterodimers varying less than 20% across the array, demonstrating precision and uniformity at a large scale. These nonlinear optical properties were mediated by interparticle plasmon coupling. Additionally, the versatility of the fabrication is demonstrated on a variety of substrates including flexible polymers. Numerical simulations guide architecture design as well as validating the experimental results, thus confirming the ability to optimize second harmonic yield and induce chiro-optical responses for compact sensors, optical modulators, and tunable light sources by rational design and fabrication of the nanostructures.

  2. Direct closed-form covariance matrix and finite alphabet constant-envelope waveforms for planar array beampatterns

    KAUST Repository

    Ahmed, Sajid

    2016-11-24

    Various examples of methods and systems are provided for direct closed-form finite alphabet constant-envelope waveforms for planar array beampatterns. In one example, a method includes defining a waveform covariance matrix based at least in part upon a two-dimensional fast Fourier transform (2D-FFT) analysis of a frequency domain matrix Hf associated with a planar array of antennas. Symbols can be encoded based upon the waveform covariance matrix and the encoded symbols can be transmitted via the planar array of antennas. In another embodiment, a system comprises an N x M planar array of antennas and transmission circuitry configured to transmit symbols via a two-dimensional waveform beampattern defined based at least in part upon a 2D-FFT analysis of a frequency domain matrix Hf associated with the planar array of antennas.

  3. High-Reliability Pump Module for Non-Planar Ring Oscillator Laser

    Science.gov (United States)

    Liu, Duncan T.; Qiu, Yueming; Wilson, Daniel W.; Dubovitsky, Serge; Forouhar, Siamak

    2007-01-01

    We propose and have demonstrated a prototype high-reliability pump module for pumping a Non-Planar Ring Oscillator (NPRO) laser suitable for space missions. The pump module consists of multiple fiber-coupled single-mode laser diodes and a fiber array micro-lens array based fiber combiner. The reported Single-Mode laser diode combiner laser pump module (LPM) provides a higher normalized brightness at the combined beam than multimode laser diode based LPMs. A higher brightness from the pump source is essential for efficient NPRO laser pumping and leads to higher reliability because higher efficiency requires a lower operating power for the laser diodes, which in turn increases the reliability and lifetime of the laser diodes. Single-mode laser diodes with Fiber Bragg Grating (FBG) stabilized wavelength permit the pump module to be operated without a thermal electric cooler (TEC) and this further improves the overall reliability of the pump module. The single-mode laser diode LPM is scalable in terms of the number of pump diodes and is capable of combining hundreds of fiber-coupled laser diodes. In the proof-of-concept demonstration, an e-beam written diffractive micro lens array, a custom fiber array, commercial 808nm single mode laser diodes, and a custom NPRO laser head are used. The reliability of the proposed LPM is discussed.

  4. Study of nonplanarity of peptide bond using theoretical calculations.

    Science.gov (United States)

    Selvarengan, P; Kolandaivel, P

    2005-08-01

    The conformational dependence of nonplanarity of the peptide bond of formylglycinamide has been studied using ab initio and density functional theory methods. Hartree-Fock self-consistent field theory (HF), Møller-Plesset perturbation theory (MP2) of ab initio and B3LYP level of theory of dft method have been used employing 6-31++G** basis set. The MP2 method predicts better results than HF and B3LYP levels of theory for conformational stability dependence of nonplanarity. Systematic dependence of planarity deviation has been observed in MP2 theory. The chemical hardness values successfully predict the conformational region, but fail to obey maximum hardness principle. It is concluded that the most reliable dft method could not successfully predict the planarity of peptide bond in comparison with electron correlated method of ab initio method.

  5. Application of Random Ferns for non-planar object detection

    Science.gov (United States)

    Mastov, Alexey; Konovalenko, Ivan; Grigoryev, Anton

    2015-12-01

    The real time object detection task is considered as a part of a project devoted to development of autonomous ground robot. This problem has been successfully solved with Random Ferns algorithm, which belongs to keypoint-based method and uses fast machine learning algorithms for keypoint matching step. As objects in the real world are not always planar, in this article we describe experiments of applying this algorithm for non-planar objects. Also we introduce a method for fast detection of a special class of non-planar objects | those which can be decomposed into planar parts (e.g. faces of a box). This decomposition needs one detector for each side, which may significantly affect speed of detection. Proposed approach copes with it by omitting repeated steps for each detector and organizing special queue of detectors. It makes the algorithm three times faster than naive one.

  6. Some remarks on non-planar Feynman diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Bielas, Krzysztof; Dubovyk, Ievgen; Gluza, Janusz [Silesia Univ., Katowice (Poland). Inst. of Physics; Riemann, Tord [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2013-12-15

    Two criteria for planarity of a Feynman diagram upon its propagators (momentum ows) are presented. Instructive Mathematica programs that solve the problem and examples are provided. A simple geometric argument is used to show that while one can planarize non-planar graphs by embedding them on higher-genus surfaces (in the example it is a torus), there is still a problem with defining appropriate dual variables since the corresponding faces of the graph are absorbed by torus generators.

  7. Longitudinal mode structure in a non-planar ring resonator

    Directory of Open Access Journals (Sweden)

    M Jaberi

    2013-09-01

    Full Text Available  The structure of longitudinal modes of a passively Q-switched, non-planar unidirectional ring-resonator,with Nd:YAG active medium is described in this article. Two different techniques are used to study the longitudinal mode structure of the laser resonator. At first, the fast-fourier transform technique is applied for analyzing the mode beating of the optical fields by intensity frequency structure of the laser pulses to determine the number of longitudinal modes. Then, an analyzer etalon is used to observe Fabry-Perot fringes to compute the numbers of the resonator longitudinal modes. The results of two techniques are in good agreement with each other. Under the proper conditions, a reliable single longitudinal mode of the non-planar ring-resonator can be achieved with a good spatial mode profile that originates from the unidirectional travelling optical field propagation in the resonator having a very low sensitivity of the non-planar ring resonator to the optical elements misalignment.

  8. A generalized Beraha conjecture for non-planar graphs

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, Jesper Lykke, E-mail: jesper.jacobsen@ens.fr [Laboratoire de Physique Théorique, École Normale Supérieure, 24 rue Lhomond, 75231 Paris (France); Université Pierre et Marie Curie, 4 place Jussieu, 75252 Paris (France); Salas, Jesús, E-mail: jsalas@math.uc3m.es [Grupo de Modelización, Simulación Numérica y Matemática Industrial, Universidad Carlos III de Madrid, Avda. de la Universidad, 30, 28911 Leganés (Spain); Grupo de Teorías de Campos y Física Estadística, Instituto Gregorio Millán, Universidad Carlos III de Madrid, Unidad Asociada al IEM–CSIC, Madrid (Spain)

    2013-10-21

    We study the partition function Z{sub G(nk,k)}(Q,v) of the Q-state Potts model on the family of (non-planar) generalized Petersen graphs G(nk,k). We study its zeros in the plane (Q,v) for 1⩽k⩽7. We also consider two specializations of Z{sub G(nk,k)}, namely the chromatic polynomial P{sub G(nk,k)}(Q) (corresponding to v=−1), and the flow polynomial Φ{sub G(nk,k)}(Q) (corresponding to v=−Q). In these two cases, we study their zeros in the complex Q-plane for 1⩽k⩽7. We pay special attention to the accumulation loci of the corresponding zeros when n→∞. We observe that the Berker–Kadanoff phase that is present in two-dimensional Potts models, also exists for non-planar recursive graphs. Their qualitative features are the same; but the main difference is that the role played by the Beraha numbers for planar graphs is now played by the non-negative integers for non-planar graphs. At these integer values of Q, there are massive eigenvalue cancellations, in the same way as the eigenvalue cancellations that happen at the Beraha numbers for planar graphs.

  9. An Electrochemical Sensing Platform Based on Liquid-Liquid Microinterface Arrays Formed in Laser-Ablated Glass Membranes.

    Science.gov (United States)

    Alvarez de Eulate, Eva; Strutwolf, Jörg; Liu, Yang; O'Donnell, Kane; Arrigan, Damien W M

    2016-03-01

    Arrays of microscale interfaces between two immiscible electrolyte solutions (μITIES) were formed using glass membranes perforated with microscale pores by laser ablation. Square arrays of 100 micropores in 130 μm thick borosilicate glass coverslips were functionalized with trichloro(1H,1H,2H,2H-perfluorooctyl)silane on one side, to render the surface hydrophobic and support the formation of aqueous-organic liquid-liquid microinterfaces. The pores show a conical shape, with larger radii at the laser entry side (26.5 μm) than at the laser exit side (11.5 μm). The modified surfaces were characterized by contact angle measurements and X-ray photoelectron spectroscopy. The organic phase was placed on the hydrophobic side of the membrane, enabling the array of μITIES to be located at either the wider or narrower pore mouth. The electrochemical behavior of the μITIES arrays were investigated by tetrapropylammonium ion transfer across water-1,6-dichlorohexane interfaces together with finite element computational simulations. The data suggest that the smallest microinterfaces (formed on the laser exit side) were located at the mouth of the pore in hemispherical geometry, while the larger microinterfaces (formed on the laser entry side) were flatter in shape but exhibited more instability due to the significant roughness of the glass around the pore mouths. The glass membrane-supported μITIES arrays presented here provide a new platform for chemical and biochemical sensing systems.

  10. Integrable system on phase space with nonplanar metrics

    CERN Document Server

    Bogdanov, E I

    2001-01-01

    The problem on the integrability of the evolution system on the phase spaces with the nonplanar metrics is studied. It is shown that in the case, when the phase space is a sphere, the system Hamiltonians are generated under the action of the Poisson operators on the variations of the phase space geodesic lines and the problem on the evolution system integrability is reduced to the task on the integrability of the repers motion equations on the phase space. The bihamiltonian representation of the evaluation systems is connected with the differential-geometric properties of the phase space

  11. Nonplanar nanoselective area growth of InGaAs/InP

    DEFF Research Database (Denmark)

    Kuznetsova, Nadezda; Colman, Pierre; Semenova, Elizaveta

    2014-01-01

    In this study, we have investigated metal-organic vapor phase epitaxial nano-patterned selective area growth of InGaAs/InP on non-planar (001) InP surfaces. Due to high etching resistance and the small molecular size of negative tone electron beam HSQ resist, the protection mask formed in HSQ has...... of the active material, the cross-sectional geometry was observed by field emission scanning electron microscopy and scanning transmission electron microscopy. The optical properties were carried out at room temperature using micro-photoluminescence setup. The results showed different deposition rates...... for openings oriented along [0-11] and [0-1-1] directions with higher rate along [0-1-1]. The fabricated active material was incorporated into photonic crystal waveguides....

  12. KAPPEL Propeller. Development of a Marine Propeller with Non-planar Lifting Surfaces

    DEFF Research Database (Denmark)

    Kappel, J.; Andersen, Poul

    2002-01-01

    The principle of non-planar lifting surfaces is applied to the design of modern aircraft wings to obtain better lift to drag ratios. Whereas a pronounced fin or "winglet" at the wingtip has been developed for aircraft, the application of the non-planar principle to marine propellers, dealt...

  13. Guided proliferation and bone-forming functionality on highly ordered large diameter TiO2 nanotube arrays.

    Science.gov (United States)

    Zhang, Ruopeng; Wu, Hongliu; Ni, Jiahua; Zhao, Changli; Chen, Yifan; Zheng, Chengjunyi; Zhang, Xiaonong

    2015-08-01

    The significantly enhanced osteoblast adhesion, proliferation and alkaline phosphatase (ALP) activity were observed on TiO2 nanotube surface in recent studies in which the scale of nanotube diameter was restricted under 100 nm. In this paper, a series of highly ordered TiO2 nanotube arrays with larger diameters ranging from 150 nm to 470 nm were fabricated via high voltage anodization. The behaviors of MC3T3-E1 cells in response to the diameter-controlled TiO2 nanotubes were investigated. A contrast between the trend of proliferation and the trend of cell elongation was observed. The highest cell elongation (nearly 10:1) and the lowest cell number were observed on the TiO2 nanotube arrays with 150 nm diameter. While, the lowest cell elongation and highest cell number were achieved on the TiO2 nanotube arrays with 470 nm diameter. Furthermore, the ALP activity peaked on the 150 nm diameter TiO2 nanotube arrays and decreased dramatically with the increase of nanotube diameter. Thus a narrow range of diameter (100-200 nm) that could induce the greatest bone-forming activity is determined. It is expected that more delicate design of orthopedic implant with regional abduction of cell proliferation or bone forming could be achieved by controlling the diameter of TiO2 nanotubes. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates.

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ken Shuang

    2004-11-01

    This report documents the author's efforts in the deterministic modeling of copper-sulfidation corrosion on non-planar substrates such as diodes and electrical connectors. A new framework based on Goma was developed for multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates. In this framework, the moving sulfidation front is explicitly tracked by treating the finite-element mesh as a pseudo solid with an arbitrary Lagrangian-Eulerian formulation and repeatedly performing re-meshing using CUBIT and re-mapping using MAPVAR. Three one-dimensional studies were performed for verifying the framework in asymptotic regimes. Limited model validation was also carried out by comparing computed copper-sulfide thickness with experimental data. The framework was first demonstrated in modeling one-dimensional copper sulfidation with charge separation. It was found that both the thickness of the space-charge layers and the electrical potential at the sulfidation surface decrease rapidly as the Cu{sub 2}S layer thickens initially but eventually reach equilibrium values as Cu{sub 2}S layer becomes sufficiently thick; it was also found that electroneutrality is a reasonable approximation and that the electro-migration flux may be estimated by using the equilibrium potential difference between the sulfidation and annihilation surfaces when the Cu{sub 2}S layer is sufficiently thick. The framework was then employed to model copper sulfidation in the solid-state-diffusion controlled regime (i.e. stage II sulfidation) on a prototypical diode until a continuous Cu{sub 2}S film was formed on the diode surface. The framework was also applied to model copper sulfidation on an intermittent electrical contact between a gold-plated copper pin and gold-plated copper pad; the presence of Cu{sub 2}S was found to raise the effective electrical resistance drastically. Lastly, future research needs in modeling atmospheric copper sulfidation are discussed.

  15. Guided proliferation and bone-forming functionality on highly ordered large diameter TiO{sub 2} nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ruopeng; Wu, Hongliu; Ni, Jiahua, E-mail: jiahua.ni@sjtu.edu.cn; Zhao, Changli; Chen, Yifan; Zheng, Chengjunyi; Zhang, Xiaonong, E-mail: xnzhang@sjtu.edu.cn

    2015-08-01

    The significantly enhanced osteoblast adhesion, proliferation and alkaline phosphatase (ALP) activity were observed on TiO{sub 2} nanotube surface in recent studies in which the scale of nanotube diameter was restricted under 100 nm. In this paper, a series of highly ordered TiO{sub 2} nanotube arrays with larger diameters ranging from 150 nm to 470 nm were fabricated via high voltage anodization. The behaviors of MC3T3-E1 cells in response to the diameter-controlled TiO{sub 2} nanotubes were investigated. A contrast between the trend of proliferation and the trend of cell elongation was observed. The highest cell elongation (nearly 10:1) and the lowest cell number were observed on the TiO{sub 2} nanotube arrays with 150 nm diameter. While, the lowest cell elongation and highest cell number were achieved on the TiO{sub 2} nanotube arrays with 470 nm diameter. Furthermore, the ALP activity peaked on the 150 nm diameter TiO{sub 2} nanotube arrays and decreased dramatically with the increase of nanotube diameter. Thus a narrow range of diameter (100–200 nm) that could induce the greatest bone-forming activity is determined. It is expected that more delicate design of orthopedic implant with regional abduction of cell proliferation or bone forming could be achieved by controlling the diameter of TiO{sub 2} nanotubes. - Highlights: • Improved anodization methods leading to more ordered large diameter TiO{sub 2} nanotubes • Significantly enhanced ALP activity was observed on 150 nm diameter TiO{sub 2} nanotubes. • The highest cell density was observed on 470 nm diameter TiO{sub 2} nanotube arrays. • Similar cell response was observed on the amorphous and anatase phased nanotube surface.

  16. Polypyrrole self-organized nanopore arrays formed by controlled electropolymerization in TiO2 nanotube template.

    Science.gov (United States)

    Kowalski, Damian; Schmuki, Patrik

    2010-12-07

    A new concept for formation of nanostructured intrinsically conducting polymers (ICP) is demonstrated. Polypyrrole can be electropolymerized from an ionic-surfactant-solution in TiO(2) nanotube framework to form a geometrical structure of self-organized nanopore arrays. Polymerization is initialized selectively in the space between nanotube walls forming a mechanically stable polymer network with controlled wall thickness from 40 to 10 nm. Such robust polymer nanostructures are very promising for application in electrochemical systems of limited charge carrier diffusion length.

  17. Probe suppression in conformal phased array

    CERN Document Server

    Singh, Hema; Neethu, P S

    2017-01-01

    This book considers a cylindrical phased array with microstrip patch antenna elements and half-wavelength dipole antenna elements. The effect of platform and mutual coupling effect is included in the analysis. The non-planar geometry is tackled by using Euler's transformation towards the calculation of array manifold. Results are presented for both conducting and dielectric cylinder. The optimal weights obtained are used to generate adapted pattern according to a given signal scenario. It is shown that array along with adaptive algorithm is able to cater to an arbitrary signal environment even when the platform effect and mutual coupling is taken into account. This book provides a step-by-step approach for analyzing the probe suppression in non-planar geometry. Its detailed illustrations and analysis will be a useful text for graduate and research students, scientists and engineers working in the area of phased arrays, low-observables and stealth technology.

  18. Effect of superthermal electrons on dust-acoustic Gardner solitons in nonplanar geometry

    Indian Academy of Sciences (India)

    Deb Kumar Ghosh; Yday Narayan Ghosh; Prasanta Chatterjee; C S Wong

    2013-04-01

    The properties of nonplanar (cylindrical and spherical) dust-acoustic solitary waves (DASWs) in an unmagnetized, collisionless three-component dusty plasma, whose constituents are negatively charged cold dust fluid, superthermal/non-Maxwellian electrons (represented by kappa distribution) and Boltzmann distributed ions, are investigated by deriving the modified Gardner (MG) equation. The well-known reductive perturbation method is employed to derive the MG equation. The basic features of nonplanar DA Gardner solitons (GSs) are discussed. It is seen that the properties of nonplanar DAGSs (positive and negative) significantly differ as the value of spectral index changes.

  19. Adenosine monophosphate forms ordered arrays in multilamellar lipid matrices: insights into assembly of nucleic acid for primitive life.

    Directory of Open Access Journals (Sweden)

    Laura Toppozini

    Full Text Available A fundamental question of biology is how nucleic acids first assembled and then were incorporated into the earliest forms of cellular life 4 billion years ago. The polymerization of nucleotides is a condensation reaction in which phosphodiester bonds are formed. This reaction cannot occur in aqueous solutions, but guided polymerization in an anhydrous lipid environment could promote a non-enzymatic condensation reaction in which oligomers of single stranded nucleic acids are synthesized. We used X-ray scattering to investigate 5'-adenosine monophosphate (AMP molecules captured in a multilamellar phospholipid matrix composed of dimyristoylphosphatidylcholine. Bragg peaks corresponding to the lateral organization of the confined AMP molecules were observed. Instead of forming a random array, the AMP molecules are highly entangled, with the phosphate and ribose groups in close proximity. This structure may facilitate polymerization of the nucleotides into RNA-like polymers.

  20. Hexagonal Boron Nitride-Graphene Core-Shell Arrays Formed by Self-Symmetrical Etching Growth.

    Science.gov (United States)

    Wang, Chenxiao; Zuo, Junlai; Tan, Lifang; Zeng, Mengqi; Zhang, Qiqi; Xia, Huinan; Zhang, Wenhao; Fu, Yingshuang; Fu, Lei

    2017-09-20

    The synthesis and integration of core-shell materials have been extensively explored in three-dimensional nanostructures, while they are hardly ever extended into the emerging two-dimensional (2D) research field. Herein, demonstrated by graphene (G) and hexagonal boron nitride (h-BN) and via a sequential chemical vapor deposition method, we succeed for the first time in synthesizing 2D h-BN-G core-shell arrays (CSA), which possess extremely high uniformity in shapes, sizes and distributions. Each of the core-shell unit is composed of G ring-shaped shell internally filled with h-BN circular core. In addition, we perform simulations to further explain the self-symmetrical etching growth mechanism of the h-BN-G CSA, demonstrating its potential to be used as an efficient synthetic method suitable for other 2D CSA systems.

  1. Hydrogel-Forming Microneedle Arrays Made from Light-Responsive Materials for On-Demand Transdermal Drug Delivery.

    Science.gov (United States)

    Hardy, John G; Larrañeta, Eneko; Donnelly, Ryan F; McGoldrick, Niamh; Migalska, Katarzyna; McCrudden, Maelíosa T C; Irwin, Nicola J; Donnelly, Louise; McCoy, Colin P

    2016-03-07

    We describe, for the first time, stimulus-responsive hydrogel-forming microneedle (MN) arrays that enable delivery of a clinically relevant model drug (ibuprofen) upon application of light. MN arrays were prepared using a polymer prepared from 2-hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA) by micromolding. The obtained MN arrays showed good mechanical properties. The system was loaded with up to 5% (w/w) ibuprofen included in a light-responsive 3,5-dimethoxybenzoin conjugate. Raman spectroscopy confirmed the presence of the conjugate inside the polymeric MN matrix. In vitro, this system was able to deliver up to three doses of 50 mg of ibuprofen upon application of an optical trigger over a prolonged period of time (up to 160 h). This makes the system appealing as a controlled release device for prolonged periods of time. We believe that this technology has potential for use in "on-demand" delivery of a wide range of drugs in a variety of applications relevant to enhanced patient care.

  2. Photochemical arrays formed by spatial compartmentalization of colloidal nanoparticles in a polymer-based hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, M. A.; Rajh, T.; Makarova, O. V.; Seifert, S.; Tiede, D. M.; Thurnauer, M. C.

    2000-01-13

    The development of practical strategies for the assembly of semiconductor and metal colloid nanoparticles into ordered architectures is an area of considerable current interest, since it offers an opportunity for exploiting the optical and electronic properties of these colloids for device development. Prior research has explored creating such organized nanoparticle assemblies by Langmuir-Blodgett techniques or controlled solvent evaporation on suitable substrates. These approaches suffer from several limitations, however, most notably the generation of relatively simple structures and the lack of structural tailorability, preventing full exploitation of these materials. More recently, directed assembly using chemisorption of streptavidin-biotin or thiol-derivatized gold nanoparticles onto substrates has been described. Alternative approaches to achieving two-dimensional confinement of nanoparticles that do not involve substrate-supported materials, but rather organize the nanoparticles into mesoscopically-ordered soft condensed matter, may offer the advantage of enhanced processability and may permit construction of nanocomposite structures based on functional nanoparticles embedded in a processable, polymer-based matrix. This work describes the development of an alternative strategy for constructing 2-D arrays of functional metal and semiconductor nanoparticles. The approach involves directing the organization of nanocrystals into a processable (i.e., by externally applied magnetic and electric fields) polymer-grafted lipid-based complex fluid. By altering the surface chemistry of the nanoparticles, they can be selectively placed into defined regions encapsulating matrix.

  3. Chemotaxis cluster 1 proteins form cytoplasmic arrays in Vibrio cholerae and are stabilized by a double signaling domain receptor DosM

    DEFF Research Database (Denmark)

    Briegel, Ariane; Ortega, Davi R; Mann, Petra

    2016-01-01

    motile bacteria contain one or more additional, sometimes purely cytoplasmic, chemoreceptor systems. Vibrio cholerae contains three chemotaxis clusters (I, II, and III). Here, using electron cryotomography, we explore V. cholerae's cytoplasmic chemoreceptor array and establish that it is formed...

  4. Digital Beam Forming and Compressive Sensing Based DOA Estimation in MIMO Arrays

    NARCIS (Netherlands)

    Belfiori, F.; Anitori, L.; Rossum, W.L. van; Otten, M.P.G.; Hoogeboom, P.

    2011-01-01

    The paper presents different processing schemes that have been investigated in order to evaluate the direction of arrival (DOA) with a multiple-input multiple-output (MIMO) radar. Conventional digital beam forming (DBF) and super resolution algorithm (MUSIC) have been applied. The results provided b

  5. Tomography of Galactic star-forming regions and spiral arms with the Square Kilometer Array

    CERN Document Server

    Loinard, Laurent; Hoare, Melvin; van Langevelde, Huib Jan; Ellingsen, Simon; Brunthaler, Andreas; Forbrich, Jan; Rygl, Kazi L J; Rodriguez, Luis F; Mioduszewski, Amy J; Torres-Lopez, Rosa M; Dzib, Sergio A; Ortiz-Leon, Gisela N; Bourke, Tyler L; Green, James A

    2014-01-01

    Very Long Baseline Interferometry (VLBI) at radio wavelengths can provide astrometry accurate to 10 micro-arcseconds or better (i.e. better than the target GAIA accuracy) without being limited by dust obscuration. This means that unlike GAIA, VLBI can be applied to star-forming regions independently of their internal and line-of-sight extinction. Low-mass young stellar objects (particularly T Tauri stars) are often non-thermal compact radio emitters, ideal for astrometric VLBI radio continuum experiments. Existing observations for nearby regions (e.g. Taurus, Ophiuchus, or Orion) demonstrate that VLBI astrometry of such active T Tauri stars enables the reconstruction of both the regions' 3D structure (through parallax measurements) and their internal kinematics (through proper motions, combined with radial velocities). The extraordinary sensitivity of the SKA telescope will enable similar "tomographic mappings" to be extended to regions located several kpc from Earth, in particular to nearby spiral arm segmen...

  6. Exact solution of planar and nonplanar weak shock wave problem in gasdynamics

    Energy Technology Data Exchange (ETDEWEB)

    Singh, L.P. [Department of Applied Mathematics, Institute of Technology, Bananas Hindu University, Varanasi 221 005 (India); Ram, S.D., E-mail: sram.rs.apm@itbhu.ac.in [Department of Applied Mathematics, Institute of Technology, Bananas Hindu University, Varanasi 221 005 (India); Singh, D.B. [Department of Applied Mathematics, Institute of Technology, Bananas Hindu University, Varanasi 221 005 (India)

    2011-11-15

    Highlights: > An exact solution is derived for a problem of weak shock wave in adiabatic gas dynamics. > The density ahead of the shock is taken as a power of the position from the origin of the shock wave. > For a planar and non-planar motion, the total energy carried by the wave varies with respect to time. > The solution obtained for the planer, and cylindrically symmetric flow is new one. > The results obtained are also presented graphically for different Mach numbers. - Abstract: In the present paper, an analytical approach is used to determine a new exact solution of the problem of one dimensional unsteady adiabatic flow of planer and non-planer weak shock waves in an inviscid ideal fluid. Here it is assumed that the density ahead of the shock front varies according to the power law of the distance from the source of disturbance. The solution of the problem is presented in the form of a power in the distance and the time.

  7. Nonplanar tertiary amides in rigid chiral tricyclic dilactams. Peptide group distortions and vibrational optical activity.

    Science.gov (United States)

    Pazderková, Markéta; Profant, Václav; Hodačová, Jana; Sebestík, Jaroslav; Pazderka, Tomáš; Novotná, Pavlína; Urbanová, Marie; Safařík, Martin; Buděšínský, Miloš; Tichý, Miloš; Bednárová, Lucie; Baumruk, Vladimír; Maloň, Petr

    2013-08-22

    We investigate amide nonplanarity in vibrational optical activity (VOA) spectra of tricyclic spirodilactams 5,8-diazatricyclo[6,3,0,0(1,5)]undecan-4,9-dione (I) and its 6,6',7,7'-tetradeuterio derivative (II). These rigid molecules constrain amide groups to nonplanar geometries with twisted pyramidal arrangements of bonds to amide nitrogen atoms. We have collected a full range vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra including signals of C-H and C-D stretching vibrations. We report normal-mode analysis and a comparison of calculated to experimental VCD and ROA. The data provide band-to-band assignment and offer a possibility to evaluate roles of constrained nonplanar tertiary amide groups and rigid chiral skeletons. Nonplanarity shows as single-signed VCD and ROA amide I signals, prevailing the couplets expected to arise from the amide-amide interaction. Amide-amide coupling dominates amide II (mainly C'-N stretching, modified in tertiary amides by the absence of a N-H bond) transitions (strong couplet in VCD, no significant ROA) probably due to the close proximity of amide nitrogen atoms. At lower wavenumbers, ROA spectra exhibit another likely manifestation of amide nonplanarity, showing signals of amide V (δ(oop)(N-C) at ~570 cm(-1)) and amide VI (δ(oop)(C'═O) at ~700 cm(-1) and ~650 cm(-1)) vibrations.

  8. Multi-projector auto-calibration and placement optimization for non-planar surfaces

    Science.gov (United States)

    Li, Dong; Xie, Jinghui; Zhao, Lu; Zhou, Lijing; Weng, Dongdong

    2015-10-01

    Non-planar projection has been widely applied in virtual reality and digital entertainment and exhibitions because of its flexible layout and immersive display effects. Compared with planar projection, a non-planar projection is more difficult to achieve because projector calibration and image distortion correction are difficult processes. This paper uses a cylindrical screen as an example to present a new method for automatically calibrating a multi-projector system in a non-planar environment without using 3D reconstruction. This method corrects the geometric calibration error caused by the screen's manufactured imperfections, such as an undulating surface or a slant in the vertical plane. In addition, based on actual projection demand, this paper presents the overall performance evaluation criteria for the multi-projector system. According to these criteria, we determined the optimal placement for the projectors. This method also extends to surfaces that can be parameterized, such as spheres, ellipsoids, and paraboloids, and demonstrates a broad applicability.

  9. Chaotic motion and its control for nonlinear nonplanar oscillations of a parametrically excited cantilever beam

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei [College of Mechanical Engineering, Beijing University of Technology, Beijing 100022 (China)] e-mail: sandyzhang0@yahoo.com

    2005-11-01

    This paper presents an analysis of the chaotic motion and its control for the nonlinear nonplanar oscillations of a cantilever beam subjected to a harmonic axial excitation and transverse excitations at the free end. A new method of controlling chaotic motion for the nonlinear nonplanar oscillations of the cantilever beam, refereed as to the force control approach, is proposed for the first time. The governing nonlinear equations of nonplanar motion under combined parametric and external excitations are obtained. The Galerkin procedure is applied to the governing equation to obtain a two-degree-of-freedom nonlinear system under combined parametric and forcing excitations for the in-plane and out-of-plane modes. The work is focused on the case of 2:1 internal resonance, principal parametric resonance-1/2 subharmonic resonance for the in-plane mode and fundamental parametric resonance-primary resonance for the out-of-plane mode. The method of multiple scales is used to transform the parametrically and externally excited system to the averaged equations which have a constant perturbation force. Based on the averaged equations obtained here, numerical simulation is utilized to discover the periodic and chaotic motions for the nonlinear nonplanar oscillations of the cantilever beam. The numerical results indicate that the transverse excitation in the z direction at the free end can control the chaotic motion to a period n motion or a static state for the nonlinear nonplanar oscillations of the cantilever beam. The methodology of controlling chaotic motion by using the transverse excitation is proposed. The transverse excitation in the z direction at the free end may be thought about to be an open-loop control. For the problem investigated in this paper, this approach is an effective methodology of controlling chaotic motion to a period n motion or a static state for the nonlinear nonplanar oscillations of the cantilever beam.

  10. General MoM Solutions for Large Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Fasenfest, B; Capolino, F; Wilton, D R; Jackson, D R; Champagne, N

    2003-07-22

    This paper focuses on a numerical procedure that addresses the difficulties of dealing with large, finite arrays while preserving the generality and robustness of full-wave methods. We present a fast method based on approximating interactions between sufficiently separated array elements via a relatively coarse interpolation of the Green's function on a uniform grid commensurate with the array's periodicity. The interaction between the basis and testing functions is reduced to a three-stage process. The first stage is a projection of standard (e.g., RWG) subdomain bases onto a set of interpolation functions that interpolate the Green's function on the array face. This projection, which is used in a matrix/vector product for each array cell in an iterative solution process, need only be carried out once for a single cell and results in a low-rank matrix. An intermediate stage matrix/vector product computation involving the uniformly sampled Green's function is of convolutional form in the lateral (transverse) directions so that a 2D FFT may be used. The final stage is a third matrix/vector product computation involving a matrix resulting from projecting testing functions onto the Green's function interpolation functions; the low-rank matrix is either identical to (using Galerkin's method) or similar to that for the bases projection. An effective MoM solution scheme is developed for large arrays using a modification of the AIM (Adaptive Integral Method) method. The method permits the analysis of arrays with arbitrary contours and nonplanar elements. Both fill and solve times within the MoM method are improved with respect to more standard MoM solvers.

  11. Nonplanar ion-acoustic shocks in electron–positron–ion plasmas: Effect of superthermal electrons

    Indian Academy of Sciences (India)

    Deb Kumar Ghosh; Prasantha Chatterjee; Pankaj Kumar Mandal; Biswajit Sahu

    2013-09-01

    Ion-acoustic shock waves (IASWs) in a homogeneous unmagnetized plasma, comprising superthermal electrons, positrons, and singly charged adiabatically hot positive ions are investigated via two-dimensional nonplanar Kadomstev–Petviashvili–Burgers (KPB) equation. It is found that the profiles of the nonlinear shock structures depend on the superthermality of electrons. The influence of other plasma parameters such as, ion kinematic viscosity and ion temperature, is discussed in the presence of superthermal electrons in nonplanar geometry. It is also seen that the IASWs propagating in cylindrical/spherical geometry with transverse perturbation will be deformed as time goes on.

  12. Nonplanar Ion-Acoustic Solitons in Electron-Positron-Ion Quantum Plasmas

    Institute of Scientific and Technical Information of China (English)

    S. A. Khan; S. Mahmood; Arshad M. Mirza

    2009-01-01

    @@ The propagation of nonplanar quantum ion-acoustic solitary waves in a dense, unmagnetized electron-positron-ion (e-p-i) plasma are studied by using the Korteweg-de Vries (KdV) model The quantum hydrodynamic (QHD) equations are used taking into account the quantum diffraction and quantum statistics corrections. The analytical and numerical solutions of KdV equation reveal that the nonplanar ion-acoustic solitons are modified significantly with quantum corrections and positron concentration, and behave differently in different geometries.

  13. Fabrication of nanotube arrays on commercially pure titanium and their apatite-forming ability in a simulated body fluid

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Chang, Yu-Chen [Department of Mechanical and Automation Engineering, Da-Yeh University, Taiwan, ROC (China); Ho, Wen-Fu, E-mail: fujii@nuk.edu.tw [Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung, Taiwan, ROC (China)

    2015-02-15

    In this study, we investigated self-organized TiO{sub 2} nanotubes that were grown using anodization of commercially pure titanium at 5 V or 10 V in NH{sub 4}F/NaCl electrolyte. The nanotube arrays were annealed at 450 °C for 3 h to convert the amorphous nanotubes to anatase and then they were immersed in simulated body fluid at 37 °C for 0.5, 1, and 14 days. The purpose of this experiment was to evaluate the apatite-formation abilities of anodized Ti nanotubes with different tube diameters and lengths. The nanotubes that formed on the surfaces of Ti were examined using a field emission scanning electron microscope, X-ray diffraction, and X-ray photoelectron spectroscope. When the anodizing potential was increased from 5 V to 10 V, the pore diameter of the nanotube increased from approximately 24–30 nm to 35–53 nm, and the tube length increased from approximately 590 nm to 730 nm. In vitro testing of the heat-treated nanotube arrays indicated that Ca-P formation occurred after only 1 day of immersion in simulated body fluid. This result was particularly apparent in the samples that were anodized at 10 V. It was also found that the thickness of the Ca-P layer increases as the applied potential for anodized c.p. Ti increases. The average thickness of the Ca-P layer on Ti that was anodized at 5 V and 10 V was approximately 170 nm and 190 nm, respectively, after immersion in simulated body fluid for 14 days. - Highlights: • TiO{sub 2} nanotube on Ti surface was formed by anodic oxidation in a NaCl/NH{sub 4}F solution. • TiO{sub 2} layers show a tube length of 590 nm and 730 nm at 5 V and 10 V, respectively. • After soaking in SBF, Ca-P layer completely covered the entire nanotubular surfaces. • The Ca-P layer was thicker on the Ti surface anodized at 10 V.

  14. Direct detection of precursors of gas giants formed by gravitational instability with the Atacama Large Millimetre/sub-millimetre Array

    CERN Document Server

    Mayer, Lucio; Pineda, Jaime E; Wadsley, James

    2016-01-01

    Phases of gravitational instability are expected in the early phases of disk evolution, when the disk mass is still a substantial fraction of the mass of the star. Disk fragmentation into sub-stellar objects could occur in the cold exterior part of the disk. Direct detection of massive gaseous clumps on their way to collapse into gas giant planets would offer an unprecedented test of the disk instability model. Here we use state-of-the-art 3D radiation-hydro simulations of disks undergoing fragmentation into massive gas giants, post-processed with the RADMC-3D ray-tracing code to produce dust continuum emission maps. These are then fed into the Common Astronomy Software Applications (CASA) ALMA simulator. The synthetic maps show that both overdense spiral arms and actual clumps at different stages of collapse can be detected with the Atacama Large Millimetre/sub-millimetre Array (ALMA) in the full configuration at the distance of the Ophiuchus star forming region (125 pc). The detection of clumps is particula...

  15. SL(2,C) Chern–Simons theory, a non-planar graph operator, and 4D quantum gravity with a cosmological constant: Semiclassical geometry

    OpenAIRE

    Haggard, Hal M.; Muxin Han; Wojciech Kamiński; Aldo Riello

    2015-01-01

    We study the expectation value of a nonplanar Wilson graph operator in SL(2,C) Chern-Simons theory on $S^3$. In particular we analyze its asymptotic behaviour in the double-scaling limit in which both the representation labels and the Chern-Simons coupling are taken to be large, but with fixed ratio. When the Wilson graph operator has a specific form, motivated by loop quantum gravity, the critical point equations obtained in this double-scaling limit describe a very specific class of flat co...

  16. Static aeroelastic analysis of very flexible wings based on non-planar vortex lattice method

    Institute of Scientific and Technical Information of China (English)

    Xie Changchuan; Wang Libo; Yang Chao; Liu Yi

    2013-01-01

    A rapid and efficient method for static aeroelastic analysis of a flexible slender wing when considering the structural geometric nonlinearity has been developed in this paper.A non-planar vortex lattice method herein is used to compute the non-planar aerodynamics of flexible wings with large deformation.The finite element method is introduced for structural nonlinear statics analysis.The surface spline method is used for structure/aerodynamics coupling.The static aeroelastic characteristics of the wind tunnel model of a flexible wing are studied by the nonlinear method presented,and the nonlinear method is also evaluated by comparing the results with those obtained from two other methods and the wind tunnel test.The results indicate that the traditional linear method of static aeroelastic analysis is not applicable for cases with large deformation because it produces results that are not realistic.However,the nonlinear methodology,which involves combining the structure finite element method with the non-planar vortex lattice method,could be used to solve the aeroelastic deformation with considerable accuracy,which is in fair agreement with the test results.Moreover,the nonlinear finite element method could consider complex structures.The non-planar vortex lattice method has advantages in both the computational accuracy and efficiency.Consequently,the nonlinear method presented is suitable for the rapid and efficient analysis requirements of engineering practice.It could be used in the preliminary stage and also in the detailed stage of aircraft design.

  17. Non-planar Feynman diagrams and Mellin-Barnes representations with AMBRE 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Dubovyk, Ievgen [Institute of Electrophysics and Radiation Technologies, Kharkiv (Ukraine); Gluza, Janusz [Univ. of Silesia, Katowice (Poland). Inst. of Physics; Riemann, Tord

    2016-04-15

    We introduce the Mellin-Barnes representation of general Feynman integrals and discuss their evaluation. The Mathematica package AMBRE has been recently extended in order to cover consistently non-planar Feynman integrals with two loops. Prospects for the near future are outlined. This write-up is an introduction to new results which have also been presented elsewhere.

  18. Structural templating in a nonplanar phthalocyanine using single crystal copper iodide

    OpenAIRE

    Rochford, L. A. (Luke A.); Ramadan, Alexandra J.; Keeble, Dean S.; Ryan, Mary P.; Heutz, Sandrine; Jones, T S

    2015-01-01

    Solution-grown copper iodide crystals are used as substrates for the templated growth of the nonplanar vanadyl phthalocyanine using organic molecular beam deposition. Structural characterization reveals a single molecular orientation produced by the (111) Miller plane of the copper iodide crystals. These fundamental measurements show the importance of morphology and structure in templating interactions for organic electronics applications.

  19. Temporal analysis of the coherent properties of optical images of rough nonplanar objects

    NARCIS (Netherlands)

    Mandrosov, V. I.

    2009-01-01

    The possibility of using temporal analysis to find the relation between chromatic properties of probe radiation and coherent properties of the optical images of rough non-planar objects is substantiated. The analysis is based on the use of the time correlation function and on the study of the speckl

  20. Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex, heterogeneous elastic solids

    Energy Technology Data Exchange (ETDEWEB)

    Duru, Kenneth, E-mail: kduru@stanford.edu [Department of Geophysics, Stanford University, Stanford, CA (United States); Dunham, Eric M. [Department of Geophysics, Stanford University, Stanford, CA (United States); Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA (United States)

    2016-01-15

    Dynamic propagation of shear ruptures on a frictional interface in an elastic solid is a useful idealization of natural earthquakes. The conditions relating discontinuities in particle velocities across fault zones and tractions acting on the fault are often expressed as nonlinear friction laws. The corresponding initial boundary value problems are both numerically and computationally challenging. In addition, seismic waves generated by earthquake ruptures must be propagated for many wavelengths away from the fault. Therefore, reliable and efficient numerical simulations require both provably stable and high order accurate numerical methods. We present a high order accurate finite difference method for: a) enforcing nonlinear friction laws, in a consistent and provably stable manner, suitable for efficient explicit time integration; b) dynamic propagation of earthquake ruptures along nonplanar faults; and c) accurate propagation of seismic waves in heterogeneous media with free surface topography. We solve the first order form of the 3D elastic wave equation on a boundary-conforming curvilinear mesh, in terms of particle velocities and stresses that are collocated in space and time, using summation-by-parts (SBP) finite difference operators in space. Boundary and interface conditions are imposed weakly using penalties. By deriving semi-discrete energy estimates analogous to the continuous energy estimates we prove numerical stability. The finite difference stencils used in this paper are sixth order accurate in the interior and third order accurate close to the boundaries. However, the method is applicable to any spatial operator with a diagonal norm satisfying the SBP property. Time stepping is performed with a 4th order accurate explicit low storage Runge–Kutta scheme, thus yielding a globally fourth order accurate method in both space and time. We show numerical simulations on band limited self-similar fractal faults revealing the complexity of rupture

  1. The Measurement of the Effects of Helmet Form on Sound Source Detection and Localization Using a Portable Four-Loudspeaker Test Array

    Science.gov (United States)

    2013-05-01

    Monaural and Binaural Localization. Hearing Res. 1986, 21, 67–73. Carlile, S.; Leong, P.; Hyams, S. The Nature and Distribution of Errors in Sound ...The Measurement of the Effects of Helmet Form on Sound Source Detection and Localization Using a Portable Four-Loudspeaker Test Array by...Aberdeen Proving Ground, MD 21005-5425 ARL-TR-6444 May 2013 The Measurement of the Effects of Helmet Form on Sound Source Detection and

  2. High-Performance, High-Index-Contrast Chalcogenide Glass Photonics on Silicon and Unconventional Non-planar Substrates

    CERN Document Server

    Zou, Yi; Lin, Hongtao; Li, Lan; Moreel, Loise; Zhou, Jie; Du, Qingyang; Ogbuu, Okechukwu; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Dobson, Kevin D; Birkmire, Robert; Hu, Juejun

    2013-01-01

    This paper reports a versatile, roll-to-roll and backend compatible technique for the fabrication of high-index-contrast photonic structures on both silicon and plastic substrates. The fabrication technique combines low-temperature chalcogenide glass film deposition and resist-free single-step thermal nanoimprint to process low-loss (1.6 dB/cm), sub-micron single-mode waveguides with a smooth surface finish using simple contact photolithography. Using this approach, the first chalcogenide glass micro-ring resonators are fabricated by thermal nanoimprint. The devices exhibit an ultra-high quality-factor of 400,000 near 1550 nm wavelength, which represents the highest value reported in chalcogenide glass micro-ring resonators. Furthermore, sub-micron nanoimprint of chalcogenide glass films on non-planar plastic substrates is demonstrated, which establishes the method as a facile route for monolithic fabrication of high-index-contrast devices on a wide array of unconventional substrates.

  3. Nonplanar electrostatic shock waves in an opposite polarity dust plasma with nonextensive electrons and ions

    Indian Academy of Sciences (India)

    M AMINA; S A EMA; A A MAMUN

    2017-06-01

    A rigorous theoretical investigation has been carried out on the propagation of nonplanar (cylindrical and spherical) dust-acoustic shock waves (DASHWs) in a collisionless four-component unmagnetized dusty plasmasystem containing massive, micron-sized, positively and negatively charged inertial dust grains along with $q$ (nonextensive) distributed electrons and ions. The well-known reductive perturbation technique has been used to derive the modified Burgers equation (which describes the shock wave properties) and its numerical solution. It has been observed that the effects of charged dust grains of opposite polarity, nonextensivity of electrons and ions, and different dusty plasma parameters have significantly modified the fundamental properties (viz., polarity, amplitude, width, etc.) of the shock waves. The properties of DASHWs in nonplanar geometry are found tobe significantly different from those in one-dimensional planar geometry. The findings of our results from this theoretical investigation may be useful in understanding the nonlinear features of localized electrostatic disturbancesin both space and laboratory dusty plasmas.

  4. Development of a testbed for flexible a-Si:H photodiode sensing arrays

    Science.gov (United States)

    Dominguez, Alfonso; Kunnen, George; Vetrano, Michael; Smith, Joseph; Marrs, Michael; Allee, David R.

    2013-05-01

    Large area, flexible sensing arrays for imaging, biochemical sensing and radiation detection are now possible with the development of flexible active matrix display technology. In particular, large-area flexible imaging arrays can provide considerable advancement in defense and security industries because of their inherent low manufacturing costs and physical plasticity that allows for increased adaptability to non-planar mounting surfaces. For example, a flexible array of photodetectors and lenslets formed into a cylinder could image simultaneously with a 360 degree view without the need for expensive bulky optics or a gimbaled mount. Here we report the design and development of a scalable 16x16 pixel testbed for flexible sensor arrays using commercial-off-the-shelf (COTS) parts and demonstrate the capture of a shadow image with an array of photodiodes and active pixel sensors on a plastic substrate. The image capture system makes use of an array of low-noise, InGaZnO active pixel amplifiers to detect changes in current in 2.4 μm-thick reverse-biased a-Si:H PIN diodes. A thorough characterization of the responsivity, detectivity, and optical gain of an a- Si:H photodiode is also provided. At the back end, analog capture circuitry progressively scans the array and constructs an image based on the electrical activity in each pixel. The use of correlated-double-sampling to remove fixed pattern noise is shown to significantly improve spatial resolution due to process variations. The testbed can be readily adapted for the development of neutron, alpha-particle, or X-ray detection arrays given an appropriate conversion layer.

  5. Properties of vortex beams formed by an array of fibre lasers and their propagation in a turbulent atmosphere

    Science.gov (United States)

    Aksenov, V. P.; Dudorov, V. V.; Kolosov, V. V.

    2016-08-01

    Using a numerical simulation, we investigate the possibility of synthesising vortex laser beams with a variable orbital angular momentum by a hexagonal array of fibre lasers under a phase control of individual subapertures of the array. We report the requirements to the parameters of the device generating a vortex beam (number and size of subapertures, as well as their mutual arrangement). The propagation dynamics of synthesised vortex beams is compared with that of conventional Laguerre-Gaussian beams in free space and in a turbulent atmosphere. The spectral properties of the synthesised beam, represented as a superposition of different azimuthal modes, are determined during its propagation in free space. The energy and statistical parameters of the synthesised and Laguerre-Gaussian vortex beams are shown to coincide with increasing propagation distance in a turbulent medium.

  6. Design of Beam-forming of Broadband Steerable-Parametric Array%相控参量阵波束合成设计

    Institute of Scientific and Technical Information of China (English)

    张富东; 徐利梅; 陈敏

    2013-01-01

    The simulation and analysis of beam-forming about broadband parametric array with rectangle trans-duction array and loop transduction array have been completed in this paper. The results show that under the condition of the same array element numbers with N=9 and same array size with rm = 49 mm,the - 3 dB beam width of rectangle array is about 6. 3° (comparing to 7. 4° of loop array), and its side-lobe amplitude is inhibited completely (comparing to the value of 10% about loop array). It means that the rectangle array is more effective at beam directivity improving and side-lobe amplitude inhibition. The method of element signal time-delay is used to parametric array signals beam-steering implement. As a result of Beam-steering, the beam main-lobe turned to width more, its peak value of amplitude reduces obviously,and it doesn't point to the direction which is planned to. The reasons of these problems are discussed in this paper. It is verified that these problems could be corrected by increasing array elements and spreading array size.%针对矩形和圆环形换能器阵列,完成了宽带参量阵信号的波束合成仿真与结果比较分析.仿真结果表明,同等阵元个数N=9、相似阵列边界半径rm=49 mm条件下,矩形阵列差频波波束主瓣-3 dB指向角约为6.3°(圆环阵列约为7.4°),旁瓣几乎被完全抑制(圆环阵列约为主瓣峰值的10%),矩形阵列更利于提高主瓣指向性和抑制旁瓣幅度.针对矩形阵列,该文仿真分析了采用阵元信号延时方法实现参量阵信号波束偏转时的各波束特征,仿真结果显示,偏转后波束存在主瓣峰值点幅值削弱、主瓣峰值点未对准预定方向、主瓣宽度增大等问题.分析表明,以上问题可通过增加阵元数目及增大阵列尺寸进行修正.

  7. An Artificial Olfaction System Formed by a Massive Sensors Array Dispersed in a Diffusion Media and an Automatically Formed Glomeruli Layer

    Science.gov (United States)

    Di Natale, Corrado; Martinelli, Eugenio; Paolesse, Roberto; D'Amico, Arnaldo; Filippini, Daniel; Lundström, Ingemar

    2009-05-01

    Optical imaging is a read-out technique for sensors that can easily provide advances in artificial olfaction implementing features such as the large number of receptors and the glomeruli layer. In this paper an artificial olfaction system based on the imaging of a continuous layer of chemical indicators is illustrated. The system results in an array of thousands of sensors, corresponding to the pixels of the image. The choice of Computer Screen Photoassisted Technology as a platform for optical interrogation of the sensing layer allows for the definition of a strategy for an automatic definition of the glomeruli layer based on the classification of the optical fingerprints of the image pixels. Chemical indicators are dissolved into a polymeric matrix mimicking the functions of the olfactory mucosa. The system is here illustrated with a simple experiment. Data are treated applying a lateral inhibition to the glomeruli layer resulting in a dynamic pattern resembling that observed in natural olfaction.

  8. Spectroscopy of a plasma formed in the vicinity of implosion of the shock wave generated by underwater electrical explosion of spherical wire array

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, O.; Efimov, S.; Gurovich, V. Tz.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel); Bernshtam, V. [Weizmann Institute of Science, Rehovot 76100 (Israel)

    2015-05-15

    The results of visible spectroscopy of the plasma formed inside a copper capillary placed at the equatorial plane of an underwater electrically exploded spherical wire array (30 mm in diameter; 40 wires, each of 100 μm in diameter) are reported. In the experiments, a pulsed power generator with current amplitude of ∼300 kA and rise time of ∼1.1 μs was used to produce wire array explosion accompanied by the formation of a converging strong shock wave. The data obtained support the assumption of uniformity of the shock wave along the main path of its convergence. The spectroscopic measurements show that this rather simple method of formation of a converging strong shock wave can be used successfully for studying the shock wave's interaction with matter and the evaporation processes of atoms from a target.

  9. Investigation of a solvent-cast organogel to form a liquid-gel microinterface array for electrochemical detection of lysozyme.

    Science.gov (United States)

    Felisilda, Bren Mark B; Alvarez de Eulate, Eva; Arrigan, Damien W M

    2015-09-17

    Ion transfer at aqueous-organogel interfaces enables the non-redox detection of ions and ionisable species by voltammetry. In this study, a non-thermal method for preparation of an organogel was employed and used for the detection of hen-egg-white-lysozyme (HEWL) via adsorptive stripping voltammetry at an array of aqueous-organogel microinterfaces. Tetrahydrofuran solvent casting was employed to prepare the organogel mixture, hence removing the need for heating of the solution to be gelled, as used in previous studies. Cyclic voltammetry of HEWL at the microinterface array revealed a broad adsorption process on the forward scan, at positive applied potentials, followed by a desorption peak at ca. 0.68 V, indicating the detection of HEWL in this region. Application of an adsorption step, where a constant optimized potential of 0.95 V was applied, followed by voltammetric detection provided for a linear response range of 0.02-0.84 μM and a detection limit of 0.030 μM for 300 s adsorption. The detection limit was further improved by utilizing differential pulse stripping voltammetry, resulting in detection limits of 0.017 μM, 0.014 μM, and 0.010 μM for adsorptive pre-concentration times of 60, 120 and 300 s, respectively, in unstirred solutions. These results are an improvement over other methods for the detection of HEWL at aqueous-organic interfaces and offers a basis for the label-free detection of protein.

  10. Superparamagnetic iron oxide nanoparticle attachment on array of micro test tubes and microbeakers formed on p-type silicon substrate for biosensor applications

    Science.gov (United States)

    Ghoshal, Sarmishtha; Ansar, Abul Am; Raja, Sufi O.; Jana, Arpita; Bandyopadhyay, Nil R.; Dasgupta, Anjan K.; Ray, Mallar

    2011-10-01

    A uniformly distributed array of micro test tubes and microbeakers is formed on a p-type silicon substrate with tunable cross-section and distance of separation by anodic etching of the silicon wafer in N, N-dimethylformamide and hydrofluoric acid, which essentially leads to the formation of macroporous silicon templates. A reasonable control over the dimensions of the structures could be achieved by tailoring the formation parameters, primarily the wafer resistivity. For a micro test tube, the cross-section (i.e., the pore size) as well as the distance of separation between two adjacent test tubes (i.e., inter-pore distance) is typically approximately 1 μm, whereas, for a microbeaker the pore size exceeds 1.5 μm and the inter-pore distance could be less than 100 nm. We successfully synthesized superparamagnetic iron oxide nanoparticles (SPIONs), with average particle size approximately 20 nm and attached them on the porous silicon chip surface as well as on the pore walls. Such SPION-coated arrays of micro test tubes and microbeakers are potential candidates for biosensors because of the biocompatibility of both silicon and SPIONs. As acquisition of data via microarray is an essential attribute of high throughput bio-sensing, the proposed nanostructured array may be a promising step in this direction.

  11. Superparamagnetic iron oxide nanoparticle attachment on array of micro test tubes and microbeakers formed on p-type silicon substrate for biosensor applications

    Directory of Open Access Journals (Sweden)

    Raja Sufi

    2011-01-01

    Full Text Available Abstract A uniformly distributed array of micro test tubes and microbeakers is formed on a p-type silicon substrate with tunable cross-section and distance of separation by anodic etching of the silicon wafer in N, N-dimethylformamide and hydrofluoric acid, which essentially leads to the formation of macroporous silicon templates. A reasonable control over the dimensions of the structures could be achieved by tailoring the formation parameters, primarily the wafer resistivity. For a micro test tube, the cross-section (i.e., the pore size as well as the distance of separation between two adjacent test tubes (i.e., inter-pore distance is typically approximately 1 μm, whereas, for a microbeaker the pore size exceeds 1.5 μm and the inter-pore distance could be less than 100 nm. We successfully synthesized superparamagnetic iron oxide nanoparticles (SPIONs, with average particle size approximately 20 nm and attached them on the porous silicon chip surface as well as on the pore walls. Such SPION-coated arrays of micro test tubes and microbeakers are potential candidates for biosensors because of the biocompatibility of both silicon and SPIONs. As acquisition of data via microarray is an essential attribute of high throughput bio-sensing, the proposed nanostructured array may be a promising step in this direction.

  12. Submillimeter Array Observations of Magnetic Fields in G240.31+0.07: an Hourglass in a Massive Cluster-forming Core

    OpenAIRE

    Qiu, Keping; Zhang, Qizhou; Menten, Karl M.; Liu, Hauyu B.; Tang, Ya-Wen; Girart, Josep M.

    2014-01-01

    We report the first detection of an hourglass magnetic field aligned with a well-defined outflow-rotation system in a high-mass star-forming region. The observations were performed with Submillimeter Array toward G240.31+0.07, which harbors a massive, flattened, and fragmenting molecular cloud core and a wide-angle bipolar outflow. The polarized dust emission at 0.88 mm reveals a clear hourglass-shaped magnetic field aligned within 20 degree of the outflow axis. Maps of high-density tracing s...

  13. Simulation study of planar and nonplanar super rogue waves in an electronegative plasma: Local discontinuous Galerkin method

    Science.gov (United States)

    El-Tantawy, S. A.; Aboelenen, Tarek

    2017-05-01

    Planar and nonplanar (cylindrical and spherical) ion-acoustic super rogue waves in an unmagnetized electronegative plasma are investigated, both analytically (for planar geometry) and numerically (for planar and nonplanar geometries). Using a reductive perturbation technique, the basic set of fluid equations is reduced to a nonplanar/modified nonlinear Schrödinger equation (NLSE), which describes a slow modulation of the nonlinear wave amplitude. The local modulational instability of the ion-acoustic structures governed by the planar and nonplanar NLSE is reported. Furthermore, the existence region of rogue waves is strictly defined. The parameters used in our calculations are from the lab observation data. The local discontinuous Galerkin (LDG) method is used to find rogue wave solutions of the planar and nonplanar NLSE and to prove L2 stability of this method. Also, it is found that the numerical simulations and the exact (analytical) solutions of the planar NLSE match remarkably well and numerical examples show that the convergence orders of the proposed LDG method are N + 1 when polynomials of degree N are used. Moreover, it is noted that the spherical rogue waves travel faster than their cylindrical counterpart. Also, the numerical solution showed that the spherical and cylindrical amplitudes of the localized pulses decrease with the increase in the time | τ |.

  14. Bistatic SAR coherence over non-planar topographies

    Science.gov (United States)

    Andre, Daniel B.; Morrison, Keith

    2012-05-01

    Monostatic Synthetic Aperture Radar (SAR) Coherent Change Detection (CCD) has been found to be of great utility in detecting changes that occur on the ground. Detectable changes of interest include vehicle tracks and water flow. The CCD procedure involves performing repeat pass radar collections, to form a coherence product, where ground disturbances can induce detectable incoherence. However there is usually a difference in the radar collection geometry which can lead to incoherent energy noise entering the CCD, which reduces the detectability of tracks. When sensing flat terrain, the incoherence due to collection geometry difference can be removed through a conventional Fourier image support trimming process. However, it has been found that when the terrain contains non-flat topography, the optimal trimming process is substantially more involved, so much so that a new per-pixel SAR back-projection imaging algorithm has been developed. This algorithm trims off incoherent energy on a per-pixel basis according to the local topography. In order to validate the bistatic SAR generalization to the monostatic per-pixel formalism and algorithm, bistatic change detection measurements were conducted with the GB-SAR system, and these are reported here.

  15. Filter arrays

    Energy Technology Data Exchange (ETDEWEB)

    Page, Ralph H.; Doty, Patrick F.

    2017-08-01

    The various technologies presented herein relate to a tiled filter array that can be used in connection with performance of spatial sampling of optical signals. The filter array comprises filter tiles, wherein a first plurality of filter tiles are formed from a first material, the first material being configured such that only photons having wavelengths in a first wavelength band pass therethrough. A second plurality of filter tiles is formed from a second material, the second material being configured such that only photons having wavelengths in a second wavelength band pass therethrough. The first plurality of filter tiles and the second plurality of filter tiles can be interspersed to form the filter array comprising an alternating arrangement of first filter tiles and second filter tiles.

  16. Nanoscale dielectric microscopy of non-planar samples by lift-mode electrostatic force microscopy.

    Science.gov (United States)

    Van Der Hofstadt, M; Fabregas, R; Biagi, M C; Fumagalli, L; Gomila, G

    2016-10-01

    Lift-mode electrostatic force microscopy (EFM) is one of the most convenient imaging modes to study the local dielectric properties of non-planar samples. Here we present the quantitative analysis of this imaging mode. We introduce a method to quantify and subtract the topographic crosstalk from the lift-mode EFM images, and a 3D numerical approach that allows for extracting the local dielectric constant with nanoscale spatial resolution free from topographic artifacts. We demonstrate this procedure by measuring the dielectric properties of micropatterned SiO2 pillars and of single bacteria cells, thus illustrating the wide applicability of our approach from materials science to biology.

  17. Transverse modes of a diode-laser pumped monolithic unidirectional non-planar ring laser

    Institute of Scientific and Technical Information of China (English)

    Keying Wu(吴克瑛); Suhui Yang(杨苏辉); Guanghui Wei(魏光辉)

    2003-01-01

    Diode-laser pumped monolithic single-frequency non-planar ring laser has the advantages of compactness,reliability and high efficiency. But when the pump power is high enough, the thermal effect will be seriousand the high-order transverse modes will appear. Therefore the single-mode output power is limited. Inthis paper, the mechanism of generating the high-order transverse modes in the monolithic unidirectionalnon-planar ring cavity is analyzed using ray tracing method. The calculated results are in agreement withthe experiments.

  18. Laser-diode-pumped 1319-nm monolithic non-planar ring single-frequency laser

    Institute of Scientific and Technical Information of China (English)

    Qing Wang(王青); Chunqing Gao(高春清); Yan Zhao(赵严); Suhui Yang(杨苏辉); Guanghui Wei(魏光辉); Dongmei Hong(洪冬梅)

    2003-01-01

    Single-frequency 1319-nm laser was obtained by using a laser-diode-pumped monolithic Nd:YAG crystalwith a non-planar ring oscillator (NPRO). When the NPRO laser was pumped by an 800-μm fiber coupledlaser diode, the output power of the single-frequency 1319-nm laser was 220 mW, and the slope efficiencywas 16%. With a 100-μm fiber coupled diode laser pumped, 99-mW single-frequency 1319-nm laser wasobtained with a slope efficiency of 29%.

  19. Nanoscale dielectric microscopy of non-planar samples by lift-mode electrostatic force microscopy

    Science.gov (United States)

    Van Der Hofstadt, M.; Fabregas, R.; Biagi, M. C.; Fumagalli, L.; Gomila, G.

    2016-10-01

    Lift-mode electrostatic force microscopy (EFM) is one of the most convenient imaging modes to study the local dielectric properties of non-planar samples. Here we present the quantitative analysis of this imaging mode. We introduce a method to quantify and subtract the topographic crosstalk from the lift-mode EFM images, and a 3D numerical approach that allows for extracting the local dielectric constant with nanoscale spatial resolution free from topographic artifacts. We demonstrate this procedure by measuring the dielectric properties of micropatterned SiO2 pillars and of single bacteria cells, thus illustrating the wide applicability of our approach from materials science to biology.

  20. Molecular Engineering of Nonplanar Porphyrin and Carbon Nanotube Assemblies: A Linear and Nonlinear Spectroscopic and Modeling Study

    Directory of Open Access Journals (Sweden)

    Éimhín M. Ní Mhuircheartaigh

    2011-01-01

    Full Text Available The importance of molecular conformation to the nature and strength of noncovalent interactions existing between a series of increasingly nonplanar tetraphenylporphyrin (TPP derivatives and carbon nanotubes was systematically investigated experimentally in solution using a range of linear and nonlinear optical techniques. Additional complementary molecular dynamics studies were found to support the experimental observations. Convincing evidence of binding between single walled nanotubes (SWNTs and some of these porphyrins was discovered, and a nonplanar macrocycle conformation was found to increase the likelihood of noncovalent binding onto nanotubes. Nonlinear optical studies showed that the optical limiting behavior of the TPP derivatives deteriorated with increasing porphyrin nonplanarity, but that formation of nanotube composites dramatically improved the optical limiting properties of all molecules studied. It was also found that the significant photoluminescence quenching behavior reported in the literature for such porphyrin/SWNT composites is at least partly caused by photoluminescence and excitation self-absorption and is, therefore, an artifact of the system.

  1. NUMERICAL ANALYSIS OF THE NON-NEWTONIAN BLOOD FLOW IN THE NON-PLANAR ARTERY WITH BIFURCATION

    Institute of Scientific and Technical Information of China (English)

    CHEN Jie; LU Xi-yun; ZHUANG Li-xian; WANG Wen

    2004-01-01

    A numerical analysis of non-Newtonian fluid flow in non-planar artery with bifurcation was performed by using a finite element method to solve the three-dimensional Navier-Stokes equations coupled with the non-Newtonian constitutive models, including Carreau,Cross and Bingham models. The objective of this study is to investigate the effects of the non-Newtonian properties of blood as well as curvature and out-of-plane geometry in the non-planar daughter vessels on the velocity distribution and wall shear stress. The results of this study support the view that the non-planarity of blood vessels and the non-Newtonian properties of blood are of important in hemodynamics and play a significant role in vascular biology and pathophysiology.

  2. Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units.

    Science.gov (United States)

    Álvarez, Celedonio M; Barbero, Héctor; Ferrero, Sergio

    2016-09-18

    The main purpose of this video is to show 6 reaction steps of a convergent synthesis and prepare a complex molecule containing up to three nonplanar polyaromatic units, which are two corannulene moieties and a racemic hexahelicene linking them. The compound described in this work is a good host for fullerenes. Several common organic reactions, such as free-radical reactions, C-C coupling or click chemistry, are employed demonstrating the versatility of functionalization that this compound can accept. All of these reactions work for planar aromatic molecules. With subtle modifications, it is possible to achieve similar results for nonplanar polyaromatic compounds.

  3. Covalent functionalization of octagraphene with magnetic octahedral B6- and non-planar C6- clusters

    Science.gov (United States)

    Chigo-Anota, E.; Cárdenas-Jirón, G.; Salazar Villanueva, M.; Bautista Hernández, A.; Castro, M.

    2017-10-01

    The interaction between the magnetic boron octahedral (B6-) and non-planar (C6-) carbon clusters with semimetal nano-sheet of octa-graphene (C64H24) in the gas phase is studied by means of DFT calculations. These results reveal that non-planar-1 (anion) carbon cluster exhibits structural stability, low chemical reactivity, magnetic (1.0 magneton bohr) and semiconductor behavior. On the other hand, there is chemisorption phenomena when the stable B6- and C6- clusters are absorbed on octa-graphene nanosheets. Such absorption generates high polarity and the low-reactivity remains as on the individual pristine cases. Electronic charge transference occurs from the clusters toward the nanosheets, producing a reduction of the work function for the complexes and also induces a magnetic behavior on the functionalized sheets. The quantum descriptors obtained for these systems reveal that they are feasible candidates for the design of molecular circuits, magnetic devices, and nano-vehicles for drug delivery.

  4. Elementary framework for cold field emission from quantum-confined, non-planar emitters

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, A. A., E-mail: apatters@mit.edu; Akinwande, A. I. [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA and Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-05-07

    For suitably small field emitters, the effects of quantum confinement at the emitter tip may have a significant impact on the emitter performance and total emitted current density (ECD). Since the geometry of a quantum system uniquely determines the magnitude and distribution of its energy levels, a framework for deriving ECD equations from cold field electron emitters of arbitrary geometry and dimensionality is developed. In the interest of obtaining semi-analytical ECD equations, the framework is recast in terms of plane wave solutions to the Schrödinger equation via the use of the Jeffreys-Wentzel-Kramers-Brillouin approximation. To demonstrate the framework's consistency with our previous work and its capabilities in treating emitters with non-planar geometries, ECD equations were derived for the normally unconfined cylindrical nanowire (CNW) and normally confined (NC) CNW emitter geometries. As a function of the emitter radius, the NC CNW emitter ECD profile displayed a strong dependence on the Fermi energy and had an average ECD that exceeded the Fowler-Nordheim equation for typical values of the Fermi energy due to closely spaced, singly degenerate energy levels (excluding electron spin), comparatively large electron supply values, and the lack of a transverse, zero-point energy. Such characteristics suggest that emitters with non-planar geometries may be ideal for emission from both an electron supply and electrostatics perspective.

  5. Nonplanar integrability

    Science.gov (United States)

    Carlson, Warren; de Mello Koch, Robert; Lin, Hai

    2011-03-01

    In this article we study operators with a dimension Δ ˜ O( N) and show that simple analytic expressions for the action of the dilatation operator can be found. The operators we consider are restricted Schur polynomials. There are two distinct classes of operators that we consider: operators labeled by Young diagrams with two long columns or two long rows. The main complication in working with restricted Schur polynomials is in building a projector from a given S n+ m irreducible representation to an S n × S m irreducible representation (both specified by the labels of the restricted Schur polynomial). We give an explicit construction of these projectors by reducing it to the simple problem of addition of angular momentum in ordinary non-relativistic quantum mechanics. The diagonalization of the dilatation operator reduces to solving three term recursion relations. The fact that the recursion relations have only three terms is a direct consequence of the weak mixing at one loop of the restricted Schur polynomials. The recursion relations can be solved exactly in terms of symmetric Kravchuk polynomials or in terms of Clebsch-Gordan coefficients. This proves that the dilatation operator reduces to a decoupled set of harmonic oscillators and therefore it is integrable.

  6. Nonplanar Integrability

    CERN Document Server

    Carlson, Warren; Lin, Hai

    2011-01-01

    In this article we study operators with a dimension $\\Delta\\sim O(N)$ and show that simple analytic expressions for the action of the dilatation operator can be found. The operators we consider are restricted Schur polynomials. There are two distinct classes of operators that we consider: operators labeled by Young diagrams with two long columns or two long rows. The main complication in working with restricted Schur polynomials is in building a projector from a given $S_{n+m}$ irreducible representation to an $S_n\\times S_m$ irreducible representation (both specified by the labels of the restricted Schur polynomial). We give an explicit construction of these projectors by reducing it to the simple problem of addition of angular momentum in ordinary non-relativistic quantum mechanics. The diagonalizationof the dilatation operator reduces to solving three term recursion relations. The fact that the recursion relations have only three terms is a direct consequence of the weak mixing at one loop of the restricte...

  7. CLOSED-FORM SPACE-TIME CHANNEL BLIND ESTIMATION FOR SPACE-TIME CODED MC-CDMA SYTEMS WITH UNIFORM LINEAR ARRAY

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper proposes a closed-form joint space-time channel and Direction Of Arrival (DOA) blind estimation algorithm for space-time coded Multi-Carrier Code Division Multiple Access (MC-CDMA) systems equipped with a Uniform Linear Array (ULA) at the base station in frequency-selective fading environments. The algorithm uses an ESPRIT-like method to separate multiple co-channel users with different impinging DOAs. As a result, the DOAs for multiple users are obtained. In particular, a set of signal subspaces,every one of which is spanned by the space-time vector channels of an individual user, are also obtained. From these signal subspaces, the space-time channels of multiple users are estimated using the subspace method.Computer simulations illustrate both the validity and the overall performance of the proposed scheme.

  8. Application of Young-Michelson and Brown-Twiss interferometers for determining geometric parameters of nonplanar rough objects

    NARCIS (Netherlands)

    Mandrosov, V. I.

    2008-01-01

    The possibility of using Young-Michelson and Brown-Twiss interferometers for measuring the angular dimensions and parameters of the surface shape of remote passively scattering and self-luminous nonplanar rough objects by optical radiation propagating from them is substantiated. The analysis is base

  9. Non-planar Rearview Mirrors: The Influence of Experience and Driver Age on Gap Acceptance and Vehicle Detection

    NARCIS (Netherlands)

    Vos, A.P. de; Horst, A.R.A. van der; Perel, M.

    2001-01-01

    Non-planar driver's side rear-view mirrors provide a wider field-of-view than planar mirrors, but produce a minified image. A field experiment was conducted to measure the performance of drivers when making lane change decisions based on mirror information. Four mirror types were included: a planar

  10. Focal plane array with modular pixel array components for scalability

    Energy Technology Data Exchange (ETDEWEB)

    Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

    2014-12-09

    A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

  11. Non-planar and Non-linear Second Sound Waves in He Ⅱ

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; KIMURA Seiji; MURAKAMI Masahide; WANG Ru-zhu

    2000-01-01

    Non-planar and non-linear second sound wave are experimentally investigated in an open He Ⅱ bath. It is found that second sound wave characterized by a negative tail part in an open He Ⅱ bath is different from that propagating through a channel, and the shape of the negative tail part of second sound wave varies at different location in an open He Ⅱ bath. Theoretical consideration is also carried out based on two-fluid model and vortex evolution equation. It is found that experimental and theoretical results agree rather well with each other. Second sound wave may develop into the thermal shock wave provided that the heat flux is large.

  12. Change of manufacturing technique for the W7-X nonplanar coil cases

    Energy Technology Data Exchange (ETDEWEB)

    Gehring, M. E-mail: michael_gehring@bb-power.de; Schaefer, P.; Herrmann, K.D.; Scheller, H

    2001-11-01

    The geometry of the coil cases of the nonplanar coil system for the Wendelstein 7-X (W7-X) experiment (Sapper, The superconducting magnet system for the W7-X stellarator. Proceedings 12th Topical Meeting on the Fusion Technology) was changed to a more complex shape compared to the DEMO Coil case (Kronhardt et al., 1998. Proceedings of the 20th SOFT (1998) 731-734). Therefore the manufacturing technique developed for the DEMO Coil case cannot be used for the series production of 50 coils. For the final design of the coil cases, investigations were performed to find a technique suitable for manufacturing the cases within the required geometrical tolerances and mechanical characteristics. In order to qualify the manufacturing technique a complete half case was cast and machined afterwards. The casting procedure was optimised with respect to the geometrical accuracy and the mechanical characteristics at 4.2 K. Measurements of the yield strength, the tensile strength, the elongation, and the Young's modulus were performed at room- and cryo-temperature (4 and 7 K). The influence of the heat treatment, the annealing temperature and the size of the casting on the mechanical values is shown. The requirements on the stainless steel are a yield strength of 800 MPa at 4 K and an elongation at fracture of >25%. The magnetic permeability has to be <1.01. Furthermore the welding properties of the case material were investigated. The development program showed that casting of complete case half shells is a feasible manufacturing technique for the series production of the Wendelstein 7-X nonplanar coil cases.

  13. Wave path calculation for phased array imaging to evaluate weld zone of elbow pipes (Conference Presentation)

    Science.gov (United States)

    Park, Choon-Su; Park, Jin Kyu; Choi, Wonjae; Cho, Seunghyun; Kim, Dong-Yeol; Han, Ki Hyung

    2017-04-01

    It has long been non-destructively evaluated on weld joints of various pipes which are indispensable to most of industrial structures. Ultrasound evaluation has been used to detect flaws in welding joints, but some technical deficiencies still remain. Especially, ultrasound imaging on weld of elbow pipes has many challenging issues due to varying surface along circumferential direction. Conventional ultrasound imaging has particularly focused on ultrasonic wave propagation based on ray theory. This confines the incident angle and the position of an array transducer as well. Total focusing method (TFM), however, can provide not only high resolution images but also flexibility that enables to use ultrasonic waves to every direction that they can reach. This leads us to develop a method to get images of weld zone from an elbow part that curves. It is inevitable of each ultrasonic wave from the array transducer to transmit through different media and to be reflected from the boundary with angles along the curved surface. To form a correct PA image, careful calculation is made to ensure that time delay of receive-after-transmit is correctly shifted and summed even under non-planar boundary condition. Here, a method to calculate wave paths for the zone of interest at weld joint of an elbow pipe is presented. Numerical simulations of wave propagation on an elbow pipe are made to verify the proposed method. It is also experimentally demonstrated that the proposed method is well applied to various actual pipes that contains artificial flaws with a flexible wedge.

  14. The glycosylphosphatidylinositol-PLC in Trypanosoma brucei forms a linear array on the exterior of the flagellar membrane before and after activation.

    Science.gov (United States)

    Hanrahan, Orla; Webb, Helena; O'Byrne, Robert; Brabazon, Elaine; Treumann, Achim; Sunter, Jack D; Carrington, Mark; Voorheis, H Paul

    2009-06-01

    Bloodstream forms of Trypanosoma brucei contain a glycosylphosphatidylinositol-specific phospholipase C (GPI-PLC) that cleaves the GPI-anchor of the variable surface glycoprotein (VSG). Its location in trypanosomes has been controversial. Here, using confocal microscopy and surface labelling techniques, we show that the GPI-PLC is located exclusively in a linear array on the outside of the flagellar membrane, close to the flagellar attachment zone, but does not co-localize with the flagellar attachment zone protein, FAZ1. Consequently, the GPI-PLC and the VSG occupy the same plasma membrane leaflet, which resolves the topological problem associated with the cleavage reaction if the VSG and the GPI-PLC were on opposite sides of the membrane. The exterior location requires the enzyme to be tightly regulated to prevent VSG release under basal conditions. During stimulated VSG release in intact cells, the GPI-PLC did not change location, suggesting that the release mechanism involves lateral diffusion of the VSG in the plane of the membrane to the fixed position of the GPI-PLC.

  15. High-Fidelity Aerostructural Optimization of Nonplanar Wings for Commercial Transport Aircraft

    Science.gov (United States)

    Khosravi, Shahriar

    Although the aerospace sector is currently responsible for a relatively small portion of global anthropogenic greenhouse gas emissions, the growth of the airline industry raises serious concerns about the future of commercial aviation. As a result, the development of new aircraft design concepts with the potential to improve fuel efficiency remains an important priority. Numerical optimization based on high-fidelity physics has become an increasingly attractive tool over the past fifteen years in the search for environmentally friendly aircraft designs that reduce fuel consumption. This approach is able to discover novel design concepts and features that may never be considered without optimization. This can help reduce the economic costs and risks associated with developing new aircraft concepts by providing a more realistic assessment early in the design process. This thesis provides an assessment of the potential efficiency improvements obtained from nonplanar wings through the application of fully coupled high-fidelity aerostructural optimization. In this work, we conduct aerostructural optimization using the Euler equations to model the flow along with a viscous drag estimate based on the surface area. A major focus of the thesis is on finding the optimal shape and performance benefits of nonplanar wingtip devices. Two winglet configurations are considered: winglet-up and winglet-down. These are compared to optimized planar wings of the same projected span in order to quantify the possible drag reductions offered by winglets. In addition, the drooped wing is studied in the context of exploratory optimization. The main results show that the winglet-down configuration is the most efficient winglet shape, reducing the drag by approximately 2% at the same weight in comparison to a planar wing. There are two reasons for the superior performance of this design. First, this configuration moves the tip vortex further away from the wing. Second, the winglet

  16. Time evolution of nonplanar dust ion-acoustic solitary waves in a charge varying dusty plasma with superthermal electrons

    Energy Technology Data Exchange (ETDEWEB)

    Mayout, Saliha; Tribeche, Mouloud, E-mail: mouloudtribeche@yahoo.fr [Plasma Physics Group (PPG), Theoretical Physics Laboratory (TPL), Faculty of Sciences- Physics, University of Bab-Ezzouar, U.S.T.H.B, B.P. 32, El Alia, Algiers 16111 (Algeria); Sahu, Biswajit [Department of Mathematics, West Bengal State University, Barasat, Kolkata-700126 (India)

    2015-12-15

    A theoretical study on the nonlinear propagation of nonplanar (cylindrical and spherical) dust ion-acoustic solitary waves (DIASW) is carried out in a dusty plasma, whose constituents are inertial ions, superthermal electrons, and charge fluctuating stationary dust particles. Using the reductive perturbation theory, a modified Korteweg-de Vries equation is derived. It is shown that the propagation characteristics of the cylindrical and spherical DIA solitary waves significantly differ from those of their one-dimensional counterpart.

  17. Towards a four-loop form factor

    CERN Document Server

    Boels, Rutger; Yang, Gang

    2016-01-01

    The four-loop, two-point form factor contains the first non-planar correction to the lightlike cusp anomalous dimension. This anomalous dimension is a universal function which appears in many applications. Its planar part in N = 4 SYM is known, in principle, exactly from AdS/CFT and integrability while its non-planar part has been conjectured to vanish. The integrand of the form factor of the stress-tensor multiplet in N = 4 SYM including the non-planar part was obtained in previous work. We parametrise the difficulty of integrating this integrand. We have obtained a basis of master integrals for all integrals in the four-loop, two-point class in two ways. First, we computed an IBP reduction of the integrand of the N = 4 form factor using massive computer algebra (Reduze). Second, we computed a list of master integrals based on methods of the Mint package, suitably extended using Macaulay2 / Singular. The master integrals obtained in both ways are consistent with some minor exceptions. The second method indic...

  18. Nonplanar ion-acoustic solitons collision in Xe+-F-- SF6- and Ar+-F-- SF6- plasmas

    Science.gov (United States)

    El-Tantawy, S. A.; Carbonaro, P.

    2016-04-01

    The solitons collision in nonplanar (cylindrical and spherical) plasmas consisting of positive ions, two different negative ions, and isothermal electrons is studied. For this purpose, the Poincaré-Lighthill-Kuo (PLK) method is used to obtain two-coupled nonplanar Korteweg-de Vries (nKdV) equations. Also, the nonplanar phase shifts are calculated. The physical parameters of two plasma experiments; namely Xe+-F-- SF6- and Ar+-F-- SF6- are used to examine the properties of the localized pulses and their phase shifts after collision. It is found that the present model gives rise to the propagation of positive and negative pulses. The effects of the total negative ions concentration, the density ratio of the second-negative ions, the temperature ratio, and the geometrical effects on the behavior of solitons collisions and their phase shifts are investigated. Furthermore, it is found that the phase shifts in the case of the Ar+-F-- SF6- plasma are much larger than those of the Xe+-F-- SF6- plasma. Also, for fixed plasma parameters, the solitons collision received the largest phase shift in spherical geometry, followed by the cylindrical and planar geometries.

  19. Coherent, non-planar illumination of a defocused specimen: consequences for transmission electron microscopy

    Science.gov (United States)

    Patwardhan, Ardan

    The objective of this study has been to examine the imaging properties of transmission electron microscopes when coherent non-planar illumination is used in conjunction with defocused specimens. This situation is reminiscent of what is commonly the case in electron microscopic phase-contrast studies of biologically relevant macromolecules, using a field emission gun as a coherent electron source. For the sake of simplicity, the imaging system has been idealized as a thin lens with properties that can be described by the Fresnel approximation of the Huygens-Fresnel principle. The resulting expressions show that the system magnification has a defocus dependent factor, as do the contrast transfer functions. These factors are normally not taken into account in conventional derivations. The defocus dependent factor can be minimized by using planar illumination. The factor approaches infinity as the crossover moves closer to the specimen, and it is in the region close to the specimen that this factor is most significant. These results can have serious implications for high-resolution single-particle cryo electron microscopy as this technique often relies on combining data taken at a range of defocus values.

  20. Block Copolymer Directed Self-Assembly Approaches for Doping Planar and Non-Planar Semiconductors

    Science.gov (United States)

    Popere, Bhooshan; Russ, Boris; Heitsch, Andrew; Trefonas, Peter; Segalman, Rachel

    As electronic circuits continue to shrink, reliable nanoscale doping of functional devices presents new challenges. While directed self-assembly (DSA) of block copolymers (BCPs) has enabled excellent pitch control for lithography, controlling the 3D dopant distribution remains a fundamental challenge. To this end, we have developed a BCP self-assembly approach to confine dopants to nanoscopic domains within a semiconductor. This relies on the supramolecular encapsulation of the dopants within the core of the block copolymer (PS- b-P4VP) micelles, self-assembly of these micelles on the substrate, followed by rapid thermal diffusion of the dopants into the underlying substrate. We show that the periodic nature of the BCP domains enables precise control over the dosage and spatial position of dopant atoms on the technologically relevant length scales (10-100 nm). Additionally, as the lateral density of 2D circuit elements approaches the Moore's limit, novel 3D architectures have emerged. We have utilized our BCP self-assembly approach towards understanding the self-assembly our micelles directed by such nanoscale non-planar features. We show that the geometric confinement imposed by the hard feature walls directs the assembly of these micelles.

  1. Elastic wave field computation in multilayered nonplanar solid structures: a mesh-free semianalytical approach.

    Science.gov (United States)

    Banerjee, Sourav; Kundu, Tribikram

    2008-03-01

    Multilayered solid structures made of isotropic, transversely isotropic, or general anisotropic materials are frequently used in aerospace, mechanical, and civil structures. Ultrasonic fields developed in such structures by finite size transducers simulating actual experiments in laboratories or in the field have not been rigorously studied. Several attempts to compute the ultrasonic field inside solid media have been made based on approximate paraxial methods like the classical ray tracing and multi-Gaussian beam models. These approximate methods have several limitations. A new semianalytical method is adopted in this article to model elastic wave field in multilayered solid structures with planar or nonplanar interfaces generated by finite size transducers. A general formulation good for both isotropic and anisotropic solids is presented in this article. A variety of conditions have been incorporated in the formulation including irregularities at the interfaces. The method presented here requires frequency domain displacement and stress Green's functions. Due to the presence of different materials in the problem geometry various elastodynamic Green's functions for different materials are used in the formulation. Expressions of displacement and stress Green's functions for isotropic and anisotropic solids as well as for the fluid media are presented. Computed results are verified by checking the stress and displacement continuity conditions across the interface of two different solids of a bimetal plate and investigating if the results for a corrugated plate with very small corrugation match with the flat plate results.

  2. Hydrogel-Forming Microneedle Arrays Allow Detection of Drugs and Glucose In Vivo: Potential for Use in Diagnosis and Therapeutic Drug Monitoring.

    Directory of Open Access Journals (Sweden)

    Ester Caffarel-Salvador

    Full Text Available We describe, for the first time the use of hydrogel-forming microneedle (MN arrays for minimally-invasive extraction and quantification of drug substances and glucose from skin in vitro and in vivo. MN prepared from aqueous blends of hydrolysed poly(methyl-vinylether-co-maleic anhydride (11.1% w/w and poly(ethyleneglycol 10,000 daltons (5.6% w/w and crosslinked by esterification swelled upon skin insertion by uptake of fluid. Post-removal, theophylline and caffeine were extracted from MN and determined using HPLC, with glucose quantified using a proprietary kit. In vitro studies using excised neonatal porcine skin bathed on the underside by physiologically-relevant analyte concentrations showed rapid (5 min analyte uptake. For example, mean concentrations of 0.16 μg/mL and 0.85 μg/mL, respectively, were detected for the lowest (5 μg/mL and highest (35 μg/mL Franz cell concentrations of theophylline after 5 min insertion. A mean concentration of 0.10 μg/mL was obtained by extraction of MN inserted for 5 min into skin bathed with 5 μg/mL caffeine, while the mean concentration obtained by extraction of MN inserted into skin bathed with 15 μg/mL caffeine was 0.33 μg/mL. The mean detected glucose concentration after 5 min insertion into skin bathed with 4 mmol/L was 19.46 nmol/L. The highest theophylline concentration detected following extraction from a hydrogel-forming MN inserted for 1 h into the skin of a rat dosed orally with 10 mg/kg was of 0.363 μg/mL, whilst a maximum concentration of 0.063 μg/mL was detected following extraction from a MN inserted for 1 h into the skin of a rat dosed with 5 mg/kg theophylline. In human volunteers, the highest mean concentration of caffeine detected using MN was 91.31 μg/mL over the period from 1 to 2 h post-consumption of 100 mg Proplus® tablets. The highest mean blood glucose level was 7.89 nmol/L detected 1 h following ingestion of 75 g of glucose, while the highest mean glucose concentration

  3. SL(2,C) Chern-Simons Theory, a non-Planar Graph Operator, and 4D Loop Quantum Gravity with a Cosmological Constant: Semiclassical Geometry

    CERN Document Server

    Haggard, Hal M; Kamiński, Wojciech; Riello, Aldo

    2014-01-01

    We study the expectation value of a nonplanar Wilson graph operator in SL(2,C) Chern-Simons theory on $S^3$. In particular we analyze its asymptotic behaviour in the double-scaling limit in which both the representation labels and the Chern-Simons coupling are taken to be large, but with fixed ratio. When the Wilson graph operator has a specific form, motivated by loop quantum gravity, the critical point equations obtained in this double-scaling limit describe a very specific class of flat connection on the graph complement manifold. We find that flat connections in this class are in correspondence with the geometries of constant curvature 4-simplices. The result is fully non-perturbative from the perspective of the reconstructed geometry. We also show that the asymptotic behavior of the amplitude contains at the leading order an oscillatory part proportional to the Regge action for the single 4-simplex in the presence of a cosmological constant. In particular, the cosmological term contains the full-fledged ...

  4. Numerical investigation of blood flow in a deformable coronary bifurcation and non-planar branch

    Science.gov (United States)

    Razavi, Seyed Esmail; Omidi, Amir Ali; Saghafi Zanjani, Massoud

    2014-01-01

    Introduction: Among cardiovascular diseases, arterials stenosis is recognized more commonly than the others. Hemodynamic characteristics of blood play a key role in the incidence of stenosis. This paper numerically investigates the pulsatile blood flow in a coronary bifurcation with a non-planar branch. To create a more realistic analysis, the wall is assumed to be compliant. Furthermore, the flow is considered to be three-dimensional, incompressible, and laminar. Methods: The effects of non-Newtonian blood, compliant walls and different angles of bifurcation on hemodynamic characteristics of flow were evaluated. Shear thinning of blood was simulated with the Carreau-Yasuda model. The current research was mainly focused on the flow characteristics in bifurcations since atherosclerosis occurs mostly in bifurcations. Moreover, as the areas with low shear stresses are prone to stenosis, these areas were identified. Results: Our findings indicated that the compliant model of the wall, bifurcation’s angle, and other physical properties of flow have an impact on hemodynamics of blood flow. Lower wall shear stress was observed in the compliant wall than that in the rigid wall. The outer wall of bifurcation in all models had lower wall shear stress. In bifurcations with larger angles, wall shear stress was higher in outer walls, and lower in inner walls. Conclusion: The non-Newtonian blood vessels and different angles of bifurcation on hemodynamic characteristics of flow evaluation confirmed a lower wall shear stress in the compliant wall than that in the rigid wall, while the wall shear stress was higher in outer walls but lower in inner walls in the bifurcation regions with larger angles. PMID:25671176

  5. Episodic slow slip events in a non-planar subduction fault model for northern Cascadia

    Science.gov (United States)

    Li, D.; Liu, Y.; Matsuzawa, T.; Shibazaki, B.

    2014-12-01

    Episodic tremor and slow slip (ETS) events have been detected along the Cascadia margin, as well as many other subduction zones, by increasingly dense seismic and geodetic networks over the past decade. In northern Cascadia, ETS events arise on the thrust fault interface of 30~50 km depth, coincident with metamorphic dehydration of the subducting oceanic slab around temperatures of 350. Previous numerical simulations (e.g., Liu and Rice 2007) suggested that near-lithostatic pore pressure in the rate-state friction stability transition zone could give rise to slow slip events (SSE) down-dip of the seismogenic zone, which provides a plausible physical mechanism for these phenomena. Here we present a 3-D numerical simulation of inter-seismic SSEs based on the rate- and state- friction law, incorporating a non-planar, realistic northern Cascadia slab geometry compiled by McCrory et al. (2012) using triangular dislocation elements. Preliminary results show that the width and pore pressure level of the transition zone can remarkably affect the recurrence of SSEs. With effective normal stress of ~1-2 MPa and characteristic slip distance of ~1.4 mm, inter-seismic SSEs can arise about every year. The duration of each event is about 2~3 weeks, with the propagating speed along strike in the range of km/day. Furthermore, the slab bending beneath southern Vancouver Island and northern Washington State appears to accelerate the along-strike propagation of SSEs. Our next step is to constrain the rate-state frictional properties using geodetic inversion of SSE slip and inter-SSE plate coupling from the Plate Boundary Observatory (PBO) GPS measurements. Incorporating the realistic fault geometry into a physics model constrained by geodetic data will enable us to transition from a conceptual towards a quantitative and predictive understanding of SSEs mechanism.

  6. 基于GS算法的圆柱共形微带阵列自适应零点形成%Adaptive Null Forming of Cylindrical Conformal Microstrip Antennas Array Based on GS Algorithm

    Institute of Scientific and Technical Information of China (English)

    王俊鸣; 齐会来; 张子华; 陆磊; 韩云

    2011-01-01

    GS algorithm is applied to form a adaptive null of a cylindrical conformal microstrip antennas array in this paper. Firstly, the radiation pattern of each microstrip antenna element is analyzed by using cavity mode theory and adding the field one by one to form the array pattern. Then, GS algorithm is adopted to form the adaptive null of the cylindrical conformal microstrip antennas array. The simulation results have shown that, GS algorithm can form null exactly in the direction of the jammer.%运用GS算法研究了圆柱共形微带阵列天线的自适应零点形成.根据腔模理论和逐元法得到圆柱共形微带阵列天线的方向性函数,将GS算法运用于共形阵列进行自适应零点形成.仿真结果表明,采用GS算法的圆柱共形微带天线阵列能准确地在干扰方向形成零陷.

  7. Low profile conformal antenna arrays on high impedance substrate

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents electromagnetic (EM) design and analysis of dipole antenna array over high impedance substrate (HIS). HIS is a preferred substrate for low-profile antenna design, owing to its unique boundary conditions. Such substrates permit radiating elements to be printed on them without any disturbance in the radiation characteristics. Moreover HIS provides improved impedance matching, enhanced bandwidth, and increased broadside directivity owing to total reflection from the reactive surface and high input impedance. This book considers different configurations of HIS for array design on planar and non-planar high-impedance surfaces. Results are presented for cylindrical dipole, printed dipole, and folded dipole over single- and double-layered square-patch-based HIS and dogbone-based HIS. The performance of antenna arrays is analyzed in terms of performance parameters such as return loss and radiation pattern. The design presented shows acceptable return loss and mainlobe gain of radiation pattern. Thi...

  8. Nonplanar positron-acoustic Gardner solitary waves in electron-positron-ion plasmas with superthermal electrons and positrons

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, M. J., E-mail: josim.phys2007@gmail.com; Alam, M. S.; Mamun, A. A. [Department of Physics, Jahangirnagar University, Savar, Dhaka-1342 (Bangladesh)

    2015-02-15

    Nonplanar (cylindrical and spherical) positron-acoustic (PA) Gardner solitary waves (SWs) in an unmagnetized plasma system consisting of immobile positive ions, mobile cold positrons, and superthermal (kappa distributed) hot positrons and electrons are investigated. The modified Gardner equation is derived by using the reductive perturbation technique. The effects of cylindrical and spherical geometries, superthermal parameter of hot positrons and electrons, relative temperature ratios, and relative number density ratios on the PA Gardner SWs are studied by using the numerical simulations. The implications of our results in various space and laboratory plasma environments are briefly discussed.

  9. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  10. A New Physics-Based Modeling of Multiple Non-Planar Hydraulic Fractures Propagation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jing [University of Utah; Huang, Hai [Idaho National Lab. (INL), Idaho Falls, ID (United States); Deo, Milind [University of Utah; Jiang, Shu [Energy & Geoscience Institute

    2015-10-01

    Because of the low permeability in shale plays, closely spaced hydraulic fractures and multilateral horizontal wells are generally required to improve production. Therefore, understanding the potential fracture interaction and stress evolution is critical in optimizing fracture/well design and completion strategy in multi-stage horizontal wells. In this paper, a novel fully coupled reservoir flow and geomechanics model based on the dual-lattice system is developed to simulate multiple non-planar fractures propagation. The numerical model from Discrete Element Method (DEM) is used to simulate the mechanics of fracture propagations and interactions, while a conjugate irregular lattice network is generated to represent fluid flow in both fractures and formation. The fluid flow in the formation is controlled by Darcy’s law, but within fractures it is simulated by using cubic law for laminar flow through parallel plates. Initiation, growth and coalescence of the microcracks will lead to the generation of macroscopic fractures, which is explicitly mimicked by failure and removal of bonds between particles from the discrete element network. We investigate the fracture propagation path in both homogeneous and heterogeneous reservoirs using the simulator developed. Stress shadow caused by the transverse fracture will change the orientation of principal stress in the fracture neighborhood, which may inhibit or alter the growth direction of nearby fracture clusters. However, the initial in-situ stress anisotropy often helps overcome this phenomenon. Under large in-situ stress anisotropy, the hydraulic fractures are more likely to propagate in a direction that is perpendicular to the minimum horizontal stress. Under small in-situ stress anisotropy, there is a greater chance for fractures from nearby clusters to merge with each other. Then, we examine the differences in fracture geometry caused by fracturing in cemented or uncemented wellbore. Moreover, the impact of

  11. Restoring in-phase emissions from non-planar radiating elements using a transformation optics based lens

    Science.gov (United States)

    Yi, Jianjia; Burokur, Shah Nawaz; Piau, Gérard-Pascal; de Lustrac, André

    2015-07-01

    The broadband directive in-phase emission from an array of sources conformed cylindrically is numerically and experimentally reported. Such manipulation is achieved through the use of a lens designed by transformation optics concept. The all-dielectric lens prototype is realized through three-dimensional (3D) polyjet printing and presents a graded refractive index. A microstrip antenna array fabricated using standard lithography techniques and conformed on a cylindrical surface is used as TE-polarized wave launcher for the lens. To experimentally demonstrate the broadband focusing properties and in-phase directive emissions, both the far-field radiation patterns and the near-field distributions have been measured. Experimental measurements agreeing qualitatively with numerical simulations validate the proposed lens and open the way to inexpensive all-dielectric microwave lenses for beam forming and collimation.

  12. Effects of nonthermal distribution of electrons and polarity of net dust-charge number density on nonplanar dust-ion-acoustic solitary waves.

    Science.gov (United States)

    Mamun, A A; Shukla, P K

    2009-09-01

    Effects of the nonthermal distribution of electrons as well as the polarity of the net dust-charge number density on nonplanar (viz. cylindrical and spherical) dust-ion-acoustic solitary waves (DIASWs) are investigated by employing the reductive perturbation method. It is found that the basic features of the DIASWs are significantly modified by the effects of nonthermal electron distribution, polarity of net dust-charge number density, and nonplanar geometry. The implications of our results in some space and laboratory dusty plasma environments are briefly discussed.

  13. Isolation and measurement of the features of arrays of cell aggregates formed by dielectrophoresis using the user-specified Multi Regions Masking (MRM) technique

    Energy Technology Data Exchange (ETDEWEB)

    Yusvana, Rama; Markx, Gerard H [School of Engineering and Physical Science, Department of Chemical Engineering, Heriot-Watt University, Riccarton Campus, Edinburgh - EH14 4AS (United Kingdom); Headon, Denis, E-mail: g.h.markx@hw.ac.u [Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, Edinburgh - EH25 9PS (United Kingdom)

    2009-08-01

    The use of dielectrophoresis for the construction of artificial skin tissue with skin cells in follicle-like 3D cell aggregates in well-defined patterns is demonstrated. To analyse the patterns produced and to study their development after their formation a Virtual Instrument (VI) system was developed using the LabVIEW IMAQ Vision Development Module. A series of programming functions (algorithms) was used to isolate the features on the image (in our case; the patterned aggregates) and separate them from all other unwanted regions on the image. The image was subsequently converted into a binary version, covering only the desired microarray regions which could then be analysed by computer for automatic object measurements. The analysis utilized the simple and easy-to-use User-Specified Multi-Regions Masking (MRM) technique, which allows one to concentrate the analysis on the desired regions specified in the mask. This simplified the algorithms for the analysis of images of cell arrays having similar geometrical properties. By having a collection of scripts containing masks of different patterns, it was possible to quickly and efficiently develop sets of custom virtual instruments for the offline or online analysis of images of cell arrays in the database.

  14. Comparison of fabrication approaches for selectively oxidized VCSEL arrays

    Energy Technology Data Exchange (ETDEWEB)

    GEIB,KENT M.; CHOQUETTE,KENT D.; ALLERMAN,ANDREW A.; BRIGGS,RONALD D.; HINDI,JANA JO

    2000-04-18

    The impressive performance improvements of laterally oxidized VCSELs come at the expense of increased fabrication complexity for 2-dimensional arrays. Since the epitaxial layers to be wet-thermally oxidized must be exposed, non-planarity can be an issue. This is particularly important in that electrical contact to both the anode and cathode of the diode must be brought out to a package. They have investigated four fabrication sequences suitable for the fabrication of 2-dimensional VCSEL arrays. These techniques include: mesa etched polymer planarized, mesa etched bridge contacted, mesa etched oxide isolated (where the electrical trace is isolated from the substrate during the oxidation) and oxide/implant isolation (oxidation through small via holes) all of which result in VCSELs with outstanding performance. The suitability of these processes for manufacturing are assessed relative to oxidation uniformity, device capacitance, and structural ruggedness for packaging.

  15. SL (2, C) Chern-Simons theory, a non-planar graph operator, and 4D quantum gravity with a cosmological constant: Semiclassical geometry

    Science.gov (United States)

    Haggard, Hal M.; Han, Muxin; Kamiński, Wojciech; Riello, Aldo

    2015-11-01

    We study the expectation value of a nonplanar Wilson graph operator in SL (2, C) Chern-Simons theory on S3. In particular we analyze its asymptotic behavior in the double-scaling limit in which both the representation labels and the Chern-Simons coupling are taken to be large, but with fixed ratio. When the Wilson graph operator has a specific form, motivated by loop quantum gravity, the critical point equations obtained in this double-scaling limit describe a very specific class of flat connection on the graph complement manifold. We find that flat connections in this class are in correspondence with the geometries of constant curvature 4-simplices. The result is fully non-perturbative from the perspective of the reconstructed geometry. We also show that the asymptotic behavior of the amplitude contains, at the leading order, an oscillatory part proportional to the Regge action for the single 4-simplex in the presence of a cosmological constant. In particular, the cosmological term contains the full-fledged curved volume of the 4-simplex. Interestingly, the volume term stems from the asymptotics of the Chern-Simons action. This can be understood as arising from the relation between Chern-Simons theory on the boundary of a region, and a theory defined by an F2 action in the bulk. Another peculiarity of our approach is that the sign of the curvature of the reconstructed geometry, and hence of the cosmological constant in the Regge action, is not fixed a priori, but rather emerges semiclassically and dynamically from the solution of the equations of motion. In other words, this work suggests a relation between 4-dimensional loop quantum gravity with a cosmological constant and SL (2, C) Chern-Simons theory in 3 dimensions with knotted graph defects.

  16. SL(2,C Chern–Simons theory, a non-planar graph operator, and 4D quantum gravity with a cosmological constant: Semiclassical geometry

    Directory of Open Access Journals (Sweden)

    Hal M. Haggard

    2015-11-01

    Full Text Available We study the expectation value of a nonplanar Wilson graph operator in SL(2,C Chern–Simons theory on S3. In particular we analyze its asymptotic behavior in the double-scaling limit in which both the representation labels and the Chern–Simons coupling are taken to be large, but with fixed ratio. When the Wilson graph operator has a specific form, motivated by loop quantum gravity, the critical point equations obtained in this double-scaling limit describe a very specific class of flat connection on the graph complement manifold. We find that flat connections in this class are in correspondence with the geometries of constant curvature 4-simplices. The result is fully non-perturbative from the perspective of the reconstructed geometry. We also show that the asymptotic behavior of the amplitude contains, at the leading order, an oscillatory part proportional to the Regge action for the single 4-simplex in the presence of a cosmological constant. In particular, the cosmological term contains the full-fledged curved volume of the 4-simplex. Interestingly, the volume term stems from the asymptotics of the Chern–Simons action. This can be understood as arising from the relation between Chern–Simons theory on the boundary of a region, and a theory defined by an F2 action in the bulk. Another peculiarity of our approach is that the sign of the curvature of the reconstructed geometry, and hence of the cosmological constant in the Regge action, is not fixed a priori, but rather emerges semiclassically and dynamically from the solution of the equations of motion. In other words, this work suggests a relation between 4-dimensional loop quantum gravity with a cosmological constant and SL(2,C Chern–Simons theory in 3 dimensions with knotted graph defects.

  17. Resolving a Long-Standing Ambiguity: the Non-Planarity of gauche-1,3-BUTADIENE Revealed by Microwave Spectroscopy

    Science.gov (United States)

    Martin-Drumel, Marie-Aline; McCarthy, Michael C.; Patterson, David; Eibenberger, Sandra; Buckingham, Grant; Baraban, Joshua H.; Ellison, Barney; Stanton, John F.

    2016-06-01

    The preferred conformation of cis-1,3-butadiene (CH_2=CH-CH=CH_2) has been of long-standing importance in organic chemistry because of its role in Diels-Alder transition states. The molecule could adopt a planar s-cis conformation, in favor of conjugations in the carbon chain, or a non-planar gauche conformation, as a result of steric interactions between the terminal H atoms. To resolve this ambiguity, we have now measured the pure rotational spectrum of this isomer in the microwave region, unambiguously establishing a significant inertial defect, and therefore a gauche conformation. Experimental measurements of gauche-1,3-butadiene and several of its isotopologues using cavity Fourier-transform microwave (FTMW) spectroscopy in a supersonic expansion and chirped-pulse FTMW spectroscopy in a 4 K buffer gas cell will be summarized, as will new quantum chemical calculations.

  18. Comment on a spurious prediction of a non-planar geometry for benzene at the MP2 level of theory

    Science.gov (United States)

    Samala, Nagaprasad Reddy; Jordan, Kenneth D.

    2017-02-01

    MP2 calculations with the full aug-cc-pVTZ basis set give a non-planar structure for benzene. Although this non-physical result can be avoided by using the smaller aug-cc-pVDZ basis set or by scaling or deleting selected functions from the aug-cc-pVTZ basis set, such changes to the basis set can result in calculated values of the frequencies of the b2g out-of-plane vibrations that are considerably underestimated. The origin of this behavior is traced to linear dependency problems with the aug-cc-pVDZ and aug-cc-pVTZ basis sets when used for benzene.

  19. Reference-free method for forming a three-dimensional image and determining the angular velocity of a remote object

    NARCIS (Netherlands)

    Mandrosov, V. I.

    2012-01-01

    We propose a reference-free method for forming a three-dimensional image and for determining the angular velocity of a remote nonplanar object. The method is based on probing an object by laser radiation with a coherence length that is smaller or larger than the size of the object and on the use of

  20. Magnetocardiography with a modular spin-exchange relaxation free atomic magnetometer array

    CERN Document Server

    Wyllie, R; Smetana, G; Wakai, R; Walker, T

    2011-01-01

    We present a portable four-channel atomic magnetometer array operating in the spin exchange relaxation-free regime. The magnetometer array has several design features intended to maximize its suitability for biomagnetic measurement, specifically foetal magnetocardiography, such as a compact modular design, and fibre coupled lasers. The modular design allows the independent positioning and orientation of each magnetometer, in principle allowing for non-planar array geometries. Using this array in a magnetically shielded room, we acquire adult magnetocadiograms. These measurements were taken with a 6-11 fT Hz^(-1/2) single-channel baseline sensitivity that is consistent with the independently measured noise level of the magnetically shielded room.

  1. Mixed Frequency Ultrasound Phased Array

    Institute of Scientific and Technical Information of China (English)

    香勇; 霍健; 施克仁; 陈以方

    2004-01-01

    A mixed frequency ultrasonic phased array (MPA) was developed to improve the focus, in which the element excitation frequencies are not all the same as in a normal constant frequency phased array. A theoretical model of the mixed frequency phased array based on the interference principle was used to simulate the array's sound distribution. The pressure intensity in the array focal area was enhanced and the scanning area having effective contrast resolution was enlarged. The system is especially useful for high intensity focused ultrasound (HIFU) with more powerful energy and ultrasound imaging diagnostics with improved signal to noise ratios, improved beam forming and more uniform imaging quality.

  2. Rapid, simple and stability-indicating determination of polyhexamethylene biguanide in liquid and gel-like dosage forms by liquid chromatography with diode-array detection

    Institute of Scientific and Technical Information of China (English)

    Markus Küsters; Sören Beyer; Stephan Kutscher; Harald Schlesinger; Michael Gerhartz

    2013-01-01

    A rapid and simple method for the determination of polyhexamethylene biguanide (polyhexanide, PHMB) in liquid and gel-like pharmaceutical formulations by means of high performance liquid chromatography coupled to diode-array detection (HPLC-DAD) was developed. Best separation was achieved using a cyanopropyl bonded phase (Agilent Zorbax Eclipse XDB-CN column 4.6 mm75 mm with particle size of 3.5 mm) as well as gradient elution consisting of acetonitrile/deionized water at a flow rate of 1.0 mL/min. The optimized and applied chromatographic conditions permitted separation of polyhexanide from interacting matrix with subsequent detection at a wavelength of 235 nm with good sensitivity. The method validation was carried out with regard to the guidelines for analytical procedures demanded by the International Conference on Harmonisation (ICH). Mean recoveries of 102% and 101% for gel-like as well as liquid preparations were obtained. Suitable repeatability as well as intermediate precision could be achieved with limits of detection r0.004 mg/mL for both formulations, equivalent to r0.004% PHMB concerning sample preparation. Determination of PHMB was accomplished without tedious sample preparation. Interacting matrix could be eliminated by the chromatographic procedure with excellent performance of system suitability. All analytical requirements were fulfilled permitting a reliable and precise determination of PHMB in pharmaceuticals. Furthermore, the developed method was applied to stability testing of pharmaceutical preparations containing PHMB.

  3. Evaporating metal nanocrystal arrays

    Science.gov (United States)

    Zhang, Xue; Joy, James C.; Zhao, Chenwei; Kim, Jin Ho; Fernandes, Gustavo; Xu, J. M.; Valles, James M., Jr.

    2017-03-01

    Anodic aluminum oxide (AAO) substrates with a self-ordered triangular array of nanopores provide the means to fabricate multiple forms of nano materials, such as nanowires and nanoparticles. This study focuses on nanostructures that emerge in thin films of metals thermally evaporated onto the surface of AAO. Previous work showed that films of different evaporated metals assume dramatically different structures, e.g. an ordered triangular array of nearly monodisperse nanoparticles forms for lead (Pb) while a polycrystalline nanohoneycomb structure forms for silver (Ag). Here, we present investigations of the effects of substrate temperature and deposition angle that reveal the processes controlling the nano particle array formation. Our findings indicate that arrays form provided the grain nucleation density exceeds the pore density and the atomic mobility is high enough to promote grain coalescence. They introduce a method for producing films with anisotropic grain array structure. The results provide insight into the influence of substrate nano-morphology on thin film growth energetics and kinetics that can be harnessed for creating films with other novel nano-structures.

  4. Effect of nonthermal distributed electrons and temperature on phase shifts during the collision of inward and outward ion-acoustic solitary waves in nonplanar geometry

    Indian Academy of Sciences (India)

    Uday Narayan Ghosh; Prasantha Chatterjee; Deb Kumar Ghosh

    2013-10-01

    Interaction of nonplanar ion-acoustic solitary waves is an important source of information for studying the nature and characteristics of ion-acoustic solitary waves (IASWs). The head-on collision between two cylindrical/spherical IASWs in un-magnetized plasmas comprising of nonthermal distributed electrons and warm ions is investigated using the extended version of Poincaré–Lighthill–Kuo (PLK) perturbation method. How the interactions are taking place in cylindrical and spherical geometries are shown numerically. Analytical phase shifts are derived for nonplanar geometry. The effects of the ion to electron temperature parameter and the nonthermal electrons parameter on the phase shift are studied. It is shown that the properties of the interaction of IASWs in different geometries are very different.

  5. Synthesis and processing strategies to tune the film structure and optoelectronic properties of non-planar molecular semiconductors

    Science.gov (United States)

    Hiszpanski, Anna Maria

    Molecular semiconductors have generated significant interest for their potential use in lightweight and mechanically flexible electronic devices. Yet, predicting how new molecular semiconductors will perform in devices remains a challenge because devices are comprised of polycrystalline thin films of molecular semiconductors, and charge transport in these films depends greatly on the details of their microstructure whose heterogeneities can span multiple length scales. The microstructure typically evolves during deposition, and thus developing organic electronics not only hinges on the success of materials discovery, but also on the ability to fine-tune deposition and processing parameters to access the thin-film structure most conducive for charge transport. This thesis explores chemical modification of a non-planar organic semiconductor, contorted hexabenzocoronene, cHBC, to tune its optoelectronic properties and processing strategies to induce structural changes in thin films. We primarily explore fluorine- and chlorine-substitution at the peripheral aromatic rings of cHBC to lower its energy levels and optical bandgap, and we demonstrate such halogenated derivatives as electron acceptors in organic solar cells. Substitution with these larger atoms also increases cHBC's intramolecular steric hindrance, providing access to an alternative molecular conformation with an order of magnitude higher solubility and systematic shifts in absorption and emission characteristics. cHBC's non-planarity provides an added dimension of tunability as it frustrates crystallization during deposition, producing amorphous films that can be subsequently crystallized with post-deposition processing. Decoupling structural development from deposition allows us to fabricate transistors from differently treated cHBC films and elucidate the effects of changes in film structure on charge transport, as measured by the field-effect mobility. With different processing, the extent of c

  6. Nonplanar on-shell diagrams and leading singularities of scattering amplitudes

    Science.gov (United States)

    Chen, Baoyi; Chen, Gang; Cheung, Yeuk-Kwan E.; Li, Yunxuan; Xie, Ruofei; Xin, Yuan

    2017-02-01

    Bipartite on-shell diagrams are the latest tool in constructing scattering amplitudes. In this paper we prove that a Britto-Cachazo-Feng-Witten (BCFW) decomposable on-shell diagram process a rational top form if and only if the algebraic ideal comprised the geometrical constraints are shifted linearly during successive BCFW integrations. With a proper geometric interpretation of the constraints in the Grassmannian manifold, the rational top form integration contours can thus be obtained, and understood, in a straightforward way. All rational top form integrands of arbitrary higher loops leading singularities can therefore be derived recursively, as long as the corresponding on-shell diagram is BCFW decomposable.

  7. Nonplanar on-shell diagrams and leading singularities of scattering amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Baoyi; Cheung, Yeuk-Kwan E.; Li, Yunxuan; Xie, Ruofei; Xin, Yuan [Nanjing University, Department of Physics, Nanjing (China); Chen, Gang [Zhejiang Normal University, Department of Physics, Jinhua, Zhejiang (China); Nanjing University, Department of Physics, Nanjing (China)

    2017-02-15

    Bipartite on-shell diagrams are the latest tool in constructing scattering amplitudes. In this paper we prove that a Britto-Cachazo-Feng-Witten (BCFW) decomposable on-shell diagram process a rational top form if and only if the algebraic ideal comprised the geometrical constraints are shifted linearly during successive BCFW integrations. With a proper geometric interpretation of the constraints in the Grassmannian manifold, the rational top form integration contours can thus be obtained, and understood, in a straightforward way. All rational top form integrands of arbitrary higher loops leading singularities can therefore be derived recursively, as long as the corresponding on-shell diagram is BCFW decomposable. (orig.)

  8. The Murchison Widefield Array

    NARCIS (Netherlands)

    Mitchell, Daniel A.; Greenhill, Lincoln J.; Ord, Stephen M.; Bernardi, Gianni

    2010-01-01

    It is shown that the excellent Murchison Radio-astronomy Observatory site allows the Murchison Widefield Array to employ a simple RFI blanking scheme and still calibrate visibilities and form images in the FM radio band. The techniques described are running autonomously in our calibration and imagin

  9. Synthesis and Characterization of Sulfonated Poly(Phenylene Containing a Non-Planar Structure and Dibenzoyl Groups

    Directory of Open Access Journals (Sweden)

    Hohyoun Jang

    2016-02-01

    Full Text Available Polymers for application as sulfonated polyphenylene membranes were prepared by nickel-catalyzed carbon-carbon coupling reaction of bis(4-chlorophenyl-1,2-diphenylethylene (BCD and 1,4-dichloro-2,5-dibenzoylbenzene (DCBP. Conjugated cis/trans isomer (BCD had a non-planar conformation containing four peripheral aromatic rings that facilitate the formation of π–π interactions. 1,4-Dichloro-2,5-dibenzoylbenzene was synthesized from the oxidation reaction of 2,5-dichloro-p-xylene, followed by Friedel-Crafts reaction with benzene. DCBP monomer had good reactivity in polymerization affecting the activity of benzophenone as an electron-withdrawing group. The polyphenylene was sulfonated using concentrated sulfuric acid. These polymers without any ether linkages on the polymer backbone were protected from nucleophilic attack by hydrogen peroxide, hydroxide anion, and radicals generated by polymer electrolyte membrane fuel cell (PEMFC operation systems. The mole fraction of the sulfonic acid groups was controlled by varying the mole ratio of bis(4-chlorophenyl-1,2-diphenylethylene in the copolymer. In comparison with Nafion 211® membrane, these SBCDCBP membranes showed ion exchange capacity (IEC ranging from 1.04 to 2.07 meq./g, water uptake from 36.5% to 69.4%, proton conductivity from 58.7 to 101.9 mS/cm, and high thermal stability.

  10. Structural stability, C--N internal rotations and vibrational spectral analysis of non-planar phenylurea and phenylthiourea.

    Science.gov (United States)

    Badawi, Hassan M

    2009-04-01

    The structural stability and C-N internal rotations of phenylurea and phenylthiourea were investigated by DFT-B3LYP and ab initio MP2 and MP4//MP2 calculations with 6-311G** and/or 6-311+G** basis sets. The complex multirotor internal rotations in phenylurea and phenylthiourea were investigated at the B3LYP/6-311+G** level of theory from which several clear minima were predicted in the calculated potential energy scans of both molecules. For phenylurea two minima that correspond to non-planar- (CNCC dihedral angle of about 45 degrees ) cis (CNCO dihedral angle is near 0 degrees ) and trans (CNCO dihedral angle is near 180 degrees ) structures were predicted to have real frequency. For phenylthiourea only the non-planar-trans structure was predicted to be the low energy minimum for the molecule. The vibrational frequencies of the lowest energy non-planar-trans conformer of each of the two molecules were computed at the B3LYP level and tentative vibrational assignments were provided on the basis of normal coordinate analysis and experimental infrared and Raman data.

  11. Structural stability, C-N internal rotations and vibrational spectral analysis of non-planar phenylurea and phenylthiourea

    Science.gov (United States)

    Badawi, Hassan M.

    2009-04-01

    The structural stability and C-N internal rotations of phenylurea and phenylthiourea were investigated by DFT-B3LYP and ab initio MP2 and MP4//MP2 calculations with 6-311G** and/or 6-311+G** basis sets. The complex multirotor internal rotations in phenylurea and phenylthiourea were investigated at the B3LYP/6-311+G** level of theory from which several clear minima were predicted in the calculated potential energy scans of both molecules. For phenylurea two minima that correspond to non-planar- (CNCC dihedral angle of about 45°) cis (CNCO dihedral angle is near 0°) and trans (CNCO dihedral angle is near 180°) structures were predicted to have real frequency. For phenylthiourea only the non- planar- trans structure was predicted to be the low energy minimum for the molecule. The vibrational frequencies of the lowest energy non-planar-trans conformer of each of the two molecules were computed at the B3LYP level and tentative vibrational assignments were provided on the basis of normal coordinate analysis and experimental infrared and Raman data.

  12. Supramolecular Corrals on Surfaces Resulting from Aromatic Interactions of Nonplanar Triazoles

    DEFF Research Database (Denmark)

    Jethwa, Siddharth; Kolsbjerg, Esben Leonhard; Vadapoo, Sundar Raja

    2017-01-01

    -shaped ensemble of bridge site positions on (111) surfaces of copper, silver, or gold. The curvature required to form the corrals is identified to result from the angle dependence of aromatic interactions between molecular phenanthrene moieties. The study provides detailed quantitative insights into triazole...

  13. SILICON NEEDLE ARRAY ON FLEXIBLE SUBSTRATE FOR FLUID TRANSFER

    Institute of Scientific and Technical Information of China (English)

    MA Bin; GAN Zhiyin; LIU Sheng

    2006-01-01

    Transdermal delivery is an attractive alternative, but it is limited by the extremely low permeability of skin. To solve this problem, a novel means-micro needle array based on micro electro-mechanical system (MEMS) technology, is provided to increase permeability of human skin with efficiency, safety and painless delivery. The fabrication method consists of a sequence of deep-reactive ion etching (DRIE), anisotropic wet etching and conformal thin film deposition. The novel technology can enable the realization of micro fabricated micro needle array on a flexible silicon substrate. The micro needle array can be mounted on non-planar surface or even on flexible objects such as a human fingers and arms. The fabricated hollow wall straight micro needles are 200 μm in length, 30 μm inner diameter, and 50 μm outer diameter with 250 μm center-to-center spacing.Flow rate test proves that the polymeric base construction is important to function of micro needles array in package. Glucose solvent tests show that surface tension is the dominant force to affect the characters of flow in micro needles channel.

  14. Superplastic Micro-forming Mechanism and Size Effects of Micro-array Made of Nanocrystalline Material%纳米材料微阵列超塑微成形机理与尺度效应

    Institute of Scientific and Technical Information of China (English)

    王国峰; 李优; 刘奇; 赵相禹

    2015-01-01

    微成形技术是未来批量制造高精密微小零件的关键技术,但是,微小尺度下材料的塑性变形行为不仅表现出明显的尺度效应,而且零件尺度已经接近常规材料的晶粒尺寸,每个晶粒的形状、取向、变形特征对整体变形产生复杂的影响,难以保证微成形的工艺稳定性。本项目采用纳米材料进行微成形,制造微阵列,零件内部包含大量的晶粒,可以排除晶粒复杂性的影响,而且纳米材料具有超塑性,在超塑状态下,变形抗力和摩擦力都明显降低,从而显著降低微成形工艺对模具性能的苛刻要求,提高工艺稳定性和成形精度。目前,纳米材料超塑性微成形技术方面的研究极少,变形时纳米材料的力学行为、变形机理、尺度效应、位错演化、力学模型等关键问题还有待研究。采用电沉积技术制备晶粒尺寸可控的纳米材料,将工艺实验研究、性能测试、组织分析、力学性能表征、数值模拟相结合,深入探究了纳米材料微阵列超塑性微成形机理和成形规律,以促进该技术的广泛应用。%ABSTRACT:Micro-forming is a key technique for fabricating high-precision micro-part in large volume. However, plastic deformation at small scale has obvious size effects. The shape, orientation and deformation behavior of each grain have complicated influence on the micro-forming, since the scale of the parts approaches to the size of grain in common materi-als. Consequently, it is very hard to ensure the processing stability of micro-forming. In the current project, nanocrystalline materials were used to form micro-array. The influence of grain complexity could be eliminated since there were a lot of grains in the micro-part. In addition, nanocrystalline materials usually have superplasticity. Under this condition, the de-formation force and friction decrease obviously, which decreases the requirement on the mechanical

  15. Color-Kinematics Duality and Sudakov Form Factor at Five Loops

    CERN Document Server

    Yang, Gang

    2016-01-01

    Using color-kinematics duality, we construct for the first time the full integrand of the five-loop Sudakov form factor in N=4 super-Yang-Mills theory, including non-planar contributions. This result also provides a first manifestation of the color-kinematics duality at five loops. The integrand is explicitly ultraviolet finite when D<26/5, coincident with the known finiteness bound for amplitudes. If the double-copy method could be applied to the form factor, this would indicate an interesting ultraviolet finiteness bound for N=8 supergravity at five loops. The result is also expected to provide an essential input towards understanding the five-loop non-planar cusp anomalous dimension.

  16. Non-Planar Nanotube and Wavy Architecture Based Ultra-High Performance Field Effect Transistors

    KAUST Repository

    Hanna, Amir

    2016-11-01

    This dissertation presents a unique concept for a device architecture named the nanotube (NT) architecture, which is capable of higher drive current compared to the Gate-All-Around Nanowire architecture when applied to heterostructure Tunnel Field Effect Transistors. Through the use of inner/outer core-shell gates, heterostructure NT TFET leverages physically larger tunneling area thus achieving higher driver current (ION) and saving real estates by eliminating arraying requirement. We discuss the physics of p-type (Silicon/Indium Arsenide) and n-type (Silicon/Germanium hetero-structure) based TFETs. Numerical TCAD simulations have shown that NT TFETs have 5x and 1.6 x higher normalized ION when compared to GAA NW TFET for p and n-type TFETs, respectively. This is due to the availability of larger tunneling junction cross sectional area, and lower Shockley-Reed-Hall recombination, while achieving sub 60 mV/dec performance for more than 5 orders of magnitude of drain current, thus enabling scaling down of Vdd to 0.5 V. This dissertation also introduces a novel thin-film-transistors architecture that is named the Wavy Channel (WC) architecture, which allows for extending device width by integrating vertical fin-like substrate corrugations giving rise to up to 50% larger device width, without occupying extra chip area. The novel architecture shows 2x higher output drive current per unit chip area when compared to conventional planar architecture. The current increase is attributed to both the extra device width and 50% enhancement in field effect mobility due to electrostatic gating effects. Digital circuits are fabricated to demonstrate the potential of integrating WC TFT based circuits. WC inverters have shown 2× the peak-to-peak output voltage for the same input, and ~2× the operation frequency of the planar inverters for the same peak-to-peak output voltage. WC NAND circuits have shown 2× higher peak-to-peak output voltage, and 3× lower high-to-low propagation

  17. Nanopatterning of tools for replication of non-planar polymer surfaces

    DEFF Research Database (Denmark)

    Cech, Jiri

    arrangement of micro- and nano- structures on the surface. Manmade nanostructured surfaces, formed by advanced microfabrication techniques, can often mimic or even exceed natural ones in some property. However, there is a substantial limitation, as most of the abovementioned techniques work only on a flat...... on the surface remains increased. These results enable us to predict the coating lifetime and the linearity of the coating removal. Based on the data, we can state that FDTS can be used for coating of molds, and is particularly suited for coating of nanostructured molds. We can also rank tested metals...

  18. Twisted cyanines: a non-planar fluorogenic dye with superior photostability and its use in a protein-based fluoromodule.

    Science.gov (United States)

    Shank, Nathaniel I; Pham, Ha H; Waggoner, Alan S; Armitage, Bruce A

    2013-01-09

    The cyanine dye thiazole orange (TO) is a well-known fluorogenic stain for DNA and RNA, but this property precludes its use as an intracellular fluorescent probe for non-nucleic acid biomolecules. Further, as is the case with many cyanines, the dye suffers from low photostability. Here, we report the synthesis of a bridge-substituted version of TO named α-CN-TO, where the central methine hydrogen of TO is replaced by an electron withdrawing cyano group, which was expected to decrease the susceptibility of the dye toward singlet oxygen-mediated degradation. An X-ray crystal structure shows that α-CN-TO is twisted drastically out of plane, in contrast to TO, which crystallizes in the planar conformation. α-CN-TO retains the fluorogenic behavior of the parent dye TO in viscous glycerol/water solvent, but direct irradiation and indirect bleaching studies showed that α-CN-TO is essentially inert to visible light and singlet oxygen. In addition, the twisted conformation of α-CN-TO mitigates nonspecific binding and fluorescence activation by DNA and a previously selected TO-binding protein and exhibits low background fluorescence in HeLa cell culture. α-CN-TO was then used to select a new protein that binds and activates fluorescence from the dye. The new α-CN-TO/protein fluoromodule exhibits superior photostability to an analogous TO/protein fluoromodule. These properties indicate that α-CN-TO will be a useful fluorogenic dye in combination with specific RNA and protein binding partners for both in vitro and cell-based applications. More broadly, structural features that promote nonplanar conformations can provide an effective method for reducing nonspecific binding of cationic dyes to nucleic acids and other biomolecules.

  19. Detection of latent fingerprints using high-resolution 3D confocal microscopy in non-planar acquisition scenarios

    Science.gov (United States)

    Kirst, Stefan; Vielhauer, Claus

    2015-03-01

    In digitized forensics the support of investigators in any manner is one of the main goals. Using conservative lifting methods, the detection of traces is done manually. For non-destructive contactless methods, the necessity for detecting traces is obvious for further biometric analysis. High resolutional 3D confocal laser scanning microscopy (CLSM) grants the possibility for a detection by segmentation approach with improved detection results. Optimal scan results with CLSM are achieved on surfaces orthogonal to the sensor, which is not always possible due to environmental circumstances or the surface's shape. This introduces additional noise, outliers and a lack of contrast, making a detection of traces even harder. Prior work showed the possibility of determining angle-independent classification models for the detection of latent fingerprints (LFP). Enhancing this approach, we introduce a larger feature space containing a variety of statistical-, roughness-, color-, edge-directivity-, histogram-, Gabor-, gradient- and Tamura features based on raw data and gray-level co-occurrence matrices (GLCM) using high resolutional data. Our test set consists of eight different surfaces for the detection of LFP in four different acquisition angles with a total of 1920 single scans. For each surface and angles in steps of 10, we capture samples from five donors to introduce variance by a variety of sweat compositions and application influences such as pressure or differences in ridge thickness. By analyzing the present test set with our approach, we intend to determine angle- and substrate-dependent classification models to determine optimal surface specific acquisition setups and also classification models for a general detection purpose for both, angles and substrates. The results on overall models with classification rates up to 75.15% (kappa 0.50) already show a positive tendency regarding the usability of the proposed methods for LFP detection on varying surfaces in non-planar

  20. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  1. Photovoltaic cell array

    Science.gov (United States)

    Eliason, J. T. (Inventor)

    1976-01-01

    A photovoltaic cell array consisting of parallel columns of silicon filaments is described. Each fiber is doped to produce an inner region of one polarity type and an outer region of an opposite polarity type to thereby form a continuous radial semi conductor junction. Spaced rows of electrical contacts alternately connect to the inner and outer regions to provide a plurality of electrical outputs which may be combined in parallel or in series.

  2. Wettability patterning for high-rate, pumpless fluid transport on open, non-planar microfluidic platforms.

    Science.gov (United States)

    Ghosh, Aritra; Ganguly, Ranjan; Schutzius, Thomas M; Megaridis, Constantine M

    2014-05-07

    Surface tension driven transport of liquids on open substrates offers an enabling tool for open micro total analysis systems that are becoming increasingly popular for low-cost biomedical diagnostic devices. The present study uses a facile wettability patterning method to produce open microfluidic tracks that - due to their shape, surface texture and chemistry - are capable of transporting a wide range of liquid volumes (~1-500 μL) on-chip, overcoming viscous and other opposing forces (e.g., gravity) at the pertinent length scales. Small volumes are handled as individual droplets, while larger volumes require repeated droplet transport. The concept is developed and demonstrated with coatings based on TiO2 filler particles, which, when present in adequate (~80 wt.%) quantities within a hydrophobic fluoroacrylic polymer matrix, form composites that are intrinsically superhydrophobic. Such composite coatings become superhydrophilic upon exposure to UV light (390 nm). A commercial laser printer-based photo-masking approach is used on the coating for spatially selective wettability conversion from superhydrophobic to superhydrophilic. Carefully designed wedge-patterned surface tension confined tracks on the open-air devices move liquid on them without power input, even when acting against gravity. Simple designs of wettability patterning are used on versatile substrates (e.g., metals, polymers, paper) to demonstrate complex droplet handling tasks, e.g., merging, splitting and metered dispensing, some of which occur in 3-D geometries. Fluid transport rates of up to 350 μL s(-1) are attained. Applicability of the design on metal substrates allows these devices to be used also for other microscale engineering applications, e.g., water management in fuel cells.

  3. Flexible and transparent silicon-on-polymer based sub-20 nm non-planar 3D FinFET for brain-architecture inspired computation

    KAUST Repository

    Sevilla, Galo T.

    2014-02-22

    An industry standard 8′′ silicon-on-insulator wafer based ultra-thin (1 μm), ultra-light-weight, fully flexible and remarkably transparent state-of-the-art non-planar three dimensional (3D) FinFET is shown. Introduced by Intel Corporation in 2011 as the most advanced transistor architecture, it reveals sub-20 nm features and the highest performance ever reported for a flexible transistor. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Production of gamma rays by pulsed laser beam Compton scattering off GeV-electrons using a non-planar four-mirror optical cavity

    CERN Document Server

    Akagi, T; Bonis, J; Chaikovska, I; Chiche, R; Cizeron, R; Cohen, M; Cormier, E; Cornebise, P; Delerue, N; Flaminio, R; Funahashi, S; Jehanno, D; Honda, Y; Labaye, F; Lacroix, M; Marie, R; Miyoshi, S; Nagata, S; Omori, T; Peinaud, Y; Pinard, L; Shimizu, H; Soskov, V; Takahashi, T; Tanaka, R; Terunuma, T; Urakawa, J; Variola, A; Zomer, F

    2011-01-01

    As part of the positron source R&D for future $e^+-e^-$ colliders and Compton based compact light sources, a high finesse non-planar four-mirror Fabry-Perot cavity has recently been installed at the ATF (KEK, Tsukuba, Japan). The first measurements of the gamma ray flux produced with a such cavity using a pulsed laser is presented here. We demonstrate the production of a flux of 2.7 $\\pm$ 0.2 gamma rays per bunch crossing ($\\sim3\\times10^6$ gammas per second) during the commissioning.

  5. DESIGN AND FEM STATIC ANALYSIS OF AN INSTRUMENT FOR SURFACE PLASTIC DEFORMATION OF NON-PLANAR FUNCTIONAL SURFACES OF MACHINE PARTS

    Directory of Open Access Journals (Sweden)

    STOYAN SLAVOV

    2015-12-01

    Full Text Available The paper presents the design of a specialized instrument for formation different types of regular microshape roughness on functional surfaces of parts with non-planar macroshape by using the process, called “surface plastic deformation”. The elements of which it is constructed are explained and the results from carried out strength and deformation analysis, obtained by Finite Element Method, conducted using the Simulation module of the SolidWorks are also represented. On this basis some advantages and limitations of some of the surface plastic deformation process technological parameters are identified and recommendations for its implementation are given.

  6. Master integrals for the four-loop Sudakov form factor

    Directory of Open Access Journals (Sweden)

    Rutger H. Boels

    2016-01-01

    Full Text Available The light-like cusp anomalous dimension is a universal function in the analysis of infrared divergences. In maximally (N=4 supersymmetric Yang–Mills theory (SYM in the planar limit, it is known, in principle, to all loop orders. The non-planar corrections are not known in any theory, with the first appearing at the four-loop order. The simplest quantity which contains this correction is the four-loop two-point form factor of the stress tensor multiplet. This form factor was largely obtained in integrand form in a previous work for N=4 SYM, up to a free parameter. In this work, a reduction of the appearing integrals obtained by solving integration-by-parts (IBP identities using a modified version of Reduze is reported. The form factor is shown to be independent of the remaining parameter at integrand level due to an intricate pattern of cancellations after IBP reduction. Moreover, two of the integral topologies vanish after reduction. The appearing master integrals are cross-checked using independent algebraic-geometry techniques explored in the Mint package. The latter results provide the basis of master integrals applicable to generic form factors, including those in Quantum Chromodynamics. Discrepancies between explicitly solving the IBP relations and the MINT approach are highlighted. Remaining bottlenecks to completing the computation of the four-loop non-planar cusp anomalous dimension in N=4 SYM and beyond are identified.

  7. Global Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamoorthy, Sriram; Daily, Jeffrey A.; Vishnu, Abhinav; Palmer, Bruce J.

    2015-11-01

    Global Arrays (GA) is a distributed-memory programming model that allows for shared-memory-style programming combined with one-sided communication, to create a set of tools that combine high performance with ease-of-use. GA exposes a relatively straightforward programming abstraction, while supporting fully-distributed data structures, locality of reference, and high-performance communication. GA was originally formulated in the early 1990’s to provide a communication layer for the Northwest Chemistry (NWChem) suite of chemistry modeling codes that was being developed concurrently.

  8. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

    This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

  9. Teaching Form as Form

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2012-01-01

    understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical...... means that form serves both as the connective value and as the concept for reflection. In other words, form is observed as form, not anything else. The didactical challenge of teaching form as form is accentuated by students’ everyday-based pre-orientation towards function at the expense of form....... In general, students enter design education as far more skilled observers with regards to function than form. They are, in other words, predisposed to observe objects asking ‘what is?’, rather than ‘how is?’. This habit has not only cognitive implications. It is closely intertwined with a rudimentary...

  10. Teaching Form as Form

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2012-01-01

    understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical...... means that form serves both as the connective value and as the concept for reflection. In other words, form is observed as form, not anything else. The didactical challenge of teaching form as form is accentuated by students’ everyday-based pre-orientation towards function at the expense of form...... vocabulary of form. Even in cases in which teaching uses terms and phrases from everyday life (for instance, ‘intersection’), the meaning of the word cannot necessarily be transmitted directly from an ordinary vocabulary into a design context. And it is clearly a common issue for the contributions...

  11. Conformal array design on arbitrary polygon surface with transformation optics

    Directory of Open Access Journals (Sweden)

    Li Deng

    2016-06-01

    Full Text Available A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

  12. Conformal array design on arbitrary polygon surface with transformation optics

    Science.gov (United States)

    Deng, Li; Wu, Yongle; Hong, Weijun; Zhu, Jianfeng; Peng, Biao; Li, Shufang

    2016-06-01

    A transformation-optics based method to design a conformal antenna array on an arbitrary polygon surface is proposed and demonstrated in this paper. This conformal antenna array can be adjusted to behave equivalently as a uniformly spaced linear array by applying an appropriate transformation medium. An typical example of general arbitrary polygon conformal arrays, not limited to circular array, is presented, verifying the proposed approach. In summary, the novel arbitrary polygon surface conformal array can be utilized in array synthesis and beam-forming, maintaining all benefits of linear array.

  13. Non-Planar Nano-Scale Fin Field Effect Transistors on Textile, Paper, Wood, Stone, and Vinyl via Soft Material-Enabled Double-Transfer Printing

    KAUST Repository

    Rojas, Jhonathan Prieto

    2015-05-01

    The ability to incorporate rigid but high-performance nano-scale non-planar complementary metal-oxide semiconductor (CMOS) electronics with curvilinear, irregular, or asymmetric shapes and surfaces is an arduous but timely challenge in enabling the production of wearable electronics with an in-situ information-processing ability in the digital world. Therefore, we are demonstrating a soft-material enabled double-transfer-based process to integrate flexible, silicon-based, nano-scale, non-planar, fin-shaped field effect transistors (FinFETs) and planar metal-oxide-semiconductor field effect transistors (MOSFETs) on various asymmetric surfaces to study their compatibility and enhanced applicability in various emerging fields. FinFET devices feature sub-20 nm dimensions and state-of-the-art, high-κ/metal gate stack, showing no performance alteration after the transfer process. A further analysis of the transferred MOSFET devices, featuring 1 μm gate length exhibits ION ~70 μA/μm (VDS = 2 V, VGS = 2 V) and a low sub-threshold swing of around 90 mV/dec, proving that a soft interfacial material can act both as a strong adhesion/interposing layer between devices and final substrate as well as a means to reduce strain, which ultimately helps maintain the device’s performance with insignificant deterioration even at a high bending state.

  14. The Murchison Widefield Array Correlator

    CERN Document Server

    Ord, S M; Emrich, D; Pallot, D; Wayth, R B; Clark, M A; Tremblay, S E; Arcus, W; Barnes, D; Bell, M; Bernardi, G; Bhat, N D R; Bowman, J D; Briggs, F; Bunton, J D; Cappallo, R J; Corey, B E; Deshpande, A A; deSouza, L; Ewell-Wice, A; Feng, L; Goeke, R; Greenhill, L J; Hazelton, B J; Herne, D; Hewitt, J N; Hindson, L; Hurley-Walker, H; Jacobs, D; Johnston-Hollitt, M; Kaplan, D L; Kasper, J C; Kincaid, B B; Koenig, R; Kratzenberg, E; Kudryavtseva, N; Lenc, E; Lonsdale, C J; Lynch, M J; McKinley, B; McWhirter, S R; Mitchell, D A; Morales, M F; Morgan, E; Oberoi, D; Offringa, A; Pathikulangara, J; Pindor, B; Prabu, T; Procopio, P; Remillard, R A; Riding, J; Rogers, A E E; Roshi, A; Salah, J E; Sault, R J; Shankar, N Udaya; Srivani, K S; Stevens, J; Subrahmanyan, R; Tingay, S J; Waterson, M; Webster, R L; Whitney, A R; Williams, A; Williams, C L; Wyithe, J S B

    2015-01-01

    The Murchison Widefield Array (MWA) is a Square Kilometre Array (SKA) Precursor. The telescope is located at the Murchison Radio--astronomy Observatory (MRO) in Western Australia (WA). The MWA consists of 4096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays (FPGAs), and others by Graphics Processing Units (GPUs) housed in general purpose rack mounted servers. The correlation capability required is approximately 8 TFLOPS (Tera FLoating point Operations Per Second). The MWA has commenced operations and the correlator is generating 8.3 TB/day of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper we outline the correlator design, signal path, and proce...

  15. Contribution of planar (0-1 Ortho) and nonplanar (2-4 Ortho) fractions of aroclor 1260 to the induction of altered hepatic foci in female sprague-dawley rats

    NARCIS (Netherlands)

    Plas, van der S.A.; Sundberg, H.; Berg, van den H.; Scheu, G.; Wester, P.; Jensen, S.; Bergman, A.; Boer, de J.; Koeman, J.H.; Brouwer, A.

    2000-01-01

    The hepatic tumor promoting activity of the planar 0–1 ortho (~9.7 /w) and the nonplanar 2–4 ortho (~90.3 /w) fraction of the commercial PCB mixture Aroclor 1260 was studied using a medium-term two-stage initiation/promotion bioassay in female Sprague–Dawley rats. Fractionation was carried out on an

  16. The Australian Square Kilometre Array Pathfinder: Performance of the Boolardy Engineering Test Array

    Science.gov (United States)

    McConnell, D.; Allison, J. R.; Bannister, K.; Bell, M. E.; Bignall, H. E.; Chippendale, A. P.; Edwards, P. G.; Harvey-Smith, L.; Hegarty, S.; Heywood, I.; Hotan, A. W.; Indermuehle, B. T.; Lenc, E.; Marvil, J.; Popping, A.; Raja, W.; Reynolds, J. E.; Sault, R. J.; Serra, P.; Voronkov, M. A.; Whiting, M.; Amy, S. W.; Axtens, P.; Ball, L.; Bateman, T. J.; Bock, D. C.-J.; Bolton, R.; Brodrick, D.; Brothers, M.; Brown, A. J.; Bunton, J. D.; Cheng, W.; Cornwell, T.; DeBoer, D.; Feain, I.; Gough, R.; Gupta, N.; Guzman, J. C.; Hampson, G. A.; Hay, S.; Hayman, D. B.; Hoyle, S.; Humphreys, B.; Jacka, C.; Jackson, C. A.; Jackson, S.; Jeganathan, K.; Joseph, J.; Koribalski, B. S.; Leach, M.; Lensson, E. S.; MacLeod, A.; Mackay, S.; Marquarding, M.; McClure-Griffiths, N. M.; Mirtschin, P.; Mitchell, D.; Neuhold, S.; Ng, A.; Norris, R.; Pearce, S.; Qiao, R. Y.; Schinckel, A. E. T.; Shields, M.; Shimwell, T. W.; Storey, M.; Troup, E.; Turner, B.; Tuthill, J.; Tzioumis, A.; Wark, R. M.; Westmeier, T.; Wilson, C.; Wilson, T.

    2016-09-01

    We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array's performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.

  17. Design and Realization of Array Signal Processor VLSI Architecture for Phased Array System

    Directory of Open Access Journals (Sweden)

    D. Govind Rao

    2016-08-01

    Full Text Available A method for implementing an array signal processor for phased array radars. The array signal processor can receive planar array antenna inputs and can process it. It is based on the application of Adaptive Digital beam formers using FPGAs. Adaptive filter algorithm used here is Inverse Q-R Decomposition based Recursive Least Squares (IQRD-RLS [1] algorithm. Array signal processor based on FPGAs is suitable in the areas of Phased Array Radar receiver, where speed, accuracy and numerical stability are of utmost important. Using IQRD-RLS algorithm, optimal weights are calculated in much less time compared to conventional QRD-RLS algorithm. A customized multiple FPGA board comprising three Kintex-7 FPGAs is employed to implement array signal processor. The proposed architecture can form multiple beams from planar array antenna elements

  18. Effects of non-extensive electrons and positive/negative dust particles on modulational instability of dust-ion-acoustic solitary waves in non-planar geometry

    Indian Academy of Sciences (India)

    M EGHBALI; B FAROKHI; M ESLAMIFAR

    2017-01-01

    The nonlinear propagation of cylindrical and spherical dust-ion-acoustic (DIA) envelope solitary waves in unmagnetized dusty plasma consisting of dust particles with opposite polarity and non-extensive distribution of electron is investigated. By using the reductive perturbation method, the modified nonlinear Schrödinger (NLS) equation in cylindrical and spherical geometry is obtained. The modulational instability (MI) of DIA waves governed by the NLS equation is also presented. The effects of different ranges of the non-extensive parameter $q$ on the MI are studied. The growth rate of the MI is also given for different values of $q$. It is found that the basic features of the DIA waves are significantly modified by non-extensive electron distribution, polarity of the netdust-charge number density and non-planar geometry.

  19. Effects of non-extensive electrons and positive /negative dust particles on modulational instability of dust-ion-acoustic solitary waves in non-planar geometry

    Science.gov (United States)

    Eghbali, M.; Farokhi, B.; Eslamifar, M.

    2017-01-01

    The nonlinear propagation of cylindrical and spherical dust-ion-acoustic (DIA) envelope solitary waves in unmagnetized dusty plasma consisting of dust particles with opposite polarity and non-extensive distribution of electron is investigated. By using the reductive perturbation method, the modified nonlinear Schrödinger (NLS) equation in cylindrical and spherical geometry is obtained. The modulational instability (MI) of DIA waves governed by the NLS equation is also presented. The effects of different ranges of the non-extensive parameter q on the MI are studied. The growth rate of the MI is also given for different values of q. It is found that the basic features of the DIA waves are significantly modified by non-extensive electron distribution, polarity of the net dust-charge number density and non-planar geometry.

  20. Alterations in geometry, biomechanics, and mineral composition of juvenile rat femur induced by nonplanar PCB-155 and/or planar PCB-169.

    Science.gov (United States)

    Brankovič, Jana; Jovanovski, Sašo; Jevnikar, Peter; Hofmeister, Alexander; Reininger-Gutmann, Birgit; Jan, Janja; Grošelj, Maja; Osredkar, Joško; Uršič, Matjaž; Fazarinc, Gregor; Pogačnik, Azra; Vrecl, Milka

    2017-04-01

    Exposure to widespread lipophilic and bioaccumulative polychlorinated biphenyls (PCBs) induces diverse biochemical and toxicological responses in various organs, including the bone. The aim of this study was to evaluate the changes in growth rate, geometry, serum, and bone biochemical parameters and biomechanics of juvenile rat femur induced by lactational exposure to nonplanar PCB-155 and planar PCB-169 individually and in combination. Fifteen lactating Wistar rats were divided into four groups (PCB-169, PCB-155, PCB-155+169, and control), and PCBs were administered intraperitoneally at different time points after delivery. Femurs from 22-day-old offspring were analyzed by microCT, three-point bending test and inductively coupled plasma-mass spectrometry (ICP-MS) to obtain data on bone geometry, biomechanics and mineral composition. The serum levels of calcium, phosphate and alkaline phosphatase were also determined. Lactational exposure to planar PCB-169 resulted in shorter and thinner femurs, reduced endosteal and periosteal perimeters, smaller total cross-sectional and medullary areas, and lowered serum bone marker levels and calcium levels in the bone, while femur mechanical properties were not significantly altered. The changes observed in the combination exposure (PCB-155+169) group were similar to those observed in the PCB-169 group but were less pronounced. In summary, our results demonstrate that alterations in lactationally exposed offspring were primarily induced by planar PCB-169. The milder outcome in the combined group suggested that the PCB-169-mediated toxic effects on the bone might be reduced by a nonplanar PCB-155 congener. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1135-1146, 2017.

  1. Coupling in reflector arrays

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1968-01-01

    In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present communic...

  2. Collaborative form(s)

    DEFF Research Database (Denmark)

    Gunn, Wendy

    Gunn asks us to consider beauty as collaborative forms of action generated by moving between design by means of anthropology and anthropology by means of design. Specifically, she gives focus to play-like reflexions on practices of designing energy products, systems and infrastructure. Design...

  3. Simultaneous use of multiple seismic arrays

    Science.gov (United States)

    Stipčević, J.; Kennett, B. L. N.; Tkalčić, H.

    2017-01-01

    Seismic arrays provide an important means of enhancing seismic signals and determining the directional properties of the wavefield by beam-forming. When multiple arrays are to be used together, the viewpoint needs to be modified from looking outwards from each array to focusing on a specific target area and so constraining the portions of the waveforms to be analysed. Beam-forming for each array is supplemented by the relative time constraints for propagation from the target to each array to provide tight spatial control. Simultaneous multiple array analysis provides a powerful tool for source characterisation, and for structural analysis of scatterers as virtual sources. The multiple array concept allows us to illuminate a specific point in the Earth from many different directions and thus map detailed patterns of heterogeneity in the Earth. Furthermore, illumination of the structure from multiple directions using data from the same event minimizes source effects to provide clearer images of heterogeneity. The analysis is based on a similar concept to the back-projection technique, where a part of the seismic wavetrain is mapped to a specific point in space by ray-tracing. In contrast to classic back-projection where the incoming energy is mapped onto a horizontal plane with limited vertical resolution, the multi-array method controls depth response by combining relative time constraints between the arrays and conventional beam-forming. We illustrate this approach with application to two earthquakes at moderate depth. The results show that the use of simultaneous multiple arrays can provide improvement both in signal quality and resolution, with the additional benefit of being able to accurately locate the source of the incoming energy and map large areas with only a limited number of such arrays.

  4. Nonlinear phased array imaging

    Science.gov (United States)

    Croxford, Anthony J.; Cheng, Jingwei; Potter, Jack N.

    2016-04-01

    A technique is presented for imaging acoustic nonlinearity within a specimen using ultrasonic phased arrays. Acoustic nonlinearity is measured by evaluating the difference in energy of the transmission bandwidth within the diffuse field produced through different focusing modes. The two different modes being classical beam forming, where delays are applied to different element of a phased array to physically focus the energy at a single location (parallel firing) and focusing in post processing, whereby one element at a time is fired and a focused image produced in post processing (sequential firing). Although these two approaches are linearly equivalent the difference in physical displacement within the specimen leads to differences in nonlinear effects. These differences are localized to the areas where the amplitude is different, essentially confining the differences to the focal point. Direct measurement at the focal point are however difficult to make. In order to measure this the diffuse field is used. It is a statistical property of the diffuse field that it represents the total energy in the system. If the energy in the diffuse field for both the sequential and parallel firing case is measured then the difference between these, within the input signal bandwidth, is largely due to differences at the focal spot. This difference therefore gives a localized measurement of where energy is moving out of the transmission bandwidth due to nonlinear effects. This technique is used to image fatigue cracks and other damage types undetectable with conventional linear ultrasonic measurements.

  5. Sensors Array Technique for Monitoring Aluminum Alloy Spot Welding

    Institute of Scientific and Technical Information of China (English)

    王蕤; 罗震; 单平; 步贤政; 袁书现; 敖三三

    2010-01-01

    In this paper,the sensors array technique is applied to the quality detection of aluminum alloy spot welding.The sensors array has three forms,i.e.,linear magnetic sensors array,annular magnetic sensors array and cross magnetic sensors array.An algorithm based on principal component analysis is proposed to extract the signal eigenvalues.The three types of magnetic sensors array are used in the experiment of monitoring the signal.After the eigenvalues are extracted,they are used to build a relationship with ...

  6. Airborne electronically steerable phased array. [steerable antennas - systems analysis

    Science.gov (United States)

    Coats, R.

    1975-01-01

    Results of a study directed to the design of a lightweight high-gain, spaceborne communications array are presented. The array includes simultaneous transmission and receiving, automatic acquisition and tracking of a signal within a 60-degree cone from the array normal, and provides for independent forming of the transmit and receive beams. Application for this array is the space shuttle, space station, or any of the advanced manned (or unmanned) orbital vehicles. Performance specifications are also given.

  7. Programmable Periodicity of Quantum Dot Arrays with DNA Origami Nanotubes

    Science.gov (United States)

    2010-01-01

    To fabricate quantum dot arrays with programmable periodicity, functionalized DNA origami nanotubes were developed. Selected DNA staple strands were biotin-labeled to form periodic binding sites for streptavidin-conjugated quantum dots. Successful formation of arrays with periods of 43 and 71 nm demonstrates precise, programmable, large-scale nanoparticle patterning; however, limitations in array periodicity were also observed. Statistical analysis of AFM images revealed evidence for steric hindrance or site bridging that limited the minimum array periodicity. PMID:20681601

  8. Clocked combustor can array

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Wook; McMahan, Kevin Weston; Srinivasan, Shiva Kumar

    2017-01-17

    The present application provides a clocked combustor can array for coherence reduction in a gas turbine engine. The clocked combustor can array may include a number of combustor cans positioned in a circumferential array. A first set of the combustor cans may have a first orientation and a second set of the combustor cans may have a second orientation.

  9. Axiom turkey genotyping array

    Science.gov (United States)

    The Axiom®Turkey Genotyping Array interrogates 643,845 probesets on the array, covering 643,845 SNPs. The array development was led by Dr. Julie Long of the USDA-ARS Beltsville Agricultural Research Center under a public-private partnership with Hendrix Genetics, Aviagen, and Affymetrix. The Turk...

  10. Clocked combustor can array

    Science.gov (United States)

    Kim, Won-Wook; McMahan, Kevin Weston; Srinivasan, Shiva Kumar

    2017-01-17

    The present application provides a clocked combustor can array for coherence reduction in a gas turbine engine. The clocked combustor can array may include a number of combustor cans positioned in a circumferential array. A first set of the combustor cans may have a first orientation and a second set of the combustor cans may have a second orientation.

  11. Electromagnetically Clean Solar Arrays

    Science.gov (United States)

    Stem, Theodore G.; Kenniston, Anthony E.

    2008-01-01

    wiring on the back of the panel. Each step increases the potential for occurrence of latent defects, loss of process control, and attrition of components. An EMCSA panel includes an integral cover made from a transparent material. The silicone cover supplants the individual cover glasses on the cells and serves as an additional unitary structural support that offers the advantage, relative to glass, of the robust, forgiving nature of the silcone material. The cover contains pockets that hold the solar cells in place during the lamination process. The cover is coated with indium tin oxide to make its surface electrically conductive, so that it serves as a contiguous, electrically grounded shield over the entire panel surface. The cells are mounted in proximity to metallic printed wiring. The painted-wiring layer comprises metal-film traces on a sheet of Kapton (or equivalent) polyimide. The traces include contact pads on one side of the sheet for interconnecting the cells. Return leads are on the opposite side of the sheet, positioned to form the return currents substantially as mirror images of, and in proximity to, the cell sheet currents, thereby minimizing magnetic moments. The printed-wiring arrangement mimics the back-wiring arrangement of conventional solar arrays, but the current-loop areas and the resulting magnetic moments are much smaller because the return-current paths are much closer to the solar-cell sheet currents. The contact pads are prepared with solder fo electrical and mechanical bonding to the cells. The pocketed cover/shield, the solar cells, the printed-wiring layer, an electrical bonding agent, a mechanical-bonding agent, a composite structural front-side face sheet, an aluminum honeycomb core, and a composite back-side face sheet are all assembled, then contact pads are soldered to the cells and the agents are cured in a single lamination process.

  12. Development of a monolithic ferrite memory array

    Science.gov (United States)

    Heckler, C. H., Jr.; Bhiwandker, N. C.

    1972-01-01

    The results of the development and testing of ferrite monolithic memory arrays are presented. This development required the synthesis of ferrite materials having special magnetic and physical characteristics and the development of special processes; (1) for making flexible sheets (laminae) of the ferrite composition, (2) for embedding conductors in ferrite, and (3) bonding ferrite laminae together to form a monolithic structure. Major problems encountered in each of these areas and their solutions are discussed. Twenty-two full-size arrays were fabricated and fired during the development of these processes. The majority of these arrays were tested for their memory characteristics as well as for their physical characteristics and the results are presented. The arrays produced during this program meet the essential goals and demonstrate the feasibility of fabricating monolithic ferrite memory arrays by the processes developed.

  13. Refracting surface plasmon polaritons with nanoparticle arrays.

    Science.gov (United States)

    Radko, Ilya P; Evlyukhin, Andrey B; Boltasseva, Alexandra; Bozhevolnyi, Sergey I

    2008-03-17

    Refraction of surface plasmon polaritons (SPPs) by various structures formed by a 100-nm-period square lattice of gold nanoparticles on top of a gold film is studied by leakage radiation microscopy. SPP refraction by a triangular-shaped nanoparticle array indicates that the SPP effective refractive index increases inside the array by a factor of approximately 1.08 (for the wavelength 800 nm) with respect to the SPP index at a flat surface. Observations of SPP focusing and deflection by circularly shaped areas as well as SPP waveguiding inside rectangular arrays are consistent with the SPP index increase deduced from the SPP refraction by triangular arrays. The SPP refractive index is found to decrease slightly for longer wavelengths within the wavelength range of 700-860 nm. Modeling based on the Green's tensor formalism is in a good agreement with the experimental results, opening the possibility to design nanoparticle arrays for specific applications requiring in-plane SPP manipulation.

  14. The Australian Square Kilometre Array Pathfinder: System Architecture and Specifications of the Boolardy Engineering Test Array

    CERN Document Server

    Hotan, A W; Harvey-Smith, L; Humphreys, B; Jeffs, B D; Shimwell, T; Tuthill, J; Voronkov, M; Allen, G; Amy, S; Ardern, K; Axtens, P; Ball, L; Bannister, K; Barker, S; Bateman, T; Beresford, R; Bock, D; Bolton, R; Bowen, M; Boyle, B; Braun, R; Broadhurst, S; Brodrick, D; Brooks, K; Brothers, M; Brown, A; Cantrall, C; Carrad, G; Chapman, J; Cheng, W; Chippendale, A; Chung, Y; Cooray, F; Cornwell, T; Davis, E; de Souza, L; DeBoer, D; Diamond, P; Edwards, P; Ekers, R; Feain, I; Ferris, D; Forsyth, R; Gough, R; Grancea, A; Gupta, N; Guzman, JC; Hampson, G; Haskins, C; Hay, S; Hayman, D; Hoyle, S; Jacka, C; Jackson, C; Jackson, S; Jeganathan, K; Johnston, S; Joseph, J; Kendall, R; Kesteven, M; Kiraly, D; Koribalski, B; Leach, M; Lenc, E; Lensson, E; Li, L; Mackay, S; Macleod, A; Maher, T; Marquarding, M; McClure-Griffiths, N; McConnell, D; Mickle, S; Mirtschin, P; Norris, R; Neuhold, S; Ng, A; O'Sullivan, J; Pathikulangara, J; Pearce, S; Phillips, C; Qiao, RY; Reynolds, J E; Rispler, A; Roberts, P; Roxby, D; Schinckel, A; Shaw, R; Shields, M; Storey, M; Sweetnam, T; Troup, E; Turner, B; Tzioumis, A; Westmeier, T; Whiting, M; Wilson, C; Wilson, T; Wormnes, K; Wu, X

    2014-01-01

    This paper describes the system architecture of a newly constructed radio telescope - the Boolardy Engineering Test Array, which is a prototype of the Australian Square Kilometre Array Pathfinder telescope. Phased array feed technology is used to form multiple simultaneous beams per antenna, providing astronomers with unprecedented survey speed. The test array described here is a 6-antenna interferometer, fitted with prototype signal processing hardware capable of forming at least 9 dual-polarisation beams simultaneously, allowing several square degrees to be imaged in a single pointed observation. The main purpose of the test array is to develop beamforming and wide-field calibration methods for use with the full telescope, but it will also be capable of limited early science demonstrations.

  15. Density controlled carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng F [Newton, MA; Tu, Yi [Belmont, MA

    2008-12-16

    CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

  16. The Murchison Widefield Array Correlator

    Science.gov (United States)

    Ord, S. M.; Crosse, B.; Emrich, D.; Pallot, D.; Wayth, R. B.; Clark, M. A.; Tremblay, S. E.; Arcus, W.; Barnes, D.; Bell, M.; Bernardi, G.; Bhat, N. D. R.; Bowman, J. D.; Briggs, F.; Bunton, J. D.; Cappallo, R. J.; Corey, B. E.; Deshpande, A. A.; deSouza, L.; Ewell-Wice, A.; Feng, L.; Goeke, R.; Greenhill, L. J.; Hazelton, B. J.; Herne, D.; Hewitt, J. N.; Hindson, L.; Hurley-Walker, N.; Jacobs, D.; Johnston-Hollitt, M.; Kaplan, D. L.; Kasper, J. C.; Kincaid, B. B.; Koenig, R.; Kratzenberg, E.; Kudryavtseva, N.; Lenc, E.; Lonsdale, C. J.; Lynch, M. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Oberoi, D.; Offringa, A.; Pathikulangara, J.; Pindor, B.; Prabu, T.; Procopio, P.; Remillard, R. A.; Riding, J.; Rogers, A. E. E.; Roshi, A.; Salah, J. E.; Sault, R. J.; Udaya Shankar, N.; Srivani, K. S.; Stevens, J.; Subrahmanyan, R.; Tingay, S. J.; Waterson, M.; Webster, R. L.; Whitney, A. R.; Williams, A.; Williams, C. L.; Wyithe, J. S. B.

    2015-03-01

    The Murchison Widefield Array is a Square Kilometre Array Precursor. The telescope is located at the Murchison Radio-astronomy Observatory in Western Australia. The MWA consists of 4 096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays, and others by Graphics Processing Units housed in general purpose rack mounted servers. The correlation capability required is approximately 8 tera floating point operations per second. The MWA has commenced operations and the correlator is generating 8.3 TB day-1 of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper, we outline the correlator design, signal path, and processing elements and present the data format for the internal and external interfaces.

  17. Refracting surface plasmon polaritons with nanoparticle arrays

    DEFF Research Database (Denmark)

    Radko, I.P.; Evlyukhin, A.B.; Boltasseva, Alexandra

    2008-01-01

    Refraction of surface plasmon polaritons (SPPs) by various structures formed by a 100-nm-period square lattice of gold nanoparticles on top of a gold film is studied by leakage radiation microscopy. SPP refraction by a triangular-shaped nanoparticle array indicates that the SPP effective refractive...... index increases inside the array by a factor of ~1.08 (for the wavelength 800 nm) with respect to the SPP index at a flat surface. Observations of SPP focusing and deflection by circularly shaped areas as well as SPP waveguiding inside rectangular arrays are consistent with the SPP index increase...

  18. Dynamic array of dark optical traps

    DEFF Research Database (Denmark)

    Daria, V.R.; Rodrigo, P.J.; Glückstad, J.

    2004-01-01

    A dynamic array of dark optical traps is generated for simultaneous trapping and arbitrary manipulation of multiple low-index microstructures. The dynamic intensity patterns forming the dark optical trap arrays are generated using a nearly loss-less phase-to-intensity conversion of a phase-encode...... optical traps for simultaneous manipulation of hollow "air-filled" glass microspheres suspended in an aqueous medium. (C) 2004 American Institute of Physics....

  19. Electronic Switch Arrays for Managing Microbattery Arrays

    Science.gov (United States)

    Mojarradi, Mohammad; Alahmad, Mahmoud; Sukumar, Vinesh; Zghoul, Fadi; Buck, Kevin; Hess, Herbert; Li, Harry; Cox, David

    2008-01-01

    Integrated circuits have been invented for managing the charging and discharging of such advanced miniature energy-storage devices as planar arrays of microscopic energy-storage elements [typically, microscopic electrochemical cells (microbatteries) or microcapacitors]. The architecture of these circuits enables implementation of the following energy-management options: dynamic configuration of the elements of an array into a series or parallel combination of banks (subarrarys), each array comprising a series of parallel combination of elements; direct addressing of individual banks for charging/or discharging; and, disconnection of defective elements and corresponding reconfiguration of the rest of the array to utilize the remaining functional elements to obtain the desited voltage and current performance. An integrated circuit according to the invention consists partly of a planar array of field-effect transistors that function as switches for routing electric power among the energy-storage elements, the power source, and the load. To connect the energy-storage elements to the power source for charging, a specific subset of switches is closed; to connect the energy-storage elements to the load for discharging, a different specific set of switches is closed. Also included in the integrated circuit is circuitry for monitoring and controlling charging and discharging. The control and monitoring circuitry, the switching transistors, and interconnecting metal lines are laid out on the integrated-circuit chip in a pattern that registers with the array of energy-storage elements. There is a design option to either (1) fabricate the energy-storage elements in the corresponding locations on, and as an integral part of, this integrated circuit; or (2) following a flip-chip approach, fabricate the array of energy-storage elements on a separate integrated-circuit chip and then align and bond the two chips together.

  20. Array Antenna Limitations

    CERN Document Server

    Jonsson, B L G; Hussain, N

    2013-01-01

    This letter defines a physical bound based array figure of merit that provides a tool to compare the performance of both single and multi-band array antennas with respect to return-loss, thickness of the array over the ground-plane, and scan-range. The result is based on a sum-rule result of Rozanov-type for linear polarization. For single-band antennas it extends an existing limit for a given fixed scan-angle to include the whole scan-range of the array, as well as the unit-cell structure in the bound. The letter ends with an investigation of the array figure of merit for some wideband and/or wide-scan antennas with linear polarization. We find arrays with a figure of merit >0.6 that empirically defines high-performance antennas with respect to this measure.

  1. Pacific Array (Transportable Broadband Ocean Floor Array)

    Science.gov (United States)

    Kawakatsu, Hitoshi; Ekstrom, Goran; Evans, Rob; Forsyth, Don; Gaherty, Jim; Kennett, Brian; Montagner, Jean-Paul; Utada, Hisashi

    2016-04-01

    Based on recent developments on broadband ocean bottom seismometry, we propose a next generation large-scale array experiment in the ocean. Recent advances in ocean bottom broadband seismometry1, together with advances in the seismic analysis methodology, have enabled us to resolve the regional 1-D structure of the entire lithosphere/asthenosphere system, including seismic anisotropy (azimuthal, and hopefully radial), with deployments of ~15 broadband ocean bottom seismometers (BBOBSs). Having ~15 BBOBSs as an array unit for a 2-year deployment, and repeating such deployments in a leap-frog way or concurrently (an array of arrays) for a decade or so would enable us to cover a large portion of the Pacific basin. Such efforts, not only by giving regional constraints on the 1-D structure beneath Pacific ocean, but also by sharing waveform data for global scale waveform tomography, would drastically increase our knowledge of how plate tectonics works on this planet, as well as how it worked for the past 150 million years. International collaborations is essential: if three countries/institutions participate this endeavor together, Pacific Array may be accomplished within five-or-so years.

  2. Dynamically Reconfigurable Microphone Arrays

    Science.gov (United States)

    2011-05-01

    Static + 2 Wireless Using only a standard computer sound card, a robot is limited to binaural inputs. Even when using wireless microphones, the audio...Abstract—Robotic sound localization has traditionally been restricted to either on-robot microphone arrays or embedded microphones in aware...a microphone array has a significant impact on the mathematics of sound source localization. Arrays, for instance, are commonly designed to

  3. Integrated avalanche photodiode arrays

    Science.gov (United States)

    Harmon, Eric S.

    2015-07-07

    The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

  4. Effect of wire shape on wire array discharge

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M. [University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto University, Department of Electrical and Computer Engineering, Kumamoto (Japan)

    2001-09-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  5. Berberine alkaloid: Quantum chemical study of different forms by the DFT and MP2 methods

    Science.gov (United States)

    Danilov, V. I.; Dailidonis, V. V.; Hovorun, D. M.; Kurita, N.; Murayama, Y.; Natsume, T.; Potopalsky, A. I.; Zaika, L. A.

    2006-10-01

    The stable structures and electronic properties for the berberine cation as well as possible ammonium, carbinol and amino-aldehyde forms of protoberberine salts in the presence of hydroxyl ions were investigated by the B3LYP/6-31G(d,p) and MP2/6-31++G(d,p) methods. The geometry optimizations by both methods lead to the nonplanar propeller-twisted and buckled structure for the all forms. The obtained bond lengths and bond angles agree with the experimental values. The comparison of total energies elucidates that the amino-aldehyde form is the most preferable tautomer in gas phase, while the carbinol form is less stable. The least stable tautomer is the ammonium form.

  6. Fast Domain Partitioning Method for dynamic boundary integral equations applicable to non-planar faults dipping in 3-D elastic half-space

    Science.gov (United States)

    Ando, Ryosuke

    2016-11-01

    The elastodynamic boundary integral equation method (BIEM) in real space and in the temporal domain is an accurate semi-analytical tool to investigate the earthquake rupture dynamics on non-planar faults. However, its heavy computational demand for a historic integral generally increases with a time complexity of O(MN3)for the number of time steps N and elements M due to volume integration in the causality cone. In this study, we introduce an efficient BIEM, termed the `Fast Domain Partitioning Method' (FDPM), which enables us to reduce the computation time to the order of the surface integral, O(MN2), without degrading the accuracy. The memory requirement is also reduced to O(M2) from O(M2N). FDPM uses the physical nature of Green's function for stress to partition the causality cone into the domains of the P and S wave fronts, the domain in-between the P and S wave fronts, and the domain of the static equilibrium, where the latter two domains exhibit simpler dependences on time and/or space. The scalability of this method is demonstrated on the large-scale parallel computing environments of distributed memory systems. It is also shown that FDPM enables an efficient use of memory storage, which makes it possible to reduce computation times to a previously unprecedented level. We thus present FDPM as a powerful tool to break through the current fundamental difficulties in running dynamic simulations of coseismic ruptures and earthquake cycles under realistic conditions of fault geometries.

  7. Subwavelength micropillar array terahertz lasers.

    Science.gov (United States)

    Krall, Michael; Brandstetter, Martin; Deutsch, Christoph; Detz, Hermann; Andrews, Aaron Maxwell; Schrenk, Werner; Strasser, Gottfried; Unterrainer, Karl

    2014-01-13

    We report on micropillar-based terahertz lasers with active pillars that are much smaller than the emission wavelength. These micropillar array lasers correspond to scaled-down band-edge photonic crystal lasers forming an active photonic metamaterial. In contrast to photonic crystal lasers which use significantly larger pillar structures, lasing emission is not observed close to high-symmetry points in the photonic band diagram, but in the effective medium regime. We measure stimulated emission at 4 THz for micropillar array lasers with pillar diameters of 5 µm. Our results not only demonstrate the integration of active subwavelength optics in a terahertz laser, but are also an important step towards the realization of nanowire-based terahertz lasers.

  8. Antenna Arrays and Automotive Applications

    CERN Document Server

    Rabinovich, Victor

    2013-01-01

    This book throws a lifeline to designers wading through mounds of antenna array patents looking for the most suitable systems for their projects. Drastically reducing the research time required to locate solutions to the latest challenges in automotive communications, it sorts and systematizes material on cutting-edge antenna arrays that feature multi-element communication systems with enormous potential for the automotive industry. These new systems promise to make driving safer and more efficient, opening up myriad applications, including vehicle-to-vehicle traffic that prevents collisions, automatic toll collection, vehicle location and fine-tuning for cruise control systems. This book’s exhaustive coverage begins with currently deployed systems, frequency ranges and key parameters. It proceeds to examine system geometry, analog and digital beam steering technology (including "smart" beams formed in noisy environments), maximizing signal-to-noise ratios, miniaturization, and base station technology that ...

  9. Analysis of VCSEL Array Module Using a Simple Microlens Array

    Institute of Scientific and Technical Information of China (English)

    Hen-Wai; Tsao; Shyh-Lin; Tsao

    2003-01-01

    A simple microlens array is designed between VCSEL array and fiber array for integration of array module. We increase the optical coupling efficiency from -32.057 dBm to -0.9054 dBm by using our designed microlens array.

  10. Analysis of VCSEL Array Module Using a Simple Microlens Array

    Institute of Scientific and Technical Information of China (English)

    Wen-Ming Cheng; Hen-Wai Tsao; Shyh-Lin Tsao

    2003-01-01

    A simple microlens array is designed between VCSEL array and fiber array for integration of array module. We increase the optical coupling efficiency from-32.057 dBm to-0.9054 dBm by using our designed microlens array.

  11. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.

  12. Solar array deployment mechanism

    Science.gov (United States)

    Calassa, Mark C.; Kackley, Russell

    1995-05-01

    This paper describes a Solar Array Deployment Mechanism (SADM) used to deploy a rigid solar array panel on a commercial spacecraft. The application required a deployment mechanism design that was not only lightweight, but also could be produced and installed at the lowest possible cost. This paper covers design, test, and analysis of a mechanism that meets these requirements.

  13. Array for detecting microbes

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Gary L.; DeSantis, Todd D.

    2014-07-08

    The present embodiments relate to an array system for detecting and identifying biomolecules and organisms. More specifically, the present embodiments relate to an array system comprising a microarray configured to simultaneously detect a plurality of organisms in a sample at a high confidence level.

  14. Advanced Rainbow Solar Photovoltaic Arrays

    Science.gov (United States)

    Mardesich, Nick; Shields, Virgil

    2003-01-01

    Photovoltaic arrays of the rainbow type, equipped with light-concentrator and spectral-beam-splitter optics, have been investigated in a continuing effort to develop lightweight, high-efficiency solar electric power sources. This investigation has contributed to a revival of the concept of the rainbow photovoltaic array, which originated in the 1950s but proved unrealistic at that time because the selection of solar photovoltaic cells was too limited. Advances in the art of photovoltaic cells since that time have rendered the concept more realistic, thereby prompting the present development effort. A rainbow photovoltaic array comprises side-by-side strings of series-connected photovoltaic cells. The cells in each string have the same bandgap, which differs from the bandgaps of the other strings. Hence, each string operates most efficiently in a unique wavelength band determined by its bandgap. To obtain maximum energy-conversion efficiency and to minimize the size and weight of the array for a given sunlight input aperture, the sunlight incident on the aperture is concentrated, then spectrally dispersed onto the photovoltaic array plane, whereon each string of cells is positioned to intercept the light in its wavelength band of most efficient operation. The number of cells in each string is chosen so that the output potentials of all the strings are the same; this makes it possible to connect the strings together in parallel to maximize the output current of the array. According to the original rainbow photovoltaic concept, the concentrated sunlight was to be split into multiple beams by use of an array of dichroic filters designed so that each beam would contain light in one of the desired wavelength bands. The concept has since been modified to provide for dispersion of the spectrum by use of adjacent prisms. A proposal for an advanced version calls for a unitary concentrator/ spectral-beam-splitter optic in the form of a parabolic curved Fresnel-like prism

  15. Acoustic transmission through compound subwavelength slit arrays

    Science.gov (United States)

    Ward, G. P.; Hibbins, A. P.; Sambles, J. R.; Smith, J. D.

    2016-07-01

    The angular dependence of the transmission of sound in air through four types of two-dimensional slit arrays formed of aluminium slats is explored, both experimentally and numerically. For a simple, subwavelength periodic slit array, it is well known that Fabry-Perot-like waveguide resonances, supported by the slit cavities, coupled to diffracted evanescent waves, result in enhanced acoustic transmission at frequencies determined by the length, width, and separation of each slit cavity. We demonstrate that altering the spacing or width of some of the slits to form a compound array (i.e., an array having a basis comprised of more than one slit) results in sharp dips in the transmission spectra, which may have a strong angular dependence. These features correspond to phase resonances, which have been studied extensively in the electromagnetic case. This geometry allows for additional near-field configurations compared to the simple array, whereby the field in adjacent cavities can be out of phase. Several types of compound slit arrays are investigated; one such structure is optimized to minimize the effect of boundary-layer loss mechanisms present in each slit cavity, thereby achieving a deep, sharp transmission minimum in a broad maximum.

  16. Photovoltaic array loss mechanisms

    Science.gov (United States)

    Gonzalez, Charles

    1986-10-01

    Loss mechanisms which come into play when solar cell modules are mounted in arrays are identified. Losses can occur either from a reduction in the array electrical performance or with nonoptimal extraction of power from the array. Electrical performance degradation is caused by electrical mismatch, transmission losses from cell surface soiling and steep angle of reflectance, and electrical losses from field wiring resistance and the voltage drop across blocking diodes. The second type of loss, concerned with the operating points of the array, can involve nonoptimal load impedance and limiting the operating envelope of the array to specific ranges of voltage and current. Each of the loss mechanisms are discussed and average energy losses expected from soiling, steep reflectance angles and circuit losses are calculated.

  17. Microfabricated ion trap array

    Science.gov (United States)

    Blain, Matthew G.; Fleming, James G.

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  18. Fabrication and characterization of CaP-coated nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Kuan-Chen; Chen, Jia-Ling [Institute of Oral Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); Liu, Yen-Ting [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Lee, Tzer-Min, E-mail: tmlee@mail.ncku.edu.tw [Institute of Oral Medicine, National Cheng Kung University, Tainan 701, Taiwan (China); Medical Device Innovation Center, National Cheng Kung University, Tainan 701, Taiwan (China); School of Dentistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2015-03-01

    Modified anodization techniques have been shown to improve the biocompatibility of titanium. This study demonstrated the anodic formation of self-organized nanotube arrays on titanium from an electrolyte solution containing 1 M H{sub 3}PO{sub 4} and 1 wt% hydrofluoric acid (HF). Our aim was to investigate the effects of sputter-deposited CaP on nanotube arrays. SEM images revealed a surface with uniform morphology and an average pore diameter of 29 nm. XRD results indicated that the phase of the nanotube arrays was amorphous. Electron spectroscopy for chemical analysis (ESCA) confirmed that the nanotube arrays were coated with calcium and phosphorus. Cell culture experiments using human osteosarcoma (HOS) cells demonstrated that the CaP/nanotube arrays had a pronounced effect on initial cell attachment as well as on the number of cells at 1, 7, and 14 days. Compared to as-polished titanium, the CaP/nanotube arrays accelerated cell proliferation, attachment, and spreading. Our results demonstrate the pronounced effects of CaP/nanotube arrays on the biological responses of HOS cells. - Highlights: • Self-organized nanotube arrays were anodically formed on titanium. • Surfaces of nanotube arrays exhibited uniform morphology and pore size. • According to ESCA results, Ca and P were successfully coated on nanotube arrays. • CaP/nanotube arrays accelerated the attachment and spreading of cells. • CaP/nanotube arrays were shown to affect biological responses of cells.

  19. Variable-focus cylindrical liquid lens array

    Science.gov (United States)

    Zhao, Wu-xiang; Liang, Dong; Zhang, Jie; Liu, Chao; Zang, Shang-fei; Wang, Qiong-hua

    2013-06-01

    A variable-focus cylindrical liquid lens array based on two transparent liquids of different refractive index is demonstrated. An elastic membrane divides a transparent reservoir into two chambers. The two chambers are filled with liquid 1 and liquid 2, respectively, which are of different refractive index. The micro-clapboards help liquid 1, liquid 2 and the elastic membrane form a cylindrical lens array. Driving these two liquids to flow can change the shape of the elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. A demo lens array of positive optical power is developed and tested. Moreover, a potential application of the proposed lens array for autostereoscopic 3D displays is emphasized.

  20. Surface Modifications of Support Partitions for Stabilizing Biomimetic Membrane Arrays

    DEFF Research Database (Denmark)

    Perry, Mark; Hansen, Jesper Schmidt; Jensen, Karin Bagger Stibius;

    2011-01-01

    Black lipid membrane (BLM) formation across apertures in an ethylene tetra-fluoroethylene (ETFE) partition separating two aqueous compartments is an established technique for the creation of biomimetic membranes. Recently multi-aperture BLM arrays have attracted interest and in order to increase...... modified partitions were similar and significantly lower than for arrays formed using untreated ETFE partitions. For single side n-hexene modification average membrane array lifetimes were not significantly changed compared to untreated ETFE. Double-sided n-hexene modification greatly improved average...... membrane array lifetimes compared to membrane arrays formed across untreated ETFE partitions. n-hexene modifications resulted in BLM membrane arrays which over time developed significantly lower conductance (Gm) and higher capacitance (Cm) values compared to the other membranes with the strongest effect...

  1. Introduction to adaptive arrays

    CERN Document Server

    Monzingo, Bob; Haupt, Randy

    2011-01-01

    This second edition is an extensive modernization of the bestselling introduction to the subject of adaptive array sensor systems. With the number of applications of adaptive array sensor systems growing each year, this look at the principles and fundamental techniques that are critical to these systems is more important than ever before. Introduction to Adaptive Arrays, 2nd Edition is organized as a tutorial, taking the reader by the hand and leading them through the maze of jargon that often surrounds this highly technical subject. It is easy to read and easy to follow as fundamental concept

  2. Piezoelectric transducer array microspeaker

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of a piezoelectric micro-speaker. The speaker is an array of micro-machined piezoelectric membranes, fabricated on silicon wafer using advanced micro-machining techniques. Each array contains 2n piezoelectric transducer membranes, where “n” is the bit number. Every element of the array has a circular shape structure. The membrane is made out four layers: 300nm of platinum for the bottom electrode, 250nm or lead zirconate titanate (PZT), a top electrode of 300nm and a structural layer of 50

  3. P systems with array objects and array rewriting rules

    Institute of Scientific and Technical Information of China (English)

    K.G. Subramanian; R. Saravanan; M. Geethalakshmi; P. Helen Chandra; M. Margenstern

    2007-01-01

    Array P systems were introduced by Pǎun Gh. which is linking the two areas of membrane computing and picture grammars. Puzzle grammars were introduced by us for generating connected picture arrays in the two-dimensional plane, motivated by the problem of tiling the plane. On the other hand, incorporating into arrays the developmental type of generation used in the well-known biologically motivated L systems, Siromoney and Siromoney proposed a very general rectangular array generating model, called extended controlled tabled L array system (ECTLAS). In this paper we introduce two variations of the array P system, called BPG array P system and parallel array P system. The former has in the regions array objects and basic puzzle grammar rules (BPG), which are a specific kind of puzzle grammar rules. In the latter, the regions have rectangular array objects and tables of context-free rules. We examine these two types of P systems for their array generative power.

  4. Analysis of Optical-Axis Perturbation in Non-Planar Ring Oscillator%非平面环形腔的光轴失谐分析

    Institute of Scientific and Technical Information of China (English)

    冯滔; 张雪洁; 张燕; 刘芳; 任志远; 朱健强

    2013-01-01

    In order to analyze the self-consistence characteristics of optical-axis perturbation due to the manufacturing error of monolithic crystal, mathematical model for the mirror tilt of the non-planar ring cavity has been developed and optical-axis perturbation is discussed by utilizing the augmented ray matrix formulation. The results show that: self-consistence of the optical-axis is not sensitive to distance deviation and it can be realized by designing the input-output coupling mirror to be a curved surface. Static analysis indicates that the optical-axis is still self-consistent for the plane input-output coupling mirror when the angles of two symmetric totally reflective planes satisfy the certain relationship. Besides, if the certain condition of the angles cannot be satisfied, steps to reduce the deviation of coupling point position are considered from aspects of making manufacturing error symmetrical and decreasing error. At last, dynamic analysis provides a much more reasonable method to explore the manufacturing tolerance, offering a theoretical guide for the experiment.%为了分析光轴在单块晶体加工过程中镜面失谐的自洽特征,建立了非平面环形腔镜面倾斜的数学模型,利用增广的光线矩阵讨论了光轴变动.结论显示:当存在距离误差时,不会影响光轴闭合;当输入输出耦合面设计成曲面时,能实现光轴自洽闭合;当它为平面时,静态分析表明,如果两个对称全反面的失谐角度满足特定关系,能再次实现光轴的闭合.如果失谐角度不满足对应关系,对称失谐和减小失谐量能减小耦合点偏离距离.动态分析过程则给出了一个更加合理的分析加工容差方法,同时为实验的调光过程提供了理论指导.

  5. MODELLING AND CONTROL OF PARTIALLY SHADED PHOTOVOLTAIC ARRAYS

    Directory of Open Access Journals (Sweden)

    Chia Seet Chin

    2013-01-01

    Full Text Available The photovoltaic (PV array controlled by Maximum Power Point Tracking (MPPT method for optimum PV power generation, particularly when the PV array is under partially shaded condition is presented in this paper. The system modelling is carried out in MATLAB-SIMULINK where the PV array is formed by five series connected identical PV modules. Under uniform solar irradiance conditions, the PV module and the PV array present nonlinear P-V characteristic but the maximum power point (MPP can be easily identified. However, when the PV array is under shaded conditions, the P-V characteristic becomes more complex with the present of multiple MPP. While the PV array operated at local MPP, the generated power is limited. Thus, the investigation on MPPT approach is carried out to maximize the PV generated power even when the PV array is under partially shaded conditions (PSC. Fuzzy logic is adopted into the conventional MPPT to form fuzzy logic based MPPT (FMPPT for better performance. The developed MPPT and FMPPT are compared, particularly the performances on the transient response and the steady state response when the array is under various shaded conditions. FMPPT shows better performance where the simulation results demonstrate FMPPT is able to facilitate the PV array to reach the MPP faster while it helps the PV array to produce a more stable output power.

  6. Array antennas design in dependence of element-phasing

    Science.gov (United States)

    Zichner, R.; Chandra, M.

    2009-05-01

    Array antennas are used in science as well as for commercial and military purposes. The used element antennas act in accordance to their desired uses, for example radars or stationer GPS satellites. Typical components are for example slotted waveguides, patches, yagi-antennas and helix-antennas. All these elements do stand out with their own characteristics based on their special applications. If these elements are formed into an array configuration, the effectiveness can be improved immensely. There is a relation between the array functions and the physical array properties like the element alignment (linear, planar, circular), distances between the elements and so on. Among the physical properties there are other attributes like phase or amplitude coefficients, which are of great significance. The aim of this study was to provide an insight into the problem of array design, as far as the antenna element phase is concerned. Along with this, array radiation characteristics effects are presented. With the help of the extracted cognitions beam forming behaviour can be shown and the array phase behaviour can be analysed. One of the main applications is to simulate the array characteristics, like the radiation characteristic or the gain, for displacements of the array feeding point. A software solution that simulates the phase shift of a given array pattern is sought to adjust the feeding point.

  7. Array antennas design in dependence of element-phasing

    Directory of Open Access Journals (Sweden)

    R. Zichner

    2009-05-01

    Full Text Available Array antennas are used in science as well as for commercial and military purposes. The used element antennas act in accordance to their desired uses, for example radars or stationer GPS satellites. Typical components are for example slotted waveguides, patches, yagi-antennas and helix-antennas. All these elements do stand out with their own characteristics based on their special applications. If these elements are formed into an array configuration, the effectiveness can be improved immensely. There is a relation between the array functions and the physical array properties like the element alignment (linear, planar, circular, distances between the elements and so on. Among the physical properties there are other attributes like phase or amplitude coefficients, which are of great significance. The aim of this study was to provide an insight into the problem of array design, as far as the antenna element phase is concerned. Along with this, array radiation characteristics effects are presented. With the help of the extracted cognitions beam forming behaviour can be shown and the array phase behaviour can be analysed. One of the main applications is to simulate the array characteristics, like the radiation characteristic or the gain, for displacements of the array feeding point. A software solution that simulates the phase shift of a given array pattern is sought to adjust the feeding point.

  8. Protein Functionalized Nanodiamond Arrays

    Directory of Open Access Journals (Sweden)

    Liu YL

    2010-01-01

    Full Text Available Abstract Various nanoscale elements are currently being explored for bio-applications, such as in bio-images, bio-detection, and bio-sensors. Among them, nanodiamonds possess remarkable features such as low bio-cytotoxicity, good optical property in fluorescent and Raman spectra, and good photostability for bio-applications. In this work, we devise techniques to position functionalized nanodiamonds on self-assembled monolayer (SAMs arrays adsorbed on silicon and ITO substrates surface using electron beam lithography techniques. The nanodiamond arrays were functionalized with lysozyme to target a certain biomolecule or protein specifically. The optical properties of the nanodiamond-protein complex arrays were characterized by a high throughput confocal microscope. The synthesized nanodiamond-lysozyme complex arrays were found to still retain their functionality in interacting with E. coli.

  9. The data array, a tool to interface the user to a large data base

    Science.gov (United States)

    Foster, G. H.

    1974-01-01

    Aspects of the processing of spacecraft data is considered. Use of the data array in a large address space as an intermediate form in data processing for a large scientific data base is advocated. Techniques for efficient indexing in data arrays are reviewed and the data array method for mapping an arbitrary structure onto linear address space is shown. A compromise between the two forms is given. The impact of the data array on the user interface are considered along with implementation.

  10. Improved array illuminators.

    Science.gov (United States)

    Lohmann, A W; Sinzinger, S

    1992-09-10

    The job of an array illuminator is to provide an array of optical gates or smart pixels with photon power or with synchronous clock signals. So far it has been common to take the power from one big laser and distribute it to perhaps a million gates. An obvious alternative is to assign one private small source to each gate. We favor an in-between approach: a few medium-size sources share the job of providing photons. This hybrid approach has several advantages, such as better homogeneity, less coherent noise, and a distributed risk of source failure. We propose several setups and present some experimental results. Our concept calls for an array of incoherent point sources. We simulate such an array experimentally with a single source, which is virtually expanded into a source array by grating diffraction. Ordinarily these virtual sources are mutually coherent, which is undesirable for our aims. We destroy the mutual coherence by moving the grating during the photographic recording of the output array.

  11. Thermally Conductive Tape Based on Carbon Nanotube Arrays

    Science.gov (United States)

    Kashani, Ali

    2011-01-01

    To increase contact conductance between two mating surfaces, a conductive tape has been developed by growing dense arrays of carbon nanotubes (CNTs, graphite layers folded into cylinders) on both sides of a thermally conductive metallic foil. When the two mating surfaces are brought into contact with the conductive tape in between, the CNT arrays will adhere to the mating surface. The van der Waals force between the contacting tubes and the mating surface provides adhesion between the two mating surfaces. Even though the thermal contact conductance of a single tube-to-tube contact is small, the tremendous amount of CNTs on the surface leads to a very large overall contact conductance. Interface contact thermal resistance rises from the microroughness and the macroscopic non-planar quality of mating surfaces. When two surfaces come into contact with each other, the actual contact area may be much less than the total area of the surfaces. The real area of contact depends on the load, the surface roughness, and the elastic and inelastic properties of the surface. This issue is even more important at cryogenic temperatures, where materials become hard and brittle and vacuum is used, which prevents any gas conduction through the interstitial region. A typical approach to increase thermal contact conductance is to use thermally conducting epoxies or greases, which are not always compatible with vacuum conditions. In addition, the thermal conductivities of these compounds are often relatively low. The CNTs used in this approach can be metallic or semiconducting, depending on the folding angle and diameter. The electrical resistivity of multiwalled carbon nanotubes (MWCNTs) has been reported. MWCNTs can pass a current density and remain stable at high temperatures in air. The thermal conductivity of a MWCNT at room temperature is measured to be approximately 3,000 W/m-K, which is much larger than that of diamond. At room temperature, the thermal conductance of a 0.3 sq cm

  12. Hard Transparent Arrays for Polymer Pen Lithography.

    Science.gov (United States)

    Hedrick, James L; Brown, Keith A; Kluender, Edward J; Cabezas, Maria D; Chen, Peng-Cheng; Mirkin, Chad A

    2016-03-22

    Patterning nanoscale features across macroscopic areas is challenging due to the vast range of length scales that must be addressed. With polymer pen lithography, arrays of thousands of elastomeric pyramidal pens can be used to write features across centimeter-scales, but deformation of the soft pens limits resolution and minimum feature pitch, especially with polymeric inks. Here, we show that by coating polymer pen arrays with a ∼175 nm silica layer, the resulting hard transparent arrays exhibit a force-independent contact area that improves their patterning capability by reducing the minimum feature size (∼40 nm), minimum feature pitch (<200 nm for polymers), and pen to pen variation. With these new arrays, patterns with as many as 5.9 billion features in a 14.5 cm(2) area were written using a four hundred thousand pyramid pen array. Furthermore, a new method is demonstrated for patterning macroscopic feature size gradients that vary in feature diameter by a factor of 4. Ultimately, this form of polymer pen lithography allows for patterning with the resolution of dip-pen nanolithography across centimeter scales using simple and inexpensive pen arrays. The high resolution and density afforded by this technique position it as a broad-based discovery tool for the field of nanocombinatorics.

  13. Novel Deployment Mechanism for Conventional Solar Array Enhancement

    Directory of Open Access Journals (Sweden)

    Hodgetts Paul A.

    2017-01-01

    Full Text Available A novel mechanism is described, by which flexible blankets could be deployed from existing solar panel designs. These blankets could be covered with flexible cells, or they could be reflective films to form a concentrator array. Either way, the performance of an existing array design could be enhanced.

  14. rasdaman Array Database: current status

    Science.gov (United States)

    Merticariu, George; Toader, Alexandru

    2015-04-01

    rasdaman (Raster Data Manager) is a Free Open Source Array Database Management System which provides functionality for storing and processing massive amounts of raster data in the form of multidimensional arrays. The user can access, process and delete the data using SQL. The key features of rasdaman are: flexibility (datasets of any dimensionality can be processed with the help of SQL queries), scalability (rasdaman's distributed architecture enables it to seamlessly run on cloud infrastructures while offering an increase in performance with the increase of computation resources), performance (real-time access, processing, mixing and filtering of arrays of any dimensionality) and reliability (legacy communication protocol replaced with a new one based on cutting edge technology - Google Protocol Buffers and ZeroMQ). Among the data with which the system works, we can count 1D time series, 2D remote sensing imagery, 3D image time series, 3D geophysical data, and 4D atmospheric and climate data. Most of these representations cannot be stored only in the form of raw arrays, as the location information of the contents is also important for having a correct geoposition on Earth. This is defined by ISO 19123 as coverage data. rasdaman provides coverage data support through the Petascope service. Extensions were added on top of rasdaman in order to provide support for the Geoscience community. The following OGC standards are currently supported: Web Map Service (WMS), Web Coverage Service (WCS), and Web Coverage Processing Service (WCPS). The Web Map Service is an extension which provides zoom and pan navigation over images provided by a map server. Starting with version 9.1, rasdaman supports WMS version 1.3. The Web Coverage Service provides capabilities for downloading multi-dimensional coverage data. Support is also provided for several extensions of this service: Subsetting Extension, Scaling Extension, and, starting with version 9.1, Transaction Extension, which

  15. The GPS Laser Retroreflector Array Project

    Science.gov (United States)

    Merkowitz, Stephen M.

    2012-01-01

    Systematic co-location in space through the precision orbit determination of GPS satellites via satellite laser ranging will contribute significantly towards improving the accuracy and stability of the international terrestrial reference frame. NASA recently formed the GPS Laser Retroreflector Array Project to develop and deliver retroreflectors for integration on the next generation of GPS satellites. These retroreflectors will be an important contributor to achieving a global accuracy of 1.0 mm and 0.1 mm/year stability in the international terrestrial reference frame. We report here the current status of the GPS Laser Retroreflector Array Project.

  16. An LTCC 94 GHz Antenna Array

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, J; Pao, H; Lin, H; Garland, P; O' Neill, D; Horton, K

    2007-12-21

    An antenna array is designed in low-temperature cofired ceramic (LTCC) Ferro A6M{trademark} for a mm-wave application. The antenna is designed to operate at 94 GHz with a few percent bandwidth. A key manufacturing technology is the use of 3 mil diameter vias on a 6 mil pitch to construct the laminated waveguides that form the beamforming network and radiating elements. Measurements for loss in the laminated waveguide are presented. The slot-fed cavity-radiating element is designed to account for extremely tight mutual coupling between elements. The array incorporates a slot-fed multi-layer beamforming network.

  17. Fabrication of Polypyrrole Nanowire and Nanotube Arrays

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2005-04-01

    Full Text Available Large area highly uniform and ordered polypyrrole nanowire and nanotubearrays were fabricated by chemical oxidation polymerization with the help of a porousanodic aluminium oxide (AAO template. Under 0.2 moL/L pyrrole (H2O and 0.2 moL/LFeCl3 (H2O pattern, polypyrrole nanowire arrays were obtained after 2.0 hourspolymerization reaction in a two-compartment reaction cell. When the reaction wasstopped after 15 minutes, polypyrrole nanotube arrays have been formed. The diameter,length and density of compositive nanowires and nanotubes could be controlled byparameters of AAO template.

  18. Optical beam forming for phased-array antennas

    NARCIS (Netherlands)

    Meijerink, A.; Roeloffzen, C.G.H.; Zhuang, L.; Marpaung, D.A.I.; Heideman, R.G.; Borreman, A.; Etten, van W.

    2007-01-01

    The activities of the Telecommunication Engineering (TE) group span the communications spectrum from copper cables, optical fibres, microwaves, radio and electromagnetic compatibility. Our research concentrates on optical signal processing and networks, mobile communications, microwave techniques an

  19. Conformal phased array with beam forming for airborne satellite communication

    NARCIS (Netherlands)

    Schippers, H.; Verpoorte, J.; Jorna, P.; Hulzinga, A.; Meijerink, A.; Roeloffzen, C.G.H.; Heideman, R.G.; Leinse, A.; Wintels, M.

    2008-01-01

    For enhanced communication on board of aircraft novel antenna systems with broadband satellite-based capabilities are required. The installation of such systems on board of aircraft requires the development of a very low-profile aircraft antenna, which can point to satellites anywhere in the upper h

  20. Compound liquid crystal microlens array with convergent and divergent functions.

    Science.gov (United States)

    Kang, Shengwu; Zhang, Xinyu

    2016-04-20

    Based on the common liquid crystal microlens, a new compound structure for a liquid crystal (LC) microlens array is proposed. The structure consists of two sub LC microlens arrays with properties of light divergence and convergence. The structure has two LC layers: one to form the positive sub lens, one for the negative. The patterned electrode and plane electrode are used in both sub microlens arrays. When two sub microlens arrays are electrically controlled separately, they can diverge or converge the incident light, respectively. As two sub microlens arrays are both applied on the voltage, the focal length of the compound LC microlens becomes larger than that of the LC microlens with a single LC layer. Another feature of a compound LC microlens array is that it can make the target contour become visible under intense light. The mechanisms are described in detail, and the experimental data are given.

  1. Developing barbed microtip-based electrode arrays for biopotential measurement.

    Science.gov (United States)

    Hsu, Li-Sheng; Tung, Shu-Wei; Kuo, Che-Hsi; Yang, Yao-Joe

    2014-07-10

    This study involved fabricating barbed microtip-based electrode arrays by using silicon wet etching. KOH anisotropic wet etching was employed to form a standard pyramidal microtip array and HF/HNO3 isotropic etching was used to fabricate barbs on these microtips. To improve the electrical conductance between the tip array on the front side of the wafer and the electrical contact on the back side, a through-silicon via was created during the wet etching process. The experimental results show that the forces required to detach the barbed microtip arrays from human skin, a polydimethylsiloxane (PDMS) polymer, and a polyvinylchloride (PVC) film were larger compared with those required to detach microtip arrays that lacked barbs. The impedances of the skin-electrode interface were measured and the performance levels of the proposed dry electrode were characterized. Electrode prototypes that employed the proposed tip arrays were implemented. Electroencephalogram (EEG) and electrocardiography (ECG) recordings using these electrode prototypes were also demonstrated.

  2. Narrative form

    CERN Document Server

    Keen, Suzanne

    2015-01-01

    This revised and expanded handbook concisely introduces narrative form to advanced students of fiction and creative writing, with refreshed references and new discussions of cognitive approaches to narrative, nonfiction, and narrative emotions.

  3. Sensors Array Technique for Monitoring Aluminum Alloy Spot Welding

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; LUO Zhen; SHAN Ping; BU Xianzheng; YUAN Shuxian; AO Sansan

    2010-01-01

    In this paper, the sensors array technique is applied to the quality detection of aluminum alloy spot weld-ing. The sensors array has three forms, i.e., linear magnetic sensors array, annular magnetic sensors array and cross magnetic sensors array. An algorithm based on principal component analysis is proposed to extract the signal eigen-values. The three types of magnetic sensors array are used in the experiment of monitoring the signal. After the eigen-values are extracted, they are used to build a relationship with the nugget information. The result shows that when the distance between the core of the array and the pole is 60 mm, the arrays work best. In this case, when the eigenvalues' range of the linear array is 0.006 5-0.015 1, the quality of the spots is eligible. To the annular and cross array, when the ranges are 0.082 9—0.131 6 and 0.085 1—0.098 2 respectively, the nugget quality is eligible.

  4. Wireless Josephson Junction Arrays

    Science.gov (United States)

    Adams, Laura

    2015-03-01

    We report low temperature, microwave transmission measurements on a wireless two- dimensional network of Josephson junction arrays composed of superconductor-insulator -superconductor tunnel junctions. Unlike their biased counterparts, by removing all electrical contacts to the arrays and superfluous microwave components and interconnects in the transmission line, we observe new collective behavior in the transmission spectra. In particular we will show emergent behavior that systematically responds to changes in microwave power at fixed temperature. Likewise we will show the dynamic and collective response of the arrays while tuning the temperature at fixed microwave power. We discuss these spectra in terms of the Berezinskii-Kosterlitz-Thouless phase transition and Shapiro steps. We gratefully acknowledge the support Prof. Steven Anlage at the University of Maryland and Prof. Allen Goldman at the University of Minnesota. Physics and School of Engineering and Applied Sciences.

  5. ZnO nanowire arrays with and without cavity tops

    Energy Technology Data Exchange (ETDEWEB)

    Li Hongyu; Quan Baogang; Tang Haoying; Guo Chuanfei [National Center for Nanoscience and Technology, Beijing 100190 (China); Jiang Peng, E-mail: pjiang@nanoctr.cn [National Center for Nanoscience and Technology, Beijing 100190 (China); Yu Aifang [National Center for Nanoscience and Technology, Beijing 100190 (China); Xie Sishen, E-mail: ssxie@aphy.iphy.ac.cn [Institute of Physics, Chinese Academy of Sciences (CAS), Beijing 100190 (China); Wang Zhonglin, E-mail: zhong.wang@mse.gatech.edu [National Center for Nanoscience and Technology, Beijing 100190 (China); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)

    2011-10-03

    Highlights: {yields} ZnO NW array structure was formed on a ZnO-seed-layer-patterned Si substrate. {yields} Both e-beam lithography and a wet chemical method were employed. {yields} A bubble-assisted method was used for constructing ZnO nanowire arrays with cavity tops. {yields} ZnO NW array structures with different morphologies exhibited different photoluminescence properties. - Abstract: We report a new bubble-assisted growing and etching method for constructing ZnO nanowire (NW) arrays with cavity tops. Firstly, a ZnO NW array structure was formed on a ZnO-seed-layer-patterned Si substrate by combining e-beam lithography and a wet chemical method. Secondly, a new kind of ZnO NW array with cavity tops could be formed by a subsequent bubble-assisted growing and etching. These ZnO NW array structures with different morphologies exhibited different photoluminescence properties, showing their potential applications in lasing cavities, stimulated emitters, nanogenerator, photocatalysis and light-emitting diodes. The bubble-assisted etching method will open a new door for morphology design of ZnO and other semiconductor nanowire arrays at special sites.

  6. Photovoltaic array performance model.

    Energy Technology Data Exchange (ETDEWEB)

    Kratochvil, Jay A.; Boyson, William Earl; King, David L.

    2004-08-01

    This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance.

  7. The Submillimeter Array

    CERN Document Server

    Ho, P T P; Lo, K Y; Ho, Paul T.P.; Moran, James M.; Lo, Kwok Yung

    2004-01-01

    The Submillimeter Array (SMA), a collaborative project of the Smithsonian Astrophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), has begun operation on Mauna Kea in Hawaii. A total of eight 6-m telescopes comprise the array, which will cover the frequency range of 180-900 GHz. All eight telescopes have been deployed and are operational. First scientific results utilizing the three receiver bands at 230, 345, and 690 GHz have been obtained and are presented in the accompanying papers.

  8. Selecting Sums in Arrays

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jørgensen, Allan Grønlund

    2008-01-01

    In an array of n numbers each of the \\binomn2+nUnknown control sequence '\\binom' contiguous subarrays define a sum. In this paper we focus on algorithms for selecting and reporting maximal sums from an array of numbers. First, we consider the problem of reporting k subarrays inducing the k larges...... an algorithm with this running time and by proving a matching lower bound. Finally, we combine the ideas and obtain an O(n· max {1,log(k/n)}) time algorithm that selects a subarray storing the k’th largest sum among all subarrays of length at least l and at most u....

  9. Master integrals for the four-loop Sudakov form factor

    CERN Document Server

    Boels, Rutger; Yang, Gang

    2016-01-01

    The light-like cusp anomalous dimension is a universal function in the analysis of infrared divergences. In maximally ($\\mathcal{N}=4$) supersymmetric Yang-Mills theory (SYM) in the planar limit, it is known, in principle, to all loop orders. The non-planar corrections are not known in any theory, with the first appearing at the four-loop order. Probably the simplest quantity which contains this correction is the four-loop two-point form factor of the stress tensor multiplet. This form factor was obtained in integrand form in a previous work for $\\mathcal{N}=4$ SYM, up to a single parameter. In this work, a reduction of the appearing integrals obtained by solving integration-by-parts (IBP) identities using (a tweaked version of) Reduze is reported. The form factor is shown to be independent of the remaining parameter at integrand level due to an intricate pattern of cancellations after IBP reduction. The appearing master integrals are cross-checked using algebraic techniques explored in the Mint package. The ...

  10. Theoretical Study on a New Non-Planar Multi-Pass Laser Amplifier%新型非平面多程激光放大器的理论研究

    Institute of Scientific and Technical Information of China (English)

    杨清; 霍玉晶; 何淑芳

    2012-01-01

    A new non-planar multi-pass laser amplifier based on the two-mirror ring optical path is proposed. It has the advantages of simple structure, small size, good space symmetry, easily adjustable and more amplification times. In the cavity of the amplifier, the signal beam goes through the laser medium many times for amplification along the three-dimensional non-planar symmetric path, and the high-power amplified laser can be obtained in a small-size laser medium. Theoretical modeling and parametric analysis of the optical path in the cavity of the amplifier are done. Simulation graphs for a portion of modes of optical path are given, optical loss and power amplification are also analyzed. A basic design of a solid-state non-planar multi-pass thin-disk laser amplifier based on Yb: YAG thin disk and laser diode (LD) end-pumping is given for high-power laser amplification.%提出了一种基于双镜环行光路的新型非平面多程激光放大器,它具有结构简单、体积小、空间对称性好、调节容易、光通放大次数多的优点.信号光束在放大器腔内沿着立体环行的非平面空间对称路径多次通过激光介质被放大,可在小型激光介质中获得高功率的放大激光输出.对放大器腔内光路进行了理论建模和参量分析,给出了部分光路模式的模拟图,分析了光路损耗与功率放大;初步设计了基于Yb∶YAG薄片和激光二极管(LD)端面抽运的全固态非平面多程薄片激光放大器,适用于高功率激光放大.

  11. Electronically Steerable Spherical Array capabilities and interfaces

    Science.gov (United States)

    Taylor, T. H., Jr.

    1982-01-01

    The development of the Electronically Steerable Spherical Array (ESSA) was started in 1975. ESSA provides the inertialess antenna needed by user satellites for communication over their large coverage angles towards the Tracking Data Relay Satellite System (TDRSS). The performance of ESSA over large coverage angles is better than the performance provided by phased arrays. The primary difference between the two antenna types is the method of beam forming. The ESSA steers a beam by illuminating a set of elements which point in the desired direction. This set of elements is illuminated by a simple multipole switch called a switching power divider (SPD). Attention is given to details regarding the difference in performance between ESSA and phased arrays, the ESSA block diagram, the performance improvement achieved by phase compensation, power requirements, the four operating modes, multibeam operation, and the data interface.

  12. Modal liquid crystal array of optical elements.

    Science.gov (United States)

    Algorri, J F; Love, G D; Urruchi, V

    2013-10-21

    In this study, a novel liquid crystal array based on modal control principle is proposed and demonstrated. The advanced device comprises a six striped electrode structure that forms a configurable 2D matrix of optical elements. A simulation program based on the Frank-Oseen equations and modal control theory has been developed to predict the device electrooptic response, that is, voltage distribution, interference pattern and unwrapped phase. A low-power electronics circuit, that generates complex waveforms, has been built for driving the device. A combined variation of the waveform amplitude and phase has provided a high tuning versatility to the device. Thus, the simulations have demonstrated the generation of a liquid crystal prism array with tunable slope. The proposed device has also been configured as an axicon array. Test measurements have allowed us to demonstrate that electrooptic responses, simulated and empirical, are fairly in agreement.

  13. Microneedle arrays for biosensing and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Joseph; Windmiller, Joshua Ray; Narayan, Roger; Miller, Philip; Polsky, Ronen; Edwards, Thayne L.

    2017-08-22

    Methods, structures, and systems are disclosed for biosensing and drug delivery techniques. In one aspect, a^ device for detecting an analyte and/or releasing a biochemical into a biological fluid can include an array of hollowed needles, in which each needle includes a protruded needle structure including an exterior wall forming a hollow interior and an opening at a terminal end of the protruded needle structure that exposes the hollow interior, and a probe inside the exterior wall to interact with one or more chemical or biological substances that come in contact with the probe via the opening to produce a probe sensing signal, and an array of wires that are coupled to probes of the array of hollowed needles, respectively, each wire being electrically conductive to transmit the probe sensing signal produced by a respective probe.

  14. Microneedle arrays for biosensing and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Joseph; Windmiller, Joshua Ray; Narayan, Roger; Miller, Philip

    2017-08-29

    Methods, structures, and systems are disclosed for biosensing and drug delivery techniques. In one aspect, a device for detecting an analyte and/or releasing a biochemical into a biological fluid can include an array of hollowed needles, in which each needle includes a protruded needle structure including an exterior wall forming a hollow interior and an opening at a terminal end of the protruded needle structure that exposes the hollow interior, and a probe inside the exterior wall to interact with one or more chemical or biological substances that come in contact with the probe via the opening to produce a probe sensing signal, and an array of wires that are coupled to probes of the array of hollowed needles, respectively, each wire being electrically conductive to transmit the probe sensing signal produced by a respective probe.

  15. Stochastic synaptic plasticity with memristor crossbar arrays

    KAUST Repository

    Naous, Rawan

    2016-11-01

    Memristive devices have been shown to exhibit slow and stochastic resistive switching behavior under low-voltage, low-current operating conditions. Here we explore such mechanisms to emulate stochastic plasticity in memristor crossbar synapse arrays. Interfaced with integrate-and-fire spiking neurons, the memristive synapse arrays are capable of implementing stochastic forms of spike-timing dependent plasticity which parallel mean-rate models of stochastic learning with binary synapses. We present theory and experiments with spike-based stochastic learning in memristor crossbar arrays, including simplified modeling as well as detailed physical simulation of memristor stochastic resistive switching characteristics due to voltage and current induced filament formation and collapse. © 2016 IEEE.

  16. Solid-state curved focal plane arrays

    Science.gov (United States)

    Nikzad, Shouleh (Inventor); Hoenk, Michael (Inventor); Jones, Todd (Inventor)

    2010-01-01

    The present invention relates to curved focal plane arrays. More specifically, the present invention relates to a system and method for making solid-state curved focal plane arrays from standard and high-purity devices that may be matched to a given optical system. There are two ways to make a curved focal plane arrays starting with the fully fabricated device. One way, is to thin the device and conform it to a curvature. A second way, is to back-illuminate a thick device without making a thinned membrane. The thick device is a special class of devices; for example devices fabricated with high purity silicon. One surface of the device (the non VLSI fabricated surface, also referred to as the back surface) can be polished to form a curved surface.

  17. Fri form

    DEFF Research Database (Denmark)

    Jensen, Henrik

    2006-01-01

    Dette Kompendiun er lavet i forbindelse med en workshop i møbeldesign. En række af form-Z's værktøjer til konstruktion af dobbeltkrumme flader gennemgås. Kompendiet kan bruges til selvstudie.......Dette Kompendiun er lavet i forbindelse med en workshop i møbeldesign. En række af form-Z's værktøjer til konstruktion af dobbeltkrumme flader gennemgås. Kompendiet kan bruges til selvstudie....

  18. Bandwidth Reconfigurable Metamaterial Arrays

    Directory of Open Access Journals (Sweden)

    Nathanael J. Smith

    2014-01-01

    Full Text Available Metamaterial structures provide innovative ways to manipulate electromagnetic wave responses to realize new applications. This paper presents a conformal wideband metamaterial array that achieves as much as 10 : 1 continuous bandwidth. This was done by using interelement coupling to concurrently achieve significant wave slow-down and cancel the inductance stemming from the ground plane. The corresponding equivalent circuit of the resulting array is the same as that of classic metamaterial structures. In this paper, we present a wideband Marchand-type balun with validation measurements demonstrating the metamaterial (MTM array’s bandwidth from 280 MHz to 2800 MHz. Bandwidth reconfiguration of this class of array is then demonstrated achieving a variety of band-pass or band-rejection responses within its original bandwidth. In contrast with previous bandwidth and frequency response reconfigurations, our approach does not change the aperture’s or ground plane’s geometry, nor does it introduce external filtering structures. Instead, the new responses are realized by making simple circuit changes into the balanced feed integrated with the wideband MTM array. A variety of circuit changes can be employed using MEMS switches or variable lumped loads within the feed and 5 example band-pass and band-rejection responses are presented. These demonstrate the potential of the MTM array’s reconfiguration to address a variety of responses.

  19. Visible Genotype Sensor Array

    Directory of Open Access Journals (Sweden)

    Takashi Imai

    2008-04-01

    Full Text Available A visible sensor array system for simultaneous multiple SNP genotyping has been developed using a new plastic base with specific surface chemistry. Discrimination of SNP alleles is carried out by an allele-specific extension reaction using immobilized oligonucleotide primers. The 3’-ends of oligonucleotide primers are modified with a locked nucleic acid to enhance their efficiency in allelic discrimination. Biotin-dUTPs included in the reaction mixture are selectively incorporated into extending primer sequences and are utilized as tags for alkaline phosphatase-mediated precipitation of colored chemical substrates onto the surface of the plastic base. The visible precipitates allow immediate inspection of typing results by the naked eye and easy recording by a digital camera equipped on a commercial mobile phone. Up to four individuals can be analyzed on a single sensor array and multiple sensor arrays can be handled in a single operation. All of the reactions can be performed within one hour using conventional laboratory instruments. This visible genotype sensor array is suitable for “focused genomics” that follows “comprehensive genomics”.

  20. Extended Array Evaluation Program

    Science.gov (United States)

    1974-01-31

    irregular structure of the Mohorovicic discontinuity (Moho) underneath the NORSAR array. • Time delay anomalies (deviation from plane wave propagation...appears that most of the amplitude vari- ations may be explained by scattering effects due to the irregular structure of the Mohorovicic discontinuity

  1. Array processors in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, N.S.

    1980-01-01

    The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

  2. TANGO Array.. 2. Simulations

    Science.gov (United States)

    Bauleo, P.; Bonifazi, C.; Filevich, A.

    2004-01-01

    The angular and energy resolutions of the TANGO Array were obtained using extensive Monte Carlo simulations performed with a double purpose: (1) to determine the appropriate parameters for the array fitting to the desired range of sensitivity (the knee energy region), and (2) to construct a reliable shower database required for reference in the analysis of experimental data. The AIRES code, with the SIBYLL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (assuming protons and iron nuclei), with energies ranging from 10 14 to 10 18 eV. These data were fed into a realistic code which simulates the response of the detectors (water Cherenkov detectors), including the electronics, pickup noise, and the signal attenuation in the connecting cables. The trigger stage was considered in the simulations in order to estimate the trigger efficiency of the array and to verify the accuracy of the reconstruction codes. This paper delineates the simulations performed to obtain the expected behavior of the array, and describes the simulated data. The results of these simulations suggest that we can expect an error in the energy of the primary cosmic-ray of ˜60% of the estimated value and that the error in the measurement of the direction of arrival can be estimated as ˜4°. The present simulations also indicate that unambiguous assignments of the primary energy cannot be obtained because of the uncertainty in the nature of the primary cosmic ray.

  3. TANGO Array. 2. Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Bauleo, P. E-mail: pablo.bauleo@colostate.edu; Bonifazi, C.; Filevich, A

    2004-01-11

    The angular and energy resolutions of the TANGO Array were obtained using extensive Monte Carlo simulations performed with a double purpose: (1) to determine the appropriate parameters for the array fitting to the desired range of sensitivity (the knee energy region), and (2) to construct a reliable shower database required for reference in the analysis of experimental data. The AIRES code, with the SIBYLL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (assuming protons and iron nuclei), with energies ranging from 10{sup 14} to 10{sup 18} eV. These data were fed into a realistic code which simulates the response of the detectors (water Cherenkov detectors), including the electronics, pickup noise, and the signal attenuation in the connecting cables. The trigger stage was considered in the simulations in order to estimate the trigger efficiency of the array and to verify the accuracy of the reconstruction codes. This paper delineates the simulations performed to obtain the expected behavior of the array, and describes the simulated data. The results of these simulations suggest that we can expect an error in the energy of the primary cosmic-ray of {approx}60% of the estimated value and that the error in the measurement of the direction of arrival can be estimated as {approx}4 deg. . The present simulations also indicate that unambiguous assignments of the primary energy cannot be obtained because of the uncertainty in the nature of the primary cosmic ray.

  4. Microelectronic Stimulator Array

    Science.gov (United States)

    2000-08-09

    retinal prosthesis test device. Figure 3b shows an enlarged view of a nano-channel glass (NCG) electrode array. Figure 4 shows a conceptual layout (floor...against a visual cortex. 10 This involves invasive brain surgery through the cranium . From a surgical point of view, the intra ocular approach is

  5. TRMM Solar Array Panels

    Science.gov (United States)

    1998-01-01

    This final report presents conclusions/recommendations concerning the TRMM Solar Array; deliverable list and schedule summary; waivers and deviations; as-shipped performance data, including flight panel verification matrix, panel output detail, shadow test summary, humidity test summary, reverse bias test panel; and finally, quality assurance summary.

  6. Arrays of magnetic nanoparticles capped with alkylamines

    Indian Academy of Sciences (India)

    P John Thomas; P Saravanan; G U Kulkarni; C N R Rao

    2002-02-01

    Magnetic metal and metal oxide nanoparticles capped with alkylamines have been synthesized and characterized by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray analysis and magnetization measurements. Core-shell Pd–Ni particles with composition, Pd561Ni3000, (diameter ∼ 3.3 nm) are superparamagnetic at 5 K and organize themselves into two-dimensional crystalline arrays. Similar arrays are obtained with Pd561Ni3000Pd1500 nanoparticles containing an additional Pd shell. Magnetic spinel particles of -Fe2O3, Fe3O4 and CoFe2O4 of average diameters in the 4–6 nm range coated with octylamine are all supermagnetic at room temperature and yield close-packed disordered arrays. Relatively regular arrays are formed by dodecylamine-capped Fe3O4 nanoparticles (∼ 8.6 nm diameter) while well-ordered hexagonal arrays were obtained with octylamine-covered Co3O4 nanoparticles (∼ 4.2 nm diameter).

  7. Analytical Description and Design of Printed Dipole Arrays for Wideband Wide-Scan Applications

    NARCIS (Netherlands)

    Cavallo, D.; Neto, A.; Gerini, G.

    2012-01-01

    Wideband arrays of printed dipoles with inter-element loads are investigated. A closed-form expression for the active input impedance of the array element is derived with a spectral domain approach. The procedure is based on an extension of the Green's function formulation for arrays of connected di

  8. Piezoelectric impact force sensor array for tribological research on rigid disk storage media

    NARCIS (Netherlands)

    Burger, G.J.; Lammerink, T.S.J.; Fluitman, J.H.J.; Imai, S.; Tokuyama, M.; Hirose, S.

    1995-01-01

    This paper presents a method to measure impact forces on a surface by means of a piezoelectric thin film sensor array. The output signals of the sensor array provide information about the position, magnitude and wave form of the impact force. The sensor array may be used for tribological studies to

  9. The Australian Square Kilometre Array Pathfinder: Performance of the Boolardy Engineering Test Array

    CERN Document Server

    McConnell, D; Bannister, K; Bell, M E; Bignall, H E; Chippendale, A P; Edwards, P G; Harvey-Smith, L; Hegarty, S; Heywood, I; Hotan, A W; Indermuehle, B T; Lenc, E; Marvil, J; Popping, A; Raja, W; Reynolds, J E; Sault, R J; Serra, P; Voronkov, M A; Whiting, M; Amy, S W; Axtens, P; Ball, L; Bateman, T J; Bock, D C -J; Bolton, R; Brodrick, D; Brothers, M; Brown, A J; Bunton, J D; Cheng, W; Cornwell, T; DeBoer, D; Feain, I; Gough, R; Gupta, N; Guzman, J C; Hampson, G A; Hay, S; Hayman, D B; Hoyle, S; Humphreys, B; Jacka, C; Jackson, C A; Jackson, S; Jeganathan, K; Joseph, J; Koribalski, B S; Leach, M; Lensson, E S; MacLeod, A; Mackay, S; Marquarding, M; McClure-Griffiths, N M; Mirtschin, P; Mitchell, D; Neuhold, S; Ng, A; Norris, R; Pearce, S; Qiao, R Y; Schinckel, A E T; Shields, M; Shimwell, T W; Storey, M; Troup, E; Turner, B; Tuthill, J; Tzioumis, A; Wark, R M; Westmeier, T; Wilson, C; Wilson, T

    2016-01-01

    We describe the performance of the Boolardy Engineering Test Array (BETA), the prototype for the Australian Square Kilometre Array Pathfinder telescope ASKAP. BETA is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarization beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of BETA's performance: sensitivity, beam characteristics, polarimetric properties and image quality. We summarise the astronomical science that it has produced and draw lessons from operating BETA that will be relevant to the commissioning and operation of the final ASKAP telescope.

  10. Automorphic Forms

    DEFF Research Database (Denmark)

    von Essen, Flemming Brændgaard

    systems. For automorphic forms wrt. Hecke triangle groups and Fuchsian groups with no elliptic elements and genus 0, we show that some logarithms of multiplier systems can be interpreted as a linking number. Finally we show a "twisted" version of the prime geodesics theorem, and logarithms of multiplier...

  11. Cosmic Forms

    CERN Document Server

    Kleman, Maurice

    2011-01-01

    The continuous 1D defects of an isotropic homogeneous material in an Euclidean 3D space are classified by a construction method, the Volterra process (VP). We employ the same method to classify the continuous 2D defects (which we call \\textit{cosmic forms}) of a vacuum in a 4D maximally symmetric spacetime. These defects fall into three different classes: i)- $m$-forms, akin to 3D space disclinations, related to ordinary rotations and analogous to Kibble's global cosmic strings (except that being continuous any deficit angle is allowed); ii)- $t$-forms, related to Lorentz boosts (hyperbolic rotations); iii)- $r$-forms, never been considered so far, related to null rotations. A detailed account of their metrics is presented. Their inner structure in many cases appears as a non-singular \\textit{core} separated from the outer part by a timelike hypersurface with distributional curvature and/or torsion, yielding new types of geometrical interactions with cosmic dislocations and other cosmic disclinations. Whereas...

  12. Piezoelectric micromachined ultrasound transducer (PMUT) arrays for integrated sensing, actuation and imaging

    National Research Council Canada - National Science Library

    Qiu, Yongqiang; Gigliotti, James V; Wallace, Margeaux; Griggio, Flavio; Demore, Christine E M; Cochran, Sandy; Trolier-McKinstry, Susan

    2015-01-01

    .... Piezoelectric micromachined ultrasound transducers (PMUTs), diaphragm-like thin film flexural transducers typically formed on silicon substrates, are a potential solution for integrated transducer arrays...

  13. Microlens arrays with integrated pores

    Directory of Open Access Journals (Sweden)

    Shu Yang

    2005-12-01

    Full Text Available Microlenses are important optical components that image, detect, and couple light. But most synthetic microlenses have fixed position and shape once they are fabricated, so their possible range of tunability and complexity is rather limited. By comparison, biology provides many varied, new paradigms for the development of adaptive optical networks. Here, we discuss inspirational examples of biological lenses and their synthetic analogs. We focus on the fabrication and characterization of biomimetic microlens arrays with integrated pores, whose appearance and function are similar to highly efficient optical elements formed by brittlestars. The complex design can be created by three-beam interference lithography. The synthetic lens has strong focusing ability for use as an adjustable lithographic mask and a tunable optical device coupled with the microfluidic system. Replacing rigid microlenses with soft hydrogels provides a way of changing the lens geometry and refractive index continuously in response to external stimuli, resulting in intelligent, multifunctional, tunable optics.

  14. Gigapixel imaging with microlens arrays

    Science.gov (United States)

    Orth, Antony; Schonbrun, Ethan

    2016-03-01

    A crucial part of the drug discovery process involves imaging the response of thousands of cell cultures to candidate drugs. Quantitative parameters from these "high content screens", such as protein expression and cell morphology, are extracted from fluorescence and brightfield micrographs. Due to the sheer number of cells that need to imaged for adequate statistics, the imaging time itself is a major bottleneck. Automated microscopes image small fields-of-view (FOVs) serially, which are then stitched together to form gigapixel-scale mosaics. We have developed a microscopy architecture that reduces mechanical overhead of traditional large field-of-view by parallelizing the image capture process. Instead of a single objective lens imaging FOVs one by one, we employ a microlens array for continuous photon capture, resulting in a 3-fold throughput increase. In this contribution, we present the design and imaging results of this microscopy architecture in three different contrast modes: multichannel fluorescence, hyperspectral fluorescence and brightfield.

  15. Wind farm array wake losses

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W. [Impact Weather, Washougal, WA (United States); McCarthy, E.F. [Wind Economics & Technology, Inc., Martinez, CA (United States)

    1997-12-31

    A wind turbine wake study was conducted in the summer of 1987 at an Altamont Pass wind electric generating facility. The wind speed deficits, turbulence, and power deficits from an array consisting of several rows of wind turbines is discussed. A total of nine different test configurations were evaluated for a downwind spacing ranging from 7 rotor diameters (RD) to 34 RD and a cross wind spacing of 1.3 RD and 2.7 RD. Wake power deficits of 15% were measured at 16 RD and power losses of a few percent were even measurable at 27 RD for the closer cross wind spacing. For several rows of turbines separated by 7-9 RD the wake zones overlapped and formed compound wakes with higher velocity deficits. The wind speed and direction turbulence in the wake was much higher than the ambient turbulence. The results from this study are compared to the findings from other similar field measurements.

  16. Sputtering in supported cluster arrays

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Sáez, J.C., E-mail: jc.jimenez@upm.es [Dept. Física Aplicada a la Ingeniería Aeronáutica y Naval, ETSIAE, Universidad Politécnica de Madrid (UPM), 28040 Madrid (Spain); Pérez-Martín, A.M.C.; Jiménez-Rodríguez, J.J. [Dept. Física Aplicada III, Facultad de Ciencias Físicas, Universidad Complutense de Madrid (UCM), 28040 Madrid (Spain)

    2015-06-01

    Bombardment of periodical arrays formed by Co nanoislands deposited on a Cu(0 0 1) substrate with 1-keV argon ions is simulated by using molecular dynamics. Sputtering yield is analyzed distinguishing between particles sputtered across the supported cluster surface and across the flat substrate surface without nanoparticle above. The dependence of this magnitude on the height and the periodical spacing between nanoislands has been investigated. Results show that this dependence for the sputtering across the nanoislands and across the substrate is different. In the case of the total sputtering, the “substrate” effect prevails since the behavior of this magnitude is approximately analogous to the sputtering across the substrate. The more probable causes are analyzed in this article.

  17. Synthesis Array Topology Metrics in Location Characterization

    Science.gov (United States)

    Shanmugha Sundaram, GA

    2015-08-01

    Towards addressing some of the fundamental mysteries in physics at the micro- and macro-cosm level, that form the Key Science Projects (KSPs) for the Square Kilometer Array (SKA; such as Probing the Dark Ages and the Epoch of Reionization in the course of an Evolving Universe; Galaxy Evolution, Cosmology, and Dark Energy; and the Origin and evolution of Cosmic Magnetism) a suitable interfacing of these goals has to be achieved with its optimally designed array configuration, by means of a critical evaluation of the radio imagingcapabilities and metrics. Of the two forerunner sites, viz. Australia and South Africa, where pioneering advancements to state-of-the-art in synthesis array radio astronomy instrumentation are being attempted in the form of pathfinders to the SKA, for its eventual deployment, a diversity of site-dependent topology and design metrics exists. Here, the particular discussion involves those KSPs that relate to galactic morphology and evolution, and explores their suitability as a scientific research goal from the prespective of the location-driven instrument design specification. Relative merits and adaptability with regard to either site shall be presented from invoking well-founded and established array-design and optimization principles designed into a customized software tool.

  18. Integration of spintronic interface for nanomagnetic arrays

    Directory of Open Access Journals (Sweden)

    Andrew Lyle

    2011-12-01

    Full Text Available An experimental demonstration utilizing a spintronic input/output (I/O interface for arrays of closely spaced nanomagnets is presented. The free layers of magnetic tunnel junctions (MTJs form dipole coupled nanomagnet arrays which can be applied to different contexts including Magnetic Quantum Cellular Automata (MQCA for logic applications and self-biased devices for field sensing applications. Dipole coupled nanomagnet arrays demonstrate adaptability to a variety of contexts due to the ability for tuning of magnetic response. Spintronics allows individual nanomagnets to be manipulated with spin transfer torque and monitored with magnetoresistance. This facilitates measurement of the magnetic coupling which is important for (yet to be demonstrated data propagation reliability studies. In addition, the same magnetic coupling can be tuned to reduce coercivity for field sensing. Dipole coupled nanomagnet arrays have the potential to be thousands of times more energy efficient than CMOS technology for logic applications, and they also have the potential to form multi-axis field sensors.

  19. A Novel DOA Estimation Algorithm Using Array Rotation Technique

    Directory of Open Access Journals (Sweden)

    Xiaoyu Lan

    2014-03-01

    Full Text Available The performance of traditional direction of arrival (DOA estimation algorithm based on uniform circular array (UCA is constrained by the array aperture. Furthermore, the array requires more antenna elements than targets, which will increase the size and weight of the device and cause higher energy loss. In order to solve these issues, a novel low energy algorithm utilizing array base-line rotation for multiple targets estimation is proposed. By rotating two elements and setting a fixed time delay, even the number of elements is selected to form a virtual UCA. Then, the received data of signals will be sampled at multiple positions, which improves the array elements utilization greatly. 2D-DOA estimation of the rotation array is accomplished via multiple signal classification (MUSIC algorithms. Finally, the Cramer-Rao bound (CRB is derived and simulation results verified the effectiveness of the proposed algorithm with high resolution and estimation accuracy performance. Besides, because of the significant reduction of array elements number, the array antennas system is much simpler and less complex than traditional array.

  20. A carbon nanotube field emission multipixel x-ray array source for microradiotherapy application

    OpenAIRE

    Wang, Sigen; Calderon, Xiomara; Peng, Rui; Schreiber, Eric C.; Zhou, Otto; Chang, Sha

    2011-01-01

    The authors report a carbon nanotube (CNT) field emission multipixel x-ray array source for microradiotherapy for cancer research. The developed multipixel x-ray array source has 50 individually controllable pixels and it has several distinct advantages over other irradiation source including high-temporal resolution (millisecond level), the ability to electronically shape the form, and intensity distribution of the radiation fields. The x-ray array was generated by a CNT cathode array (5×10)...

  1. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  2. Timed arrays wideband and time varying antenna arrays

    CERN Document Server

    Haupt, Randy L

    2015-01-01

    Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

  3. Atacama Compact Array Antennas

    CERN Document Server

    Saito, Masao; Nakanishi, Kouichiro; Naoi, Takahiro; Yamada, Masumi; Saito, Hiro; Ikenoue, Bungo; Kato, Yoshihiro; Morita, Kou-ichiro; Mizuno, Norikazu; Iguchi, Satoru

    2011-01-01

    We report major performance test results of the Atacama Compact Array (ACA) 7-m and 12-m antennas of ALMA (Atacama Large Millimeter/submillimeter Array). The four major performances of the ACA antennas are all-sky pointing (to be not more than 2.0 arcsec), offset pointing (to be < 0.6 arcsec) surface accuracy (< 25(20) micrometer for 12(7)m-antenna), stability of path-length (15 micrometer over 3 min), and high servo capability (6 degrees/s for Azimuth and 3 degrees/s for Elevation). The high performance of the ACA antenna has been extensively evaluated at the Site Erection Facility area at an altitude of about 2900 meters. Test results of pointing performance, surface performance, and fast motion capability are demonstrated.

  4. The Cherenkov Telescope Array

    Science.gov (United States)

    Connaughton, Valerie

    2014-03-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort dedicated to the design and operation of the next-generation ground-based very high-energy gamma-ray observatory. CTA will improve by about one order of magnitude the sensitivity with respect to the current major arrays (VERITAS, H.E.S.S., and MAGIC) in the core energy range of 100 GeV to 10 TeV, and will extend the viability of the imaging atmospheric Cherenkov technique (IACT) down to tens of GeV and above 100 TeV. In order to achieve such improved performance at both a northern and southern CTA site, four 23m diameter Large Size Telescopes (LST) optimized for low energy gamma rays will be deployed close to the centre of the array. A larger number of Medium Size Telescopes (MST) will be optimized for the core IACT energy range. The southern site will include 25 12m single-mirror MSTs and a US contribution of up to 24 novel dual-mirror design Schwarzschild-Couder (SC) type MSTs with a primary mirror of 9.5m diameter, and will also include an array of Small Size Telescopes (SST) to observe the highest-energy gamma rays from galactic sources. The SSTs can be smaller and more widely separated because more energetic gamma rays produce a larger Cherenkov light pool with many photons. The SSTs achieve a large collection area by covering a wide (10 sq km) footprint on the ground. The CTA project is finishing its preparatory phase, and the pre-production phase will start this year. I will review the status and the expected performance of CTA as well as the main scientific goals for the observatory.

  5. Solar collector array

    Energy Technology Data Exchange (ETDEWEB)

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

    A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

  6. YBCO Josephson Junction Arrays

    Science.gov (United States)

    1993-07-14

    40, 489 (1961). [8] W. H. Press, B. P. Flannery, S. A. Teukolsky and W. T. Vetterling, Numerical recipes: the art of scientific computing (Cambridge...has recently become a commercial product. He has developed processes for depositing state-of-the art YBCO films on buffered sapphire substrates. His...technology can most improve and on what subsystems would benefit most from the pt.. .imance available from these arrays. Aqppoved f or publicO re󈧎OSI AIR

  7. Pulsar Timing Arrays

    OpenAIRE

    Joshi, Bhal Chandra

    2013-01-01

    In the last decade, the use of an ensemble of radio pulsars to constrain the characteristic strain caused by a stochastic gravitational wave background has advanced the cause of detection of very low frequency gravitational waves significantly. This electromagnetic means of gravitational wave detection, called Pulsar Timing Array(PTA), is reviewed in this article. The principle of operation of PTA, the current operating PTAs and their status is presented along-with a discussion of the main ch...

  8. The TALE Infill Array

    Science.gov (United States)

    Bergman, Douglas

    2009-05-01

    The TALE Infill Array in conjunction with the TALE Tower Detector will provide hybrid coverage of the cosmic ray energy spectrum down to 3x10^16 eV. It will consist of about 100, two square meter scintillators on the surface spaced at 400 m; and 24 buried twelve square meter scintillators. The combination of surface and underground detectors will allow for the determination of the muon content of showers and thus give a handle on cosmic ray composition.

  9. Mir Cooperative Solar Array

    Science.gov (United States)

    Skor, Mike; Hoffman, Dave J.

    1997-01-01

    The Mir Cooperative Solar Array (MCSA), produced jointly by the United States and Russia, was deployed on the Mir Russian space station on May 25, 1996. The MCSA is a photovoltaic electrical power system that can generate up to 6 kW. The power from the MCSA is needed to extend Mir's lifetime and to support experiments conducted there by visiting U.S. astronauts. The MCSA was brought to Mir via the Space Shuttle Atlantis on the STS-74 mission, launched November 12, 1995. This cooperative venture combined the best technology of both countries: the United States provided high-efficiency, lightweight photovoltaic panel modules, whereas Russia provided the array structure and deployment mechanism. Technology developed in the Space Station Freedom Program, and now being used in the International Space Station, was used to develop MCSA's photovoltaic panel. Performance data obtained from MCSA operation on Mir will help engineers better understand the performance of the photovoltaic panel modules in orbit. This information will be used to more accurately predict the performance of the International Space Station solar arrays. Managed by the NASA Lewis Research Center for NASA's International Space Station Program Office in Houston, Texas, the MCSA Project was completed on time and under budget despite a very aggressive schedule.

  10. DSN Array Simulator

    Science.gov (United States)

    Tikidjian, Raffi; Mackey, Ryan

    2008-01-01

    The DSN Array Simulator (wherein 'DSN' signifies NASA's Deep Space Network) is an updated version of software previously denoted the DSN Receive Array Technology Assessment Simulation. This software (see figure) is used for computational modeling of a proposed DSN facility comprising user-defined arrays of antennas and transmitting and receiving equipment for microwave communication with spacecraft on interplanetary missions. The simulation includes variations in spacecraft tracked and communication demand changes for up to several decades of future operation. Such modeling is performed to estimate facility performance, evaluate requirements that govern facility design, and evaluate proposed improvements in hardware and/or software. The updated version of this software affords enhanced capability for characterizing facility performance against user-defined mission sets. The software includes a Monte Carlo simulation component that enables rapid generation of key mission-set metrics (e.g., numbers of links, data rates, and date volumes), and statistical distributions thereof as functions of time. The updated version also offers expanded capability for mixed-asset network modeling--for example, for running scenarios that involve user-definable mixtures of antennas having different diameters (in contradistinction to a fixed number of antennas having the same fixed diameter). The improved version also affords greater simulation fidelity, sufficient for validation by comparison with actual DSN operations and analytically predictable performance metrics.

  11. Spaceborne Processor Array

    Science.gov (United States)

    Chow, Edward T.; Schatzel, Donald V.; Whitaker, William D.; Sterling, Thomas

    2008-01-01

    A Spaceborne Processor Array in Multifunctional Structure (SPAMS) can lower the total mass of the electronic and structural overhead of spacecraft, resulting in reduced launch costs, while increasing the science return through dynamic onboard computing. SPAMS integrates the multifunctional structure (MFS) and the Gilgamesh Memory, Intelligence, and Network Device (MIND) multi-core in-memory computer architecture into a single-system super-architecture. This transforms every inch of a spacecraft into a sharable, interconnected, smart computing element to increase computing performance while simultaneously reducing mass. The MIND in-memory architecture provides a foundation for high-performance, low-power, and fault-tolerant computing. The MIND chip has an internal structure that includes memory, processing, and communication functionality. The Gilgamesh is a scalable system comprising multiple MIND chips interconnected to operate as a single, tightly coupled, parallel computer. The array of MIND components shares a global, virtual name space for program variables and tasks that are allocated at run time to the distributed physical memory and processing resources. Individual processor- memory nodes can be activated or powered down at run time to provide active power management and to configure around faults. A SPAMS system is comprised of a distributed Gilgamesh array built into MFS, interfaces into instrument and communication subsystems, a mass storage interface, and a radiation-hardened flight computer.

  12. TANGO ARRAY II: Simulations

    Science.gov (United States)

    Bauleo, P.; Bonifazi, C.; Filevich, A.

    The angular and energy resolution of the TANGO Array has been obtained using Monte Carlo simulations. The AIRES code, with the SYBILL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (protons and iron nuclei), with energies ranging from 1014 eV to 1018 eV. These data were fed into a realistic code which simulates the response of the detector stations (water ˇCerenkov detectors), including the electronics, pick up noise, and the signal attenuation in the connecting cabling. The trigger stage is taken into account in order to produce estimates of the trigger efficiency of the array and to check the accuracy of the reconstruction codes. This paper describes the simulations performed to obtain the expected behavior of the array, and presents the simulated data. These simulations indicate that the accuracy of the cosmic ray primary energy determination is expected to be ˜ 60 % and the precision in the measurement of the direction of arrival can be estimated as ˜ 4 degrees.

  13. Basic characteristics of array of pulsatile jet

    Directory of Open Access Journals (Sweden)

    Vestfálová Magda

    2012-04-01

    Full Text Available The presented paper shows the results of measurement of basic characteristics of array of pulsatile jets which are used to enhance the efficiency of ejectors. Four pulsatile jets forms cross like structure where perpendicular couples are operating in two basic modes (a in phase and (b in antiphase. Paper presents phase averaged velocity profiles and velocity fields. All of the presented experiments are realized using hot wire anemometry method.

  14. Localized waves supported by the rotating waveguide array

    Science.gov (United States)

    Zhang, Xiao; Ye, Fangwei; Kartashov, Yaroslav V.; Vysloukh, Victor A.; Chen, Xianfeng

    2016-09-01

    We show that truncated rotating square waveguide arrays support new types of localized modes that exist even in the linear case, in complete contrast to localized excitations in nonrotating arrays requiring nonlinearity for their existence and forming above the energy flow threshold. These new modes appear either around array center, since rotation leads to the emergence of the effective attractive potential with a minimum at the rotation axis, or in the array corners, in which case localization occurs due to competition between centrifugal force (in terms of quasi-particle analogy) and total internal reflection at the interface of the truncated array. The degree of localization of the central and corner modes mediated by rotation increases with rotation frequency. Stable rotating soliton families bifurcating from linear modes are analyzed in both focusing and defocusing media.

  15. Multiplexed optical operation of distributed nanoelectromechanical systems arrays.

    Science.gov (United States)

    Sampathkumar, A; Ekinci, K L; Murray, T W

    2011-03-09

    We report a versatile all optical technique to excite and read-out a distributed nanoelectromechanical systems (NEMS) array. The NEMS array is driven by a distributed, intensity modulated optical pump through the photothermal effect. The ensuing vibrational response of the array is multiplexed onto a single probe beam in the form of a high frequency phase modulation. The phase modulation is optically down converted to a low frequency intensity modulation using an adaptive full-field interferometer, and subsequently detected using a CCD array. Rapid and single step mechanical characterization of ∼44 nominally identical high-frequency resonators is demonstrated. The technique may enable sensitivity improvements over single NEMS resonators by averaging signals coming from a multitude of devices in the array. In addition, the diffraction limited spatial resolution may allow for position-dependent read-out of NEMS sensor chips for sensing multiple analytes or spatially inhomogeneous forces.

  16. Localized waves supported by the rotating waveguide array

    CERN Document Server

    Zhang, Xiao; Kartashov, Yaroslav V; Vysloukh, Victor A; Chen, Xianfeng

    2016-01-01

    We show that truncated rotating square waveguide arrays support new types of localized modes that exist even in the linear case, in complete contrast to localized excitations in nonrotating arrays requiring nonlinearity for their existence and forming above the energy flow threshold. These new modes appear either around array center, since rotation leads to the emergence of the effective attractive potential with a minimum at the rotation axis, or in the array corners, in which case localization occurs due to competition between centrifugal force (in terms of quasi-particle analogy) and total internal reflection at the interface of the truncated array. The degree of localization of the central and corner modes mediated by rotation increases with rotation frequency. Stable rotating soliton families bifurcating from linear modes are analyzed in both focusing and defocusing media.

  17. Preparation of array of long carbon nanotubes and fibers therefrom

    Science.gov (United States)

    Arendt, Paul N.; DePaula, Ramond F.; Zhu, Yuntian T.; Usov, Igor O.

    2015-11-19

    An array of carbon nanotubes is prepared by exposing a catalyst structure to a carbon nanotube precursor. Embodiment catalyst structures include one or more trenches, channels, or a combination of trenches and channels. A system for preparing the array includes a heated surface for heating the catalyst structure and a cooling portion that cools gas above the catalyst structure. The system heats the catalyst structure so that the interaction between the precursor and the catalyst structure results in the formation of an array of carbon nanotubes on the catalyst structure, and cools the gas near the catalyst structure and also cools any carbon nanotubes that form on the catalyst structure to prevent or at least minimize the formation of amorphous carbon. Arrays thus formed may be used for spinning fibers of carbon nanotubes.

  18. Titania nanotube array based photovoltaic cells

    Science.gov (United States)

    Yip, C. T.; Cheung, K. Y.; Djurišić, A. B.; Chan, W. K.

    2007-09-01

    It has been shown that dye sensitized solar cells (DSSCs) based on porous titanium dioxide (titania) layers have efficiencies exceeding 10%. Although porous structure has the advantage of large surface area for light harvesting, electron transport through the random nanoparticle network forming a porous film results in electron mobilities which are two orders of magnitude lower compared to the single crystal materials. Therefore, considerable efforts have been made to fabricate DSSC based on one dimensional nanostructures, such as nanowires or nanotubes. Titania nanotube arrays are typically made by anodization of titanium, followed by annealing to improve crystallinity. In this work, we investigated the influence of annealing temperature and annealing atmosphere on the crystal structure, the electron transport, and the solar cell performance of titania nanotube arrays. The titania nanotube arrays were prepared from electrochemically anodized titanium foils and their morphology and crystal structure were characterized by scanning electron microscopy and transmission electron microscopy. The crystal phases and the compositions of nanotube arrays were further investigated by X-ray diffraction for different annealing temperatures and X-ray photoelectron spectroscopy for different annealing atmospheres. For optimal annealing conditions, the short circuit current density of 4.27 mA/cm2 and power conversion efficiency of 1.30% could be achieved under AM 1.5 simulated solar irradiation for 2 μm long nanotubes.

  19. The Future of Pulsar Timing Arrays

    Science.gov (United States)

    Stappers, B. W.

    Significant advances have been made in the sensitivity of pulsar timing arrays for the detection of gravitational waves in the last decade. This presentation looked forward to consider where the development of pulsar timing arrays might go as we head towards the Square Kilometre Array (SKA) and then beyond. I reviewed where progress needs to be made in terms of sensitivity to gravitational waves, including improvements to existing observing approaches and new telescopes such as MeerKAT and FAST and techniques like LEAP. The dramatic increase in the number of millisecond pulsars is presented and how that might affect progress towards a first detection is discussed. Developments in analytic techniques were also discussed, including the removal of interstellar medium effects, red noise and pulse profile variations. A summary of how the SKA can contribute through an increased millisecond pulsar population and pulsar timing sensitivity was presented. With the likelihood that the SKA will implement some form of Key Science Project approach, some ideas of how will this affect how the International Pulsar Timing Array effort and how it might evolve into a KSP were discussed.

  20. Battery Charge Equalizer with Transformer Array

    Science.gov (United States)

    Davies, Francis

    2013-01-01

    High-power batteries generally consist of a series connection of many cells or cell banks. In order to maintain high performance over battery life, it is desirable to keep the state of charge of all the cell banks equal. A method provides individual charging for battery cells in a large, high-voltage battery array with a minimum number of transformers while maintaining reasonable efficiency. This is designed to augment a simple highcurrent charger that supplies the main charge energy. The innovation will form part of a larger battery charge system. It consists of a transformer array connected to the battery array through rectification and filtering circuits. The transformer array is connected to a drive circuit and a timing and control circuit that allow individual battery cells or cell banks to be charged. The timing circuit and control circuit connect to a charge controller that uses battery instrumentation to determine which battery bank to charge. It is important to note that the innovation can charge an individual cell bank at the same time that the main battery charger is charging the high-voltage battery. The fact that the battery cell banks are at a non-zero voltage, and that they are all at similar voltages, can be used to allow charging of individual cell banks. A set of transformers can be connected with secondary windings in series to make weighted sums of the voltages on the primaries.

  1. Photocatalytic TiO2/glass nanoflake array films.

    Science.gov (United States)

    Ho, Wingkei; Yu, Jimmy C; Yu, Jiaguo

    2005-04-12

    A new approach for the fabrication of oriented TiO2/glass nanoflake arrays has been developed. The ceramic nanoflake array was formed on a glass substrate via a simple, low temperature, and one-step hydrothermally induced phase separation approach without using any templates or additives. The factors affecting the formation of ceramic nanoflakes were examined by various characterization techniques. The results showed that the leaching of the soluble phase from the glass surface through hydrothermal processes resulted in oriented uniform ceramic nanoflake arrays. Electron microscope observations revealed that the nanoflakes formed a continuous porous three-dimensional-network array with a large surface-to-volume ratio. In addition, an anatase TiO2 film was successfully coated onto the nanoflake array by the sol-gel method. The TiO2/glass nanoflake array exhibited high activity for the photocatalytic degradation of acetone and for photoinduced hydrophilic conversion. Such enhancements were attributed to the beneficial effects of the new continuous porous three-dimensional-interconnected nanoflake network and its surface geometrical nanostructure. The present approach provides a convenient route to modify a photocatalytic coating with a porous nano-architectured substrate. This opens extensive new opportunities in the design of semiconductor/ceramic nanostructural array thin films with unusual properties for future optical and electronic applications.

  2. Compact Transducers and Arrays

    Science.gov (United States)

    2005-05-01

    Soc. Am., 104, pp.64-71 44 25.Decarpigny, J.N., J.C. Debus, B. Tocquet & D. Boucher. 1985. "In-Air Analysis Of Piezoelectric Tonpilz Transducers In A... Transducers and Arrays Final Report May 2005 Contacts: Dr. Robert E. Newnham The Pennsylvania State University, 251 MRL, University Park, PA 16802 phone...814) 865-1612 fax: (814) 865-2326 email: ....c xx.....i.i.....ht.. .u a.p.u..c.e.du. Dr. Richard J. Meyer, Jr. Systems Engineering ( Transducers ), ARL

  3. A Flexible Phased-MIMO Array Antenna with Transmit Beamforming

    Directory of Open Access Journals (Sweden)

    Wen-Qin Wang

    2012-01-01

    Full Text Available Although phased-array antennas have been widely employed in modern radars, the requirements of many emerging applications call for new more advanced array antennas. This paper proposes a flexible phased-array multiple-input multiple-output (MIMO array antenna with transmit beamforming. This approach divides the transmit antenna array into multiple subarrays that are allowed to overlap each subarray coherently transmits a distinct waveform, which is orthogonal to the waveforms transmitted by other subarrays, at a distinct transmit frequency. That is, a small frequency increment is employed in each subarray. Each subarray forms a directional beam and all beams may be steered to different directions. The subarrays jointly offer flexible operating modes such as MIMO array which offers spatial diversity gain, phased-array which offers coherent directional gain and frequency diverse array which provides range-dependent beampattern. The system performance is examined by analyzing the transmit-receive beampatterns. The proposed approach is validated by extensive numerical simulation results.

  4. Full light absorption in single arrays of spherical nanoparticles

    CERN Document Server

    Ra'di, Y; Kosulnikov, S U; Omelyanovich, M M; Morits, D; Osipov, A V; Simovski, C R; Tretyakov, S A

    2015-01-01

    In this paper we show that arrays of core-shell nanoparticles function as effective thin absorbers of light. In contrast to known metamaterial absorbers, the introduced absorbers are formed by single planar arrays of spherical inclusions and enable full absorption of light incident on either or both sides of the array. We demonstrate possibilities for realizing different kinds of symmetric absorbers, including resonant, ultra-broadband, angularly selective, and all-angle absorbers. The physical principle behind these designs is explained considering balanced electric and magnetic responses of unit cells. Photovoltaic devices and thermal emitters are the two most important potential applications of the proposed designs.

  5. Tidal Forms

    Science.gov (United States)

    Bolla Pittaluga, M.; Seminara, G.; Tambroni, N.

    2003-04-01

    We give an overview of some recent investigations on the mechanics of the processes whereby forms develop in tidal environments. The viewpoint taken here is mechanistic. Some of the questions which deserve an answer may be summarised as follows: i) do tidal channels tend to some altimetric long term equilibrium? ii) why are they typically convergent and weakly meandering? iii) how is such equilibrium affected by the hydrodynamics and morphodynamics of tidal inlets? iv) what is the hydrodynamic and morphodynamic role played by tidal flats adjacent to the channels? Some of the above questions have received a considerable attention in the last few years. Schuttelaars and de Swart (1996), Lanzoni and Seminara (2002) and, more recently, Bolla Pittaluga (2003) have investigated the first problem. In particular, the latter two contributions have shown that a straight tidal channel connected to a tidal sea at one end and closed at the other end tends to reach a long term equilibrium profile, which is slightly concave seaward and convex landward where a beach forms. The equilibrium profile is strongly sensitive to the harmonic content of the tidal forcing as well as to the value of sediment concentration established by the coastal hydrodynamics in the far field of the inlet region. Less important are the effect of channel convergence and the role of settling lag in the transport of suspended load. Insufficient attention has been devoted to the understanding of what mechanisms control channel convergence and meandering, though some similarities and differences between tidal and fluvial channels have emerged from some recent works. In particular, free bars form in tidal channels due to an instability mechanism essentially similar to that occurring under steady conditions though the oscillatory character of the flow field makes the bar pattern non migrating (Seminara and Tubino, 2001). Similarly, forced bars in curved tidal channels are driven by the development of

  6. Microplasma generating array

    Energy Technology Data Exchange (ETDEWEB)

    Hopwood, Jeffrey A.; Wu, Chen; Hoskinson, Alan R.; Sonkusale, Sameer

    2016-10-04

    A microplasma generator includes first and second conductive resonators disposed on a first surface of a dielectric substrate. The first and second conductive resonators are arranged in line with one another with a gap defined between a first end of each resonator. A ground plane is disposed on a second surface of the dielectric substrate and a second end of each of the first and second resonators is coupled to the ground plane. A power input connector is coupled to the first resonator at a first predetermined distance from the second end chosen as a function of the impedance of the first conductive resonator. A microplasma generating array includes a number of resonators in a dielectric material substrate with one end of each resonator coupled to ground. A micro-plasma is generated at the non-grounded end of each resonator. The substrate includes a ground electrode and the microplasmas are generated between the non-grounded end of the resonator and the ground electrode. The coupling of each resonator to ground may be made through controlled switches in order to turn each resonator off or on and therefore control where and when a microplasma will be created in the array.

  7. Electrodynamic Arrays Having Nanomaterial Electrodes

    Science.gov (United States)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  8. Combinatorial aspects of covering arrays

    Directory of Open Access Journals (Sweden)

    Charles J. Colbourn

    2004-11-01

    Full Text Available Covering arrays generalize orthogonal arrays by requiring that t -tuples be covered, but not requiring that the appearance of t -tuples be balanced.Their uses in screening experiments has found application in software testing, hardware testing, and a variety of fields in which interactions among factors are to be identified. Here a combinatorial view of covering arrays is adopted, encompassing basic bounds, direct constructions, recursive constructions, algorithmic methods, and applications.

  9. Flexible parylene-film optical waveguide arrays

    Science.gov (United States)

    Yamagiwa, S.; Ishida, M.; Kawano, T.

    2015-08-01

    Modulation of neuronal activities by light [e.g., laser or light-emitting diode] using optogenetics is a powerful tool for studies on neuronal functions in a brain. Herein, flexible thin-film optical waveguide arrays based on a highly biocompatible material of parylene are reported. Parylene-C and -N thin layers with the different refractive indices form the clad and the core of the waveguide, respectively, and neural recording microelectrodes are integrated to record optical stimuli and electrical recordings simultaneously using the same alignment. Both theoretical and experimental investigations confirm that light intensities of more than 90% can propagate in a bent waveguide with a curvature radius of >5 mm. The proposed flexible thin-film waveguide arrays with microelectrodes can be used for numerous spherical bio-tissues, including brain and spinal cord samples.

  10. Sensor Arrays and Electronic Tongue Systems

    Directory of Open Access Journals (Sweden)

    Manel del Valle

    2012-01-01

    Full Text Available This paper describes recent work performed with electronic tongue systems utilizing electrochemical sensors. The electronic tongues concept is a new trend in sensors that uses arrays of sensors together with chemometric tools to unravel the complex information generated. Initial contributions and also the most used variant employ conventional ion selective electrodes, in which it is named potentiometric electronic tongue. The second important variant is the one that employs voltammetry for its operation. As chemometric processing tool, the use of artificial neural networks as the preferred data processing variant will be described. The use of the sensor arrays inserted in flow injection or sequential injection systems will exemplify attempts made to automate the operation of electronic tongues. Significant use of biosensors, mainly enzyme-based, to form what is already named bioelectronic tongue will be also presented. Application examples will be illustrated with selected study cases from the Sensors and Biosensors Group at the Autonomous University of Barcelona.

  11. Cosmology with the Square Kilometre Array

    CERN Document Server

    Rawlings, Steve

    2011-01-01

    We review how the Square Kilometre Array (SKA) will address fundamental questions in cosmology, focussing on its use for neutral Hydrogen (HI) surveys. A key enabler of its unique capabilities will be large (but smart) receptors in the form of aperture arrays. We outline the likely contributions of Phase-1 of the SKA (SKA1), Phase-2 SKA (SKA2) and pathfinding activities (SKA0). We emphasise the important role of cross-correlation between SKA HI results and those at other wavebands such as: surveys for objects in the EoR with VISTA and the SKA itself; and huge optical and near-infrared redshift surveys, such as those with HETDEX and Euclid. We note that the SKA will contribute in other ways to cosmology, e.g. through gravitational lensing and $H_{0}$ studies.

  12. Contributors Form

    Directory of Open Access Journals (Sweden)

    Chief Editor

    2016-06-01

    to produce preprints or reprints and translate into languages other than English for sale or free distribution; and 4 the right to republish the work in a collection of articles in any other mechanical or electronic format. We give the rights to the corresponding author to make necessary changes as per the request of the journal, do the rest of the correspondence on our behalf and he/she will act as the guarantor for the manuscript on our behalf. All persons who have made substantial contributions to the work reported in the manuscript, but who are not contributors, are named in the Acknowledgment and have given me/us their written permission to be named. If I/we do not include an Acknowledgment that means I/we have not received substantial contributions from non-contributors and no contributor has been omitted.S NoAuthors' NamesContribution (IJCME Guidelines{1 substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; 2 drafting the article or revising it critically for important intellectual content; and 3 final approval of the version to be published. Authors should meet conditions 1, 2, and 3}.SignatureDate                              Note: All the authors are required to sign independently in this form in the sequence given above. In case an author has left the institution/country and whose whereabouts are not known, the senior author may sign on his/her behalf taking the responsibility.No addition/deletion/ or any change in the sequence of the authorship will be permissible at a later stage, without valid reasons and permission of the Editor.If the authorship is contested at any stage, the article will be either returned or will not be processed for publication till the issue is solved.Maximum up to 4 authors for short communication and up to 6 authors for original article.

  13. Cascading Constrained 2-D Arrays using Periodic Merging Arrays

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Laursen, Torben Vaarby

    2003-01-01

    We consider a method for designing 2-D constrained codes by cascading finite width arrays using predefined finite width periodic merging arrays. This provides a constructive lower bound on the capacity of the 2-D constrained code. Examples include symmetric RLL and density constrained codes....... Numerical results for the capacities are presented....

  14. Silicon Micromachined Microlens Array for THz Antennas

    Science.gov (United States)

    Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, IImran; Gill, John J.; Jung-Kubiak, Cecile D.; Llombart, Nuria

    2013-01-01

    5 5 silicon microlens array was developed using a silicon micromachining technique for a silicon-based THz antenna array. The feature of the silicon micromachining technique enables one to microfabricate an unlimited number of microlens arrays at one time with good uniformity on a silicon wafer. This technique will resolve one of the key issues in building a THz camera, which is to integrate antennas in a detector array. The conventional approach of building single-pixel receivers and stacking them to form a multi-pixel receiver is not suited at THz because a single-pixel receiver already has difficulty fitting into mass, volume, and power budgets, especially in space applications. In this proposed technique, one has controllability on both diameter and curvature of a silicon microlens. First of all, the diameter of microlens depends on how thick photoresist one could coat and pattern. So far, the diameter of a 6- mm photoresist microlens with 400 m in height has been successfully microfabricated. Based on current researchers experiences, a diameter larger than 1-cm photoresist microlens array would be feasible. In order to control the curvature of the microlens, the following process variables could be used: 1. Amount of photoresist: It determines the curvature of the photoresist microlens. Since the photoresist lens is transferred onto the silicon substrate, it will directly control the curvature of the silicon microlens. 2. Etching selectivity between photoresist and silicon: The photoresist microlens is formed by thermal reflow. In order to transfer the exact photoresist curvature onto silicon, there needs to be etching selectivity of 1:1 between silicon and photoresist. However, by varying the etching selectivity, one could control the curvature of the silicon microlens. The figure shows the microfabricated silicon microlens 5 x5 array. The diameter of the microlens located in the center is about 2.5 mm. The measured 3-D profile of the microlens surface has a

  15. The Submillimeter Array Polarimeter

    CERN Document Server

    Marrone, Daniel P

    2008-01-01

    We describe the Submillimeter Array (SMA) Polarimeter, a polarization converter and feed multiplexer installed on the SMA. The polarimeter uses narrow-band quarter-wave plates to generate circular polarization sensitivity from the linearly-polarized SMA feeds. The wave plates are mounted in rotation stages under computer control so that the polarization handedness of each antenna is rapidly selectable. Positioning of the wave plates is found to be highly repeatable, better than 0.2 degrees. Although only a single polarization is detected at any time, all four cross correlations of left- and right-circular polarization are efficiently sampled on each baseline through coordinated switching of the antenna polarizations in Walsh function patterns. The initial set of anti-reflection coated quartz and sapphire wave plates allows polarimetry near 345 GHz; these plates have been have been used in observations between 325 and 350 GHz. The frequency-dependent cross-polarization of each antenna, largely due to the varia...

  16. Diagnosable structured logic array

    Science.gov (United States)

    Whitaker, Sterling (Inventor); Miles, Lowell (Inventor); Gambles, Jody (Inventor); Maki, Gary K. (Inventor)

    2009-01-01

    A diagnosable structured logic array and associated process is provided. A base cell structure is provided comprising a logic unit comprising a plurality of input nodes, a plurality of selection nodes, and an output node, a plurality of switches coupled to the selection nodes, where the switches comprises a plurality of input lines, a selection line and an output line, a memory cell coupled to the output node, and a test address bus and a program control bus coupled to the plurality of input lines and the selection line of the plurality of switches. A state on each of the plurality of input nodes is verifiably loaded and read from the memory cell. A trusted memory block is provided. The associated process is provided for testing and verifying a plurality of truth table inputs of the logic unit.

  17. Array biosensor: recent developments

    Science.gov (United States)

    Golden, Joel P.; Rowe-Taitt, Chris A.; Feldstein, Mark J.; Ligler, Frances S.

    1999-05-01

    A fluorescence-based immunosensor has been developed for simultaneous analyses of multiple samples for 1 to 6 different antigens. A patterned array of recognition antibodies immobilized on the surface of a planar waveguide is used to 'capture' analyte present in samples. Bound analyte is then quantified by means of fluorescent detector molecules. Upon excitation of the fluorescent label by a small diode laser, a CCD camera detects the pattern of fluorescent antigen:antibody complexes on the sensor surface. Image analysis software correlates the position of fluorescent signals with the identity of the analyte. A new design for a fluidics distribution system is shown, as well as results from assays for physiologically relevant concentrations of staphylococcal enterotoxin B (SEB), F1 antigen from Yersinia pestis, and D- dimer, a marker of sepsis and thrombotic disorders.

  18. Quantitative ultrasonic phased array imaging

    Science.gov (United States)

    Engle, Brady J.; Schmerr, Lester W., Jr.; Sedov, Alexander

    2014-02-01

    When imaging with ultrasonic phased arrays, what do we actually image? What quantitative information is contained in the image? Ad-hoc delay-and-sum methods such as the synthetic aperture focusing technique (SAFT) and the total focusing method (TFM) fail to answer these questions. We have shown that a new quantitative approach allows the formation of flaw images by explicitly inverting the Thompson-Gray measurement model. To examine the above questions, we have set up a software simulation test bed that considers a 2-D scalar scattering problem of a cylindrical inclusion with the method of separation of variables. It is shown that in SAFT types of imaging the only part of the flaw properly imaged is the front surface specular response of the flaw. Other responses (back surface reflections, creeping waves, etc.) are improperly imaged and form artifacts in the image. In the case of TFM-like imaging the quantity being properly imaged is an angular integration of the front surface reflectivity. The other, improperly imaged responses are also averaged, leading to a reduction in some of the artifacts present. Our results have strong implications for flaw sizing and flaw characterization with delay-and-sum images.

  19. Faraday Cup Array Integrated with a Readout IC and Method for Manufacture Thereof

    Science.gov (United States)

    Bower, Christopher A. (Inventor); Hedgepath Gilchrist, Kristin (Inventor); Stoner, Brian R. (Inventor); Temple, Dorota (Inventor)

    2014-01-01

    A detector array and method for making the detector array. The array includes a substrate including a plurality of trenches formed therein, and includes a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charge particles incident on respective ones of the collectors and to output from said collectors signals indicative of charged particle collection. The array includes a plurality of readout circuits disposed on a side of the substrate opposite openings to the collectors. The readout circuits are configured to read charge collection signals from respective ones of the plurality of collectors.

  20. Automated Solar-Array Assembly

    Science.gov (United States)

    Soffa, A.; Bycer, M.

    1982-01-01

    Large arrays are rapidly assembled from individual solar cells by automated production line developed for NASA's Jet Propulsion Laboratory. Apparatus positions cells within array, attaches interconnection tabs, applies solder flux, and solders interconnections. Cells are placed in either straight or staggered configurations and may be connected either in series or in parallel. Are attached at rate of one every 5 seconds.

  1. The OncoArray Consortium

    DEFF Research Database (Denmark)

    Amos, Christopher I; Dennis, Joe; Wang, Zhaoming

    2017-01-01

    BACKGROUND: Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wi...

  2. Tremor as observed by the Array of Arrays in Cascadia

    Science.gov (United States)

    Ghosh, A.; Vidale, J. E.; Creager, K. C.

    2010-12-01

    We are capturing the intimate details of tremor activity in Cascadia with 8 small-aperture seismic arrays in northwestern Washington. The Array of Arrays (AoA) focuses on the tremor-active megathrust, including the area we previously imaged with a solo seismic array in 2008 [Ghosh et al., GRL, 2009, 2010]. Each array consists of 10 to 20 three-component sensors recording in continuous mode. Since it became operational in June 2009, the AoA has recorded several minor tremor episodes, and the recent episodic tremor and slip (ETS) event in August 2010. During the ETS event, each array was augmented by 10 additional single-channel, vertical-component sensors. We have already started to analyze seismic data for tremor episodes in July 2009, and March 2010. At each array, we apply a beamforming technique to stack the seismic energy at every 0.2 Hz from 2 to 15 Hz. During active tremor, the arrays show stable slowness, and azimuth over time, and up to 15 Hz energy on vertical channels, and 6 Hz on horizontals, with slowness consistent with the P and S waves respectively (Figure 1). Vidale et al. in this meeting provide a detailed description of a weeklong tremor episode in March 2010. The ETS started early second week of August about 60 km south of our arrays, and in a week or so, migrated along-strike to the north passing directly underneath the arrays. Strong tremor is still active about 50 km north of the arrays as we write this abstract. We will imminently analyze this data, and by the time of AGU, have preliminary results to present. Currently, we are developing an algorithm to focus as many arrays as possible to locate the tremor sources. With fine tremor detection capability and good azimuthal coverage, our AoA will better resolve the various confounding features of tremor spatiotemporal distribution (e.g., tremor patches, bands, streaks, rapid tremor reversals, low frequency earthquakes) that have been recently discovered in Cascadia. The AoA is poised to provide

  3. Compensated individually addressable array technology for human breast imaging

    Science.gov (United States)

    Lewis, D. Kent

    2003-01-01

    A method of forming broad bandwidth acoustic or microwave beams which encompass array design, array excitation, source signal preprocessing, and received signal postprocessing. This technique uses several different methods to achieve improvement over conventional array systems. These methods are: 1) individually addressable array elements; 2) digital-to-analog converters for the source signals; 3) inverse filtering from source precompensation; and 4) spectral extrapolation to expand the bandwidth of the received signals. The components of the system will be used as follows: 1) The individually addressable array allows scanning around and over an object, such as a human breast, without any moving parts. The elements of the array are broad bandwidth elements and efficient radiators, as well as detectors. 2) Digital-to-analog converters as the source signal generators allow virtually any radiated field to be created in the half-space in front of the array. 3) Preprocessing allows for corrections in the system, most notably in the response of the individual elements and in the ability to increase contrast and resolution of signal propagating through the medium under investigation. 4) Postprocessing allows the received broad bandwidth signals to be expanded in a process similar to analytic continuation. Used together, the system allows for compensation to create beams of any desired shape, control the wave fields generated to correct for medium differences, and improve contract and resolution in and through the medium.

  4. Automatic array alignment in data-parallel programs

    Science.gov (United States)

    Chatterjee, Siddhartha; Gilbert, John R.; Schreiber, Robert; Teng, Shang-Hua

    1993-01-01

    FORTRAN 90 and other data-parallel languages express parallelism in the form of operations on data aggregates such as arrays. Misalignment of the operands of an array operation can reduce program performance on a distributed-memory parallel machine by requiring nonlocal data accesses. Determining array alignments that reduce communication is therefore a key issue in compiling such languages. We present a framework for the automatic determination of array alignments in array-based, data-parallel languages. Our language model handles array sectioning, reductions, spreads, transpositions, and masked operations. We decompose alignment functions into three constituents: axis, stride, and offset. For each of these subproblems, we show how to solve the alignment problem for a basic block of code, possibly containing common subexpressions. Alignments are generated for all array objects in the code, both named program variables and intermediate results. We assign computation to processors by virtue of explicit alignment of all temporaries; the resulting work assignment is in general better than that provided by the 'owner-computes' rule. Finally, we present some ideas for dealing with control flow, replication, and dynamic alignments that depend on loop induction variables.

  5. Passive microfluidic array card and reader

    Science.gov (United States)

    Dugan, Lawrence Christopher [Modesto, CA; Coleman, Matthew A [Oakland, CA

    2011-08-09

    A microfluidic array card and reader system for analyzing a sample. The microfluidic array card includes a sample loading section for loading the sample onto the microfluidic array card, a multiplicity of array windows, and a transport section or sections for transporting the sample from the sample loading section to the array windows. The microfluidic array card reader includes a housing, a receiving section for receiving the microfluidic array card, a viewing section, and a light source that directs light to the array window of the microfluidic array card and to the viewing section.

  6. Nanocoax Arrays for Sensing Devices

    Science.gov (United States)

    Rizal, Binod

    We have adapted a nanocoax array architecture for high sensitivity, all-electronic, chemical and biological sensing. Arrays of nanocoaxes with various dielectric annuli were developed using polymer replicas of Si nanopillars made via soft lithography. These arrays were implemented in the development of two different kinds of chemical detectors. First, arrays of nanocoaxes constructed with different porosity dielectric annuli were employed to make capacitive detectors for gaseous molecules and to investigate the role of dielectric porosity in the sensitivity of the device. Second, arrays of nanocoaxes with partially hollowed annuli were used to fabricate three-dimensional electrochemical biosensors within which we studied the role of nanoscale gap between electrodes on device sensitivity. In addition, we have employed a molecular imprint technique to develop a non-conducting molecularly imprinted polymer thin film of thickness comparable to size of biomolecules as an "artificial antibody" architecture for the detection of biomolecules.

  7. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  8. Chunking of Large Multidimensional Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rotem, Doron; Otoo, Ekow J.; Seshadri, Sridhar

    2007-02-28

    Data intensive scientific computations as well on-lineanalytical processing applications as are done on very large datasetsthat are modeled as k-dimensional arrays. The storage organization ofsuch arrays on disks is done by partitioning the large global array intofixed size hyper-rectangular sub-arrays called chunks or tiles that formthe units of data transfer between disk and memory. Typical queriesinvolve the retrieval of sub-arrays in a manner that accesses all chunksthat overlap the query results. An important metric of the storageefficiency is the expected number of chunks retrieved over all suchqueries. The question that immediately arises is "what shapes of arraychunks give the minimum expected number of chunks over a query workload?"In this paper we develop two probabilistic mathematical models of theproblem and provide exact solutions using steepest descent and geometricprogramming methods. Experimental results, using synthetic workloads onreal life data sets, show that our chunking is much more efficient thanthe existing approximate solutions.

  9. Low Power Systolic Array Based Digital Filter for DSP Applications

    Directory of Open Access Journals (Sweden)

    S. Karthick

    2015-01-01

    Full Text Available Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  10. Low Power Systolic Array Based Digital Filter for DSP Applications.

    Science.gov (United States)

    Karthick, S; Valarmathy, S; Prabhu, E

    2015-01-01

    Main concepts in DSP include filtering, averaging, modulating, and correlating the signals in digital form to estimate characteristic parameter of a signal into a desirable form. This paper presents a brief concept of low power datapath impact for Digital Signal Processing (DSP) based biomedical application. Systolic array based digital filter used in signal processing of electrocardiogram analysis is presented with datapath architectural innovations in low power consumption perspective. Implementation was done with ASIC design methodology using TSMC 65 nm technological library node. The proposed systolic array filter has reduced leakage power up to 8.5% than the existing filter architectures.

  11. SAQC: SNP Array Quality Control

    Directory of Open Access Journals (Sweden)

    Li Ling-Hui

    2011-04-01

    Full Text Available Abstract Background Genome-wide single-nucleotide polymorphism (SNP arrays containing hundreds of thousands of SNPs from the human genome have proven useful for studying important human genome questions. Data quality of SNP arrays plays a key role in the accuracy and precision of downstream data analyses. However, good indices for assessing data quality of SNP arrays have not yet been developed. Results We developed new quality indices to measure the quality of SNP arrays and/or DNA samples and investigated their statistical properties. The indices quantify a departure of estimated individual-level allele frequencies (AFs from expected frequencies via standardized distances. The proposed quality indices followed lognormal distributions in several large genomic studies that we empirically evaluated. AF reference data and quality index reference data for different SNP array platforms were established based on samples from various reference populations. Furthermore, a confidence interval method based on the underlying empirical distributions of quality indices was developed to identify poor-quality SNP arrays and/or DNA samples. Analyses of authentic biological data and simulated data show that this new method is sensitive and specific for the detection of poor-quality SNP arrays and/or DNA samples. Conclusions This study introduces new quality indices, establishes references for AFs and quality indices, and develops a detection method for poor-quality SNP arrays and/or DNA samples. We have developed a new computer program that utilizes these methods called SNP Array Quality Control (SAQC. SAQC software is written in R and R-GUI and was developed as a user-friendly tool for the visualization and evaluation of data quality of genome-wide SNP arrays. The program is available online (http://www.stat.sinica.edu.tw/hsinchou/genetics/quality/SAQC.htm.

  12. Array gain for a cylindrical array with baffle scatter effects.

    Science.gov (United States)

    Bertilone, Derek C; Killeen, Damien S; Bao, Chaoying

    2007-11-01

    Cylindrical arrays used in sonar for passive underwater surveillance often have sensors surrounding a cylindrical metal baffle. In some operational sonars, the phones in each stave (i.e., each line of phones aligned with the cylinder axis) are hardwired together so that the array is equivalent to a baffled circular array of directional elements, where each element corresponds to a line array of omnidirectional phones steered to broadside. In this paper a model is introduced for computing the array gain of such an array at high frequencies, which incorporates baffle scatter using infinite, rigid cylinder scattering theory, and with ambient noise described by an angular spectral density function. In practice the phones are often offset from the baffle surface, and the acoustic field sampled by the staves is distorted at high frequencies due to interference between the incident and scattered fields. Examples are given to illustrate the resulting array gain degradation, using three noise distributions that are frequently used in sonar performance modeling: three-dimensional isotropic, two-dimensional isotropic, and surface dipole noise.

  13. Square Kilometre Array station configuration using two-stage beamforming

    CERN Document Server

    Jiwani, Aziz; Razavi-Ghods, Nima; Hall, Peter J; Padhi, Shantanu; de Vaate, Jan Geralt bij

    2012-01-01

    The lowest frequency band (70 - 450 MHz) of the Square Kilometre Array will consist of sparse aperture arrays grouped into geographically-localised patches, or stations. Signals from thousands of antennas in each station will be beamformed to produce station beams which form the inputs for the central correlator. Two-stage beamforming within stations can reduce SKA-low signal processing load and costs, but has not been previously explored for the irregular station layouts now favoured in radio astronomy arrays. This paper illustrates the effects of two-stage beamforming on sidelobes and effective area, for two representative station layouts (regular and irregular gridded tile on an irregular station). The performance is compared with a single-stage, irregular station. The inner sidelobe levels do not change significantly between layouts, but the more distant sidelobes are affected by the tile layouts; regular tile creates diffuse, but regular, grating lobes. With very sparse arrays, the station effective area...

  14. The Long Wavelength Array

    Science.gov (United States)

    Taylor, G. B.

    2006-08-01

    The Long Wavelength Array (LWA) will be a new, open, user-oriented astronomical instrument operating in the poorly explored window from 20-80 MHz at arcsecond level resolution and mJy level sensitivity. Key science drivers include (1) acceleration, propagation, and turbulence in the ISM, including the space-distribution and spectrum of Galactic cosmic rays, supernova remnants, and pulsars; (2) the high redshift universe, including the most distant radio galaxies and clusters - tools for understanding the earliest black holes and the cosmological evolution of Dark Matter and Dark Energy; (3) planetary, solar, and space science, including space weather prediction and extra-solar planet searches; and (4) the radio transient universe: including the known (e.g., SNe, GRBs) and the unknown. Because the LWA will explore one of the last and least investigated regions of the spectrum, the potential for new discoveries, including new classes of physical phenomena, is high, and there is a strong synergy with exciting new X-ray and Gamma-ray measurements, e.g. for cosmic ray acceleration, transients, and galaxy clusters. Operated by the University of New Mexico on behalf of the South West Consortium (SWC) the LWA will also provide a unique training ground for the next generation of radio astronomers. Students may also put skills learned on the LWA to work in computer science, electrical engineering, and the communications industry, among others. The development of the LWA will follow a phased build, which benefits from lessons learned at each phase. Four university-based Scientific Testing and Evaluation (ST&E) teams with different areas of concentration (1. High resolution imaging and particle acceleration; 2. Wide field imaging and large scale structures; 3. Ionosphere, and 4. RFI suppression and transient detection) will provide the feedback needed to assure that science objectives are met as the build develops. Currently in its first year of construction funding, the LWA

  15. Massive star forming environments

    Science.gov (United States)

    Devine, Kathryn Elizabeth

    2010-12-01

    We present a study of the earliest stages of massive star formation, in which we focus on Infrared Dark Clouds (IRDCs) and young massive clusters. We present Very Large Array spectral line observations of ammonia (NH 3) and CCS toward four IRDCs. The NH3 lines provide diagnostics of the temperature and density structure within IRDCs. Based upon the NH 3 column density, IRDCs have masses of ˜ 103 to 10 4 M⊙ . We detect twenty NH3 clumps within four IRDCs, with radii regions are presented from the Near Infrared Imager (NIRIM) camera on the 3.5 m WIYN telescope. We report J, H, and K' band photometry in the clusters AFGL437, AFGL5180, and AFGL5142 and use these results to probe the stellar populations, extinction, and ages of the clusters. We find that all three clusters suffer significant extinction (AK ˜1), have ages ≤ 5 Myr, and are actively forming stars. We conclude that the properties of these embedded clusters are consistent with their evolving from IRDC clumps.

  16. Engaging with Molecular Form to Understand Function

    Science.gov (United States)

    Barber, Nicola C.; Stark, Louisa A.

    2014-01-01

    Cells are bustling factories with diverse and prolific arrays of molecular machinery. Remarkably, this machinery self-organizes to carry out the complex biochemical activities characteristic of life. When Watson and Crick published the structure of DNA, they noted that DNA base pairing creates a double-stranded form that provides a means of…

  17. The Cherenkov Telescope Array

    CERN Document Server

    Bigongiari, Ciro

    2016-01-01

    The Cherenkov Telescope Array (CTA) is planned to be the next generation ground based observatory for very high energy (VHE) gamma-ray astronomy. Gamma-rays provide a powerful insight into the non-thermal universe and hopefully a unique probe for new physics. Imaging Cherenkov telescopes have already discovered more than 170 VHE gamma-ray emitters providing plentiful of valuable data and clearly demonstrating the power of this technique. In spite of the impressive results there are indications that the known sources represent only the tip of the iceberg. A major step in sensitivity is needed to increase the number of detected sources, observe short time-scale variability and improve morphological studies of extended sources. An extended energy coverage is advisable to observe far-away extragalactic objects and improve spectral analysis. CTA aims to increase the sensitivity by an order of magnitude compared to current facilities, to extend the accessible gamma-ray energies from a few tens of GeV to a hundred o...

  18. Mechanical design and development of TES bolometer detector arrays for the Advanced ACTPol experiment

    CERN Document Server

    Ward, Jonathan T; Beall, James A; Choi, Steve K; Crowley, Kevin T; Devlin, Mark J; Duff, Shannon M; Gallardo, Patricio M; Henderson, Shawn W; Ho, Shuay-Pwu Patty; Hilton, Gene; Hubmayr, Johannes; Khavari, Niloufar; Klein, Jeffrey; Koopman, Brian J; Li, Dale; McMahon, Jeffrey; Mumby, Grace; Nati, Federico; Niemack, Michael D; Page, Lyman A; Salatino, Maria; Schillaci, Alessandro; Schmitt, Benjamin L; Simon, Sara M; Staggs, Suzanne T; Thornton, Robert; Ullom, Joel N; Vavagiakis, Eve M; Wollack, Edward J

    2016-01-01

    The next generation Advanced ACTPol (AdvACT) experiment is currently underway and will consist of four Transition Edge Sensor (TES) bolometer arrays, with three operating together, totaling ~5800 detectors on the sky. Building on experience gained with the ACTPol detector arrays, AdvACT will utilize various new technologies, including 150mm detector wafers equipped with multichroic pixels, allowing for a more densely packed focal plane. Each set of detectors includes a feedhorn array of stacked silicon wafers which form a spline profile leading to each pixel. This is then followed by a waveguide interface plate, detector wafer, back short cavity plate, and backshort cap. Each array is housed in a custom designed structure manufactured from high purity copper and then gold plated. In addition to the detector array assembly, the array package also encloses cryogenic readout electronics. We present the full mechanical design of the AdvACT high frequency (HF) detector array package along with a detailed look at t...

  19. LOFAR: The LOw-Frequency ARray

    CERN Document Server

    van Haarlem, M P; Gunst, A W; Heald, G; McKean, J P; Hessels, J W T; de Bruyn, A G; Nijboer, R; Swinbank, J; Fallows, R; Brentjens, M; Nelles, A; Beck, R; Falcke, H; Fender, R; Hörandel, J; Mann, L V E Koopmans G; Miley, G; Röttgering, H; Stappers, B W; Wijers, R A M J; Zaroubi, S; Akker, M van den; Alexov, A; Anderson, J; Anderson, K; van Ardenne, A; Arts, M; Asgekar, A; Avruch, I M; Batejat, F; Bähren, L; Bell, M E; Bell, M R; van Bemmel, I; Bennema, P; Bentum, M J; Bernardi, G; Best, P; Bîrzan, L; Bonafede, A; Boonstra, A -J; Braun, R; Bregman, J; Breitling, F; van de Brink, R H; Broderick, J; Broekema, P C; Brouw, W N; Brüggen, M; Butcher, H R; van Cappellen, W; Ciardi, B; Coenen, T; Conway, J; Coolen, A; Corstanje, A; Damstra, S; Davies, O; Deller, A T; Dettmar, R -J; van Diepen, G; Dijkstra, K; Donker, P; Doorduin, A; Dromer, J; Drost, M; van Duin, A; Eislöffel, J; van Enst, J; Ferrari, C; Frieswijk, W; Gankema, H; Garrett, M A; de Gasparin, F; Gerbers, M; de Geus, E; Grießmeier, J -M; Grit, T; Gruppen, P; Hamaker, J P; Hassall, T; Hoeft, M; Holties, H; Horneffer, A; van der Horst, A; van Houwelingen, A; Huijgen, A; Iacobelli, M; Intema, H; Jackson, N; Jelic, V; de Jong, A; Kant, D; Karastergiou, A; Koers, A; Kollen, H; Kondratiev, V I; Kooistra, E; Koopman, Y; Koster, A; Kuniyoshi, M; Kramer, M; Kuper, G; Lambropoulos, P; Law, C; van Leeuwen, J; Lemaitre, J; Loose, M; Maat, P; Macario, G; Markoff, S; Masters, J; McKay-Bukowski, D; Meijering, H; Meulman, H; Mevius, M; Millenaar, R; Miller-Jones, J C A; Mohan, R N; Mol, J D; Morawietz, J; Morganti, R; Mulcahy, D D; Mulder, E; Munk, H; Nieuwenhuis, L; van Nieuwpoort, R; Noordam, J E; Norden, M; Noutsos, A; Offringa, A R; Olofsson, H; Omar, A; Orrú, E; Overeem, R; Paas, H; Pandey-Pommier, M; Pandey, V N; Pizzo, R; Polatidis, A; Rafferty, D; Rawlings, S; Reich, W; de Reijer, J -P; Reitsma, J; Renting, A; Riemers, P; Rol, E; Romein, J W; Roosjen, J; Ruiter, M; Scaife, A; van der Schaaf, K; Scheers, B; Schellart, P; Schoenmakers, A; Schoonderbeek, G; Serylak, M; Shulevski, A; Sluman, J; Smirnov, O; Sobey, C; Spreeuw, H; Steinmetz, M; Sterks, C G M; Stiepel, H -J; Stuurwold, K; Tagger, M; Tang, Y; Tasse, C; Thomas, I; Thoudam, S; Toribio, M C; van der Tol, B; Usov, O; van Veelen, M; van der Veen, A -J; ter Veen, S; Verbiest, J P W; Vermeulen, R; Vermaas, N; Vocks, C; Vogt, C; de Vos, M; van der Wal, E; van Weeren, R; Weggemans, H; Weltevrede, P; White, S; Wijnholds, S J; Wilhelmsson, T; Wucknitz, O; Yatawatta, S; Zarka, P; Zensus, A; van Zwieten, J

    2013-01-01

    LOFAR, the LOw-Frequency ARray, is a new-generation radio interferometer constructed in the north of the Netherlands and across europe. Utilizing a novel phased-array design, LOFAR covers the largely unexplored low-frequency range from 10-240 MHz and provides a number of unique observing capabilities. Spreading out from a core located near the village of Exloo in the northeast of the Netherlands, a total of 40 LOFAR stations are nearing completion. A further five stations have been deployed throughout Germany, and one station has been built in each of France, Sweden, and the UK. Digital beam-forming techniques make the LOFAR system agile and allow for rapid repointing of the telescope as well as the potential for multiple simultaneous observations. With its dense core array and long interferometric baselines, LOFAR achieves unparalleled sensitivity and angular resolution in the low-frequency radio regime. The LOFAR facilities are jointly operated by the International LOFAR Telescope (ILT) foundation, as an ob...

  20. LEAP: the large European array for pulsars

    CERN Document Server

    Bassa, C G; Karuppusamy, R; Kramer, M; Lee, K J; Liu, K; McKee, J; Perrodin, D; Purver, M; Sanidas, S; Smits, R; Stappers, B W

    2015-01-01

    The Large European Array for Pulsars (LEAP) is an experiment that harvests the collective power of Europe's largest radio telescopes in order to increase the sensitivity of high-precision pulsar timing. As part of the ongoing effort of the European Pulsar Timing Array (EPTA), LEAP aims to go beyond the sensitivity threshold needed to deliver the first direct detection of gravitational waves. The five telescopes presently included in LEAP are: the Effelsberg telescope, the Lovell telescope at Jodrell Bank, the Nan\\c cay radio telescope, the Sardinia Radio Telescope and the Westerbork Synthesis Radio Telescope. Dual polarization, Nyquist-sampled time-series of the incoming radio waves are recorded and processed offline to form the coherent sum, resulting in a tied-array telescope with an effective aperture equivalent to a 195-m diameter circular dish. All observations are performed using a bandwidth of 128 MHz centered at a frequency of 1396 MHz. In this paper, we present the design of the LEAP experiment, the ...

  1. Passive cavitation imaging with ultrasound arrays.

    Science.gov (United States)

    Salgaonkar, Vasant A; Datta, Saurabh; Holland, Christy K; Mast, T Douglas

    2009-12-01

    A method is presented for passive imaging of cavitational acoustic emissions using an ultrasound array, with potential application in real-time monitoring of ultrasound ablation. To create such images, microbubble emissions were passively sensed by an imaging array and dynamically focused at multiple depths. In this paper, an analytic expression for a passive image is obtained by solving the Rayleigh-Sommerfield integral, under the Fresnel approximation, and passive images were simulated. A 192-element array was used to create passive images, in real time, from 520-kHz ultrasound scattered by a 1-mm steel wire. Azimuthal positions of this target were accurately estimated from the passive images. Next, stable and inertial cavitation was passively imaged in saline solution sonicated at 520 kHz. Bubble clusters formed in the saline samples were consistently located on both passive images and B-scans. Passive images were also created using broadband emissions from bovine liver sonicated at 2.2 MHz. Agreement was found between the images and source beam shape, indicating an ability to map therapeutic ultrasound beams in situ. The relation between these broadband emissions, sonication amplitude, and exposure conditions are discussed.

  2. Dynamically Alterable Arrays of Polymorphic Data Types

    Science.gov (United States)

    James, Mark

    2006-01-01

    An application library package was developed that represents data packets for Deep Space Network (DSN) message packets as dynamically alterable arrays composed of arbitrary polymorphic data types. The software was to address a limitation of the present state of the practice for having an array directly composed of a single monomorphic data type. This is a severe limitation when one is dealing with science data in that the types of objects one is dealing with are typically not known in advance and, therefore, are dynamic in nature. The unique feature of this approach is that it enables one to define at run-time the dynamic shape of the matrix with the ability to store polymorphic data types in each of its indices. Existing languages such as C and C++ have the restriction that the shape of the array must be known in advance and each of its elements be a monomorphic data type that is strictly defined at compile-time. This program can be executed on a variety of platforms. It can be distributed in either source code or binary code form. It must be run in conjunction with any one of a number of Lisp compilers that are available commercially or as shareware.

  3. Magnetic properties of self-assembled iron nanoparticle arrays

    Science.gov (United States)

    Farrell, Dorothy

    Nanoparticles of Fe were synthesized via thermal decomposition of iron pentacarbonyl, Fe(CO)5, in the presence of surfactants. Heterogeneously nucleating particles from Pt seeds led to high moment, minimally oxidized Fe particles 4.5--9 nm in diameter. Homogeneous nucleation of particles in the presence of an excess of oleic acid led to formation of partially oxidized particles, consisting of an Fe core and an oxide shell, 9--19 nm in diameter. Once synthesized, the particles were dispersed in hexane, and the hexane evaporated from the dispersion. During the evaporation, the particles self-assembled to form particle superlattices. The size and quality of the particle arrays depended on particle and surfactant concentration and drying conditions. Transmission electron microscopy (TEM) was used to characterize the size and structure of both particles and particle superlattices. Structural evidence for magnetic interactions between particles in the arrays was observed. Samples of hcp superlattices of 6.6 nm, high moment Fe particles displayed a preference for odd numbers of layers. This was not observed in arrays of low moment particles, and has not been reported for non-magnetic particles. The magnetic properties of dilute particle suspensions and dried particle arrays were measured using a Quantum Design MPMS magnetometer. The hysteretic and remanent behavior of both the dispersions and dried assemblies were indicative of the existence of dipole interactions between particles. Differences in the magnetic behavior of dispersions and arrays indicated that dipole interaction effects depend on the size and structure of particle assemblies. Magnetizing interactions play a larger role in the large, close-packed arrays than in the smaller, loosely-associated clusters contained in the dispersions. The magnetizing effects in the arrays can be enhanced by decreasing the interparticle spacing. The arrays were also magnetically anisotropic, with magnetic properties depending on

  4. Abductive Inference using Array-Based Logic

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Falster, Peter; Møller, Gert L.;

    The notion of abduction has found its usage within a wide variety of AI fields. Computing abductive solutions has, however, shown to be highly intractable in logic programming. To avoid this intractability we present a new approach to logicbased abduction; through the geometrical view of data...... employed in array-based logic we embrace abduction in a simple structural operation. We argue that a theory of abduction on this form allows for an implementation which, at runtime, can perform abductive inference quite efficiently on arbitrary rules of logic representing knowledge of finite domains....

  5. Broadband Multilayered Array Antenna with EBG Reflector

    Directory of Open Access Journals (Sweden)

    P. Chen

    2013-01-01

    Full Text Available Most broadband microstrip antennae are implemented in the form of slot structure or laminate structure. The impedance bandwidth is broadened, but meanwhile, the sidelobe of the directivity pattern and backlobe level are enlarged. A broadband stacked slot coupling microstrip antenna array with EBG structure reflector is proposed. Test results indicate that the proposed reflector structure can effectively improve the directivity pattern of stacked antenna and aperture coupled antenna, promote the front-to-back ratio, and reduce the thickness of the antenna. Therefore, it is more suitable to be applied as an airborne antenna.

  6. Neuroelectronic device based on nanocoax arrays

    Science.gov (United States)

    Naughton, Jeffrey R.; Lundberg, Jaclyn N.; Varela, Juan A.; Burns, Michael J.; Chiles, Thomas C.; Christianson, John P.; Naughton, Michael J.

    2015-03-01

    We report on development of a nanocoax-based neuroelectronic array. The device has been used in real time to noninvasively couple to a ganglion sac located along the main nerve cord of the leech Hirudo medicinalis. This allowed for extracellular recording of synaptic activity in the form of spontaneous synapse firing in pre- and post-synaptic somata, with the next target being recording of local field potentials from rat hippocampal cells. We also discuss an alteration of the architecture to facilitate optical integration of the nanoarray, toward utilizing the so-modified device to elicit / inhibit action potentials in optogenetically-modified cells.

  7. Development of an Automation Technique for the Establishment of Functional Lipid Bilayer Arrays

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg;

    2009-01-01

    of the lipid membranes to the formation of bilayers. The results showed that multiple lipid bilayers could be reproducible formed across the airbrush-pretreated 8 x 8 rectangular arrays. The ionophoric peptide valinomycin was incorporated into established membrane arrays, resulting in ionic currents that could......In the present work, a technique for establishing multiple black lipid membranes (BLMs) in arrays of micro structured ethylene tetrafluoroethylene (ETFE) films, and supported by a micro porous material was developed. Rectangular 8 x 8 arrays with apertures having diameters of 301 +/- 5 mu m were...... fabricated in ETFE Teflon film by laser ablation using a carbon dioxide laser. Multiple lipid membranes could be formed across the micro structured 8 x 8 array ETFE partitions. Success rates for the establishment of cellulose-supported BLMs across the multiple aperture arrays were above 95%. However...

  8. Circularly Polarized Antenna Array Fed by Air-Bridge Free CPW-Slotline Network

    Directory of Open Access Journals (Sweden)

    Yilin Liu

    2017-01-01

    Full Text Available A novel design of 1×2 and 2×2 circularly polarized (CP microstrip patch antenna arrays is presented in this paper. The two CP antenna arrays are fed by sequentially rotated coplanar waveguide (CPW to slotline networks and are processed on 1 mm thick single-layer FR4 substrates. Both of the two arrays are low-profile and lightweight. An air-bridge free CPW-slotline power splitter is appropriately designed to form the feeding networks and realize the two CP antenna arrays. The mechanism of circular polarization in this design is explained. The simulated and measured impedance bandwidths as well as the 3 dB axial ratio bandwidths and the radiation patterns of the two proposed antenna arrays are presented. This proposed design can be easily extended to form a larger plane array with good performance owing to its simple structure.

  9. Imaging Properties of Planar Microlens Arrays

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The planar microlens arrays is a two-dimensional array of optical component which is fabricated monolithically available. Imaging properties of planar microlens arrays are described, which provide both image multiplexer and erect, unit magnification images.

  10. Selective carrier injection into patterned arrays of pyramidal quantum dots for entangled photon light-emitting diodes

    Science.gov (United States)

    Chung, T. H.; Juska, G.; Moroni, S. T.; Pescaglini, A.; Gocalinska, A.; Pelucchi, E.

    2016-12-01

    Scalability and foundry compatibility (as apply to conventional silicon-based integrated computer processors, for example) in developing quantum technologies are major challenges facing current research. Here we introduce a quantum photonic technology that has the potential to enable the large-scale fabrication of semiconductor-based, site-controlled, scalable arrays of electrically driven sources of polarization-entangled photons that may be able to encode quantum information. The design of the sources is based on quantum dots grown in micrometre-sized pyramidal recesses along the crystallographic direction (111)B, which theoretically ensures high symmetry of the quantum dots—a requirement for bright entangled-photon emission. A selective electric injection scheme in these non-planar structures allows a high density of light-emitting diodes to be obtained, with some producing entangled photon pairs that also violate Bell's inequality. Compatibility with semiconductor fabrication technology, good reproducibility and lithographic position control make these devices attractive candidates for integrated photonic circuits for quantum information processing.

  11. Antenna arrays a computational approach

    CERN Document Server

    Haupt, Randy L

    2010-01-01

    This book covers a wide range of antenna array topics that are becoming increasingly important in wireless applications, particularly in design and computer modeling. Signal processing and numerical modeling algorithms are explored, and MATLAB computer codes are provided for many of the design examples. Pictures of antenna arrays and components provided by industry and government sources are presented with explanations of how they work. Antenna Arrays is a valuable reference for practicing engineers and scientists in wireless communications, radar, and remote sensing, and an excellent textbook for advanced antenna courses.

  12. Fiber Optic Geophysics Sensor Array

    Science.gov (United States)

    Grochowski, Lucjan

    1989-01-01

    The distributed optical sensor arrays are analysed in view of specific needs of 3-D seismic explorations methods. There are compared advantages and disadventages of arrays supported by the sensors which are modulated in intensity and phase. In these systems all-fiber optic structures and their compabilities with digital geophysic formats are discussed. It was shown that the arrays based on TDM systems with the intensity modulated sensors are economically and technically the best matched for geophysic systems supported by a large number of the sensors.

  13. Terahertz superconducting plasmonic hole array

    CERN Document Server

    Tian, Zhen; Han, Jiaguang; Gu, Jianqiang; Xing, Qirong; Zhang, Weili

    2010-01-01

    We demonstrate thermally tunable superconductor hole array with active control over their resonant transmission induced by surface plasmon polaritons . The array was lithographically fabricated on high temperature YBCO superconductor and characterized by terahertz-time domain spectroscopy. We observe a clear transition from the virtual excitation of the surface plasmon mode to the real surface plasmon mode. The highly tunable superconducting plasmonic hole arrays may have promising applications in the design of low-loss, large dynamic range amplitude modulation, and surface plasmon based terahertz devices.

  14. Reconfigurable Pico-cell Antenna Array for Indoor Coverage in GSM 900 Band

    Directory of Open Access Journals (Sweden)

    B. Ivsic

    2009-12-01

    Full Text Available This paper proposes a simple antenna array based on three stacked shorted patches aimed to be used as GSM (900 MHz indoor base station antenna. Three same linearly polarized stacked patches are set in three orthogonal planes in space forming pyramid-like structure. The antenna array can be used for nearly omnidirectional coverage as well as for covering three 120º sectors. The proposed array also offers the possibility of polarization diversity.

  15. Silicon Heat Pipe Array

    Science.gov (United States)

    Yee, Karl Y.; Ganapathi, Gani B.; Sunada, Eric T.; Bae, Youngsam; Miller, Jennifer R.; Beinsford, Daniel F.

    2013-01-01

    Improved methods of heat dissipation are required for modern, high-power density electronic systems. As increased functionality is progressively compacted into decreasing volumes, this need will be exacerbated. High-performance chip power is predicted to increase monotonically and rapidly with time. Systems utilizing these chips are currently reliant upon decades of old cooling technology. Heat pipes offer a solution to this problem. Heat pipes are passive, self-contained, two-phase heat dissipation devices. Heat conducted into the device through a wick structure converts the working fluid into a vapor, which then releases the heat via condensation after being transported away from the heat source. Heat pipes have high thermal conductivities, are inexpensive, and have been utilized in previous space missions. However, the cylindrical geometry of commercial heat pipes is a poor fit to the planar geometries of microelectronic assemblies, the copper that commercial heat pipes are typically constructed of is a poor CTE (coefficient of thermal expansion) match to the semiconductor die utilized in these assemblies, and the functionality and reliability of heat pipes in general is strongly dependent on the orientation of the assembly with respect to the gravity vector. What is needed is a planar, semiconductor-based heat pipe array that can be used for cooling of generic MCM (multichip module) assemblies that can also function in all orientations. Such a structure would not only have applications in the cooling of space electronics, but would have commercial applications as well (e.g. cooling of microprocessors and high-power laser diodes). This technology is an improvement over existing heat pipe designs due to the finer porosity of the wick, which enhances capillary pumping pressure, resulting in greater effective thermal conductivity and performance in any orientation with respect to the gravity vector. In addition, it is constructed of silicon, and thus is better

  16. The Square Kilometer Array

    Science.gov (United States)

    Cordes, James M.

    2006-06-01

    The SKA is an observatory for m/cm wavelengths that will provide quantum leaps in studies of the early universe, the high-energy universe, and astrobiology. Key science areas include:(1) Galaxy Evolution and Large-Scale Structure, including Dark Energy;(2) Probing the Dark Ages through studies of highly redshifted hydrogen and carbon monoxide;(3) Cosmic magnetism;(4) Probing Gravity with Pulsars and Black Holes; and(5) The Cradle of Life, including real-time images of protoplanetary disks, inventory of organic molecules, and the search for signals from extraterrestrial intelligence.From a phase-space point of view, the SKA will expand enormously our ability to discover new and known phenomena, including transient sources with time scales from nano-seconds to years. Particular examples include coherent emissions from extrasolar planets and gamma-ray burst afterglows, detectable at levels 100 times smaller than currently. Specifications needed to meet the science requirements are technically quite challenging: a frequency range of approximately 0.1 to 25 GHz; wide field of view, tens of square degrees (frequency dependent); high dynamic range and image fidelity; flexibility in imaging on scales from sub-mas to degrees; and sampling the time-frequency domain as demanded by transient objects. Meeting these specifications requires collaboration of a world-wide group of engineers and scientists. For this and other reasons, the SKA will be realized internationally. Initially, several concepts have been explored for building inexpensive collecting area that provides broad frequency coverage. The Reference Design now specifies an SKA based on a large number of small-diameter dish antennas with "smart feeds." Complementary to the dishes is a phased aperture array that will provide very wide-field capability. I will discuss the Reference Design, along with a timeline for developing the technology, building the first 10% of the SKA, and finishing the full SKA, along with the

  17. Fracture characterisation using geoelectric null-arrays

    Science.gov (United States)

    Falco, Pierik; Negro, François; Szalai, Sándor; Milnes, Ellen

    2013-06-01

    The term "geoelectric null-array" is used for direct current electrode configurations yielding a potential difference of zero above a homogeneous half-space. This paper presents a comparative study of the behaviour of three null-arrays, midpoint null-array (MAN), Wenner-γ null-array and Schlumberger null-array in response to a fracture, both in profiling and in azimuthal mode. The main objective is to determine which array(s) best localise fractures or best identify their orientation. Forward modelling of the three null-arrays revealed that the Wenner-γ and Schlumberger null-arrays localise vertical fractures the most accurately, whilst the midpoint null-array combined with the Schlumberger null-array allows accurate orientation of a fracture. Numerical analysis then served as a basis to interpret the field results. Field test measurements were carried out above a quarry in Les Breuleux (Switzerland) with the three null-arrays and classical arrays. The results were cross-validated with quarry-wall geological mapping. In real field circumstances, the Wenner-γ null-array proved to be the most efficient and accurate in localising fractures. The orientations of the fractures according to the numerical results were most efficiently determined with the midpoint null-array, whilst the Schlumberger null-array adds accuracy to the results. This study shows that geoelectrical null-arrays are more suitable than classical arrays for the characterisation of fracture geometry.

  18. Densified waste form and method for forming

    Science.gov (United States)

    Garino, Terry J.; Nenoff, Tina M.; Sava Gallis, Dorina Florentina

    2015-08-25

    Materials and methods of making densified waste forms for temperature sensitive waste material, such as nuclear waste, formed with low temperature processing using metallic powder that forms the matrix that encapsulates the temperature sensitive waste material. The densified waste form includes a temperature sensitive waste material in a physically densified matrix, the matrix is a compacted metallic powder. The method for forming the densified waste form includes mixing a metallic powder and a temperature sensitive waste material to form a waste form precursor. The waste form precursor is compacted with sufficient pressure to densify the waste precursor and encapsulate the temperature sensitive waste material in a physically densified matrix.

  19. Piezoelectric array elements for sound reconstruction with a digital input

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-10-13

    Various examples are provided for digital sound reconstruction using piezoelectric array elements. In one example, a digital loudspeaker includes a fixed frame and an array of transducers disposed on the fixed frame. Individual transducers of the array of transducers can include a flexible membrane disposed on a piezoelectric actuation element positioned over a corresponding opening that extends through the fixed frame. In another example, a method includes forming a flexible membrane structure on a substrate and backetching the substrate opposite the flexible membrane structure. The flexible membrane structure can be formed by disposing a first electrode layer on a substrate, disposing a piezoelectric layer on the first electrode layer and disposing a second electrode layer on the piezoelectric layer. A flexible membrane layer (e.g., polyimide) can be disposed on the second electrode layer.

  20. Optical phased arrays with evanescently-coupled antennas

    Science.gov (United States)

    Sun, Jie; Watts, Michael R; Yaacobi, Ami; Timurdogan, Erman

    2015-03-24

    An optical phased array formed of a large number of nanophotonic antenna elements can be used to project complex images into the far field. These nanophotonic phased arrays, including the nanophotonic antenna elements and waveguides, can be formed on a single chip of silicon using complementary metal-oxide-semiconductor (CMOS) processes. Directional couplers evanescently couple light from the waveguides to the nanophotonic antenna elements, which emit the light as beams with phases and amplitudes selected so that the emitted beams interfere in the far field to produce the desired pattern. In some cases, each antenna in the phased array may be optically coupled to a corresponding variable delay line, such as a thermo-optically tuned waveguide or a liquid-filled cell, which can be used to vary the phase of the antenna's output (and the resulting far-field interference pattern).

  1. CMOS-Based Biosensor Arrays

    CERN Document Server

    Thewes, R; Schienle, M; Hofmann, F; Frey, A; Brederlow, R; Augustyniak, M; Jenkner, M; Eversmann, B; Schindler-Bauer, P; Atzesberger, M; Holzapfl, B; Beer, G; Haneder, T; Hanke, H -C

    2011-01-01

    CMOS-based sensor array chips provide new and attractive features as compared to today's standard tools for medical, diagnostic, and biotechnical applications. Examples for molecule- and cell-based approaches and related circuit design issues are discussed.

  2. Bolometric Arrays for Millimeter Wavelengths

    Science.gov (United States)

    Castillo, E.; Serrano, A.; Torres-Jácome, A.

    2009-11-01

    During last years, semiconductor bolometers using thin films have been developed at INAOE, specifically boron-doped hydrogenated amorphous silicon films. The characteristics shown by these devices made them attractive to be used in astronomical instrumentation, mainly in two-dimentional arrays. These detector arrays used at the Large Millimeter Telescope will make possible to obtain astronomical images in millimeter and sub-millimeter wavelengths. With this in mind, we are developing a method to produce, with enough reliability, bolometer arrays at INAOE. Until now, silicon nitride diaphragm arrays, useful as radiation absorbers, have succesfully been obtained. Sizes going from one to four millimeter by element in a consistent way; however we have not tested thermometers and metallic contact deposition yet. At the same time, we are working on two possible configurations for the readout electronics; one of them using commercial components while the other will be an integrated circuit specifically designed for this application. Both versions will work below 77K.

  3. Next Generation Microshutter Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop the next generation MicroShutter Array (MSA) as a multi-object field selector for missions anticipated in the next two decades. For many...

  4. Integrated Spatial Filter Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA Earth Science Division need for spatial filter arrays for amplitude and wavefront control, Luminit proposes to develop a novel Integrated Spatial...

  5. Large scale biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg

    2009-01-01

    To establish planar biomimetic membranes across large scale partition aperture arrays, we created a disposable single-use horizontal chamber design that supports combined optical-electrical measurements. Functional lipid bilayers could easily and efficiently be established across CO2 laser micro......-structured 8 x 8 aperture partition arrays with average aperture diameters of 301 +/- 5 mu m. We addressed the electro-physical properties of the lipid bilayers established across the micro-structured scaffold arrays by controllable reconstitution of biotechnological and physiological relevant membrane...... peptides and proteins. Next, we tested the scalability of the biomimetic membrane design by establishing lipid bilayers in rectangular 24 x 24 and hexagonal 24 x 27 aperture arrays, respectively. The results presented show that the design is suitable for further developments of sensitive biosensor assays...

  6. Thermopile Area Array Readout Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA/JPL thermopile detector linear arrays, wire bonded to Black Forest Engineering (BFE) CMOS readout integrated circuits (ROICs), have been utilized in NASA...

  7. Tent Shaped Phased Array Tests.

    Science.gov (United States)

    1982-01-01

    AD-A113 191 HARRIS CORP MELBOURNE FL GOVERNMENT COMMUNICATION SY-ETC Fi 20/11TENT SHAPED PHASED ARRAY TESTS.(U JAN 82 C A CHUANG F19628-79-C-T173...821714f1 45 0 +450 SCAN PLANE ARRAY PATTERNS FIG. B-31 B- 31 AD-AL13 191 HARRS CRP PMELBOURNE FLY GOVERNMENT COMMUNICATION ST--ETC F/6 20/14 TENT SHAPED

  8. Flexible solar-array mechanism

    Science.gov (United States)

    Olson, M. C.

    1972-01-01

    One of the key elements of the flexible rolled-up solar array system is a mechanism to deploy, retract, and store the flexible solar-cell arrays. The selection of components, the design of the mechanism assembly, and the tests that were performed are discussed. During 6 months in orbit, all mission objectives were satisfied, and inflight performance has shown good correlation with preflight analyses and tests.

  9. Hemocompatibility of titania nanotube arrays.

    Science.gov (United States)

    Smith, Barbara S; Yoriya, Sorachon; Grissom, Laura; Grimes, Craig A; Popat, Ketul C

    2010-11-01

    Hemocompatibility is a key consideration for the long-term success of blood contacting biomaterials; hence, there is a critical need to understand the physiological response elicited from blood/nano-biomaterial interactions. In this study, we have investigated the adsorption of key blood serum proteins, in vitro adhesion and activation of platelets, and clotting kinetics of whole blood on titania nanotube arrays. Previous studies have demonstrated improved mesenchymal stem cell functionality, osteoblast phenotypic behavior, localized drug delivery, and the production of endothelial cell ECM on titania nanotube arrays. Furthermore, these titania nanotube arrays have elicited minimal levels of monocyte activation and cytokine secretion, thus exhibiting a very low degree of immunogenicity. Titania nanotube arrays were fabricated using anodization technique and the surface morphology was examined through scanning electron microscopy (SEM). The crystalline phases were identified using glancing angled X-ray diffraction (GAXRD). Nanoindentation and scratch tests were used to characterize the mechanical properties of titania nanotube arrays. The adsorption of key blood proteins (albumin, fibrinogen, and immunoglobulin-g) was evaluated using a micro-BCA assay and X-ray photoelectron spectroscopy (XPS). The adhesion and activation of platelets was investigated using live-cell staining, MTT assay, and SEM. Whole blood clotting kinetics was evaluated by measuring the free hemoglobin concentration, and SEM was used to visualize the clot formation. Our results indicate increased blood serum protein adsorption, platelet adhesion and activation, and whole blood clotting kinetics on titania nanotube arrays.

  10. Array imaging system for lithography

    Science.gov (United States)

    Kirner, Raoul; Mueller, Kevin; Malaurie, Pauline; Vogler, Uwe; Noell, Wilfried; Scharf, Toralf; Voelkel, Reinhard

    2016-09-01

    We present an integrated array imaging system based on a stack of microlens arrays. The microlens arrays are manufactured by melting resist and reactive ion etching (RIE) technology on 8'' wafers (fused silica) and mounted by wafer-level packaging (WLP)1. The array imaging system is configured for 1X projection (magnification m = +1) of a mask pattern onto a planar wafer. The optical system is based on two symmetric telescopes, thus anti-symmetric wavefront aberrations like coma, distortion, lateral color are minimal. Spherical aberrations are reduced by using microlenses with aspherical lens profiles. In our system design approach, sub-images of individual imaging channels do not overlap to avoid interference. Image superposition is achieved by moving the array imaging system during the exposure time. A tandem Koehler integrator illumination system (MO Exposure Optics) is used for illumination. The angular spectrum of the illumination light underfills the pupils of the imaging channels to avoid crosstalk. We present and discuss results from simulation, mounting and testing of a first prototype of the investigated array imaging system for lithography.

  11. Optimal Chunking of Large Multidimensional Arrays for Data Warehousing

    Energy Technology Data Exchange (ETDEWEB)

    Otoo, Ekow J; Otoo, Ekow J.; Rotem, Doron; Seshadri, Sridhar

    2008-02-15

    Very large multidimensional arrays are commonly used in data intensive scientific computations as well as on-line analytical processingapplications referred to as MOLAP. The storage organization of such arrays on disks is done by partitioning the large global array into fixed size sub-arrays called chunks or tiles that form the units of data transfer between disk and memory. Typical queries involve the retrieval of sub-arrays in a manner that access all chunks that overlap the query results. An important metric of the storage efficiency is the expected number of chunks retrieved over all such queries. The question that immediately arises is"what shapes of array chunks give the minimum expected number of chunks over a query workload?" The problem of optimal chunking was first introduced by Sarawagi and Stonebraker who gave an approximate solution. In this paper we develop exact mathematical models of the problem and provide exact solutions using steepest descent and geometric programming methods. Experimental results, using synthetic and real life workloads, show that our solutions are consistently within than 2.0percent of the true number of chunks retrieved for any number of dimensions. In contrast, the approximate solution of Sarawagi and Stonebraker can deviate considerably from the true result with increasing number of dimensions and also may lead to suboptimal chunk shapes.

  12. Developing Barbed Microtip-Based Electrode Arrays for Biopotential Measurement

    Directory of Open Access Journals (Sweden)

    Li-Sheng Hsu

    2014-07-01

    Full Text Available This study involved fabricating barbed microtip-based electrode arrays by using silicon wet etching. KOH anisotropic wet etching was employed to form a standard pyramidal microtip array and HF/HNO3 isotropic etching was used to fabricate barbs on these microtips. To improve the electrical conductance between the tip array on the front side of the wafer and the electrical contact on the back side, a through-silicon via was created during the wet etching process. The experimental results show that the forces required to detach the barbed microtip arrays from human skin, a polydimethylsiloxane (PDMS polymer, and a polyvinylchloride (PVC film were larger compared with those required to detach microtip arrays that lacked barbs. The impedances of the skin-electrode interface were measured and the performance levels of the proposed dry electrode were characterized. Electrode prototypes that employed the proposed tip arrays were implemented. Electroencephalogram (EEG and electrocardiography (ECG recordings using these electrode prototypes were also demonstrated.

  13. Nanoantenna array-induced fluorescence enhancement and reduced lifetimes

    DEFF Research Database (Denmark)

    Bakker, R. M.; Drachev, V. P.; Liu, Z.;

    2008-01-01

    Enhanced fluorescence is observed from dye molecules interacting with optical nanoantenna arrays. Elliptical gold dimers form individual nanoantennae with tunable plasmon resonances depending upon the geometry of the two particles and the size of the gap between them. A fluorescent dye, Rhodamine...

  14. Fabrication of cell container arrays with overlaid surface topographies.

    NARCIS (Netherlands)

    Truckenmuller, R.; Giselbrecht, S.; Escalante-Marun, M.; Groenendijk, M.; Papenburg, B.; Rivron, N.; Unadkat, H.; Saile, V.; Subramaniam, V.; Berg, A. van den; Blitterswijk, C. Van; Wessling, M.; Boer, J. den; Stamatialis, D.

    2012-01-01

    This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

  15. Fabrication of cell container arrays with overlaid surface topographies

    NARCIS (Netherlands)

    Truckenmüller, R.K.; Giselbrecht, S.; Escalante, M.; Groenendijk, M.N.W.; Papenburg, B.J.; Rivron, N.C.; Unadkat, H.V.; Saile, V.; Subramaniam, V.; Blitterswijk, van C.A.; Wessling, M.; Boer, de J.; Stamatialis, D.

    2012-01-01

    This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

  16. An Optical Phased Array for LIDAR

    Science.gov (United States)

    Wang, Y.; Wu, M. C.

    2016-11-01

    We have previously demonstrated the development of an Optical Phased Array (OPA) micromechanical system (MEMS) used for beam steering, which shows great advantages over previous mechanisms such as opto-mechanical, acousto-optical (AO) or electro-optical (EO). We aim to integrate the OPA MEMS system into the application of automobile navigation, which is currently primarily dominated by opto-mechanical scanning based systems. Opto-mechanical scanning devices are usually bulky and relatively slow, while competing technologies (AO, EO) utilize devices that while small in size, cannot provide the steering speeds and versatility necessary for many applications. In drawing from phased array concepts that revolutionized RADAR technology by providing a compact, agile alternative to mechanically steered technology, the OPA based LIDAR program seeks to integrate thousands of closely packed optical emitting facets, precise relative electronic phase control of these facets, and all within a very small form factor. Comparing with other competing LIDAR system, the OPA based LIDAR system will have multiple degrees of freedom for phase control which enables not only agile beam steering but also beam forming and multiple beam generation, greatly expanding the diversity of applications.

  17. Quantitative flaw characterization with ultrasonic phased arrays

    Science.gov (United States)

    Engle, Brady John

    Ultrasonic nondestructive evaluation (NDE) is a critical diagnostic tool in many industries. It is used to characterize potentially dangerous flaws in critical components for aerospace, automotive, and energy applications. The use of phased array transducers allows for the extension of traditional techniques and the introduction of new methods for quantitative flaw characterization. An equivalent flaw sizing technique for use in time-of-flight diffraction setups is presented that provides an estimate of the size and orientation of isolated cracks, surface-breaking cracks, and volumetric flaws such as voids and inclusions. Experimental validation is provided for the isolated crack case. A quantitative imaging algorithm is developed that corrects for system effects and wave propagation, making the images formed directly related to the properties of the scatterer present. Simulated data is used to form images of cylindrical and spherical inclusions. The contributions of different signals to the image formation process are discussed and examples of the quantitative nature of the images are shown.

  18. Thermal microphotonic sensor and sensor array

    Science.gov (United States)

    Watts, Michael R.; Shaw, Michael J.; Nielson, Gregory N.; Lentine, Anthony L.

    2010-02-23

    A thermal microphotonic sensor is disclosed for detecting infrared radiation using heat generated by the infrared radiation to shift the resonant frequency of an optical resonator (e.g. a ring resonator) to which the heat is coupled. The shift in the resonant frequency can be determined from light in an optical waveguide which is evanescently coupled to the optical resonator. An infrared absorber can be provided on the optical waveguide either as a coating or as a plate to aid in absorption of the infrared radiation. In some cases, a vertical resonant cavity can be formed about the infrared absorber to further increase the absorption of the infrared radiation. The sensor can be formed as a single device, or as an array for imaging the infrared radiation.

  19. A Phased Array Antenna Signal Processing Structure, a Method and a Computer Program Product

    NARCIS (Netherlands)

    Vliet, F.E. van; Dijk, R. van

    2011-01-01

    The invention relates to a phased array antenna signal processing structure. The structure comprises a processor that includes a digital beam forming unit for generating partial beam data from digitized samples of a set of phased array antenna elements. The processor further comprises a set of input

  20. Constraint Programming Approach to the Problem of Generating Milton Babbitt's All-partition Arrays

    DEFF Research Database (Denmark)

    Tanaka, Tsubasa; Bemman, Brian; Meredith, David

    2016-01-01

    Milton Babbitt (1916–2011) was a composer of twelve-tone serial music noted for creating the all-partition array. One part of the problem in generating an all-partition array requires finding a covering of a pitch-class matrix by a collection of sets, each forming a region containing 12 distinct ...

  1. DC and RF Measurements of Serial Bi-SQUID Arrays

    CERN Document Server

    Prokopenko, G V; de Escobar, A Leese; Taylor, B; de Andrade, M C; Berggren, S; Longhini, P; Palacios, A; Nisenoff, M; Fagaly, R L

    2012-01-01

    SQUID arrays are promising candidates for low profile antennas and low noise amplifier applications. We present the integrated circuit designs and results of DC and RF measurements of the wideband serial arrays based on integration of linear bi-SQUID cells forming a Superconducting Quantum Interference Filter (bi-SQUID SQIF). Various configurations of serial arrays designs are described. The measured linearity, power gain, and noise temperature are analyzed and compared. The experimental results are matched to results of mathematical modeling. A serial bi-SQUID SQIF arrays are mounted into a coplanar waveguide (CPW) and symmetrically grounded to corresponding sides of CPW. The RF output comes out from the central common line, which is also used for DC biasing and forms a symmetrical balanced output. The signal and DC flux biasing line is designed as coplanar lines passed in parallel over each bi-SQUID cell in a bidirectional fashion concentrating magnetic flux inside of each cell. Serial bi-SQUID SQIF arrays ...

  2. Design and array signal suggestion of array type pulsed eddy current probe for health monitoring of metal tubes

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Young Kil [Dept. of Electrical Engineering, Kunsan National University, Kunsan (Korea, Republic of)

    2015-10-15

    An array type probe for monitoring metal tubes is proposed in this paper which utilizes peak value and peak time of a pulsed eddy current(PEC) signal. The probe consists of an array of encircling coils along a tube and the outside of coils is shielded by ferrite to prevent source magnetic fields from directly affecting sensor signals since it is the magnetic fields produced by eddy currents that reflect the condition of metal tubes. The positions of both exciter and sensor coils are consecutively moved automatically so that manual scanning is not necessary. At one position of send-receive coils, peak value and peak time are extracted from a sensor PEC signal and these data are accumulated for all positions to form an array type peak value signal and an array type peak time signal. Numerical simulation was performed using the backward difference method in time and the finite element method for spatial analysis. Simulation results showed that peak value increases and the peak appears earlier as the defect depth or length increases. The proposed array signals are shown to be excellent in reflecting the defect location as well as variations of defect depth and length within the array probe.

  3. Instrumentation for multi-detector arrays

    Indian Academy of Sciences (India)

    R K Bhowmik

    2001-07-01

    The new generation of detector arrays require complex instrumentation and data acquisition system to ensure increased reliability of operation, high degree of integration, software control and faster data handling capability. The main features of some of the existing multi-detector arrays like MSU 4 array, Gammasphere and Eurogam are summarized. The instrumentation for the proposed INGA array in India is discussed.

  4. Metal nanodot arrays fabricated via seed-mediated electroless plating with block copolymer thin film scaffolding.

    Science.gov (United States)

    Komiyama, Hideaki; Iyoda, Tomokazu; Sanji, Takanobu

    2015-10-02

    We present an alternative approach to fabricating hexagonally arranged nanodot arrays of various metals by seed-mediated electroless plating with a cylinder-forming block copolymer thin film, PEO-b-PMA(Az), as a scaffold. Metal ions were selectively incorporated into PEO cylinders, followed by their reduction to metal and the etching of the scaffold to obtain highly ordered seed arrays of Au, Pd, and Pt. Nanodot arrays of the target metals (Au, Ag, and Ni) were selectively grown on the seed with their highly ordered arrangement by electroless plating. We studied the fabrication processes' suitability for control of the nanodot array size, as well as the plasmonic properties thereof.

  5. Joint Gain/Phase and Mutual Coupling Array Calibration Technique with Single Calibrating Source

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2012-01-01

    Full Text Available An iterative-based method for joint gain/phase and mutual coupling array calibration is proposed in this paper. It estimates the array gain/phase and mutual coupling coefficients with a set of simultaneous equations formed by using the beam pattern property of the array. Only one calibrating source with known direction is requiblue to obtain the unique estimate. The effectiveness of this approach is illustrated by simulation results and by experimental data collected with an antenna array operating in high-frequency radio band.

  6. 2D aperture synthesis for Lamb wave imaging using co-arrays

    Science.gov (United States)

    Ambrozinski, Lukasz; Stepinski, Tadeusz; Uhl, Tadeusz

    2014-03-01

    2D ultrasonic arrays in Lamb wave based SHM systems can operate in the phased array (PA) or synthetic focusing (SF) mode. In the real-time PA approach, multiple electronically delayed signals excite transmitting elements to form the desired wave-front, whereas receiving elements are used to sense scattered waves. Due to that, the PA mode requires multi channeled hardware and multiple excitations at numerous azimuths to scan the inspected region of interest. To the contrary, the SF mode, assumes a single element excitation of subsequent transmitters and off-line processing of the acquired data. In the simplest implementation of the SF technique, a single multiplexed input and output channels are required, which results in significant hardware simplification. Performance of a 2D imaging array depends on many parameters, such as, its topology, number of its transducers and their spacing in terms of wavelength as well as the type of weighting function (apodization). Moreover, it is possible to use sparse arrays, which means that not all array elements are used for transmitting and/ or receiving. In this paper the co-array concept is applied to facilitate the synthesis process of an array's aperture used in the multistatic synthetic focusing approach in Lamb waves-based imaging systems. In the coherent imaging, performed in the transmit/receive mode, the sum co-array is a morphological convolution of the transmit/receive sub-arrays. It can be calculated as the set of sums of the individual elements' locations in the sub-arrays used for imaging. The coarray framework will be presented here using two different array topologies, aID uniform linear array and a cross-shaped array that will result in a square coarray. The approach will be discussed in terms of array patterns and beam patterns of the resulting imaging systems. Both, theoretical and experimental results will be given.

  7. Retrieval of Mir Solar Array

    Science.gov (United States)

    Rutledge, Sharon K.; deGroh, Kim K.

    1999-01-01

    A Russian solar array panel removed in November 1997 from the non-articulating photovoltaic array on the Mir core module was returned to Earth on STS-89 in January 1998. The panel had been exposed to low Earth orbit (LEO) for 10 years prior to retrieval. The retrieval provided a unique opportunity to study the effects of the LEO environment on a functional solar array. To take advantage of this opportunity, a team composed of members from RSC-Energia (Russia), the Boeing Company, and the following NASA Centers--Johnson Space Center, Kennedy Space Center, Langley Research Center, Marshall Space Flight Center, and Lewis Research Center--was put together to analyze the array. After post-retrieval inspections at the Spacehab Facility at Kennedy in Florida, the array was shipped to Lewis in Cleveland for electrical performance tests, closeup photodocumentation, and removal of selected solar cells and blanket material. With approval from RSC-Energia, five cell pairs and their accompanying blanket and mesh material, and samples of painted handrail materials were selected for removal on the basis of their ability to provide degradation information. Sites were selected that provided different sizes and shapes of micrometeoroid impacts and different levels of surface contamination. These materials were then distributed among the team for round robin testing.

  8. Modeling of phased array transducers.

    Science.gov (United States)

    Ahmad, Rais; Kundu, Tribikram; Placko, Dominique

    2005-04-01

    Phased array transducers are multi-element transducers, where different elements are activated with different time delays. The advantage of these transducers is that no mechanical movement of the transducer is needed to scan an object. Focusing and beam steering is obtained simply by adjusting the time delay. In this paper the DPSM (distributed point source method) is used to model the ultrasonic field generated by a phased array transducer and to study the interaction effect when two phased array transducers are placed in a homogeneous fluid. Earlier investigations modeled the acoustic field for conventional transducers where all transducer points are excited simultaneously. In this research, combining the concepts of delayed firing and the DPSM, the phased array transducers are modeled semi-analytically. In addition to the single transducer modeling the ultrasonic fields from two phased array transducers placed face to face in a fluid medium is also modeled to study the interaction effect. The importance of considering the interaction effect in multiple transducer modeling is discussed, pointing out that neighboring transducers not only act as ultrasonic wave generators but also as scatterers.

  9. Wavenumber response of Shanghai Seismic Array

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Seismic array can be traced back to 1950s when it mainly aimed at detecting and distinguishing the signals of nuclear explosion and seismic signals. The research on seismic array includes seismic array techniques and applications of array in geophysics. Array techniques involve array design and data processing methods (Anne, 1990). Nowadays, the continuous development of seismic array¢s theory could relate to many scientific issues in geophysical field (Tormod, 1989; Mykkeltveit, Bungum, 1984). Seismic array is mainly applied to detect weak events. The response characteristic of array is an important indication of array¢s detection ability. Therefore, when we study an array or construct an array, one of the neces-sary works is to calculate the response characteristics of the array (Harjes, 1990). The aperture and layout of array are two dominating geometrical features. The typical aperture of interna-tional array is generally from several to tens kilometers. For instance, arrays with aperture of dozens kilometers aperture are KSA, WRA, YKA, etc, while arrays with several kilometer aperture are ARC, FIN, GEE, etc. Moreo-ver, in the view of array¢s layout, NOR, GER, etc have circle layout, while WRA, YKA, etc have decussating layout. This paper mainly discusses the relation between deployment of array and wavenumber response. With the example of constructing Shanghai Seismic Array, this paper provides one practical solution to search the proper array deployment. In this paper, the simple delay beam technique is adopted to calculate the response characteris-tics of array. Certainly, the different processing methods have different result, but the result from the simple delay beam processing could be enough to reflect the feature of an array.

  10. A Novel Robot of Manufacturing Space Solar Cell Arrays

    Directory of Open Access Journals (Sweden)

    Wu Yuexin

    2008-11-01

    Full Text Available This paper presents a novel robot employed to manufacture space solar cell arrays. First of all including the mechanical configuration and control system, the architecture of the robot is described. Then the flow velocity field of adhesive in the dispensing needles is acquired based on hydrodynamics. The accurate section form model of adhesive dispensed on the solar cells is obtained, which is essential for the robot to control the uniformity of dispensing adhesive. Finally the experiment validates the feasibility and reliability of the robot system. The application of robots instead of manual work in manufacturing space solar cell arrays will enhance the development of space industry.

  11. A Novel Robot of Manufacturing Space Solar Cell Arrays

    Directory of Open Access Journals (Sweden)

    Wu Yuexin

    2007-03-01

    Full Text Available This paper presents a novel robot employed to manufacture space solar cell arrays. First of all including the mechanical configuration and control system, the architecture of the robot is described. Then the flow velocity field of adhesive in the dispensing needles is acquired based on hydrodynamics. The accurate section form model of adhesive dispensed on the solar cells is obtained, which is essential for the robot to control the uniformity of dispensing adhesive. Finally the experiment validates the feasibility and reliability of the robot system. The application of robots instead of manual work in manufacturing space solar cell arrays will enhance the development of space industry.

  12. Mathematical Simulating Model of Phased-Array Antenna in Multifunction Array Radar

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A mathematical simulating model of phased-array antenna in multifunction array radar has been approached in this paper, including the mathematical simulating model of plane phased-array pattern, the mathematical simulating model of directionality factor, the mathematical simulating model of array factor, the mathematical simulating model of array element factor and the mathematical simulating model of beam steering.

  13. New high fill-factor triangular micro-lens array fabrication method using UV proximity printing

    CERN Document Server

    Lin, T -H; Chao, C -K

    2008-01-01

    A simple and effective method to fabricate a high fill-factor triangular microlens array using the proximity printing in lithography process is reported. The technology utilizes the UV proximity printing by controlling a printing gap between the mask and substrate. The designed approximate triangle microlens array pattern can be fabricated the high fill-factor triangular microlens array in photoresist. It is due to the UV light diffraction to deflect away from the aperture edges and produce a certain exposure in photoresist material outside the aperture edges. This method can precisely control the geometric profile of high fill factor triangular microlens array. The experimental results showed that the triangular micro-lens array in photoresist could be formed automatically when the printing gap ranged from 240 micrometers to 840 micrometers. The gapless triangular microlens array will be used to increases of luminance for backlight module of liquid crystal displays.

  14. Demonstration of a passive, low-noise, millimeter-wave detector array for imaging

    Science.gov (United States)

    Wikner, David; Grossman, Erich

    2009-05-01

    The design of a millimeter-wave (MMW) camera is presented. The camera is meant to serve as a demonstration platform for a new 32-channel MMW detector array that requires no pre-amplification prior to detection. The Army Research Laboratory (ARL) and National Institute of Standards and Technology (NIST) have worked with the Defense Advanced Research Projects Agency and several contractors for four years to develop an affordable MMW detector array technology suitable for use in a large staring array. The camera described uses one particular embodiment of detector array that resulted from the program. This paper reviews the design of the MMW optics that will be used to form imagery with the linear array and the tradeoffs made in that design. Also presented are the results of laboratory tests of the detector array that were made at both ARL and NIST.

  15. An Iterative Technique for the Synthesis of Active Antenna Oscillator Arrays

    Directory of Open Access Journals (Sweden)

    Theodoros N. Kaifas

    2009-01-01

    Full Text Available A design procedure for the synthesis of a coupled active antenna oscillator array is presented. Such an array is synthesized by deriving two sets of parameters: the radiators' positions and the oscillators' outputs. The outputs are used to excite the radiators. Minimization of the mean square error between the desired pattern and the resulting one is made. Synthesis starts from an initial array, which is perturbed iteratively by varying simultaneously the element excitations and positions. In the iteration, the first variation of the cost function is set equal to zero. The final array results from the last iteration, where the stopping criteria are met. The procedure designs simultaneously both the antenna and the attached coupled oscillator array providing viable solutions. The second by properly configuring the tuning parameters through the use of closed-form formulas. The resulting arrays are shown to comply with the desired pattern and the nonlinear dynamics thus proving the validity of our method.

  16. Photoluminescence Properties of Silicon Nanowires and Carbon Nanotube-Silicon Nanowire Composite Arrays

    Institute of Scientific and Technical Information of China (English)

    李梦轲; 陆梅; 孔令斌; 王成伟; 郭新勇; 力虎林

    2002-01-01

    Composite arrays of multi-wall carbon nanotubes (MWNTs) and silicon nanowires (SiNWs) are fabricated by means of the chemical vapour deposition method in porous anodic aluminium oxide (AAO) templates. The results of the scanning electron microscopy, high-resolution transmission electron microscopy, and transmission electron microscopy have shown that SiNWs are successful nested or filled in the hollow cavities of synthesized MWNT arrays in AAO templates to form MWNT-SiNW composite arrays. The photoluminescence (PL) intensity degradation and a blueshift of PL peak position, usually created from the chemical instability of the SiNW surfaces, are decreased and eliminated clearly in the composite arrays. The composite arrays of MWNTs-SiNWs exhibit more enhanced intensity and stability of PL performance than the SiNW arrays deposited in AAO templates.

  17. Thin films of porphyrin-perylene molecular array fabricated by electrophoresis methodology

    Institute of Scientific and Technical Information of China (English)

    SUN Jingzhi; YANG Xinguo; WANG Mang

    2005-01-01

    Thin solid films of organic conjugated molecules are at the center of organic electronics. Low solubility and high sublimation temperature of porphyrin-perylene arrays make it impossible to fabricate uniform solid films with spin-coating and vacuum deposition methodology, though these arrays have important applications in the area of opto-electronics. Here we show that high quality thin films of a porphyrin-perylene array can be prepared by electrochemical deposition, a facile and widely used film-forming technique. The electrophoretic species are protonated porphyrin-perylene molecules, which allow us to grow molecular array films on electrodes. By annealing in ammonia atmosphere or in vacuum at elevated temperature, the protons coordinated with molecular arrays on the deposited films can be eliminated and the porphyrin-perylene arrays recovered to their pristine state.

  18. Photovoltaic cell and array technology development for future unique NASA missions

    Science.gov (United States)

    Bailey, S.; Curtis, H.; Piszczor, M.; Surampudi, R.; Hamilton, T.; Rapp, D.; Stella, P.; Mardesich, N.; Mondt, J.; Bunker, R.; Nesmith, B.; Gaddy, E.; Marvin, D.; Kazmerski, L.

    2002-01-01

    A technology review committee from NASA, the U.S. Department of Energy (DOE), and the Air Force Research Lab, was formed to assess solar cell and array technologies required for future NASA science missions.

  19. High Density Faraday Cup Array or Other Open Trench Structures and Method of Manufacture Thereof

    Science.gov (United States)

    Bower, Christopher A. (Inventor); Gilchrist, Kristin Hedgepath (Inventor); Stoner, Brian R. (Inventor)

    2014-01-01

    A detector array and method for making the detector array. The detector array includes a substrate including a plurality of trenches formed therein, and a plurality of collectors electrically isolated from each other, formed on the walls of the trenches, and configured to collect charged particles incident on respective ones of the collectors and to output from the collectors signals indicative of charged particle collection. In the detector array, adjacent ones of the plurality of trenches are disposed in a staggered configuration relative to one another. The method forms in a substrate a plurality of trenches across a surface of the substrate such that adjacent ones of the trenches are in a staggered sequence relative to one another, forms in the plurality of trenches a plurality of collectors, and connects a plurality of electrodes respectively to the collectors.

  20. Thin, Flexible IMM Solar Array

    Science.gov (United States)

    Walmsley, Nicholas

    2015-01-01

    NASA needs solar arrays that are thin, flexible, and highly efficient; package compactly for launch; and deploy into large, structurally stable high-power generators. Inverted metamorphic multijunction (IMM) solar cells can enable these arrays, but integration of this thin crystalline cell technology presents certain challenges. The Thin Hybrid Interconnected Solar Array (THINS) technology allows robust and reliable integration of IMM cells into a flexible blanket comprising standardized modules engineered for easy production. The modules support the IMM cell by using multifunctional materials for structural stability, shielding, coefficient of thermal expansion (CTE) stress relief, and integrated thermal and electrical functions. The design approach includes total encapsulation, which benefits high voltage as well as electrostatic performance.

  1. 10-kilowatt Photovoltaic Concentrator Array

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, R.L.; Broadbent, S.

    1978-05-01

    Martin Marietta has designed a Photovoltaic Concentrator Array (PCA) for Sandia Laboratories, Kirtland AFB, New Mexico. The PCA is based on the use of an acrylic Fresnel lens to concentrate sunlight on high intensity solar cells. The objective of the development was to obtain economical photovoltaic power generation by replacing relatively high priced solar cells with low cost lenses. Consequently, a major task of the program was to optimize the design for minimum cost per unit power output. Major design aspects considered for optimization were the concentration ratio, size and shape of the Fresnel lens, array size and shape, structure minimization, tracking and control and the practical aspects of operation and maintenance. In addition to design of the complete array, several porototype photovoltaic concentrator module subassemblies were fabricated and delivered to Sandia for evaluation. These prototypes exceed the 9.0% efficiency requirement established for this program.

  2. Optical phased-array ladar.

    Science.gov (United States)

    Montoya, Juan; Sanchez-Rubio, Antonio; Hatch, Robert; Payson, Harold

    2014-11-01

    We demonstrate a ladar with 0.5 m class range resolution obtained by integrating a continuous-wave optical phased-array transmitter with a Geiger-mode avalanche photodiode receiver array. In contrast with conventional ladar systems, an array of continuous-wave sources is used to effectively pulse illuminate a target by electro-optically steering far-field fringes. From the reference frame of a point in the far field, a steered fringe appears as a pulse. Range information is thus obtained by measuring the arrival time of a pulse return from a target to a receiver pixel. This ladar system offers a number of benefits, including broad spectral coverage, high efficiency, small size, power scalability, and versatility.

  3. Coherent magnetic semiconductor nanodot arrays

    Directory of Open Access Journals (Sweden)

    Xiu Faxian

    2011-01-01

    Full Text Available Abstract In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors. Up to now, lack of reliable methods to obtain high-quality MnGe nanostructures with a desired shape and a good controllability has been a barrier to make these materials practically applicable for spintronic devices. Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility. Magnetotransport experiments reveal that the nanodot arrays possess giant magneto-resistance associated with geometrical effects. The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation.

  4. Fabrication and optical properties of Alq 3 doped PMMA microsphere arrays templated by ZnO inverse opal structure

    Science.gov (United States)

    Fu, Ming; Deng, Lier; Zhao, Ailun; Wang, Yongsheng; He, Dawei

    2010-07-01

    PMMA microsphere arrays are fabricated by a double replicating method with common used polystyrene colloidal crystal template. High quality ZnO inverse opals formed by electrodeposition play the key role between the PMMA microsphere arrays and polystyrene colloidal crystals. The electrodeposition method has advantage on fabricating IO structures with high solid fraction. After the subsequently in-situ polymerization of MMA in the voids of ZnO inverse opals, the ZnO is removed by hydrochloric acid solution. Microsphere arrays fabricated by PMMA or PMMA doped with Alq 3 are prepared. Reflection stop bands are detected from the formed PMMA microsphere arrays. Solid fraction from 37% to 50% of the PMMA arrays can be formed by different in-situ polymerization modes of MMA. The photoluminescence of Alq 3 in the PMMA spheres is partly suppressed at the wavelength of the photonic stop band induced by PMMA arrays.

  5. Campaign of measurements to probe the good performance of the new array FARCOS for spectroscopy and correlations.

    Science.gov (United States)

    Acosta, L.; Andolina, R.; Auditore, L.; Boiano, C.; Cardella, G.; Castoldi, A.; D'Andrea, M.; De Filippo, E.; De Luca, S.; Dell'Aquila, D.; Francalanza, L.; Gnoffo, B.; Guazzoni, C.; Lanzalone, G.; Lombardo, I.; Martorana, N.; Minniti, T.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Parsani, T.; Pirrone, S.; Politi, G.; Porto, F.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Saccá, G.; Trifirò, A.; Trimarchi, M.; Verde, G.; Vigilante, M.; Zambon, P.

    2016-07-01

    During the last four years, several measurements have been carried out where the capabilities of FARCOS array were tested. In some of this occasions, FARCOS was coupled to the 4π array CHIMERA, permanently placed at INFN-Laboratori Nazionali del Sud, Catania in order to be tested in real experimental measurements. At the present situation, the FARCOS demonstrator is formed by 4 telescopes out of the originally 20 that will constitute the final array. Here are presented some preliminary results obtained with the new array, probing its qualities and showing the effectiveness of FARCOS telescopes. The initial encouraging results support the construction of the complete array.

  6. EHF multifunction phased array antenna

    Science.gov (United States)

    Solbach, Klaus

    1986-07-01

    The design of a low cost demonstration EHF multifunction-phased array antenna is described. Both, the radiating elements and the phase-shifter circuits are realized on microstrip substrate material in order to allow photolithographic batch fabrication. Self-encapsulated beam-lead PIN-diodes are employed as the electronic switch elements to avoid expensive hermetic encapsulation of the semiconductors or complete circuits. A space-feed using a horn-radiator to illuminate the array from the front-side is found to be the simplest and most inexpensive feed. The phased array antenna thus operates as a reflect-array, the antenna elements employed in a dual role for the collection of energy from the feed-horn and for the re-radiation of the phase-shifted waves (in transmit-mode). The antenna is divided into modules containing the radiator/phase-shifter plate plus drive- and BITE-circuitry at the back. Both drive- and BITE-components use gate-array integrated circuits especially designed for the purpose. Several bus-systems are used to supply bias and logical data flows to the modules. The beam-steering unit utilizes several signal processors and high-speed discrete adder circuits to combine the pointing, frequency and beam-shape information from the radar system computer with the stored phase-shift codes for the array elements. Since space, weight and power consumption are prime considerations only the most advanced technology is used in the design of both the microwave and the digital/drive circuitry.

  7. Airborne electronically steerable phased array

    Science.gov (United States)

    1972-01-01

    The results are presented of the second stage of a program for the design and development of a phased array capable of simultaneous and separate transmission and reception of radio frequency signals at S-band frequencies. The design goals of this stage were the development of three major areas of interest required for the final prototype model. These areas are the construction and testing of the low-weight, full-scale 128-element array of antenna elements, the development of the RF manifold feed system, and the construction and testing of a working module containing diplexer and transmit and receive circuits.

  8. Versatile Flexible Graphene Multielectrode Arrays.

    Science.gov (United States)

    Kireev, Dmitry; Seyock, Silke; Ernst, Mathis; Maybeck, Vanessa; Wolfrum, Bernhard; Offenhäusser, Andreas

    2016-12-23

    Graphene is a promising material possessing features relevant to bioelectronics applications. Graphene microelectrodes (GMEAs), which are fabricated in a dense array on a flexible polyimide substrate, were investigated in this work for their performance via electrical impedance spectroscopy. Biocompatibility and suitability of the GMEAs for extracellular recordings were tested by measuring electrical activities from acute heart tissue and cardiac muscle cells. The recordings show encouraging signal-to-noise ratios of 65 ± 15 for heart tissue recordings and 20 ± 10 for HL-1 cells. Considering the low noise and excellent robustness of the devices, the sensor arrays are suitable for diverse and biologically relevant applications.

  9. Versatile Flexible Graphene Multielectrode Arrays

    Directory of Open Access Journals (Sweden)

    Dmitry Kireev

    2016-12-01

    Full Text Available Graphene is a promising material possessing features relevant to bioelectronics applications. Graphene microelectrodes (GMEAs, which are fabricated in a dense array on a flexible polyimide substrate, were investigated in this work for their performance via electrical impedance spectroscopy. Biocompatibility and suitability of the GMEAs for extracellular recordings were tested by measuring electrical activities from acute heart tissue and cardiac muscle cells. The recordings show encouraging signal-to-noise ratios of 65 ± 15 for heart tissue recordings and 20 ± 10 for HL-1 cells. Considering the low noise and excellent robustness of the devices, the sensor arrays are suitable for diverse and biologically relevant applications.

  10. Substrate integrated antennas and arrays

    CERN Document Server

    Cheng, Yu Jian

    2015-01-01

    Substrate Integrated Antennas and Arrays provides a single source for cutting-edge information on substrate integrated circuits (SICs), substrate integrated waveguide (SIW) feeding networks, SIW slot array antennas, SIC traveling-wave antennas, SIW feeding antennas, SIW monopulse antennas, and SIW multibeam antennas. Inspired by the author's extensive research, this comprehensive book:Describes a revolutionary SIC-based antenna technique with the potential to replace existing antenna technologiesExamines theoretical and experimental results connected to electrical and mechanical performanceExp

  11. Highlights from the Telescope Array

    Science.gov (United States)

    Matthews, J. N.

    2016-11-01

    The Telescope Array measures the properties of ultra high energy cosmic ray induced extensive air showers. We do this using a variety of techniques including an array of scintillator detectors to sample the footprint of the air shower when it reaches the Earth's surface and telescopes to measure the fluorescence and Cerenkov light of the air shower. From this we determine the energy spectrum and chemical composition of the primary particles. We also search for sources of cosmic rays and anisotropy. We have found evidence of a possible source of ultra high energy cosmic rays in the northern sky. The experiment and its most recent measurements will be discussed.

  12. Wicking a confined micropillar array

    CERN Document Server

    Texier, Baptiste Darbois; Stoukatch, Serguei; Dorbolo, Stéphane

    2016-01-01

    This study considers the spreading of a Newtonian and perfectly wetting liquid in a square array of cylindric micropillars confined between two plates. We show experimentally that the dynamics of the contact line follows a Washburn-like law which depends on the characteristics of the micropillar array (height, diameter and pitch). The presence of pillars can either enhanced or slow down the motion of the contact line. A theoretical model based on capillary and viscous forces has been developed in order to rationalize our observations. Finally, the impact of pillars on the volumic flow rate of liquid which is pumped in the microchannel is inspected.

  13. Speckle imaging from an array

    Science.gov (United States)

    Riker, Jim F.; Tyler, Glenn A.; Vaughn, Jeff L.

    2016-09-01

    In this paper, we present two analytic theories developed recently to predict the performance of an imaging system composed of a phased array illuminator and a set of receiver subapertures. The receiver need not coincide with the transmitter. The two theories have been documented separately (ref. 1, 2), and the reader can find more details there - the theories present the analytic phased array irradiance on target in the presence of piston errors, and the resulting speckle pattern-induced imaging noise. The principal results presented here are the Signal to Noise Ratios (SNR) for both the radiometric portion of the problem and the speckle imaging portion of the problem.

  14. Phased arrays: inline flow line hub inspection using phased arrays

    NARCIS (Netherlands)

    Bloom, J.G.P.; Chougrani, K.; Rundberg, H.; Oldenziel, G.; Deleye, X.; Martina, Q.

    2011-01-01

    The feasibility of the inspection of flow line hubs using the phased array technique was investigated to determine the surface area of the seal area degraded by corrosion. A clean model of the hub was simulated to gain insight into the geometrical echoes and to determine the area covered by the ultr

  15. Design Considerations for Array CGH to OligonucleotideArrays

    Energy Technology Data Exchange (ETDEWEB)

    Baldocchi, R.A.; Glynne, R.J.; Chin, K.; Kowbel, D.; Collins, C.; Mack, D.H.; Gray, J.W.

    2005-03-04

    Background: Representational oligonucleotide microarray analysis has been developed for detection of single nucleotide polymorphisms and/or for genome copy number changes. In this process, the intensity of hybridization to oligonucleotides arrays is increased by hybridizing a polymerase chain reaction (PCR)-amplified representation of reduced genomic complexity. However, hybridization to some oligonucleotides is not sufficiently high to allow precise analysis of that portion of the genome. Methods: In an effort to identify aspects of oligonucleotide hybridization affecting signal intensity, we explored the importance of the PCR product strand to which each oligonucleotide is homologous and the sequence of the array oligonucleotides. We accomplished this by hybridizing multiple PCR-amplified products to oligonucleotide arrays carrying two sense and two antisense 50-mer oligonucleotides for each PCR amplicon. Results: In some cases, hybridization intensity depended more strongly on the PCR amplicon strand (i.e., sense vs. antisense) than on the detection oligonucleotide sequence. In other cases, the oligonucleotide sequence seemed to dominate. Conclusion: Oligonucleotide arrays for analysis of DNA copy number or for single nucleotide polymorphism content should be designed to carry probes to sense and antisense strands of each PCR amplicon to ensure sufficient hybridization and signal intensity.

  16. Magnetic focusing of cold atomic beam with a 2D array of current-carrying wires

    Institute of Scientific and Technical Information of China (English)

    Yang Liu; Min Yun; Jianping Yin

    2006-01-01

    @@ A new scheme to realize a two-dimensional (2D) array of magnetic micro-lenses for a cold atomic beam,formed by an array of square current-carrying wires,is proposed.We calculate the spatial distributions of the magnetic fields from the array of current-carrying wires and the magnetic focusing potential for cold rubidium atoms,and study the dynamic focusing processes of cold atoms passing through the magnetic micro-lens array and its focusing properties by using Monte-Carlo simulations and trajectory tracing method.The result shows that the proposed micro-lens array can be used to focus effectively a cold atomic beam,even to load ultracold atoms or a BEC sample into a 2D optical lattice formed by blue detuned hollow beams.

  17. A design concept for an MMIC microstrip phased array

    Science.gov (United States)

    Lee, R. Q.; Smetana, J.; Acosta, R.

    A conceptual design for a microstrip phased array with monolithic microwave integrated circuit (MMIC) amplitude and phase controls is described. The MMIC devices used are 20 GHz variable power amplifiers and variable phase shifters recently developed by NASA contractors for applications in future Ka band advanced satellite communication antenna systems. The proposed design concept is for a general NxN element array of rectangular lattice geometry. Subarray excitation is incorporated in the MMIC phased array design to reduce the complexity of the beam forming network and the number of MMIC components required. The proposed design concept takes into consideration the RF characteristics and actual phyical dimensions of the MMIC devices. Also, solutions to spatial constraints and interconnections associated with currently available packaging designs are discussed. Finally, the design of the microstrip radiating elements and their radiation characteristics are examined.

  18. Creating Usable Pin Array Tactons for Non-Visual Information

    CERN Document Server

    Pietrzak, Thomas; Stephen, Brewster A; Martin, Benoît; Pecci, Isabelle; 10.1109/TOH.2009.6

    2012-01-01

    Spatial information can be difficult to present to a visually impaired computer user. In this paper we examine a new kind of tactile cueing for non-visual interaction as a potential solution, building on earlier work on vibrotactile Tactons. However, unlike vibrotactile Tactons, we use a pin array to stimulate the finger tip. Here, we describe how to design static and dynamic Tactons by defining their basic components. We then present user tests examining how easy it is to distinguish between different forms of pin array Tactons demonstrating accurate Tacton sets to represent directions. These experiments demonstrate usable patterns for static, wave and blinking pin array Tacton sets for guiding a user in one of eight directions. A study is then described that shows the benefits of structuring Tactons to convey information through multiple parameters of the signal. By using multiple independent parameters for a Tacton, this study demonstrates participants perceive more information through a single Tacton. Two...

  19. Full-matrix capture with a customizable phased array instrument

    Science.gov (United States)

    Dao, Gavin; Braconnier, Dominique; Gruber, Matt

    2015-03-01

    In recent years, a technique known as Full-Matrix Capture (FMC) has gained some headway in the NDE community for phased array applications. It's important to understand that FMC is the method that the instrumentation acquires the ultrasonic signals, but further post-processing is required in software to create a meaningful image for a particular application. Having a flexible software interface, small form factor, excellent signal-to-noise ratio per acquisition channel on a 64/64 or 128/128 phased array module with FMC capability proves beneficial in both industrial implementation and in further investigation of post-processing techniques. This paper will provide an example of imaging with a 5MHz linear phased array transducer with 128 elements using FMC and a popular post-processing algorithm known as Total-Focus Method (TFM).

  20. Microchannel cross load array with dense parallel input

    Science.gov (United States)

    Swierkowski, Stefan P.

    2004-04-06

    An architecture or layout for microchannel arrays using T or Cross (+) loading for electrophoresis or other injection and separation chemistry that are performed in microfluidic configurations. This architecture enables a very dense layout of arrays of functionally identical shaped channels and it also solves the problem of simultaneously enabling efficient parallel shapes and biasing of the input wells, waste wells, and bias wells at the input end of the separation columns. One T load architecture uses circular holes with common rows, but not columns, which allows the flow paths for each channel to be identical in shape, using multiple mirror image pieces. Another T load architecture enables the access hole array to be formed on a biaxial, collinear grid suitable for EDM micromachining (square holes), with common rows and columns.

  1. Light-Patterned Current Generation in a Droplet Bilayer Array

    Science.gov (United States)

    Restrepo Schild, Vanessa; Booth, Michael J.; Box, Stuart J.; Olof, Sam N.; Mahendran, Kozhinjampara R.; Bayley, Hagan

    2017-04-01

    We have created a 4 × 4 droplet bilayer array comprising light-activatable aqueous droplet bio-pixels. Aqueous droplets containing bacteriorhodopsin (bR), a light-driven proton pump, were arranged on a common hydrogel surface in lipid-containing oil. A separate lipid bilayer formed at the interface between each droplet and the hydrogel; each bilayer then incorporated bR. Electrodes in each droplet simultaneously measured the light-driven proton-pumping activities of each bio-pixel. The 4 × 4 array derived by this bottom-up synthetic biology approach can detect grey-scale images and patterns of light moving across the device, which are transduced as electrical current generated in each bio-pixel. We propose that synthetic biological light-activatable arrays, produced with soft materials, might be interfaced with living tissues to stimulate neuronal pathways.

  2. Full process for integrating silicon nanowire arrays into solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Perraud, Simon; Poncet, Severine; Noel, Sebastien; Levis, Michel; Faucherand, Pascal; Rouviere, Emmanuelle [CEA, LITEN, Laboratoire des Composants pour la Recuperation d' Energie, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Thony, Philippe; Jaussaud, Claude; Delsol, Regis [CEA, LITEN, Laboratoire des Composants Solaires, INES-RDI, Savoie Technolac, 50 avenue du Lac Leman, 73377 Le-Bourget-du-Lac (France)

    2009-09-15

    A novel process was developed for integrating silicon nanowire arrays into solar cells. n-Type silicon nanowires were grown by chemical-vapour deposition via the gold-catalysed vapour-liquid-solid method, on a p-type silicon substrate. After the growth, the nanowire array was planarized, by embedding the nanowires in a spin-on glass matrix and subsequent chemical-mechanical polishing of the front surface. This planarization step allows to deposit a continuous and uniform conductive film on top of the nanowire array, and thus to form a high-quality front electrical contact. For an illumination intensity of 100 mW/cm{sup 2}, our devices exhibit an energy conversion efficiency of 1.9%. The main performance limiting factor is a high pn junction reverse current, due to contamination by the growth catalyst or to a lack of passivation of surface electronic defects. (author)

  3. Reconfigurable time-steered array-antenna beam former.

    Science.gov (United States)

    Frankel, M Y; Esman, R D

    1997-12-10

    We present and analyze a hardware-optimized technique that provides true-time-delay steering for broadband two-dimensional array-antenna applications. The technique improves on previous approaches by the reduction of the two-dimensional beam-former architecture complexity, by the provision of flexibility in time-delay unit selection, and by the potential reduction of optical loss. The technique relies on a one-dimensional bank of time-delay units to form the required time-delay gradient for proper off-broadside angle steering. A reconfigurable optical interconnection fabric is used to reassign dynamically the connections between the time-delay units and individual array elements of a two-dimensional array to effect the proper steering angle along the off-broadside cone.

  4. Careers (A Course of Study). Unit V: Forms, Forms, Forms.

    Science.gov (United States)

    Turley, Kay

    Designed to enable special needs students to understand and complete various job-related forms, this set of activities devoted to forms encountered before and after one obtains a job is the fifth in a nine-unit secondary level careers course intended to provide handicapped students with the knowledge and tools necessary to succeed in the world of…

  5. Anatomy of the six-part all-partition array as used by Milton Babbitt

    DEFF Research Database (Denmark)

    Bemman, Brian; Meredith, David

    For Milton Babbitt (1916–2011), twelve-tone techniques were indispensable forms of musical composition because they are fundamentally derived from mathematical constructs. Perhaps his most complex form of composition is the all-partition array. Its large-scale structure is formed by concatenated...

  6. Microfabricated Arrays for Splitting and Assay of Clonal Colonies

    Science.gov (United States)

    Gach, Philip C.; Xu, Wei; King, Samantha J.; Sims, Christopher E.; Bear, James; Allbritton, Nancy L.

    2012-01-01

    A microfabricated platform was developed for highly parallel and efficient colony picking, splitting and clone identification. A pallet array provided patterned cell colonies which mated to a second printing array composed of bridging microstructures formed by a supporting base and attached post. The posts enabled mammalian cells from colonies initially cultured on the pallet array to migrate to corresponding sites on the printing array. Separation of the arrays simultaneously split the colonies creating a patterned replica. Optimization of array elements provided transfer efficiencies greater than 90% using bridging posts of 30 μm diameter and 100 μm length and total colony numbers of 3000. Studies using five mammalian cell lines demonstrated that a variety of adherent cell types could be cultured and effectively split with printing efficiencies of 78–92%. To demonstrate the technique’s utility, clonal cell lines with siRNA knockdown of Coronin 1B were generated using the arrays and compared to a traditional FACS/Western Blotting-based approach. Identification of target clones required a destructive assay to identify cells with an absence of Coronin 1B brought about by the successful infection of interfering shRNA construct. By virtue of miniaturization and its parallel format, the platform enabled the identification and generation of 12 target clones from a starting sample of only 3900 cells and required only 5-man hours over 11 days. In contrast, the traditional method required 500,000 cells and generated only 5 target clones with 34-man hours expended over 47 days. These data support the considerable reduction in time, manpower and reagents using the miniaturized platform for clonal selection by destructive assay versus conventional approaches. PMID:23153031

  7. Parallel imaging methods for phased array MRI

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Two parallel methods for magnetic resonance imaging (MRI) using radio frequency (RF) phased array surface coils, named spatial local Fourier encoding (SLFE) and spatial RF encoding (SRFE), are presented. The MR signals are acquired from separate channels across the coils, each of which covers a sub-FOV (field-of-view) in a parallel fashion, and the acquired data are combined to form an image of entire FOV. These two parallel encoding techniques can accelerate MR imaging greatly, yet associated artifact may appear, although the SLFE is an effective image reconstruction method which can reduce the localized artifact in some degrees. By the SRFE, RF coil array can be utilized for spatial encoding through a specialized coil design. The images are acquired in a snapshot with a high signal-to-noise ratio (SNR) without the costly gradient system, resulting in great saving of cost. Both mutual induction and aliasing effect of adjacent coils are critical to the success of SRFE. The strategies of inverse source problem and wavelet transform (WT) can be employed to eliminate them. The results simulated by MATLAB are reported.

  8. Synthesis and screening combinatorial arrays of zeolites

    Science.gov (United States)

    Schultz, Peter G.; Xiang, Xiaodong; Goldwasser, Isy

    2003-11-18

    Methods and apparatus for the preparation and use of a substrate having an array of diverse materials in predefined regions thereon. A substrate having an array of diverse materials thereon is generally prepared by delivering components of materials to predefined regions on a substrate, and simultaneously reacting the components to form at least two materials. Materials which can be prepared using the methods and apparatus of the present invention include, for example, covalent network solids, ionic solids and molecular solids. More particularly, materials which can be prepared using the methods and apparatus of the present invention include, for example, inorganic materials, intermetallic materials, metal alloys, ceramic materials, organic materials, organometallic materials, non-biological organic polymers, composite materials (e.g., inorganic composites, organic composites, or combinations thereof), etc. Once prepared, these materials can be screened for useful properties including, for example, electrical, thermal, mechanical, morphological, optical, magnetic, chemical, or other properties. Thus, the present invention provides methods for the parallel synthesis and analysis of novel materials having useful properties.

  9. Context-free Grammars for Triangular Arrays

    Institute of Scientific and Technical Information of China (English)

    Robert X. J. HAO; Larry X. W. WANG; Harold R. L. YANG

    2015-01-01

    We consider context-free grammars of the form G={f →fb1+b2+1ga1+a2, g→fb1ga1+1}, where ai and bi are integers subject to certain positivity conditions. Such a grammar G gives rise to triangular arrays {T (n, k)}0≤k≤n satisfying a three-term recurrence relation. Many combinatorial sequences can be generated in this way. Let Tn(x)=? nk=0 T (n, k)xk. Based on the diff erential operator with respect to G, we define a sequence of linear operators Pn such that Tn+1(x)=Pn(Tn(x)). Applying the characterization of real stability preserving linear operators on the multivariate polynomials due to Borcea and Bra¨nd´en, we obtain a necessary and suffi cient condition for the operator Pn to be real stability preserving for any n. As a consequence, we are led to a suffi cient condition for the real-rootedness of the polynomials defined by certain triangular arrays, obtained by Wang and Yeh. Moreover, as special cases we obtain grammars that lead to identities involving the Whitney numbers and the Bessel numbers.

  10. The Very Large Array Expansion Project

    Science.gov (United States)

    Rupen, Michael P.

    2003-02-01

    The National Radio Astronomy Observatory (NRAO) is undertaking a major expansion of the Very Large Array (VLA), the most powerful and flexible radio instrument in the world. This VLA Expansion Project combines the existing infrastructure with state-of-the-art electronics and instrumentation to improve the scientific capabilities of the array by a factor 10 or more in all key observational parameters. Some of the most important advances include: (1) replacing the existing waveguide with optical fiber, allowing total bandwidths of up to 16 GHz, rather than the current 200 MHz; (2) installing wideband receiver systems, for continuous coverage of the entire centimeter radio spectrum from Mexican National Council for Science and Technology (CONACyT). We plan to finish the entire project within a decade. The EVLA will inaugurate a new era in radio astronomy, allowing extinction-free imaging of star-forming galaxies out to z>5, measurements of the three-dimensional structure of magnetic fields in objects ranging from the Sun to nearby galaxies, and parallaxes and proper motion measurements of pulsars spread throughout the Galaxy. The EVLA is intended not to perform a single, particular experiment, but to provide an essential tool across the entire range of modern astrophysics.

  11. The Solar Imaging Radio Array (SIRA) Mission

    Science.gov (United States)

    Jones, D. L.; MacDowall, R.; Gopalswamy, N.; Kaiser, M.; Reiner, M.; Demaio, L.; Weiler, K.; Kasper, J.; Bale, S.; Howard, R.

    2004-12-01

    The Solar Imaging Radio Array will be proposed to NASA as a Medium Explorer (MIDEX) mission by a team of investigators at GSFC, JPL, NRL, MIT, and UC Berkeley. The main science goal of the mission is imaging and tracking of solar radio bursts, particularly those associated with coronal mass ejections, and understanding their evolution and influence on Earth's magnetosphere. Related goals are mapping the 3-dimensional morphology of the interplanetary magnetic field and improving the prediction of geomagnetic storms. A number of topics in galactic and extragalactic astrophysics will also be addressed by SIRA. The mission concept is a free-flying array of about 16 small, inexpensive satellites forming an aperture synthesis interferometer in space. By observing from above the ionosphere, and far from terrestrial radio interference, SIRA will cover frequencies between a few tens of kHz up to 15 MHz. This wide spectral window is essentially unexplored with high angular resolution. Part of this work is being carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

  12. GRIFFIN's Fast-Timing Array

    Science.gov (United States)

    Olaizola, Bruno; Griffin Collaboration

    2016-09-01

    The Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN) is the new β-decay spectrometer facility at TRIUMF-ISAC. Consists of an array of 16 large-volume HPGe clover detectors with an unparalleled efficiency of 19% at 1.33 MeV. Its strongest advantage is the versatility of the ancillary detectors that can be coupled to the main array to tag on β particles, neutrons or precisely measure conversion electron spectra. An ancillary array of 8 LaBr3(Ce) detectors for γ-rays and a fast plastic scintillator for β-particles has been optimized for fast-timing experiments with GRIFFIN. The 51 mm x 51 mm cylindrical LaBr3(Ce) crystals are coupled to Hamamatsu R2083 photomultipliers. Timing resolutions as good as FWHM 200 ps and time-walks below +/- 30 ps have been obtained for individual crystals using analog electronics. There is also an ongoing project to develop an active BGO shield for the LaBr3(Ce) crystals. The LaBr3(Ce) array commissioning experiment to measure the 145,146Cs decay to 145,146Ba will test its capabilities over a wide range of lifetimes. Preliminary results on the lifetimes of some of the low-laying states will be presented.

  13. High density arrays of micromirrors

    Energy Technology Data Exchange (ETDEWEB)

    Folta, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, J. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kolman, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lee, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brase, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-02-01

    We established and achieved our goal to (1) fabricate and evaluate test structures based on the micromirror design optimized for maskless lithography applications, (2) perform system analysis and code development for the maskless lithography concept, and (3) identify specifications for micromirror arrays (MMAs) for LLNL's adaptive optics (AO) applications and conceptualize new devices.

  14. Gamma-ray array physics.

    Energy Technology Data Exchange (ETDEWEB)

    Lister, C. J.

    1999-05-25

    In this contribution I am going to discuss the development of large arrays of Compton Suppressed, High Purity Germanium (HpGe) detectors and the physics that has been, that is being, and that will be done with them. These arrays and their science have dominated low-energy nuclear structure research for the last twenty years and will continue to do so in the foreseeable future. John Sharpey Schafer played a visionary role in convincing a skeptical world that the development of these arrays would lead to a path of enlightenment. The extent to which he succeeded can be seen both through the world-wide propagation of ever more sophisticated devices, and through the world-wide propagation of his students. I, personally, would not be working in research if it were not for Johns inspirational leadership. I am eternally grateful to him. Many excellent reviews of array physics have been made in the past which can provide detailed background reading. The review by Paul Nolan, another ex-Sharpey Schafer student, is particularly comprehensive and clear.

  15. BOLOMETRIC ARRAYS FOR MILLIMETER WAVELENGTHS

    Directory of Open Access Journals (Sweden)

    E. Castillo

    2009-01-01

    Full Text Available During last years, semiconductor bolometers using thin lms have been developed at INAOE, speci cally boron-doped hydrogenated amorphous silicon lms. The characteristics shown by these devices made them attractive to be used in astronomical instrumentation, mainly in two-dimentional arrays. These detector arrays used at the Large Millimeter Telescope will make possible to obtain astronomical images in millimeter and submillimeter wavelengths. With this in mind, we are developing a method to produce, with enough reliability, bolometer arrays at INAOE. Until now, silicon nitride diaphragm arrays, useful as radiation absorbers, have succesfully been obtained. Sizes going from one to four millimeter by element in a consistent way; however we have not tested thermometers and metallic contact deposition yet. At the same time, we are working on two possible con gurations for the readout electronics; one of them using commercial components while the other will be an integrated circuit speci cally designed for this application. Both versions will work below 77K.

  16. Directivity of basic linear arrays

    DEFF Research Database (Denmark)

    Bach, Henning

    1970-01-01

    For a linear uniform array ofnelements, an expression is derived for the directivity as a function of the spacing and the phase constants. The cases of isotropic elements, collinear short dipoles, and parallel short dipoles are included. The formula obtained is discussed in some detail and contour...

  17. TANGO Array. 1. The instrument

    Energy Technology Data Exchange (ETDEWEB)

    Bauleo, P. E-mail: pablo.bauleo@colostate.edu; Bonifazi, C.; Filevich, A.; Reguera, A

    2004-01-11

    TANGO Array is an air shower experiment which has been constructed in Buenos Aires, Argentina. It was commissioned during the year 2000 becoming fully operational in September, 2000. The array consists of four water Cherenkov detectors enclosing a geometrical area of {approx}30,000 m{sup 2} and its design has been optimized for the observation of Extended Air Showers produced by cosmic rays near the 'knee' energy region {approx}4x10{sup 15} eV. Three of the detectors have been constructed using 12,000-l stainless-steel tanks, and the fourth has been mounted in a smaller, 400-l plastic container. The detectors are connected by cables to the data acquisition room, where a very simple system, which takes advantage of the features of a four-channel digital oscilloscope, was set for data collection. This data collection setup allows a fully automatic experiment control which does not require operator intervention. It includes monitoring, data logging, and daily calibration of all detectors. This paper describes the detectors and their associated electronics, and details are given on the data acquisition system, the triggering and calibration procedures, and the operation of the array. Examples of air shower traces, recorded by the array, are presented.

  18. TANGO Array.. 1. The instrument

    Science.gov (United States)

    Bauleo, P.; Bonifazi, C.; Filevich, A.; Reguera, A.

    2004-01-01

    TANGO Array is an air shower experiment which has been constructed in Buenos Aires, Argentina. It was commissioned during the year 2000 becoming fully operational in September, 2000. The array consists of four water Cherenkov detectors enclosing a geometrical area of ˜30,000 m2 and its design has been optimized for the observation of Extended Air Showers produced by cosmic rays near the "knee" energy region ˜4×10 15 eV. Three of the detectors have been constructed using 12,000-l stainless-steel tanks, and the fourth has been mounted in a smaller, 400-l plastic container. The detectors are connected by cables to the data acquisition room, where a very simple system, which takes advantage of the features of a four-channel digital oscilloscope, was set for data collection. This data collection setup allows a fully automatic experiment control which does not require operator intervention. It includes monitoring, data logging, and daily calibration of all detectors. This paper describes the detectors and their associated electronics, and details are given on the data acquisition system, the triggering and calibration procedures, and the operation of the array. Examples of air shower traces, recorded by the array, are presented.

  19. Light weight digital array SAR

    NARCIS (Netherlands)

    Otten, M.; Maas, N.; Bolt, R.; Anitori, L.

    2010-01-01

    A light weight SAR has been designed, suitable for short range tactical UAVs, consisting of a fully digital receive array, and a very compact active transmit antenna. The weight of the complete RF front is expected to be below 3 kg, with a power consumption below 30 W. This X-band system can provide

  20. Photoelectrochemistry of Semiconductor Nanowire Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, Thomas E; Redwing, Joan M

    2009-11-10

    This project supported research on the growth and photoelectrochemical characterization of semiconductor nanowire arrays, and on the development of catalytic materials for visible light water splitting to produce hydrogen and oxygen. Silicon nanowires were grown in the pores of anodic aluminum oxide films by the vapor-liquid-solid technique and were characterized electrochemically. Because adventitious doping from the membrane led to high dark currents, silicon nanowire arrays were then grown on silicon substrates. The dependence of the dark current and photovoltage on preparation techniques, wire diameter, and defect density was studied for both p-silicon and p-indium phosphide nanowire arrays. The open circuit photovoltage of liquid junction cells increased with increasing wire diameter, reaching 350 mV for micron-diameter silicon wires. Liquid junction and radial p-n junction solar cells were fabricated from silicon nano- and microwire arrays and tested. Iridium oxide cluster catalysts stabilized by bidentate malonate and succinate ligands were also made and studied for the water oxidation reaction. Highlights of this project included the first papers on silicon and indium phosphide nanowire solar cells, and a new procedure for making ligand-stabilized water oxidation catalysts that can be covalently linked to molecular photosensitizers or electrode surfaces.

  1. Modelling clustering of vertically aligned carbon nanotube arrays

    Science.gov (United States)

    Schaber, Clemens F.; Filippov, Alexander E.; Heinlein, Thorsten; Schneider, Jörg J.; Gorb, Stanislav N.

    2015-01-01

    Previous research demonstrated that arrays of vertically aligned carbon nanotubes (VACNTs) exhibit strong frictional properties. Experiments indicated a strong decrease of the friction coefficient from the first to the second sliding cycle in repetitive measurements on the same VACNT spot, but stable values in consecutive cycles. VACNTs form clusters under shear applied during friction tests, and self-organization stabilizes the mechanical properties of the arrays. With increasing load in the range between 300 µN and 4 mN applied normally to the array surface during friction tests the size of the clusters increases, while the coefficient of friction decreases. To better understand the experimentally obtained results, we formulated and numerically studied a minimalistic model, which reproduces the main features of the system with a minimum of adjustable parameters. We calculate the van der Waals forces between the spherical friction probe and bunches of the arrays using the well-known Morse potential function to predict the number of clusters, their size, instantaneous and mean friction forces and the behaviour of the VACNTs during consecutive sliding cycles and at different normal loads. The data obtained by the model calculations coincide very well with the experimental data and can help in adapting VACNT arrays for biomimetic applications. PMID:26464787

  2. Sparse Planar Array Synthesis Using Matrix Enhancement and Matrix Pencil

    Directory of Open Access Journals (Sweden)

    Mei-yan Zheng

    2013-01-01

    Full Text Available The matrix enhancement and matrix pencil (MEMP plays important roles in modern signal processing applications. In this paper, MEMP is applied to attack the problem of two-dimensional sparse array synthesis. Firstly, the desired array radiation pattern, as the original pattern for approximating, is sampled to form an enhanced matrix. After performing the singular value decomposition (SVD and discarding the insignificant singular values according to the prior approximate error, the minimum number of elements can be obtained. Secondly, in order to obtain the eigenvalues, the generalized eigen-decomposition is employed on the approximate matrix, which is the optimal low-rank approximation of the enhanced matrix corresponding to sparse planar array, and then the ESPRIT algorithm is utilized to pair the eigenvalues related to each dimension of the planar array. Finally, element positions and excitations of the sparse planar array are calculated according to the correct pairing of eigenvalues. Simulation results are presented to illustrate the effectiveness of the proposed approach.

  3. Study of stacked microstrip phased arrays

    Science.gov (United States)

    Arts, M. J.; Smolders, A. B.

    1993-06-01

    Two theoretical methods for studying stacked-patch microstrip phased arrays are compared: (1) the element-by-element approach (finite array approach) of Pozar (1986) and Smolders (1992); and (2) the infinite approach of Pozar and Shaubert (1984) and Liu et al. (1988). Both theories were found to give almost the same results for a 7 x 7 stacked microstrip antenna, except for edge array elements and for large scan angles. Edge array elements could only be analyzed properly by using a finite array approach. Coupling measurements were made on a 7 x 7 array with a single patch layer, and the results agreed well with calculations.

  4. Process for forming synapses in neural networks and resistor therefor

    Science.gov (United States)

    Fu, C.Y.

    1996-07-23

    Customizable neural network in which one or more resistors form each synapse is disclosed. All the resistors in the synaptic array are identical, thus simplifying the processing issues. Highly doped, amorphous silicon is used as the resistor material, to create extremely high resistances occupying very small spaces. Connected in series with each resistor in the array is at least one severable conductor whose uppermost layer has a lower reflectivity of laser energy than typical metal conductors at a desired laser wavelength. 5 figs.

  5. Process for forming synapses in neural networks and resistor therefor

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Chi Y. (San Francisco, CA)

    1996-01-01

    Customizable neural network in which one or more resistors form each synapse. All the resistors in the synaptic array are identical, thus simplifying the processing issues. Highly doped, amorphous silicon is used as the resistor material, to create extremely high resistances occupying very small spaces. Connected in series with each resistor in the array is at least one severable conductor whose uppermost layer has a lower reflectivity of laser energy than typical metal conductors at a desired laser wavelength.

  6. On good ETOL forms

    DEFF Research Database (Denmark)

    Skyum, Sven

    1978-01-01

    This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete.......This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete....

  7. The Global Array of Primitve Arc Melts

    Science.gov (United States)

    Schmidt, M. W.; Jagoutz, O. E.

    2015-12-01

    A longstanding question concerns the nature of the melts forming in the subarc mantle and giving rise to arc magmatism. The global array of primitive arc melts (1180 volcanic rocks in 25 arcs extracted from the georoc database, calculated to be in equilibrium with mantle olivine) yields five principal melt types: calc-alkaline basalts and high-Mg andesites, tholeiitic basalts and high-Mg andesites, and shoshonitic or alkaline arc melts; many arcs have more than one type. Primitive calc-alkaline basalts occur in 11 arcs but most strikingly, 8 continental arcs (incl. Aleutians, Cascades, Japan, Mexico, Kamtschatka) have a continuous range of calc-alkaline basalts to high-Mg andesites with mostly 48-58 wt% SiO2. In each arc, these are spatially congruent, trace element patterns overlap, and major elements form a continuum. Their Ca-Mg-Si systematics suggests saturation in olivine+opx+cpx. We hence interpret the large majority of high-Mg andesites as derived from primitive calc-alkaline basalts through fractionation and reaction in the shallower mantle. Removal of anhydrous mantle phases at lower pressures increases SiO2 and H2O-contents while Mg# and Ni remain buffered to mantle values. Primitive tholeiitic basalts (Cascades, Kermadec, Marianas, Izu-Bonin, Japan, Palau, Sunda) have a much lesser subduction signal (e.g. in LILE) than the calc-alkaline suite. These tholeiites have been interpreted to form through decompression melting, but also characterize young intraoceanic arcs. In the two continental arcs with both tholeiitic and calc-alkaline primitive basalts (clearly distinct in trace patterns), there is no clear spatial segregation (Casacades, Japan). Three intraoceanic arcs (Marianas, Izu-Bonin, Tonga) have primitive tholeiitic, highly depleted high-Mg andesites (boninites) with HFSE and HREE slightly above primitive mantle values. These deviate in majors from the array formed by the basalts and calc-alkaline andesites suggesting that only these formed from a

  8. Compact stereo endoscopic camera using microprism arrays.

    Science.gov (United States)

    Yang, Sung-Pyo; Kim, Jae-Jun; Jang, Kyung-Won; Song, Weon-Kook; Jeong, Ki-Hun

    2016-03-15

    This work reports a microprism array (MPA) based compact stereo endoscopic camera with a single image sensor. The MPAs were monolithically fabricated by using two-step photolithography and geometry-guided resist reflow to form an appropriate prism angle for stereo image pair formation. The fabricated MPAs were transferred onto a glass substrate with a UV curable resin replica by using polydimethylsiloxane (PDMS) replica molding and then successfully integrated in front of a single camera module. The stereo endoscopic camera with MPA splits an image into two stereo images and successfully demonstrates the binocular disparities between the stereo image pairs for objects with different distances. This stereo endoscopic camera can serve as a compact and 3D imaging platform for medical, industrial, or military uses.

  9. Microwell Arrays for Studying Many Individual Cells

    Science.gov (United States)

    Folch, Albert; Kosar, Turgut Fettah

    2009-01-01

    "Laboratory-on-a-chip" devices that enable the simultaneous culturing and interrogation of many individual living cells have been invented. Each such device includes a silicon nitride-coated silicon chip containing an array of micromachined wells sized so that each well can contain one cell in contact or proximity with a patch clamp or other suitable single-cell-interrogating device. At the bottom of each well is a hole, typically 0.5 m wide, that connects the well with one of many channels in a microfluidic network formed in a layer of poly(dimethylsiloxane) on the underside of the chip. The microfluidic network makes it possible to address wells (and, thus, cells) individually to supply them with selected biochemicals. The microfluidic channels also provide electrical contact to the bottoms of the wells.

  10. Periodic Arrays of M2-Branes

    CERN Document Server

    Jeon, Imtak; Richmond, Paul

    2012-01-01

    We consider periodic arrays of M2-branes in the ABJM model in the spirit of a circle compactification to D2-branes in type IIA string theory. The result is a curious formulation of three-dimensional maximally supersymmetric Yang-Mills theory in terms of fermions, seven transverse scalars, a non-dynamical gauge field and an additional scalar `dual gluon'. Upon further T-duality on a transverse torus we obtain a non-manifest-Lorentz-invariant description of five-dimensional maximally supersymmetric Yang-Mills. Here the additional scalar field can be thought of as the components of a two-form along the torus. This action can be viewed as an M-theory description of M5-branes on ${\\mathbb T}^3$.

  11. Receiver control for the Submillimeter Array

    CERN Document Server

    Hunter, T R; Kimberk, R; Leiker, P S; Christensen, R D

    2002-01-01

    Efficient operation of a submillimeter interferometer requires remote (preferably automated) control of mechanically tuned local oscillators, phase-lock loops, mixers, optics, calibration vanes and cryostats. The present control system for these aspects of the Submillimeter Array (SMA) will be described. Distributed processing forms the underlying architecture. In each antenna cabin, a serial network of up to ten independent 80C196 microcontroller boards attaches to the real-time PowerPC computer (running LynxOS). A multi-threaded, gcc-compiled program on the PowerPC accepts top-level requests via remote procedure calls (RPC), subsequently dispatches tuning commands to the relevant microcontrollers, and regularly reports the system status to optical-fiber-based reflective memory for common access by the telescope monitor and error reporting system. All serial communication occurs asynchronously via encoded, variable-length packets. The microcontrollers respond to the requested commands and queries by accessin...

  12. Microfluidic gene arrays for rapid genomic profiling

    Science.gov (United States)

    West, Jay A.; Hukari, Kyle W.; Hux, Gary A.; Shepodd, Timothy J.

    2004-12-01

    Genomic analysis tools have recently become an indispensable tool for the evaluation of gene expression in a variety of experiment protocols. Two of the main drawbacks to this technology are the labor and time intensive process for sample preparation and the relatively long times required for target/probe hybridization. In order to overcome these two technological barriers we have developed a microfluidic chip to perform on chip sample purification and labeling, integrated with a high density genearray. Sample purification was performed using a porous polymer monolithic material functionalized with an oligo dT nucleotide sequence for the isolation of high purity mRNA. These purified mRNA"s can then rapidly labeled using a covalent fluorescent molecule which forms a selective covalent bond at the N7 position of guanine residues. These labeled mRNA"s can then released from the polymer monolith to allow for direct hybridization with oligonucletide probes deposited in microfluidic channel. To allow for rapid target/probe hybridization high density microarray were printed in microchannels. The channels can accommodate array densities as high as 4000 probes. When oligonucleotide deposition is complete, these channels are sealed using a polymer film which forms a pressure tight seal to allow sample reagent flow to the arrayed probes. This process will allow for real time target to probe hybridization monitoring using a top mounted CCD fiber bundle combination. Using this process we have been able to perform a multi-step sample preparation to labeled target/probe hybridization in less than 30 minutes. These results demonstrate the capability to perform rapid genomic screening on a high density microfluidic microarray of oligonucleotides.

  13. Large Format Uncooled Focal Plane Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Uncooled focal plane arrays have improved dramatically and array sizes of 320x240 elements in a 50-?m pitch are commercially available at affordable cost. Black...

  14. NRAO Very Long Baseline Array (VLBA)

    Data.gov (United States)

    Federal Laboratory Consortium — The Very Long Baseline Array (VLBA) comprises ten radio telescopes spanning 5,351 miles. It's the world's largest, sharpest, dedicated telescope array. With an eye...

  15. Low Cost Phased Array Antenna System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — JEM Engineering proved the technical feasibility of the FlexScan array?a very low-cost, highly-efficient, wideband phased array antenna?in Phase I, and stands ready...

  16. Mechanical Design and Development of TES Bolometer Detector Arrays for the Advanced ACTPol Experiment

    Science.gov (United States)

    Ward, Jonathan T.; Austermann, Jason; Beall, James A.; Choi, Steve K.; Crowley, Kevin T.; Devlin, Mark J.; Duff, Shannon M.; Gallardo, Patricio M.; Henderson, Shawn W.; Ho, Shuay-Pwu Patty; Hilton, Gene; Hubmayr, Johannes; Khavari, Niloufar; Klein, Jeffrey; Koopman, Brian J.; Li, Dale; McMahon, Jeffrey; Mumby, Grace; Nati, Federico; Wollack, Edward J.

    2016-01-01

    The next generation Advanced ACTPol (AdvACT) experiment is currently underway and will consist of four Transition Edge Sensor (TES) bolometer arrays, with three operating together, totaling 5800 detectors on the sky. Building on experience gained with the ACTPol detector arrays, AdvACT will utilize various new technologies, including 150 mm detector wafers equipped with multichroic pixels, allowing for a more densely packed focal plane. Each set of detectors includes a feedhorn array of stacked silicon wafers which form a spline pro le leading to each pixel. This is then followed by a waveguide interface plate, detector wafer, back short cavity plate, and backshort cap. Each array is housed in a custom designed structure manufactured from high purity copper and then gold plated. In addition to the detector array assembly, the array package also encloses cryogenic readout electronics. We present the full mechanical design of the AdvACT high frequency (HF) detector array package along with a detailed look at the detector array stack assemblies. This experiment will also make use of extensive hardware and software previously developed for ACT, which will be modi ed to incorporate the new AdvACT instruments. Therefore, we discuss the integration of all AdvACT arrays with pre-existing ACTPol infrastructure.

  17. Array Antennas Based Joint Beamforming for IEEE 802.11n Wi-Fi

    Directory of Open Access Journals (Sweden)

    Cheng Guo

    2015-09-01

    Full Text Available In order to achieve array gain and spatial diversity or multiplexing gain simultaneously, a novel joint beamforming based on MIMO and array antenna techniques, referred to as J-BF, is proposed for the LTE and Wifi downlink. Array gain is achieved from array antenna based beamforming, referred to as AA-BF. Spatial diversity and multiplexing gains are achieved from MIMO based beamforming, referred to as MIMO-BF. To implement J-BF, i.e., joint AA-BF and MIMO-BF, an access point (AP is equipped with separate array antennas. Before sending any data-frame in the J-BF mode, firstly, based on the estimated omni-directional CSI, the directional beam can be formed by the array antenna, and the array gain is achieved. Secondly, based on the estimated directional CSI, MIMO-BF is implemented to achieve the spatial diversity or multiplexing gain. More importantly, the J-BF algorithm maintains compatibility with 802.11n and there is not any change in terminals. Simulation results show that the proposed scheme can support the joint AA-BF and MIMO-BF effectively and provide much higher array gain or spatial gains than the traditional MIMO or array antenna respectively.

  18. Neuro-Prosthetic Implants With Adjustable Electrode Arrays

    Science.gov (United States)

    Whitacre, Jay; DelCastillo, Linda Y.; Mojarradi, Mohammad; Johnson, Travis; West, William; Andersen, Richard

    2006-01-01

    Brushlike arrays of electrodes packaged with application-specific integrated circuits (ASICs) are undergoing development for use as electronic implants especially as neuro-prosthetic devices that might be implanted in brains to detect weak electrical signals generated by neurons. These implants partly resemble the ones reported in Integrated Electrode Arrays for Neuro-Prosthetic Implants (NPO-21198), NASA Tech Briefs, Vol. 27, No. 2 (February 2003), page 48. The basic idea underlying both the present and previously reported implants is that the electrodes would pick up signals from neurons and the ASICs would amplify and otherwise preprocess the signals for monitoring by external equipment. The figure presents a simplified and partly schematic view of an implant according to the present concept. Whereas the electrodes in an implant according to the previously reported concept would be microscopic wires, the electrodes according to the present concept are in the form of microscopic needles. An even more important difference would be that, unlike the previously reported concept, the present concept calls for the inclusion of microelectromechanical actuators for adjusting the depth of penetration of the electrodes into brain tissue. The prototype implant now under construction includes an array of 100 electrodes and corresponding array of electrode contact pads formed on opposite faces of a plate fabricated by techniques that are established in the art of microelectromechanical systems (MEMS). A mixed-signal ASIC under construction at the time of reporting the information for this article will include 100 analog amplifier channels (one amplifier per electrode). On one face of the mixed-signal ASIC there will be a solder-bump/micro-pad array that will have the same pitch as that of the electrode array, and that will be used to make the electrical and mechanical connections between the electrode array and the ASIC. Once the electrode array and the ASIC are soldered

  19. Defect Characterization Using Two-Dimensional Arrays

    Science.gov (United States)

    Velichko, A.; Wilcox, P. D.

    2011-06-01

    2D arrays are able to `view' a given defect from a range of angles leading to the possibility of obtaining richer characterization detail than possible with 1D arrays. In this paper a quantitative comparison of 2D arrays with different element layouts is performed. A technique for extracting the scattering matrix of a defect from the raw 2D array data is also presented. The method is tested on experimental data for characterization of various volumetric defects.

  20. Leakage analysis of crossbar memristor arrays

    KAUST Repository

    Zidan, Mohammed A.

    2014-07-01

    Crossbar memristor arrays provide a promising high density alternative for the current memory and storage technologies. These arrays suffer from parasitic current components that significantly increase the power consumption, and could ruin the readout operation. In this work we study the trade-off between the crossbar array density and the power consumption required for its readout. Our analysis is based on simulating full memristor arrays on a SPICE platform.

  1. Simulations of astronomical imaging phased arrays.

    Science.gov (United States)

    Saklatvala, George; Withington, Stafford; Hobson, Michael P

    2008-04-01

    We describe a theoretical procedure for analyzing astronomical phased arrays with overlapping beams and apply the procedure to simulate a simple example. We demonstrate the effect of overlapping beams on the number of degrees of freedom of the array and on the ability of the array to recover a source. We show that the best images are obtained using overlapping beams, contrary to common practice, and show how the dynamic range of a phased array directly affects the image quality.

  2. Nonplanar Integrability:. Beyond the SU(2) Sector

    Science.gov (United States)

    de Mello Koch, Robert; Mohammed, Badr Awad Elseid; Smith, Stephanie

    We compute the one-loop anomalous dimensions of restricted Schur polynomials with a classical dimension Δ~O(N). The operators that we consider are labeled by Young diagrams with two long columns or two long rows. Simple analytic expressions for the action of the dilatation operator are found. The projection operators needed to define the restricted Schur polynomials are constructed by translating the problem into a spin chain language, generalizing earlier results obtained in the SU(2) sector of the theory. The diagonalization of the dilatation operator reduces to solving five term recursion relations. The recursion relations can be solved exactly in terms of products of symmetric Kravchuk polynomials with Hahn polynomials. This proves that the dilatation operator reduces to a decoupled set of harmonic oscillators and therefore it is integrable, extending a similar conclusion reached for the SU(2) sector of the theory.

  3. Nonplanar Integrability: Beyond the SU(2) Sector

    CERN Document Server

    Koch, Robert de Mello; Smith, Stephanie

    2011-01-01

    We compute the one loop anomalous dimensions of restricted Schur polynomials with a classical dimension \\Delta\\sim O(N). The operators that we consider are labeled by Young diagrams with two long columns or two long rows. Simple analytic expressions for the action of the dilatation operator are found. The projection operators needed to define the restricted Schur polynomials are constructed by translating the problem into a spin chain language, generalizing earlier results obtained in the SU(2) sector of the theory. The diagonalization of the dilatation operator reduces to solving five term recursion relations. The recursion relations can be solved exactly in terms of products of symmetric Kravchuk polynomials with Hahn polynomials. This proves that the dilatation operator reduces to a decoupled set of harmonic oscillators and therefore it is integrable, extending a similar conclusion reached for the SU(2) sector of the theory.

  4. Physisorbed Films on Planar and Nonplanar Surfaces.

    Science.gov (United States)

    Cheng, E.

    1990-01-01

    In the case of multilayer liquid films on planar surfaces, we found that the widely used Frenkel-Halsey -Hill theory is the leading term of a many-body expansion of the more general Dzyaloshinskii-Lifshitz-Pitaevskii theory in the nonretardation limit. While the FHH theory is a good approximation in the thin film region, retardation has been shown to be important at thickness d >=q 100 A. A universal behavior of the retardation has also been found. Submonolayer He film on weak-binding substrate surfaces have been found to have unexpected and exciting new features. The weak binding of the substrate potential supports only low density monolayer He films so that the monolayer He solid can be eliminated. Meanwhile, the z -wise delocalization of He atoms reduces the He-He interaction and the lateral binding. It is possible that the 2D liquid film will be eliminated as well and a quasi-2D bose gas is expected. A further possibility is that no He monolayer film at all will be present on a weak-binding substrate. The possibility of using the fractal geometry to describe (global) surface roughness has been investigated. A power-law relation between the coverage and thickness is found on a fractally rough surface, with its exponent determined by the surface fractal dimension. A new and interesting phenomenon has been found: the adsorbed film "defractalizes" the substrate surface; this is observable by small angle x-ray and neutron scattering measurements. Adsorption inside a cylindrical pore and near an oblique corner have also been discussed.

  5. Optimized Volumetric Scanning for X-Ray Array Sources

    Energy Technology Data Exchange (ETDEWEB)

    Lehman, S K; Foudray, A M; Wang, A; Kallman, J S; Martz, H

    2009-09-29

    Non-destructive evaluation (NDE) is the science and technology of determining non-invasively the internal structure of manufactured parts, objects, and materials. NDE application areas include medicine, industrial manufacturing, military, homeland security, and airport luggage screening. X-ray measurement systems are most widely used because of their ability to image through a wide range of material densities (from human tissue in medical applications to the dense materials of weapon components). Traditional x-ray systems involve a single source and detector system that rotate and/or translate about the object under evaluation. At each angular location, the source projects x-rays through the object. The rays undergo attenuation proportional to the density of the object's constitutive material. The detector records a measure of the attenuation. Mathematical algorithms are used to invert the forward attenuated ray projection process to form images of the object. This is known as computed tomography (CT). In recent years, the single-source x-ray NDE systems have been generalized to arrays of x-ray sources. Array sources permit multiple views of the object with fewer rotations and translations of the source/detector system. The spatially diverse nature of x-ray array sources has the potential of reducing data collection time, reducing imaging artifacts, and increasing the resolution of the resultant images. Most of the existing CT algorithms were not derived from array source models with a spatially diverse set of viewing perspectives. Single-source x-ray CT data collection, processing, and imaging methods and algorithms are not applicable when the source location is expanded from one dimension (a rotating and/or translating point source) to two (a rotating and/or translating array). They must be reformulated. The goal of this project is to determine the applicability of x-ray array sources to problems of interest to LLNL and its customers. It is believed array

  6. Modular Forms and Weierstrass Mock Modular Forms

    Directory of Open Access Journals (Sweden)

    Amanda Clemm

    2016-02-01

    Full Text Available Alfes, Griffin, Ono, and Rolen have shown that the harmonic Maass forms arising from Weierstrass ζ-functions associated to modular elliptic curves “encode” the vanishing and nonvanishing for central values and derivatives of twisted Hasse-Weil L-functions for elliptic curves. Previously, Martin and Ono proved that there are exactly five weight 2 newforms with complex multiplication that are eta-quotients. In this paper, we construct a canonical harmonic Maass form for these five curves with complex multiplication. The holomorphic part of this harmonic Maass form arises from the Weierstrass ζ-function and is referred to as the Weierstrass mock modular form. We prove that the Weierstrass mock modular form for these five curves is itself an eta-quotient or a twist of one. Using this construction, we also obtain p-adic formulas for the corresponding weight 2 newform using Atkin’s U-operator.

  7. Kronecker Product of Two-dimensional Arrays

    Institute of Scientific and Technical Information of China (English)

    Lei Hu

    2006-01-01

    Kronecker sequences constructed from short sequences are good sequences for spread spectrum communication systems. In this paper we study a similar problem for two-dimensional arrays, and we determine the linear complexity of the Kronecker product of two arrays. Our result shows that similar good property on linear complexity holds for Kronecker product of arrays.

  8. Maximum gain of Yagi-Uda arrays

    DEFF Research Database (Denmark)

    Bojsen, J.H.; Schjær-Jacobsen, Hans; Nilsson, E.

    1971-01-01

    Numerical optimisation techniques have been used to find the maximum gain of some specific parasitic arrays. The gain of an array of infinitely thin, equispaced dipoles loaded with arbitrary reactances has been optimised. The results show that standard travelling-wave design methods are not optimum....... Yagi–Uda arrays with equal and unequal spacing have also been optimised with experimental verification....

  9. Recent Results from Telescope Array

    CERN Document Server

    Fukushima, M

    2015-01-01

    The Telescope Array (TA) is an experiment to observe Ultra-High Energy Cosmic Rays (UHECRs). TA's recent results, the energy spectrum and anisotropy based on the 6-year surface array data, and the primary composition obtained from the shower maximum Xmax are reported. The spectrum demonstrates a clear dip and cutoff. The shape of the spectrum is well described by the energy loss of extra-galactic protons interacting with the cosmic microwave background (CMB). Above the cutoff, a medium-scale (20 degrees radius) flux enhancement was observed near the Ursa-Major. A chance probability of creating this hotspot from the isotropic flux is 4.0 sigma. The measured Xmax is consistent with the primary being proton or light nuclei for energies 10^18.2 eV - 10^19.2 eV.

  10. Sandia concentrator array testing experiences

    Science.gov (United States)

    Gerwin, H. J.; Rogers, C. B.; Beavis, L. C.

    An assortment of PV concentrator modules and arrays have been tested and evaluated at the Sandia outdoor test facility. These test items include actively-cooled parabolic reflector and linear Fresnel lens concentrators, and actively- and passively-cooled point focus collectors. Maximum power efficiencies were measured over a range of sunlight intensities and cell temperatures, then a linear equation relating efficiency to cell temperature and insolation was developed for each module and array by using a multiple linear regression analysis technique on the data. An evaluation of the suitability of Polyvinyl-Butyral (PVB) as a material used to laminate solar cells to glass is presented. Some general observations are made on the accuracy of tracking systems, and the maintenance of these systems.

  11. Invasive tightly coupled processor arrays

    CERN Document Server

    LARI, VAHID

    2016-01-01

    This book introduces new massively parallel computer (MPSoC) architectures called invasive tightly coupled processor arrays. It proposes strategies, architecture designs, and programming interfaces for invasive TCPAs that allow invading and subsequently executing loop programs with strict requirements or guarantees of non-functional execution qualities such as performance, power consumption, and reliability. For the first time, such a configurable processor array architecture consisting of locally interconnected VLIW processing elements can be claimed by programs, either in full or in part, using the principle of invasive computing. Invasive TCPAs provide unprecedented energy efficiency for the parallel execution of nested loop programs by avoiding any global memory access such as GPUs and may even support loops with complex dependencies such as loop-carried dependencies that are not amenable to parallel execution on GPUs. For this purpose, the book proposes different invasion strategies for claiming a desire...

  12. Highlights from the Telescope Array

    Directory of Open Access Journals (Sweden)

    Matthews J.N.

    2016-01-01

    Full Text Available The Telescope Array measures the properties of ultra high energy cosmic ray induced extensive air showers. We do this using a variety of techniques including an array of scintillator detectors to sample the footprint of the air shower when it reaches the Earth’s surface and telescopes to measure the fluorescence and Cerenkov light of the air shower. From this we determine the energy spectrum and chemical composition of the primary particles. We also search for sources of cosmic rays and anisotropy. We have found evidence of a possible source of ultra high energy cosmic rays in the northern sky. The experiment and its most recent measurements will be discussed.

  13. High voltage load resistor array

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, Monty Ray [Smithfield, VA

    2005-01-18

    A high voltage resistor comprising an array of a plurality of parallel electrically connected resistor elements each containing a resistive solution, attached at each end thereof to an end plate, and about the circumference of each of the end plates, a corona reduction ring. Each of the resistor elements comprises an insulating tube having an electrode inserted into each end thereof and held in position by one or more hose clamps about the outer periphery of the insulating tube. According to a preferred embodiment, the electrode is fabricated from stainless steel and has a mushroom shape at one end, that inserted into the tube, and a flat end for engagement with the end plates that provides connection of the resistor array and with a load.

  14. A Systolic Array RLS Processor

    OpenAIRE

    Asai, T.; Matsumoto, T.

    2000-01-01

    This paper presents the outline of the systolic array recursive least-squares (RLS) processor prototyped primarily with the aim of broadband mobile communication applications. To execute the RLS algorithm effectively, this processor uses an orthogonal triangularization technique known in matrix algebra as QR decomposition for parallel pipelined processing. The processor board comprises 19 application-specific integrated circuit chips, each with approximately one million gates. Thirty-two bit ...

  15. Micromirror Arrays for Adaptive Optics

    Energy Technology Data Exchange (ETDEWEB)

    Carr, E.J.

    2000-08-07

    The long-range goal of this project is to develop the optical and mechanical design of a micromirror array for adaptive optics that will meet the following criteria: flat mirror surface ({lambda}/20), high fill factor (> 95%), large stroke (5-10 {micro}m), and pixel size {approx}-200 {micro}m. This will be accomplished by optimizing the mirror surface and actuators independently and then combining them using bonding technologies that are currently being developed.

  16. Nonlinear Ultrasonic Phased Array Imaging

    Science.gov (United States)

    Potter, J. N.; Croxford, A. J.; Wilcox, P. D.

    2014-10-01

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging through depth.

  17. Nonlinear ultrasonic phased array imaging

    OpenAIRE

    Potter, J N; Croxford, A.J.; Wilcox, P. D.

    2014-01-01

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging t...

  18. Array Imaging of Noisy Materials

    Science.gov (United States)

    Wilcox, P. D.

    2011-06-01

    The ultimate limit on ultrasonic defect detectability is the coherent noise due to material backscatter. A model of such noise in ultrasonic array images is developed based on the single scattering assumption. The implications of the model are discussed and supported with some experimental examples. In the case of a copper specimen, it is shown that an improvement in signal to coherent noise ratio of over 30 dB can be obtained by optimization of imaging parameters.

  19. Nonlinear ultrasonic phased array imaging.

    Science.gov (United States)

    Potter, J N; Croxford, A J; Wilcox, P D

    2014-10-03

    This Letter reports a technique for the imaging of acoustic nonlinearity. By contrasting the energy of the diffuse field produced through the focusing of an ultrasonic array by delayed parallel element transmission with that produced by postprocessing of sequential transmission data, acoustic nonlinearity local to the focal point is measured. Spatially isolated wave distortion is inferred without requiring interrogation of the wave at the inspection point, thereby allowing nonlinear imaging through depth.

  20. Array-based photoacoustic spectroscopy

    Science.gov (United States)

    Autrey, S. Thomas; Posakony, Gerald J.; Chen, Yu

    2005-03-22

    Methods and apparatus for simultaneous or sequential, rapid analysis of multiple samples by photoacoustic spectroscopy are disclosed. A photoacoustic spectroscopy sample array including a body having at least three recesses or affinity masses connected thereto is used in conjunction with a photoacoustic spectroscopy system. At least one acoustic detector is positioned near the recesses or affinity masses for detection of acoustic waves emitted from species of interest within the recesses or affinity masses.

  1. Automated array assembly. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Williams, B.F.

    1977-05-01

    The goal of the ERDA/JPL LSSA program of $0.50/W selling price for array modules in 1986 turns out to have been remarkably appropriate. An extensive and detailed analysis of technologies which could be related to array module manufacturing was completed and a minimum manufacturing cost in a highly automated line of $0.30/W was found assuming the silicon is free. The panels are of a double glass construction and are based on round wafers. Screen printed silver has been used as the metallization with a spray-coated AR layer. The least expensive junction formation technology appears to be ion implantation; however, several other technologies also may be used with very little cost penalty as described. Based on the required investment, a profit of $0.05/W appears reasonable. If silicon wafers are available at a price of $20 to 40/M/sup 2/, a selling price for these array modules of $0.50 to 0.66/W is projected. An analysis of the impact of factory size has been made. For a production level of 500 MW/yr, the price above is derived. For comparison, a factory processing 50 MW/yr using the same technology would sell modules for $0.54/W to $0.70/W. An analysis of the impact of wafer size indicates that with traditional metallization and panel designs there is no advantage in increasing wafer size from 3 in. to 5 in., and, in fact, there is some penalty (10% in $/W) due to increasedmetallization costs and reduced system performance. There is a premium placed on high efficiency due to its impact, not only on array module cost, but on system cost. For the near term goals of this program, wafers cut from single-crystal material seem the most likely sheet configuration.

  2. The Parkes Pulsar Timing Array

    CERN Document Server

    Hobbs, G

    2013-01-01

    The aims of the Parkes Pulsar Timing Array (PPTA) project are to 1) make a direct detection of gravitational waves, 2) improve the solar system planetary ephemeris and 3) develop a pulsar-based time scale. In this article we describe the project, explain how the data are collected and processed and describe current research. Our current data sets are able to place an upper bound on the gravitational wave background that is the most stringent to date.

  3. A distributed array antenna system

    Science.gov (United States)

    Shaw, R.; Kovitz, J.

    1986-01-01

    The Space Station communication system will use microwave frequency radio links to carry digitized information from sender to receiver. The ability of the antenna system to meet stringent requirements on coverage zones, multiple users, and reliability will play an important part in the overall multiple access communication system. This paper will describe the configuration of a multibeam conformal phased array antenna and the individual microwave integrated components incoporated into this antenna system.

  4. Multi-view display module employing MEMS projector array.

    Science.gov (United States)

    Takaki, Yasuhiro; Takenaka, Hiromitsu; Morimoto, Yasuhiro; Konuma, Osamu; Hirabayashi, Kenji

    2012-12-17

    A frameless multi-view display module that consists of an array of microelectromechanical system (MEMS) based projectors, a sparse lenticular lens, and a vertical diffuser is proposed to provide a large-screen autostereoscopic display. The projectors are positioned in a horizontal vector form or in a matrix form in front of the transfer screen in order to produce the same number of three-dimensional (3D) pixels in each cylindrical lens constituting the lenticular lens to increase the horizontal resolution of the module. The projectors generate a slanted two-dimensional array of dots on the vertical diffuser to provide a large number of viewpoints. The experimental display system was constructed using four projectors. The system had a 3D resolution of 160 × 120, and it provided 64 views. The screen size was 14.4 in.

  5. 3D target array for pulsed multi-sourced radiography

    Science.gov (United States)

    Le Galloudec, Nathalie Joelle

    2016-02-23

    The various technologies presented herein relate to the generation of x-rays and other charged particles. A plurality of disparate source materials can be combined on an array to facilitate fabrication of co-located mixed tips (point sources) which can be utilized to form a polychromatic cloud, e.g., a plurality of x-rays having a range of energies and or wavelengths, etc. The tips can be formed such that the x-rays are emitted in a direction different to other charged particles to facilitate clean x-ray sourcing. Particles, such as protons, can be directionally emitted to facilitate generation of neutrons at a secondary target. The various particles can be generated by interaction of a laser irradiating the array of tips. The tips can be incorporated into a plurality of 3D conical targets, the conical target sidewall(s) can be utilized to microfocus a portion of a laser beam onto the tip material.

  6. Soliton nanoantennas in two-dimensional arrays of quantum dots

    CERN Document Server

    Gligorić, G; Hadžievski, Lj; Slepyan, G Ya; Malomed, B A

    2015-01-01

    We consider two-dimensional (2D) arrays of self-organized semiconductor quantum dots (QDs) strongly interacting with electromagnetic field in the regime of Rabi oscillations. The QD array built of two-level states is modelled by two coupled systems of discrete nonlinear Schr\\"{o}dinger equations. Localized modes in the form of single-peaked fundamental and vortical stationary Rabi solitons and self-trapped breathers have been found. The results for the stability, mobility and radiative properties of the Rabi modes suggest a concept of a self-assembled 2D \\textit{% soliton-based nano-antenna}, which should be stable against imperfections In particular, we discuss the implementation of such a nano-antenna in the form of surface plasmon solitons in graphene, and illustrate possibilities to control their operation by means of optical tools.

  7. Hydrogels for in situ encapsulation of biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Ibragimova, Sania; Jensen, Karin Bagger Stibius; Szewczykowski, Piotr Przemyslaw

    2012-01-01

    . We investigated gels for in situ encapsulation of multiple BLMs formed across apertures in a hydrophobic ethylene tetrafluoroethylene (ETFE) support. The encapsulation gels consisted of networks of poly(ethylene glycol)-dimethacrylate or poly(ethylene glycol)-diacrylate polymerized using either...... to chemically initiated hydrogels; however, for all hydrogels the permeability was several-fold higher than the water permeability of conventional reverse osmosis (RO) membranes. Lifetimes of freestanding BLM arrays in gel precursor solutions were short compared to arrays formed in buffer. However, polymerizing......Hydrogels are hydrophilic, porous polymer networks that can absorb up to thousands of times their own weight in water. They have many potential applications, one of which is the encapsulation of freestanding black lipid membranes (BLMs) for novel separation technologies or biosensor applications...

  8. The source of high signal cooperativity in bacterial chemosensory arrays.

    Science.gov (United States)

    Piñas, Germán E; Frank, Vered; Vaknin, Ady; Parkinson, John S

    2016-03-22

    The Escherichia coli chemosensory system consists of large arrays of transmembrane chemoreceptors associated with a dedicated histidine kinase, CheA, and a linker protein, CheW, that couples CheA activity to receptor control. The kinase activity responses to receptor ligand occupancy changes can be highly cooperative, reflecting allosteric coupling of multiple CheA and receptor molecules. Recent structural and functional studies have led to a working model in which receptor core complexes, the minimal units of signaling, are linked into hexagonal arrays through a unique interface 2 interaction between CheW and the P5 domain of CheA. To test this array model, we constructed and characterized CheA and CheW mutants with amino acid replacements at key interface 2 residues. The mutant proteins proved defective in interface 2-specific in vivo cross-linking assays, and formed signaling complexes that were dispersed around the cell membrane rather than clustered at the cell poles as in wild type chemosensory arrays. Interface 2 mutants down-regulated CheA activity in response to attractant stimuli in vivo, but with much less cooperativity than the wild type. Moreover, mutant cells containing fluorophore-tagged receptors exhibited greater basal anisotropy that changed rapidly in response to attractant stimuli, consistent with facile changes in loosely packed receptors. We conclude that interface 2 lesions disrupt important network connections between core complexes, preventing receptors from operating in large, allosteric teams. This work confirms the critical role of interface 2 in organizing the chemosensory array, in directing the clustered array to the cell poles, and in producing its highly cooperative signaling properties.

  9. Fabrication of titanium oxide nanotube arrays by anodic oxidation

    Science.gov (United States)

    Zhao, Jianling; Wang, Xiaohui; Chen, Renzheng; Li, Longtu

    2005-06-01

    The formation of titanium oxide nanotube arrays on titanium substrates was investigated in HF electrolytes. Under optimized electrolyte and oxidation conditions, well-ordered nanotubes of titania were fabricated. Topologies of the anodized titanium change remarkably along with the changing of applied voltages, electrolyte concentration and oxidation time. Electrochemical determination and scanning electron microscope indicate the nanotubes are formed due to the competition of titania formation and dissolution under the assistance of electric field. A possible growth mechanism has also been presented.

  10. A novel method to design sparse linear arrays for ultrasonic phased array.

    Science.gov (United States)

    Yang, Ping; Chen, Bin; Shi, Ke-Ren

    2006-12-22

    In ultrasonic phased array testing, a sparse array can increase the resolution by enlarging the aperture without adding system complexity. Designing a sparse array involves choosing the best or a better configuration from a large number of candidate arrays. We firstly designed sparse arrays by using a genetic algorithm, but found that the arrays have poor performance and poor consistency. So, a method based on the Minimum Redundancy Linear Array was then adopted. Some elements are determined by the minimum-redundancy array firstly in order to ensure spatial resolution and then a genetic algorithm is used to optimize the remaining elements. Sparse arrays designed by this method have much better performance and consistency compared to the arrays designed only by a genetic algorithm. Both simulation and experiment confirm the effectiveness.

  11. Measured Aperture-Array Noise Temperature of the Mark II Phased Array Feed for ASKAP

    CERN Document Server

    Chippendale, A P; Beresford, R J; Hampson, G A; Shaw, R D; Hayman, D B; Macleod, A; Forsyth, A R; Hay, S G; Leach, M; Cantrall, C; Brothers, M L; Hotan, A W

    2015-01-01

    We have measured the aperture-array noise temperature of the first Mk. II phased array feed that CSIRO has built for the Australian Square Kilometre Array Pathfinder telescope. As an aperture array, the Mk. II phased array feed achieves a beam equivalent noise temperature less than 40 K from 0.78 GHz to 1.7 GHz and less than 50 K from 0.7 GHz to 1.8 GHz for a boresight beam directed at the zenith. We believe these are the lowest reported noise temperatures over these frequency ranges for ambient-temperature phased arrays. The measured noise temperature includes receiver electronics noise, ohmic losses in the array, and stray radiation from sidelobes illuminating the sky and ground away from the desired field of view. This phased array feed was designed for the Australian Square Kilometre Array Pathfinder to demonstrate fast astronomical surveys with a wide field of view for the Square Kilometre Array.

  12. The Colorado Lightning Mapping Array

    Science.gov (United States)

    Rison, W.; Krehbiel, P. R.; Thomas, R. J.; Rodeheffer, D.; Fuchs, B.

    2012-12-01

    A fifteen station Lightning Mapping Array (LMA) was installed in northern Colorado in the spring of 2012. While the driving force for the array was to produce 3-dimensional lightning data to support the Deep Convective Clouds and Chemistry (DC3) Experiment (Barth, this conference), data from the array are being used for several other projects. These include: electrification studies in conjunction with the CSU CHILL radar (Lang et al, this conference); observations of the parent lightning discharges of sprites (Lyons et al, this conference); trying to detect upward discharges triggered by wind turbines, characterizing conditions in which aircraft flying through clouds produce discharges which can be detected by the LMA, and other opportunities, such as observations of lightning in pyrocumulus clouds produced by the High Park Fire west of Fort Collins, CO. All the COLMA stations are solar-powered, and use broadband cellular modems for data communications. This makes the stations completely self-contained and autonomous, allowing a station to be installed anywhere a cellular signal is available. Because most of the stations were installed well away from anthropogenic noise sources, the COLMA is very sensitive. This is evidenced by the numerous plane tracks detected in its the vicinity. The diameter, D, of the COLMA is about 100 km, significantly larger than other LMAs. Because the error in the radial distance r is proportional to (r/D)2, and the error in the altitude z is proportional to (z/D)2, the larger array diameter greatly expands the usable range of the COLMA. The COLMA is able to detect and characterize lighting flashes to a distance of about 350 km from the array center. In addition to a web-based display (lightning.nmt.edu/colma), geo-referenced images are produced and updated at one-minute intervals. These geo-referenced images can be used to overlay the real-time lightning data on Google Earth and other mapping software. These displays were used by the DC3

  13. Acoustic array systems theory, implementation, and application

    CERN Document Server

    Bai, Mingsian R; Benesty, Jacob

    2013-01-01

    Presents a unified framework of far-field and near-field array techniques for noise source identification and sound field visualization, from theory to application. Acoustic Array Systems: Theory, Implementation, and Application provides an overview of microphone array technology with applications in noise source identification and sound field visualization. In the comprehensive treatment of microphone arrays, the topics covered include an introduction to the theory, far-field and near-field array signal processing algorithms, practical implementations, and common applic

  14. Beam combining of quantum cascade laser arrays.

    Science.gov (United States)

    Lee, Benjamin G; Kansky, Jan; Goyal, Anish K; Pflügl, Christian; Diehl, Laurent; Belkin, Mikhail A; Sanchez, Antonio; Capasso, Federico A

    2009-08-31

    Wavelength beam combining was used to co-propagate beams from 28 elements in an array of distributed-feedback quantum cascade lasers (DFB-QCLs). The beam-quality product of the array, defined as the product of near-field spot size and far-field divergence for the entire array, was improved by a factor of 21 by using wavelength beam combining. To demonstrate the applicability of wavelength beam combined DFB-QCL arrays for remote sensing, we obtained the absorption spectrum of isopropanol at a distance of 6 m from the laser array.

  15. Silver nanorod arrays for photocathode applications

    Energy Technology Data Exchange (ETDEWEB)

    Vilayurganapathy, Subramanian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Western Michigan Univ., Kalamazoo MI (United States); Nandasiri, Manjula I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Western Michigan Univ., Kalamazoo MI (United States); Joly, Alan G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); El-Khoury, Patrick Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Varga, Tamas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Greg W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schwenzer, Birgit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pandey, Archana [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kayani, Asghar N. [Western Michigan Univ., Kalamazoo MI (United States); Hess, Wayne P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thevuthasan, Suntharampillai [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-10-16

    In this study, we explore the possibility of using plasmonic Ag nanorod arrays featuring enhanced photoemission as high-brightness photocathode material. Silver nanorod arrays are synthesized by the DC electrodeposition method and their dimensionality, uniformity, crystallinity and oxide/impurity content are characterized. These Ag nanorod arrays exhibit greatly enhanced two-photon photoemission under 400 nm femtosecond pulsed laser excitation. Plasmonic field enhancement in the array produces photoemission hot spots that are mapped using photoemission electron microscopy (PEEM). The relative photoemission enhancement of nanorod array hot spots relative to that of a flat Ag thin film is found to range between 102 and 3 x 103.

  16. Ultrasonic stair case array for NDE

    Science.gov (United States)

    Oliver, K.; Tittmann, B. R.; Kropf, M.

    2006-03-01

    In this paper we present the results on the design of a unique two-dimensional phased array with low channel applications for imaging defects on a metal surface. First, basic transducer calculations will be shown. Followed by the results of important phased array variables, such as focusing, and angle beam sweeping ability, The final design will be given. Next the computer simulation results will be discussed. These results will indicate the performance of the actual array. The second half of the paper will be devoted to a discussion on the phased array testing results with a demonstration phased array.

  17. Effects of forming parameters on temperature in frictional stir incremental sheet forming

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin; Jiang, Husen [Qingdao Technological University, Qingdao (China); Li, Lihua [Qingdao University, Qingdao (China)

    2016-05-15

    Frictional stir Incremental sheet forming (ISF) is a new technology used to fabricate parts of hard-to-form materials without using heating equipment. Thus far, limited information is known about the effects of main forming parameters, except spindle speed of the tool, on the temperature of formed sheet in friction-stir ISF. The effects of six forming parameters, namely, sheet thickness, tool vertical step, tool diameter, spindle speed, feed rate, and wall angle of the formed part, were identified using the design of experiment of orthogonal array, analysis of response tables and graphs, and analysis of variance. Results show that spindle speed, feed rate, sheet thickness, and tool vertical step significantly affect the temperature of the sheet. In addition, the temperature of the sheet is significantly increased by increasing sheet thickness, tool vertical step, and spindle speed but significantly decreased with increasing tool feed rate.

  18. Self-organized magnetic nanowire arrays based on alumina and titania templates.

    Science.gov (United States)

    Prida, V M; Pirota, K R; Navas, D; Asenjo, A; Hernández-Vélez, M; Vázquez, M

    2007-01-01

    Densely packed arrays of magnetic nanowires have been synthesized by electrodeposition filling of nanopores in alumina and titania membranes formed by self-assembling during anodization process. Emphasis is made on the control of the production parameters leading to ordering degree and lattice parameter of the array as well as nanowires diameter and length. Structural, morphological and magnetic properties exhibited by nanowire arrays have been studied for several nanowire compositions, different ordering degree and for different nanowire aspect ratios. The magnetic behaviour of nanowires array is governed by the balance between different energy contributions: shape anisotropy of individual nanowires, the magnetostatic interaction of dipolar origin among nanowires, and magnetocrystalline and magnetoelastic anisotropies induced by the pattern templates. These novel nanocomposites, based on ferromagnetic nanowires embedded in anodic nanoporous templates, are becoming promising candidates for technological applications such as functionalised arrays for magnetic sensing, ultrahigh density magnetic storage media or spin-based electronic devices.

  19. A new method of broadband constant beamwidth beamforming for arbitrary geometry arrays

    Institute of Scientific and Technical Information of China (English)

    YANG Yixin; SUN Chao; LI Bin

    2001-01-01

    A new method of broadband constant beamwidth beamforming for arbitrary geometry arrays is proposed. In this method, the response vector of an arbitrary geometry array is expanded into the form of sum of an infinite series, whose core function is the first kind Bessel function. The high terms of this series are truncated so that the array response vectors at different frequencies can be transformed to a reference frequency arid then the constant beamwidth beamforming vectors are ready to obtain. With these beamforming vectors, beams at different frequencies are same as the reference beam. A reference beam optimizing method based on adaptive processing is also proposed to optimize the reference beam of arbitrary geometry arrays. Computer simulation for a uniform circular array verified the effectiveness of the new method proposed.

  20. Transmit Array Interpolation for DOA Estimation via Tensor Decomposition in 2-D MIMO Radar

    Science.gov (United States)

    Cao, Ming-Yang; Vorobyov, Sergiy A.; Hassanien, Aboulnasr

    2017-10-01

    In this paper, we propose a two-dimensional (2D) joint transmit array interpolation and beamspace design for planar array mono-static multiple-input-multiple-output (MIMO) radar for direction-of-arrival (DOA) estimation via tensor modeling. Our underlying idea is to map the transmit array to a desired array and suppress the transmit power outside the spatial sector of interest. In doing so, the signal-tonoise ratio is improved at the receive array. Then, we fold the received data along each dimension into a tensorial structure and apply tensor-based methods to obtain DOA estimates. In addition, we derive a close-form expression for DOA estimation bias caused by interpolation errors and argue for using a specially designed look-up table to compensate the bias. The corresponding Cramer-Rao Bound (CRB) is also derived. Simulation results are provided to show the performance of the proposed method and compare its performance to CRB.