WorldWideScience

Sample records for broadband multiplex spectroscopy

  1. Helicity multiplexed broadband metasurface holograms.

    Science.gov (United States)

    Wen, Dandan; Yue, Fuyong; Li, Guixin; Zheng, Guoxing; Chan, Kinlong; Chen, Shumei; Chen, Ming; Li, King Fai; Wong, Polis Wing Han; Cheah, Kok Wai; Pun, Edwin Yue Bun; Zhang, Shuang; Chen, Xianzhong

    2015-09-10

    Metasurfaces are engineered interfaces that contain a thin layer of plasmonic or dielectric nanostructures capable of manipulating light in a desirable manner. Advances in metasurfaces have led to various practical applications ranging from lensing to holography. Metasurface holograms that can be switched by the polarization state of incident light have been demonstrated for achieving polarization multiplexed functionalities. However, practical application of these devices has been limited by their capability for achieving high efficiency and high image quality. Here we experimentally demonstrate a helicity multiplexed metasurface hologram with high efficiency and good image fidelity over a broad range of frequencies. The metasurface hologram features the combination of two sets of hologram patterns operating with opposite incident helicities. Two symmetrically distributed off-axis images are interchangeable by controlling the helicity of the input light. The demonstrated helicity multiplexed metasurface hologram with its high performance opens avenues for future applications with functionality switchable optical devices.

  2. Broadband Rotational Spectroscopy

    Science.gov (United States)

    Pate, Brooks

    2014-06-01

    The past decade has seen several major technology advances in electronics operating at microwave frequencies making it possible to develop a new generation of spectrometers for molecular rotational spectroscopy. High-speed digital electronics, both arbitrary waveform generators and digitizers, continue on a Moore's Law-like development cycle that started around 1993 with device bandwidth doubling about every 36 months. These enabling technologies were the key to designing chirped-pulse Fourier transform microwave (CP-FTMW) spectrometers which offer significant sensitivity enhancements for broadband spectrum acquisition in molecular rotational spectroscopy. A special feature of the chirped-pulse spectrometer design is that it is easily implemented at low frequency (below 8 GHz) where Balle-Flygare type spectrometers with Fabry-Perot cavity designs become technologically challenging due to the mirror size requirements. The capabilities of CP-FTMW spectrometers for studies of molecular structure will be illustrated by the collaborative research effort we have been a part of to determine the structures of water clusters - a project which has identified clusters up to the pentadecamer. A second technology trend that impacts molecular rotational spectroscopy is the development of high power, solid state sources in the mm-wave/THz regions. Results from the field of mm-wave chirped-pulse Fourier transform spectroscopy will be described with an emphasis on new problems in chemical dynamics and analytical chemistry that these methods can tackle. The third (and potentially most important) technological trend is the reduction of microwave components to chip level using monolithic microwave integrated circuits (MMIC) - a technology driven by an enormous mass market in communications. Some recent advances in rotational spectrometer designs that incorporate low-cost components will be highlighted. The challenge to the high-resolution spectroscopy community - as posed by Frank De

  3. Femtosecond Broadband Stimulated Raman Spectroscopy

    International Nuclear Information System (INIS)

    Lee, Soo-Y; Yoon, Sagwoon; Mathies, Richard A

    2006-01-01

    Femtosecond broadband stimulated Raman spectroscopy (FSRS) is a new technique where a narrow bandwidth picosecond Raman pump pulse and a red-shifted broadband femtosecond Stokes probe pulse (with or without time delay between the pulses) act on a sample to produce a high resolution Raman gain spectrum with high efficiency and speed, free from fluorescence background interference. It can reveal vibrational structural information and dynamics of stationary or transient states. Here, the quantum picture for femtosecond broadband stimulated Raman spectroscopy (FSRS) is used to develop the semiclassical coupled wave theory of the phenomenon and to derive an expression for the measurable Raman gain in FSRS. The semiclassical theory is applied to study the dependence of lineshapes in FSRS on the pump-probe time delay and to deduce vibrational dephasing times in cyclohexane in the ground state

  4. Ionomer Dynamics: Insights from Broadband Dielectric Spectroscopy

    Science.gov (United States)

    Runt, James

    2015-03-01

    Ionomers (polymers containing ionic functionality) have been traditionally used as packaging materials and in molding applications, and are now of increasing interest as candidate single ion conductors for energy storage devices, in energy conversion, and for other electroactive materials applications. The focus of this presentation is on the insight that broadband dielectric (impedance) spectroscopy brings to our understanding of ion and polymer dynamics of this family of materials. As an example of our recent work on relatively conductive ionomers, the first portion of the presentation will focus on anion conducting polyphosphazene ionomers, in which polymer bound cations are quaternized with either short alkyl or short ether oxygen chains. The low Tg, amorphous nature, and cation-solvating backbone distinguish polyphosphazenes as promising materials for ion conduction, the iodide variants being of particular interest in solar cells. In the second part of this overview, the first findings on the molecular dynamics of linear precise polyethylene-based ionomers containing 1-methylimidazolium bromide pendants on exactly every 9th, 15th, or 21st carbon atom will be summarized. In order to develop a robust interpretation of the dynamics of these materials, it is imperative to develop a thorough understanding of microphase separation (e.g. ion aggregation), and each of the above studies is complimented by multiangle X-ray scattering experiments. Supported by the NSF Polymers Program and DOE Basic Energy Sciences.

  5. Electronic resonances in broadband stimulated Raman spectroscopy

    Science.gov (United States)

    Batignani, G.; Pontecorvo, E.; Giovannetti, G.; Ferrante, C.; Fumero, G.; Scopigno, T.

    2016-01-01

    Spontaneous Raman spectroscopy is a formidable tool to probe molecular vibrations. Under electronic resonance conditions, the cross section can be selectively enhanced enabling structural sensitivity to specific chromophores and reaction centers. The addition of an ultrashort, broadband femtosecond pulse to the excitation field allows for coherent stimulation of diverse molecular vibrations. Within such a scheme, vibrational spectra are engraved onto a highly directional field, and can be heterodyne detected overwhelming fluorescence and other incoherent signals. At variance with spontaneous resonance Raman, however, interpreting the spectral information is not straightforward, due to the manifold of field interactions concurring to the third order nonlinear response. Taking as an example vibrational spectra of heme proteins excited in the Soret band, we introduce a general approach to extract the stimulated Raman excitation profiles from complex spectral lineshapes. Specifically, by a quantum treatment of the matter through density matrix description of the third order nonlinear polarization, we identify the contributions which generate the Raman bands, by taking into account for the cross section of each process.

  6. Subcarrier multiplexing tolerant dispersion transmission system employing optical broadband sources.

    Science.gov (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José

    2009-03-16

    This paper presents a novel SCM optical transmission system for next-generation WDM-PONs combining broadband optical sources and a Mach-Zehnder interferometric structure. The approach leeds to transport RF signals up to 50 GHz being compatible with RoF systems since a second configuration has been proposed in order to overcome dispersion carrier suppression effect using DSB modulation. The theoretical analysis validates the potentiality of the system also considering the effects of the dispersion slope over the transmission window. (c) 2009 Optical Society of America

  7. Broadband Spectroscopy of Nanoporous-Gold Promoter

    Directory of Open Access Journals (Sweden)

    S. K. Nakatani

    2014-02-01

    Full Text Available The efficiency of UV photocatalysis on TiO2 particles was increased by mixing TiO2 particles with nanoporous gold (NPG with pore diameters of 10–40 nm. This means that NPG acts as a promoter in the photocatalytic reaction of TiO2. Broadband spectroscopic results from millimeter wave to ultra violet of NPG membrane are discussed to estimate plasmonic effect on the catalysis.

  8. Broadband multiplex coherent anti-Stokes Raman scattering microscopy employing photonic-crystal fibers

    DEFF Research Database (Denmark)

    Andresen, Esben Ravn; Paulsen, Henrik Nørgaard; Birkedal, Victoria

    2006-01-01

    We demonstrate spectral multiplex coherent anti-Stokes Raman scattering (CARS) spectroscopy and microscopy based on a single Ti:sapphire oscillator and a nonlinear photonic-crystal fiber (PCF). The Stokes pulse is generated by spectral conversion of the laser pulse in a PCF. The pump pulse is eit...

  9. Broadband dielectric spectroscopy of oxidized porous silicon

    International Nuclear Information System (INIS)

    Axelrod, Ekaterina; Urbach, Benayahu; Sa'ar, Amir; Feldman, Yuri

    2006-01-01

    Dielectric measurements accompanied by infrared absorption and photoluminescence (PL) spectroscopy were used to investigate the electrical and optical properties of oxidized porous silicon (PS). As opposed to non-oxidized PS, only high temperature relaxation processes could be resolved for oxidized PS. Two relaxation processes have been observed. The first process is related to dc-conductivity that dominates at high temperatures and low frequencies. After subtraction of dc-conductivity we could analyse a second high-temperature relaxation process that is related to interface polarization induced by charge carriers trapped at the host matrix-pore interfaces. We found that, while the main effect of the oxidation on the PL appears to be a size reduction in the silicon nanocrystals that gives rise to a blue shift of the PL spectrum, its main contribution to the dielectric properties turns out to be blocking of transport channels in the host tissue and activation of hopping conductivity between silicon nanocrystals

  10. Broadband dielectric spectroscopy of oxidized porous silicon

    Energy Technology Data Exchange (ETDEWEB)

    Axelrod, Ekaterina [Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel); Urbach, Benayahu [Racah Institute of Physics and the Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel); Sa' ar, Amir [Racah Institute of Physics and the Center for Nanoscience and Nanotechnology, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel); Feldman, Yuri [Department of Applied Physics, Hebrew University of Jerusalem, Jerusalem, 91904 (Israel)

    2006-04-07

    Dielectric measurements accompanied by infrared absorption and photoluminescence (PL) spectroscopy were used to investigate the electrical and optical properties of oxidized porous silicon (PS). As opposed to non-oxidized PS, only high temperature relaxation processes could be resolved for oxidized PS. Two relaxation processes have been observed. The first process is related to dc-conductivity that dominates at high temperatures and low frequencies. After subtraction of dc-conductivity we could analyse a second high-temperature relaxation process that is related to interface polarization induced by charge carriers trapped at the host matrix-pore interfaces. We found that, while the main effect of the oxidation on the PL appears to be a size reduction in the silicon nanocrystals that gives rise to a blue shift of the PL spectrum, its main contribution to the dielectric properties turns out to be blocking of transport channels in the host tissue and activation of hopping conductivity between silicon nanocrystals.

  11. Structure of fenchone by broadband rotational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Loru, Donatella; Bermúdez, Miguel A.; Sanz, M. Eugenia [Department of Chemistry, King’s College London, London SE1 1DB (United Kingdom)

    2016-08-21

    The bicyclic terpenoid fenchone (C{sub 10}H{sub 16}O, 1,3,3-trimethylbicyclo[2.2.1]heptan-2-one) has been investigated by chirped pulse Fourier transform microwave spectroscopy in the 2-8 GHz frequency region. The parent species and all heavy atom isotopologues have been observed in their natural abundance. The experimental rotational constants of all isotopic species observed have been determined and used to obtain the substitution (r{sub s}) and effective (r{sub 0}) structures of fenchone. Calculations at the B3LYP, M06-2X, and MP2 levels of theory with different basis sets were carried out to check their performance against experimental results. The structure of fenchone has been compared with those of norbornane (bicyclo[2.2.1]heptane) and the norbornane derivatives camphor (1,7,7-trimethylbicyclo[2.2.1]heptan-2-one) and camphene (3,3-dimethyl-2-methylenebicyclo[2.2.1]heptane), both with substituents at C{sub 2}. The structure of fenchone is remarkably similar to those of camphor and camphene. Comparison with camphor allows identification of changes in ∠CCC angles due to the different position of the methyl groups. All norbornane derivatives display similar structural changes with respect to norbornane. These changes mainly affect the bond lengths and angles of the six-membered rings, indicating that the substituent at C{sub 2} drives structural adjustments to minimise ring strain after its introduction.

  12. Gain-assisted broadband ring cavity enhanced spectroscopy

    Science.gov (United States)

    Selim, Mahmoud A.; Adib, George A.; Sabry, Yasser M.; Khalil, Diaa

    2017-02-01

    Incoherent broadband cavity enhanced spectroscopy can significantly increase the effective path length of light-matter interaction to detect weak absorption lines over broad spectral range, for instance to detect gases in confined environments. Broadband cavity enhancement can be based on the decay time or the intensity drop technique. Decay time measurement is based on using tunable laser source that is expensive and suffers from long scan time. Intensity dependent measurement is usually reported based on broadband source using Fabry-Perot cavity, enabling short measurement time but suffers from the alignment tolerance of the cavity and the cavity insertion loss. In this work we overcome these challenges by using an alignment-free ring cavity made of an optical fiber loop and a directional coupler, while having a gain medium pumped below the lasing threshold to improve the finesse and reduce the insertion loss. Acetylene (C2H2) gas absorption is measured around 1535 nm wavelength using a semiconductor optical amplifier (SOA) gain medium. The system is analyzed for different ring resonator forward coupling coefficient and loses, including the 3-cm long gas cell insertion loss and fiber connector losses used in the experimental verification. The experimental results are obtained for a coupler ratio of 90/10 and a fiber length of 4 m. The broadband source is the amplified spontaneous emission of another SOA and the output is measured using a 70pm-resolution optical spectrum analyzer. The absorption depth and the effective interaction length are improved about an order of magnitude compared to the direct absorption of the gas cell. The presented technique provides an engineering method to improve the finesse and, consequently the effective length, while relaxing the technological constraints on the high reflectivity mirrors and free-space cavity alignment.

  13. Modulation and multiplexing in ultra-broadband photonic internet: Part II

    Science.gov (United States)

    Romaniuk, Ryszard S.

    2011-06-01

    In this paper, there is presented a review of our today's understanding of the ultimately broadband photonic Internet. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation of photonics in development of the physical layer in the future Internet will probably increase. The photonics leads now to a better usage of the available bandwidth (increase of the spectral efficiency measured in Bit/s/Hz), increase in the transmission rate (from Gbps, via Tbps up to probably Pbps), increase in the transmission distance without signal regeneration (in distortion compensated active optical cables), increase in energy/power efficiency measured in W/Gbps, etc. Photonics may lead, in the future, to fully transparent optical networks and, thus, to essential increase in bandwidth and network reliability. It is expected that photonics (with biochemistry, electronics and mechatronics) may build psychological and physiological interface for humans to the future global network. The following optical signal multiplexing methods were considered, which are possible without O/E/O conversion: TDM-OTDM, FDM-CO-OFDM, OCDM-OCDMA, WDM-DWDM.

  14. Modulation and multiplexing in ultra-broadband photonic internet: Part I

    Science.gov (United States)

    Romaniuk, Ryszard S.

    2011-06-01

    In this paper, there is presented a review of our today's understanding of the ultimately broadband photonic Internet. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation of photonics in development of the physical layer in the future Internet will probably increase. The photonics leads now to a better usage of the available bandwidth (increase of the spectral efficiency measured in Bit/s/Hz), increase in the transmission rate (from Gbps, via Tbps up to probably Pbps), increase in the transmission distance without signal regeneration (in distortion compensated active optical cables), increase in energy/power efficiency measured in W/Gbps, etc. Photonics may lead, in the future, to fully transparent optical networks and, thus, to essential increase in bandwidth and network reliability. It is expected that photonics (with biochemistry, electronics and mechatronics) may build psychological and physiological interface for humans to the future global network. The following optical signal multiplexing methods were considered, which are possible without O/E/O conversion: TDM-OTDM, FDM-CO-OFDM, OCDM-OCDMA, WDM-DWDM.

  15. Real-time multiplexed digital cavity-enhanced spectroscopy

    International Nuclear Information System (INIS)

    Boyson, Toby K.; Dagdigian, Paul J.; Pavey, Karl D.; Fitzgerald, Nicholas J.; Spence, Thomas G.; Moore, David S.; Harb, Charles C.

    2015-01-01

    Cavity-enhanced spectroscopy is a sensitive optical absorption technique but one where the practical applications have been limited to studying small wavelength ranges. In addition, this Letter shows that wideband operation can be achieved by combining techniques usually reserved for the communications community with that of cavity-enhanced spectroscopy, producing a multiplexed real-time cavity-enhanced spectrometer. We use multiple collinear laser sources operating asynchronously and simultaneously while being detected on a single photodetector. This is synonymous with radio frequency (RF) cellular systems in which signals are detected on a single antenna but decoded uniquely. Here, we demonstrate results with spectra of methyl salicylate and show parts-per-billion per root hertz sensitivity measured in real-time

  16. Broadband dielectric spectroscopy and calorimetric investigations of D-lyxose.

    Science.gov (United States)

    Singh, Lokendra P; Alegría, A; Colmenero, J

    2011-10-18

    Using broadband dielectric spectroscopy, we have studied different types of relaxation processes, namely, primary (α), secondary (β), and another sub-T(g) process called γ-process, in the supercooled state of D-lyxose, over a wide frequency (10(-2)-10(9) Hz) and temperature range (120-340 K). In addition, the same sample was analyzed by differential scanning calorimeter. The temperature dependence of the relaxation times as well as the dielectric strength of different processes has been critically examined. It has been observed that the slower secondary relaxation (designated as β-) process shifts to lower frequencies with increasing applied pressure, but not the faster one. This pressure dependence indicates that the observed slower secondary relaxation (β-) is Johari-Goldstein relaxation process and faster one (γ-process) is probably the rotation of hydroxymethyl (-CH(2)OH) side group attached to the sugar ring, that is, of intramolecular origin. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Scanning, non-contact, hybrid broadband diffuse optical spectroscopy and diffuse correlation spectroscopy system.

    Science.gov (United States)

    Johansson, Johannes D; Mireles, Miguel; Morales-Dalmau, Jordi; Farzam, Parisa; Martínez-Lozano, Mar; Casanovas, Oriol; Durduran, Turgut

    2016-02-01

    A scanning system for small animal imaging using non-contact, hybrid broadband diffuse optical spectroscopy (ncDOS) and diffuse correlation spectroscopy (ncDCS) is presented. The ncDOS uses a two-dimensional spectrophotometer retrieving broadband (610-900 nm) spectral information from up to fifty-seven source-detector distances between 2 and 5 mm. The ncDCS data is simultaneously acquired from four source-detector pairs. The sample is scanned in two dimensions while tracking variations in height. The system has been validated with liquid phantoms, demonstrated in vivo on a human fingertip during an arm cuff occlusion and on a group of mice with xenoimplanted renal cell carcinoma.

  18. Large Molecule Structures by Broadband Fourier Transform Molecular Rotational Spectroscopy

    Science.gov (United States)

    Evangelisti, Luca; Seifert, Nathan A.; Spada, Lorenzo; Pate, Brooks

    2016-06-01

    Fourier transform molecular rotational resonance spectroscopy (FT-MRR) using pulsed jet molecular beam sources is a high-resolution spectroscopy technique that can be used for chiral analysis of molecules with multiple chiral centers. The sensitivity of the molecular rotational spectrum pattern to small changes in the three dimensional structure makes it possible to identify diastereomers without prior chemical separation. For larger molecules, there is the additional challenge that different conformations of each diastereomer may be present and these need to be differentiated from the diastereomers in the spectral analysis. Broadband rotational spectra of several larger molecules have been measured using a chirped-pulse FT-MRR spectrometer. Measurements of nootkatone (C15H22O), cedrol (C15H26O), ambroxide (C16H28O) and sclareolide (C16H26O2) are presented. These spectra are measured with high sensitivity (signal-to-noise ratio near 1,000:1) and permit structure determination of the most populated isomers using isotopic analysis of the 13C and 18O isotopologues in natural abundance. The accuracy of quantum chemistry calculations to identify diastereomers and conformers and to predict the dipole moment properties needed for three wave mixing measurements is examined.

  19. Relaxations and fast dynamics of the plastic crystal cyclo-octanol investigated by broadband dielectric spectroscopy

    OpenAIRE

    Lunkenheimer, Peter

    1997-01-01

    Relaxations and fast dynamics of the plastic crystal cyclo-octanol investigated by broadband dielectric spectroscopy / R. Brand, P. Lunkenheimer, A. Loidl. - In: Physical review. B. 56. 1997. S. R5713-R5716

  20. Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

    Science.gov (United States)

    Perez, Cristobal; Schnell, Melanie; Blanco, Susana; Lopez, Juan Carlos

    2016-06-01

    Since they were first synthetized, crown ethers have been extensively used in organometallic chemistry due to their unparalleled binding selectivity with alkali metal cations. From a structural point of view, crown ethers are heterocycles containing oxygen and/or other heteroatoms, although the most common ones are formed from ethylene oxide unit. Crown ethers are conventionally seen as being hydrophilic inside and hydrophobic outside when the structures found for the metal cation complexes are considered. However, crown ethers are extremely flexible and in isolation may present a variety of stable conformations so that their structure may be easily adapted in presence of a strong ligand as an alkali metal cation minimize the energy of the resulting complex. Water can be considered a soft ligand which interacts with crown ethers through moderate hydrogen bonds. It is thus interesting to investigate which conformers are selected by water to form complexes, the preferred interaction sites and the possible conformational changes due to the presence of one or more water molecules. Previous studies identified microsolvated crown ethers but in all cases with a chromophore group attached to the structure. Here we present a broadband rotational spectroscopy study of microsolvated crown ethers produced in a pulsed molecular jet expansion. Several 1:1 and 1:2 crown ether:water aggregates are presented for 12-crown-4, 15-crown-5 and 18-crown-6. Unambiguous identification of the structures has been achieved using isotopic substitution within the water unit. The subtle changes induced in the structures of the crown ether monomer upon complexation and the hydrogen-bonding network that hold them together will be also discussed. F. Gámez, B. Martínez-Haya, S. Blanco,J. C. López and J. L. Alonso, Phys. Chem. Chem. Phys. 2014, 14 12912-12918 V. A. Shubert, C.W. Müller and T. Zwier, J. Phys. Chem. A 2009, 113 8067-8079

  1. Positron annihilation response and broadband dielectric spectroscopy: salol.

    Science.gov (United States)

    Bartoš, J; Iskrová, M; Köhler, M; Wehn, R; Sauša, O; Lunkenheimer, P; Krištiak, J; Loidl, A

    2011-09-01

    A phenomenological analysis of the ortho-positronium (o-Ps) annihilation from positron annihilation lifetime spectroscopy (PALS) and the dynamics from broadband dielectric spectroscopy (BDS) are reported on a small molecular glass former of intermediate H-bonding and fragility: salol. The dielectric spectra extend over a very broad frequency range of about 2 × 10(-2)-3.5 × 10(11) Hz, providing information on the α-relaxation, the secondary relaxation giving rise to the excess wing, and the shallow high-frequency minimum in the micro- to milli-meter wave range. A number of empirical correlations between the o-Ps lifetime, τ(3)(T), and the various spectral and relaxation features have been observed. Thus, the phenomenological evaluation of the τ(3)(T) dependence of the PALS response of the amorphous sample reveals three characteristic PALS temperatures: T(g)(PALS), T(b1)(L) = 1.15T(g)(PALS) and T(b2)(L) = 1.25T(g)(PALS), which are discussed in relation to similar findings for some typical small molecular vdW- and H-bonded glass formers. A slighter change of the slope at T(b1)(L) appears to be related to the transition from excess wing to the primary α-process-dominated behavior, with the secondary process dominating in the deeply supercooled liquid state below T(b1)(L). The high-temperature plateau effect in the τ (3)(T) plot occurs at T(b2)(L) and agrees with the characteristic Stickel temperature, T(B)(ST), marking a qualitative change of the primary α process, but it does not follow the relation T(b2)(L) application of the two-order parameter (TOP) model to the structural relaxation as represented by the primary α relaxation times from BDS leads to the characteristic TOP temperature, T(m)(c), close to T(b1) from PALS. Within this model the phenomenological interpretation is offered based on changes in the probability of occurrence of solid-like and liquid-like domains to explain the dynamic as well as PALS responses. In summary, all the empirical

  2. Direct and quantitative broadband absorptance spectroscopy with multilayer cantilever probes

    Science.gov (United States)

    Hsu, Wei-Chun; Tong, Jonathan Kien-Kwok; Liao, Bolin; Chen, Gang

    2015-04-21

    A system for measuring the absorption spectrum of a sample is provided that includes a broadband light source that produces broadband light defined within a range of an absorptance spectrum. An interferometer modulates the intensity of the broadband light source for a range of modulation frequencies. A bi-layer cantilever probe arm is thermally connected to a sample arm having at most two layers of materials. The broadband light modulated by the interferometer is directed towards the sample and absorbed by the sample and converted into heat, which causes a temperature rise and bending of the bi-layer cantilever probe arm. A detector mechanism measures and records the deflection of the probe arm so as to obtain the absorptance spectrum of the sample.

  3. Multicomponent gas analysis using broadband quantum cascade laser spectroscopy

    NARCIS (Netherlands)

    Reyes Reyes, A.; Hou, Z.; Van Mastrigt, E.; Horsten, R.C.; De Jongste, J.C.; Pijnenburg, M.W.; Urbach, H.P.; Bhattacharya, N.

    2014-01-01

    We present a broadband quantum cascade laser-based spectroscopic system covering the region between 850 and 1250 cm?1. Its robust multipass cavity ensures a constant interaction length over the entire spectral region. The device enables the detection and identification of numerous molecules present

  4. Broadband stimulated Raman spectroscopy in the deep ultraviolet region

    Science.gov (United States)

    Kuramochi, Hikaru; Fujisawa, Tomotsumi; Takeuchi, Satoshi; Tahara, Tahei

    2017-09-01

    We report broadband stimulated Raman measurements in the deep ultraviolet (DUV) region, which enables selective probing of the aromatic amino acid residues inside proteins through the resonance enhancement. We combine the narrowband DUV Raman pump pulse (1000 cm-1) to realize stimulated Raman measurements covering a >1500 cm-1 spectral window. The stimulated Raman measurements for neat solvents, tryptophan, tyrosine, and glucose oxidase are performed using 240- and 290-nm Raman pump, highlighting the high potential of the DUV stimulated Raman probe for femtosecond time-resolved study of proteins.

  5. Broadband Doppler-limited two-photon and stepwise excitation spectroscopy with laser frequency combs

    Science.gov (United States)

    Hipke, Arthur; Meek, Samuel A.; Ideguchi, Takuro; Hänsch, Theodor W.; Picqué, Nathalie

    2014-07-01

    Multiplex two-photon excitation spectroscopy is demonstrated at Doppler-limited resolution. We describe first Fourier-transform two-photon spectroscopy of an atomic sample with two mode-locked laser oscillators in a dual-comb technique. Each transition is uniquely identified by the modulation imparted by the interfering comb excitations. The temporal modulation of the spontaneous two-photon fluorescence is monitored with a single photodetector, and the spectrum of all excited transitions is revealed by a Fourier transform.

  6. Broadband dielectric and conductivity spectroscopy of inhomogeneous and composite conductors

    Czech Academy of Sciences Publication Activity Database

    Petzelt, Jan; Nuzhnyy, Dmitry; Bovtun, Viktor; Savinov, Maxim; Kempa, Martin; Rychetský, Ivan

    2013-01-01

    Roč. 210, č. 11 (2013), s. 2259-2271 ISSN 1862-6300 R&D Projects: GA ČR GAP204/12/0232; GA MŠk LD12025 Institutional support: RVO:68378271 Keywords : effective medium approximation * infrared spectroscopy * THz spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.525, year: 2013

  7. Broadband sample holder for microwave spectroscopy of superconducting qubits

    International Nuclear Information System (INIS)

    Averkin, A. S.; Karpov, A.; Glushkov, E.; Abramov, N.; Shulga, K.; Huebner, U.; Il'ichev, E.; Ustinov, A. V.

    2014-01-01

    We present a practical design and implementation of a broadband sample holder suitable for microwave experiments with superconducting integrated circuits at millikelvin temperatures. Proposed design can be easily integrated in standard dilution cryostats, has flat pass band response in a frequency range from 0 to 32 GHz, allowing the RF testing of the samples with substrate size up to 4 × 4 mm 2 . The parasitic higher modes interference in the holder structure is analyzed and prevented via design considerations. The developed setup can be used for characterization of superconducting parametric amplifiers, bolometers, and qubits. We tested the designed sample holder by characterizing of a superconducting flux qubit at 20 mK temperature

  8. Secondary structure of bovine albumin as studied by polarization-sensitive multiplex CARS spectroscopy

    NARCIS (Netherlands)

    Voroshilov, A.; Voroshilov, Artemy; Otto, Cornelis; Greve, Jan

    1996-01-01

    The first application of polarization-sensitive multiplex coherent anti-Stokes Raman spectroscopy (MCARS) in the absence of resonance enhancement to the resolution of the secondary structure of a protein in solution is reported. Polarization MCARS spectra of bovine albumin in D2O were obtained in

  9. Spectroscopy of soft X-rays by multiplex procedure under UHV conditions

    International Nuclear Information System (INIS)

    Schulenburg, M.

    1979-01-01

    By vectorial treatment of the Johannson spectrometer on the basis of new calculations a complete vector model of the spectrometer can be constructed. The obtained fully automated multiplex system is superior for the spectroscopy of homogeneous samples (thin films) to all commercial devices as time-dependent errors are completely eliminated. The combined spectroscopy of the minerals brucite, talk and chlorite demonstrates the applicability to mineralogical problems. (DG) [de

  10. Multiplexed single-molecule force spectroscopy using a centrifuge.

    Science.gov (United States)

    Yang, Darren; Ward, Andrew; Halvorsen, Ken; Wong, Wesley P

    2016-03-17

    We present a miniature centrifuge force microscope (CFM) that repurposes a benchtop centrifuge for high-throughput single-molecule experiments with high-resolution particle tracking, a large force range, temperature control and simple push-button operation. Incorporating DNA nanoswitches to enable repeated interrogation by force of single molecular pairs, we demonstrate increased throughput, reliability and the ability to characterize population heterogeneity. We perform spatiotemporally multiplexed experiments to collect 1,863 bond rupture statistics from 538 traceable molecular pairs in a single experiment, and show that 2 populations of DNA zippers can be distinguished using per-molecule statistics to reduce noise.

  11. Adaptive Channel Estimation based on Soft Information Processing in Broadband Spatial Multiplexing Receivers

    Directory of Open Access Journals (Sweden)

    P. Beinschob

    2010-11-01

    Full Text Available In this paper we present a novel approach in Multiple-Input Multiple Output (MIMO Orthogonal Frequency Division Multiplexing (OFDM channel estimation technique based on a Decision Directed Recursive Least Squares (RLS algorithm in which no pilot symbols need to be integrated in the data after a short initial preamble. The novelty and key concept of the proposed technique is the block-wise causal and anti-causal RLS processing that yields two independent processings of RLS along with the associated decisions. Due to the usage of low density parity check (LDPC channel code, the receiver operates with soft information, which enables us to introduce a new modification of the Turbo principle as well as a simple information combining approach based on approximated aposteriori log-likelihood ratios (LLRs. Although the computational complexity is increased by both of our approaches, the latter is relatively less complex than the former. Simulation results show that these implementations outperform the simple RLS-DDCE algorithm and yield lower bit error rates (BER and more accurate channel estimates.

  12. Broadband dielectric spectroscopy of inhomogeneous and composite weak conductors

    Czech Academy of Sciences Publication Activity Database

    Petzelt, Jan; Nuzhnyy, Dmitry

    2016-01-01

    Roč. 89, 7-8 (2016), 651-666 ISSN 0141-1594 R&D Projects: GA ČR GA15-08389S Institutional support: RVO:68378271 Keywords : dielectric spectroscopy * effective medium approximation * coreshell composite * giant permittivity effects * negative permittivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.060, year: 2016

  13. Broadband terahertz spectroscopy: principles, fundamental research and potential for industrial applications

    International Nuclear Information System (INIS)

    Zouaghi, W; Thomson, M D; Rabia, K; Hahn, R; Blank, V; Roskos, H G

    2013-01-01

    Terahertz radiation (also called T-rays) can be employed for spectroscopy and imaging, from the laboratory to industrial applications. In this paper we give an overview of how broadband optoelectronic THz techniques (i.e. using optical lasers to achieve THz generation and detection) can be implemented, and give examples of their unique use in solid-state physics, and in biological and industrial applications. (paper)

  14. Semiconductor Nonlinear Dynamics Study by Broadband Terahertz Spectroscopy

    Science.gov (United States)

    Ho, I.-Chen

    Semiconductor nonlinearity in the terahertz (THz) frequency range has been attracting considerable attention due to the recent development of high-power semiconductor-based nanodevices. However, the underlying physics concerning carrier dynamics in the presence of high-field THz transients is still obscure. This thesis introduces an ultrafast, time-resolved THz pump/THz probe approach to the study of semiconductor properties in the nonlinear regime. The carrier dynamics regarding two mechanisms, intervalley scattering and impact ionization, is observed for doped InAs on a sub-picosecond time scale. In addition, polaron modulation driven by intense THz pulses is experimentally and theoretically investigated. The observed polaron dynamics verifies the interaction between energetic electrons and a phonon field. In contrast to previous work which reports optical phonon responses, acoustic phonon modulations are addressed in this study. A further understanding of the intense field interacting with solid materials will accelerate the development of semiconductor devices. This thesis starts with the design and performance of a table-top THz spectrometer which has the advantages of ultra-broad bandwidth (one order higher bandwidth compared to a conventional ZnTe sensor) and high electric field strength (>100 kV/cm). Unlike the conventional THz time-domain spectroscopy, the spectrometer integrates a novel THz air-biased-coherent-detection (THz-ABCD) technique and utilizes selected gases as THz emitters and sensors. In comparison with commonly used electro-optic (EO) crystals or photoconductive (PC) dipole antennas, the gases have the benefits of no phonon absorption as existing in EO crystals and no carrier life time limitation as observed in PC dipole antennas. The newly development THz-ABCD spectrometer with a strong THz field strength capability provides a platform for various research topics especially on the nonlinear carrier dynamics of semiconductors. Two mechanisms

  15. Frequency-comb-assisted broadband precision spectroscopy with cascaded diode lasers

    DEFF Research Database (Denmark)

    Liu, Junqiu; Brasch, Victor; Pfeiffer, Martin H. P.

    2016-01-01

    Frequency-comb-assisted diode laser spectroscopy, employing both the accuracy of an optical frequency comb and the broad wavelength tuning range of a tunable diode laser, has been widely used in many applications. In this Letter, we present a novel method using cascaded frequency agile diode lasers......, which allows us to extend the measurement bandwidth to 37.4 THz (1355-1630 nm) at megahertz resolution with scanning speeds above 1 THz/s. It is demonstrated as a useful tool to characterize a broadband spectrum for molecular spectroscopy, and in particular it enables us to characterize the dispersion...

  16. Ultrafast wavelength multiplexed broad bandwidth digital diffuse optical spectroscopy for in vivo extraction of tissue optical properties

    Science.gov (United States)

    Torjesen, Alyssa; Istfan, Raeef; Roblyer, Darren

    2017-03-01

    Frequency-domain diffuse optical spectroscopy (FD-DOS) utilizes intensity-modulated light to characterize optical scattering and absorption in thick tissue. Previous FD-DOS systems have been limited by large device footprints, complex electronics, high costs, and limited acquisition speeds, all of which complicate access to patients in the clinical setting. We have developed a new digital DOS (dDOS) system, which is relatively compact and inexpensive, allowing for simplified clinical use, while providing unprecedented measurement speeds. The dDOS system utilizes hardware-integrated custom board-level direct digital synthesizers and an analog-to-digital converter to generate frequency sweeps and directly measure signals utilizing undersampling at six wavelengths modulated at discrete frequencies from 50 to 400 MHz. Wavelength multiplexing is utilized to achieve broadband frequency sweep measurements acquired at over 97 Hz. When compared to a gold-standard DOS system, the accuracy of optical properties recovered with the dDOS system was within 5.3% and 5.5% for absorption and reduced scattering coefficient extractions, respectively. When tested in vivo, the dDOS system was able to detect physiological changes throughout the cardiac cycle. The new FD-dDOS system is fast, inexpensive, and compact without compromising measurement quality.

  17. Rapid, Time-Division Multiplexed, Direct Absorption- and Wavelength Modulation-Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alexander Klein

    2014-11-01

    Full Text Available We present a tunable diode laser spectrometer with a novel, rapid time multiplexed direct absorption- and wavelength modulation-spectroscopy operation mode. The new technique allows enhancing the precision and dynamic range of a tunable diode laser absorption spectrometer without sacrificing accuracy. The spectroscopic technique combines the benefits of absolute concentration measurements using calibration-free direct tunable diode laser absorption spectroscopy (dTDLAS with the enhanced noise rejection of wavelength modulation spectroscopy (WMS. In this work we demonstrate for the first time a 125 Hz time division multiplexed (TDM-dTDLAS-WMS spectroscopic scheme by alternating the modulation of a DFB-laser between a triangle-ramp (dTDLAS and an additional 20 kHz sinusoidal modulation (WMS. The absolute concentration measurement via the dTDLAS-technique allows one to simultaneously calibrate the normalized 2f/1f-signal of the WMS-technique. A dTDLAS/WMS-spectrometer at 1.37 µm for H2O detection was built for experimental validation of the multiplexing scheme over a concentration range from 50 to 3000 ppmV (0.1 MPa, 293 K. A precision of 190 ppbV was achieved with an absorption length of 12.7 cm and an averaging time of two seconds. Our results show a five-fold improvement in precision over the entire concentration range and a significantly decreased averaging time of the spectrometer.

  18. High-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor array

    Science.gov (United States)

    Guss, Paul; Rabin, Michael; Croce, Mark; Hoteling, Nathan; Schwellenbach, David; Kruschwitz, Craig; Mocko, Veronika; Mukhopadhyay, Sanjoy

    2017-09-01

    We demonstrate very high-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor (TES) array. The readout circuit consists of superconducting microwave resonators coupled to radio frequency superconducting-quantum-interference devices (RF-SQUIDs) and transduces changes in input current to changes in phase of a microwave signal. We used a flux-ramp modulation to linearize the response and avoid low-frequency noise. The result is a very high-resolution photon spectroscopy with a microwave-multiplexed 4-pixel transition edge sensor array. We performed and validated a small-scale demonstration and test of all the components of our concept system, which encompassed microcalorimetry, microwave multiplexing, RF-SQUIDs, and software-defined radio (SDR). We shall display data we acquired in the first simultaneous combination of all key innovations in a 4-pixel demonstration, including microcalorimetry, microwave multiplexing, RF-SQUIDs, and SDR. We present the energy spectrum of a gadolinium-153 (153Gd) source we measured using our 4-pixel TES array and the RF-SQUID multiplexer. For each pixel, one can observe the two 97.4 and 103.2 keV photopeaks. We measured the 153Gd photon source with an achieved energy resolution of 70 eV, full width half maximum (FWHM) at 100 keV, and an equivalent readout system noise of 90 pA/pHz at the TES. This demonstration establishes a path for the readout of cryogenic x-ray and gamma ray sensor arrays with more elements and spectral resolving powers. We believe this project has improved capabilities and substantively advanced the science useful for missions such as nuclear forensics, emergency response, and treaty verification through the explored TES developments.

  19. Broad-band time-resolved near infrared spectroscopy in the TJ-II stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M.C.; Pastor, I.; Cal, E. de la; McCarthy, K.J. [Laboratorio Nacional de Fusion, CIEMAT, Madrid (Spain); Diaz, D. [Universidad Autonoma de Madrid, Dept Quimica Fisica Aplicada, Madrid (Spain)

    2014-11-15

    First experimental results on broad-band, time-resolved Near Infrared (NIR;here loosely defined as covering from 750 to 1650 nm) passive spectroscopy using a high sensitivity InGaAs detector are reported for the TJ-II Stellarator. Experimental set-up is described together with its main characteristics, the most remarkable ones being its enhanced NIR response, broadband spectrum acquisition in a single shot, and time-resolved measurements with up to 1.8 kHz spectral rate. Prospects for future work and more extended physics studies in this newly open spectral region in TJ-II are discussed. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Underresolved absorption spectroscopy of OH radicals in flames using broadband UV LEDs

    Science.gov (United States)

    White, Logan; Gamba, Mirko

    2018-04-01

    A broadband absorption spectroscopy diagnostic based on underresolution of the spectral absorption lines is evaluated for the inference of species mole fraction and temperature in combustion systems from spectral fitting. The approach uses spectrally broadband UV light emitting diodes and leverages low resolution, small form factor spectrometers. Through this combination, the method can be used to develop high precision measurement sensors. The challenges of underresolved spectroscopy are explored and addressed using spectral derivative fitting, which is found to generate measurements with high precision and accuracy. The diagnostic is demonstrated with experimental measurements of gas temperature and OH mole fraction in atmospheric air/methane premixed laminar flat flames. Measurements exhibit high precision, good agreement with 1-D flame simulations, and high repeatability. A newly developed model of uncertainty in underresolved spectroscopy is applied to estimate two-dimensional confidence regions for the measurements. The results of the uncertainty analysis indicate that the errors in the outputs of the spectral fitting procedure are correlated. The implications of the correlation between uncertainties for measurement interpretation are discussed.

  1. Broadband integrated mid infrared light sources as enabling technology for point of care mid-infrared spectroscopy

    Science.gov (United States)

    2017-08-20

    AFRL-AFOSR-JP-TR-2017-0061 Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy Alex...mid-infrared light sources as enabling technology for point-of-care mid-infrared spectroscopy 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-16-1-4037...Broadband integrated mid-infrared light sources as enabling technology for point-of-care mid- infrared spectroscopy ” Date: 16th August 2017 Name

  2. Broadband x-ray imaging and spectroscopy of the crab nebula and pulsar with NuSTAR

    DEFF Research Database (Denmark)

    Madsen, Kristin K.; Reynolds, Stephen; Harrison, Fiona

    2015-01-01

    We present broadband (3-78 keV) NuSTAR X-ray imaging and spectroscopy of the Crab nebula and pulsar. We show that while the phase-averaged and spatially integrated nebula + pulsar spectrum is a power law in this energy band, spatially resolved spectroscopy of the nebula finds a break at ~9 ke...

  3. Ultra-broadband THz time-domain spectroscopy of common polymers using THz air photonics

    DEFF Research Database (Denmark)

    D’Angelo, Francesco; Mics, Zoltán; Bonn, Mischa

    2014-01-01

    -domain spectrometer employing air-photonics for the generation and detection of single-cycle sub-50 fs THz transients. The time domain measurements provide direct access to both the absorption and refractive index spectra. The polymers LDPE and TOPAS® demonstrate negligible absorption and spectrally-flat refractive...... index across the entire spectroscopy window, revealing the high potential of these polymers for applications in THz photonics such as ultra-broadband polymer-based dielectric mirrors, waveguides, and fibers. Resonant high-frequency polar vibrational modes are observed and assigned in polymers PA6...... and PTFE, and their dielectric functions in the complete frequency window 2-15 THz are theoretically reproduced. Our results demonstrate the potential of ultrabroadband air-photonics-based THz time domain spectroscopy as a valuable analytic tool for materials science....

  4. Interest in broadband dielectric spectroscopy to study the electronic transport in materials for lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Badot, Jean-Claude, E-mail: jc.badot@chimie-paristech.fr [Institut de Recherche de Chimie Paris, UMR CNRS 8247, Réseau sur le Stockage Electrochimique de l' Energie (RS2E), Chimie Paris Tech, PSL*, 11 rue P. et M. Curie, 75231 Cedex 05 Paris (France); Lestriez, Bernard [Institut des Matériaux Jean Rouxel, UMR CNRS 6502, Université de Nantes, 2 rue de la Houssinière, BP32229, 44322 Nantes (France); Dubrunfaut, Olivier [GeePs | Group of electrical engineering – Paris, UMR CNRS 8507, CentraleSupélec, Univ. Paris-Sud, Université Paris-Saclay, Sorbonne Universités, UPMC Univ Paris 06, 3 & 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette CEDEX, Paris (France)

    2016-11-15

    Highlights: • Broadband dielectric spectroscopy measures the multiscale electronic conductivity from macroscopic to interatomic sizes. • There is an influence of the surface states on the electronic transfer of powdered materials (e.g. thin insulating layer of Li{sub 2}CO{sub 3} on LiNiO{sub 2} and carbon coating on LiFePO{sub 4}). • Electrical relaxations resulting from the interfacial polarizations at the different scales of the carbon black network are evidenced. - Abstract: Broadband dielectric spectroscopy (BDS) is used to measure complex permittivity and conductivity of conducting materials for lithium batteries at frequencies from a few Hz to several GHz with network and impedance analysers. Under the influence of an electric field, there will be charge density fluctuations in the conductor mainly due to electronic transfer. These fluctuations result in dielectric relaxations for frequencies below 100 GHz. The materials are compacted powders in which each element (particles, agglomerates of particles) can have different sizes and morphologies. In the present review, studies are reported on the influence of surface states in LiNiO{sub 2} (ageing and degradation in air) and LiFePO{sub 4} (carbon coating thin layer), and on a composite electrode based on the lithium trivanadate (Li{sub 1.1}V{sub 3}O{sub 8}) active material. The results have shown that the BDS technique is very sensitive to the different scales of materials architectures involved in electronic transport, from interatomic distances to macroscopic sizes.

  5. Broadband spectroscopy of magnetic response in a nano-scale magnetic wire

    International Nuclear Information System (INIS)

    Yamaguchi, A.; Motoi, K.; Miyajima, H.; Utsumi, Y.

    2014-01-01

    We measure the broadband spectra of magnetic response in a single layered ferromagnetic nano-scale wire in order to investigate the size effect on the ferromagnetic resonance. We found that the resonance frequency difference between 300-nm- and 5-μm-wide wires was varied by about 5 GHz due to the shape anisotropy. Furthermore, we experimentally detected the magnetization precession induced by the thermal fluctuation via the rectification of a radio-frequency (rf) current by incorporating an additional direct current (dc) by using Wheatstone bridge circuit. Our investigation renders that the shape anisotropy is of great importance to control the resonance frequency and to provide thermal stability of the microwave devices. - Highlights: • We describe an experimental investigation of the magnetic response of a single layered ferromagnetic nano-scale wire. • We present the conventional broadband microwave spectroscopy with a vector network analyzer and rectifying spectroscopy obtained with a Wheatstone bridge technique. • The investigation enables us to characterize the size effect on the ferromagnetic response and also to detect the magnetization precession induced by the thermal fluctuations

  6. Interest in broadband dielectric spectroscopy to study the electronic transport in materials for lithium batteries

    International Nuclear Information System (INIS)

    Badot, Jean-Claude; Lestriez, Bernard; Dubrunfaut, Olivier

    2016-01-01

    Highlights: • Broadband dielectric spectroscopy measures the multiscale electronic conductivity from macroscopic to interatomic sizes. • There is an influence of the surface states on the electronic transfer of powdered materials (e.g. thin insulating layer of Li_2CO_3 on LiNiO_2 and carbon coating on LiFePO_4). • Electrical relaxations resulting from the interfacial polarizations at the different scales of the carbon black network are evidenced. - Abstract: Broadband dielectric spectroscopy (BDS) is used to measure complex permittivity and conductivity of conducting materials for lithium batteries at frequencies from a few Hz to several GHz with network and impedance analysers. Under the influence of an electric field, there will be charge density fluctuations in the conductor mainly due to electronic transfer. These fluctuations result in dielectric relaxations for frequencies below 100 GHz. The materials are compacted powders in which each element (particles, agglomerates of particles) can have different sizes and morphologies. In the present review, studies are reported on the influence of surface states in LiNiO_2 (ageing and degradation in air) and LiFePO_4 (carbon coating thin layer), and on a composite electrode based on the lithium trivanadate (Li_1_._1V_3O_8) active material. The results have shown that the BDS technique is very sensitive to the different scales of materials architectures involved in electronic transport, from interatomic distances to macroscopic sizes.

  7. Study of high-temperature multiplex HCl coherent anti-Stokes Raman spectroscopy spectra.

    Science.gov (United States)

    Singh, J P; Yueh, F Y; Kao, W; Cook, R L

    1993-02-20

    A feasibility study of temperature measurement with multiplex HCl coherent anti-Stokes Raman spectroscopy (CARS) is investigated. The HCl CARS spectra of a 100% HCl gas sample are recorded in a quartz sample cell placed in a furnace at 1 atm pressure and at different temperatures. The nonlinear susceptibility of HCl (chi(nr)(HCl)), which is measured with the present CARS experimental setup, is reported. The experimental spectra are fit by using a library of simulated HCl CARS spectra with a least-squares-fitting program to infer the temperature. The inferred temperatures from HCl CARS spectra are in agreement with thermocouple temperatures.

  8. Highly multiplexible thermal kinetic inductance detectors for x-ray imaging spectroscopy

    International Nuclear Information System (INIS)

    Ulbricht, Gerhard; Mazin, Benjamin A.; Szypryt, Paul; Walter, Alex B.; Bockstiegel, Clint; Bumble, Bruce

    2015-01-01

    For X-ray imaging spectroscopy, high spatial resolution over a large field of view is often as important as high energy resolution, but current X-ray detectors do not provide both in the same device. Thermal Kinetic Inductance Detectors (TKIDs) are being developed as they offer a feasible way to combine the energy resolution of transition edge sensors with pixel counts approaching CCDs and thus promise significant improvements for many X-ray spectroscopy applications. TKIDs are a variation of Microwave Kinetic Inductance Detectors (MKIDs) and share their multiplexibility: working MKID arrays with 2024 pixels have recently been demonstrated and much bigger arrays are under development. In this work, we present a TKID prototype, which is able to achieve an energy resolution of 75 eV at 5.9 keV, even though its general design still has to be optimized. We further describe TKID fabrication, characterization, multiplexing, and working principle and demonstrate the necessity of a data fitting algorithm in order to extract photon energies. With further design optimizations, we expect to be able to improve our TKID energy resolution to less than 10 eV at 5.9 keV

  9. Highly multiplexible thermal kinetic inductance detectors for x-ray imaging spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ulbricht, Gerhard, E-mail: ulbricht@physics.ucsb.edu; Mazin, Benjamin A.; Szypryt, Paul; Walter, Alex B.; Bockstiegel, Clint [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Bumble, Bruce [NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91125 (United States)

    2015-06-22

    For X-ray imaging spectroscopy, high spatial resolution over a large field of view is often as important as high energy resolution, but current X-ray detectors do not provide both in the same device. Thermal Kinetic Inductance Detectors (TKIDs) are being developed as they offer a feasible way to combine the energy resolution of transition edge sensors with pixel counts approaching CCDs and thus promise significant improvements for many X-ray spectroscopy applications. TKIDs are a variation of Microwave Kinetic Inductance Detectors (MKIDs) and share their multiplexibility: working MKID arrays with 2024 pixels have recently been demonstrated and much bigger arrays are under development. In this work, we present a TKID prototype, which is able to achieve an energy resolution of 75 eV at 5.9 keV, even though its general design still has to be optimized. We further describe TKID fabrication, characterization, multiplexing, and working principle and demonstrate the necessity of a data fitting algorithm in order to extract photon energies. With further design optimizations, we expect to be able to improve our TKID energy resolution to less than 10 eV at 5.9 keV.

  10. Broadband Dielectric Spectroscopy and Quasi-Elastic Neutron Scattering on Single-Ion Polymer Conductors

    Science.gov (United States)

    Soles, Christopher; Peng, Hua-Gen; Page, Kirt; Snyder, Chad; Pandy, Ashoutosh; Jeong, Youmi; Runt, James; NIST Collaboration; Pennsylvania Collaboration

    2011-03-01

    The application of solid polymer electrolytes in rechargeable batteries has not been fully realized after decades of research due to its low conductivity. Dramatic increases of the ion conductivity are needed and this progress requires the understanding of conduction mechanism. We address this topic in two fronts, namely, the effect of plasticizer additives and geometric confinement on the charge transfer mechanism. To this end, we combine broadband dielectric spectroscopy (BDS) to characterize the ion mobility and quasi-elastic neutron scattering (QENS) to quantify segmental motion on a single-ion model polymer electrolyte. Deuterated small molecules were used as plasticizers so that the segmental motion of the polymer electrolyte could be monitored by QENS to understand the mechanism behind the increased conductivity. Anodic aluminum oxide (AAO) membranes with well defined channel sizes are used as the matrix to study the transport of ions solvated in a 1D polymer electrolyte.

  11. Josephson admittance spectroscopy application for frequency analysis of broadband THz antennas

    International Nuclear Information System (INIS)

    Volkov, O Yu; Divin, Yu Yu; Gubankov, V N; Gundareva, I I; Pavlovskiy, V V

    2010-01-01

    Application of Josephson admittance spectroscopy for the spectral analysis of a broad-band log-periodic superconducting antenna was demonstrated at the frequency range from 50 to 700 GHz. The [001]-tilt YBa 2 Cu 3 O 7-x bicrystal Josephson junctions, integrated with sinuous log-periodic YBa 2 Cu 3 O 7-x antennas, were fabricated on NdGaO 3 bicrystal substrates. A real part of the antenna admittance ReY(f) as a function of the frequency f was reconstructed from the modification of the dc current-voltage characteristic of the junction, induced by the antenna. Resonance features were observed in the recovered ReY(f)-spectra with a periodicity in the logarithmic frequency scale, corresponding to log-periodic geometry of the antenna. The ReY(f)-spectra, recovered by Josephson spectroscopy, were compared with the ReY(f)-spectra, obtained by CAD simulation, and both spectra were shown to be similar in their main features. A value of 23 was obtained for an effective permittivity of the NdGaO3 bicrystal substrates by fitting simulated data to those obtained from Josephson spectroscopy.

  12. Broadband 2D Electronic Spectroscopy Reveals Coupling Between Dark 1Bu- State of Carotenoid and Qx State of Bacteriochlorophyll

    Directory of Open Access Journals (Sweden)

    Scholes Gregory D.

    2013-03-01

    Full Text Available The study of LH2 protein of purple bacteria by broadband 2D electronic spectroscopy is presented. The dark 1Bu- carotenoid state is directly observed in 2D spectra and its role in carotenoid-bacteriochlorophyll interaction is discussed.

  13. Ultra-Broadband Infrared Pulses from a Potassium-Titanyl Phosphate Optical Parametric Amplifier for VIS-IR-SFG Spectroscopy

    Science.gov (United States)

    Isaienko, Oleksandr; Borguet, Eric

    A non-collinear KTP-OPA to provide ultra-broadband mid-infrared pulses was designed and characterized. With proper pulse-front and phase correction, the system has a potential for high-time resolution vibrational VIS-IR-SFG spectroscopy.

  14. Kinetically controlled glass transition measurement of organic aerosol thin films using broadband dielectric spectroscopy

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2018-06-01

    Full Text Available Glass transitions from liquid to semi-solid and solid phase states have important implications for reactivity, growth, and cloud-forming (cloud condensation nuclei and ice nucleation capabilities of secondary organic aerosols (SOAs. The small size and relatively low mass concentration of SOAs in the atmosphere make it difficult to measure atmospheric SOA glass transitions using conventional methods. To circumvent these difficulties, we have adapted a new technique for measuring glass-forming properties of atmospherically relevant organic aerosols. Aerosol particles to be studied are deposited in the form of a thin film onto an interdigitated electrode (IDE using electrostatic precipitation. Dielectric spectroscopy provides dipole relaxation rates for organic aerosols as a function of temperature (373 to 233 K that are used to calculate the glass transition temperatures for several cooling or heating rates. IDE-enabled broadband dielectric spectroscopy (BDS was successfully used to measure the kinetically controlled glass transition temperatures of aerosols consisting of glycerol and four other compounds with selected cooling and heating rates. The glass transition results agree well with available literature data for these five compounds. The results indicate that the IDE-BDS method can provide accurate glass transition data for organic aerosols under atmospheric conditions. The BDS data obtained with the IDE-BDS technique can be used to characterize glass transitions for both simulated and ambient organic aerosols and to model their climate effects.

  15. Vibrational dynamics of aqueous hydroxide solutions probed using broadband 2DIR spectroscopy

    International Nuclear Information System (INIS)

    Mandal, Aritra; Tokmakoff, Andrei

    2015-01-01

    We employed ultrafast transient absorption and broadband 2DIR spectroscopy to study the vibrational dynamics of aqueous hydroxide solutions by exciting the O–H stretch vibrations of the strongly hydrogen-bonded hydroxide solvation shell water and probing the continuum absorption of the solvated ion between 1500 and 3800 cm −1 . We observe rapid vibrational relaxation processes on 150–250 fs time scales across the entire probed spectral region as well as slower vibrational dynamics on 1–2 ps time scales. Furthermore, the O–H stretch excitation loses its frequency memory in 180 fs, and vibrational energy exchange between bulk-like water vibrations and hydroxide-associated water vibrations occurs in ∼200 fs. The fast dynamics in this system originate in strong nonlinear coupling between intra- and intermolecular vibrations and are explained in terms of non-adiabatic vibrational relaxation. These measurements indicate that the vibrational dynamics of the aqueous hydroxide complex are faster than the time scales reported for long-range transport of protons in aqueous hydroxide solutions

  16. Molecular dynamics of amorphous pharmaceutical fenofibrate studied by broadband dielectric spectroscopy

    Directory of Open Access Journals (Sweden)

    U. Sailaja

    2016-06-01

    Full Text Available Fenofibrate is mainly used to reduce cholesterol level in patients at risk of cardiovascular disease. Thermal transition study with the help of differential scanning calorimetry (DSC shows that the aforesaid active pharmaceutical ingredient (API is a good glass former. Based on our DSC study, the molecular dynamics of this API has been carried out by broadband dielectric spectroscopy (BDS covering wide temperature and frequency ranges. Dielectric measurements of amorphous fenofibrate were performed after its vitrification by fast cooling from a few degrees above the melting point (Tm=354.11 K to deep glassy state. The sample does not show any crystallization tendency during cooling and reaches the glassy state. The temperature dependence of the structural relaxation has been fitted by single Vogel–Fulcher–Tamman (VFT equation. From VFT fit, glass transition temperature (Tg was estimated as 250.56 K and fragility (m was determined as 94.02. This drug is classified as a fragile glass former. Deviations of experimental data from Kohlrausch–Williams–Watts (KWW fits on high-frequency flank of α-peak indicate the presence of an excess wing in fenofibrate. Based on Ngai׳s coupling model, we identified the excess wing as true Johari–Goldstein (JG process. Below the glass transition temperature one can clearly see a secondary relaxation (γ with an activation energy of 32.67 kJ/mol.

  17. Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy

    Science.gov (United States)

    Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F.

    2013-01-01

    Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detected using a calibration method that could be applied to patients. CBV, as a marker of angiogenesis, is quantified in a rat cortex before and after hypoxia acclimation. Rats are acclimated at 370-mmHg pressure for three weeks, while rats in the control group are housed under the same conditions, but under normal pressure. CBV increased in each animal in the acclimation group. The mean CBV (%volume/volume) is 3.49%±0.43% (mean±SD) before acclimation for the experimental group, and 4.76%±0.29% after acclimation. The CBV for the control group is 3.28%±0.75%, and 3.09%±0.48% for the two measurements. This demonstrates that angiogenesis can be monitored noninvasively over time using a bNIRS system with a calibration method that is compatible with human use and less stressful for studies using animals.

  18. Polymer chain dynamics in epoxy based composites as investigated by broadband dielectric spectroscopy

    Directory of Open Access Journals (Sweden)

    Mohammad K. Hassan

    2016-03-01

    Full Text Available Epoxy networks of the diglycidyl ether of bisphenol A (DGEBA were prepared using 3,3′- and 4,4′-diaminodiphenyl sulfone isomer crosslinkers. Secondary relaxations and the glass transitions of resultant networks were probed using broadband dielectric spectroscopy (BDS. A sub-Tg γ relaxation peak for both networks shifts to higher frequencies (f with increasing temperature in Arrhenius fashion, both processes having the same activation energy and being assigned to phenyl ring flipping in DGEBA chains. A β relaxation is assigned to local motions of dipoles that were created during crosslinking reactions. 4,4′-based networks exhibited higher Tg relative to 3,3′-based networks as per dynamic mechanical as well as BDS analyses. The Vogel–Fulcher–Tammann–Hesse equation fitted well to relaxation time vs. temperature data and comparison of Vogel temperatures suggests lower free volume per mass for the 3,3′-based network. The Kramers–Krönig transformation was used to directly calculate dc-free ɛ″ vs. f data from experimental ɛ′ vs. f data. Distribution of relaxation times (DRT curves are bi-modal for the 3,3′-crosslinked resin suggesting large-scale microstructural heterogeneity as opposed to homogeneity for the 4,4′-based network whose DRT consists of a single peak.

  19. Ultra-Broadband Two-Dimensional Electronic Spectroscopy and Pump-Probe Microscopy of Molecular Systems

    Science.gov (United States)

    Spokoyny, Boris M.

    Ultrafast spectroscopy offers an unprecedented view on the dynamic nature of chemical reactions. From charge transfer in semiconductors to folding and isomerization of proteins, these all important processes can now be monitored and in some instances even controlled on real, physical timescales. One of the biggest challenges of ultrafast science is the incredible energetic complexity of most systems. It is not uncommon to encounter macromolecules or materials with absorption spectra spanning significant portions of the visible spectrum. Monitoring a multitude of electronic and vibrational transitions, all dynamically interacting with each other on femtosecond timescales poses a truly daunting experimental task. The first part of this thesis deals with the development of a novel Two-Dimensional Electronic Spectroscopy (2DES) and its associated, advanced detection methodologies. Owing to its ultra-broadband implementation, this technique enables us to monitor femtosecond chemical dynamics that span the energetic landscape of the entire visible spectrum. In order to demonstrate the utility of our method, we apply it to two laser dye molecules, IR-144 and Cresyl Violet. Variation of photophysical properties on a microscopic scale in either man-made or naturally occurring systems can have profound implications on how we understand their macroscopic properties. Recently, inorganic hybrid perovskites have been tapped as the next generation solar energy harvesting materials. Their remarkable properties include low exciton binding energy, low exciton recombination rates and long carrier diffusion lengths. Nevertheless, considerable variability in device properties made with nearly identical preparation methods has puzzled the community. In the second part of this thesis we use non-linear pump probe microscopy to study the heterogeneous nature of femtosecond carrier dynamics in thin film perovskites. We show that the local morphology of the perovskite thin films has a

  20. Broadband sub-THz spectroscopy modules integrated in 65-nm CMOS technology

    NARCIS (Netherlands)

    Matters-Kammerer, M.K.; van Goor, D.; Tripodi, L.

    2017-01-01

    The design and characterization of a broadband 20-480 GHz continuously tuneable on-chip spectrometer based on non-linear transmission lines in 65-nm CMOS technology is presented. The design procedure of the sampler that detects the ultra-broadband signal from the transmitter in time and frequency

  1. Toward noninvasive detection and monitoring of malaria with broadband diffuse optical spectroscopy

    Science.gov (United States)

    Campbell, Chris; Tromberg, Bruce J.; O'Sullivan, Thomas D.

    2018-02-01

    Despite numerous advances, malaria continues to kill nearly half a million people globally every year. New analytical methods and diagnostics are critical to understanding how treatments under development affect the lifecycle of malaria parasites. A biomarker that has been gaining interest is the "malaria pigment" hemozoin. This byproduct of hemoglobin digestion by the parasite has a unique spectral signature but is difficult to differentiate from hemoglobin and other tissue chromophores. Hemozoin can be detected in blood samples, but only utilizing approaches that require specialized training and facilities. Diffuse optical spectroscopy (DOS) is a noninvasive sensing technique that is sensitive to near-infrared absorption and scattering and capable of probing centimeter-deep volumes of tissue in vivo. DOS is relatively low-cost, does not require specialized training and thus potentially suitable for use in low-resource settings. In this work, we assess the potential of DOS to detect and quantify the presence of hemozoin noninvasively and at physiologically relevant levels. We suspended synthetic hemozoin in Intralipid-based tissue-simulating phantoms in order to mimic malaria infection in multiply-scattering tissue. Using a fiber probe that combines frequency-domain and continuous-wave broadband DOS (650-1000 nm), we detected hemozoin concentrations below 250 ng/ml, which corresponds to parasitemia sensitivities comparable to modern rapid diagnostic tests. We used the experimental variability to simulate and estimate the sensitivity of DOS to hemozoin in tissue that includes hemoglobin, water, and lipid under various tissue oxygen saturation levels. The results indicate that with increased precision, it may be possible to detect Hz noninvasively with DOS.

  2. Conductivity relaxation and charge transport of trihexyl tetradecyl phosphonium dicyanamide ionic liquid by broadband dielectric spectroscopy

    Science.gov (United States)

    Thasneema K., K.; Thayyil, M. Shahin; Krishna Kumar N., S.; Govindaraj, G.; Saheer, V. C.

    2018-04-01

    Usually ionic liquids consists of a large organic cation with low symmetry such as imidazolium, pyridinium, quaternary ammonium or phosponium etc combined with enormously wide range of inorganic or organic symmetric anion with melting point below 100. Ionic liquids existing in an extremely large number of possible ion pair combinations. It offers a very wide range of thermo physical properties led to the concept of designer solvents for specific applications. Due to the features of high chemical and thermal stability, low vapor pressure non flammability high ionic conductivity, and they show a good solvent ability towards a great variety of organic or inorganic compounds, ionic liquids have a widespread use in many areas such as batteries, fuel cell, solar cells, super capacitors etc. The main focus of this work is the study of molecular dynamics and conductivity relaxation of amorphous Trihexyl tetradecyl phosphonium dicyanamide ([P14,6,6,6][N(CN)2]) ionic liquid which is proved as a better electrolyte in super capacitors, over a wide frequency 10-2 Hz to 107 Hz and the temperature range between 123k and 265 k by means of Broadband Dielectric Spectroscopy. We observe alpha conductivity relaxation and secondary relaxation above and below Glass Transition Temperature. The experimental results were analyzed using electric modulus representation. The analysis emphasis the inter molecular interaction and the nature of glass forming system, whether it is fragile or strong system. The ionic liquid shows a fragile behavior and the fragility index m=123.59. TGA result of the sample exhibit a good resistance to thermal decomposition, up to 300°C.

  3. Effects of cations and cholesterol with sphingomyelin membranes investigated by high-resolution broadband sum frequency vibrational spectroscopy

    Science.gov (United States)

    Zhang, Zhen; Feng, Rong-juan; Li, Yi-yi; Liu, Ming-hua; Guo, Yuan

    2017-08-01

    Sphingomyelin(SM) is specifically enriched in the plasma membrane of mammalian cells. Its molecular structure is compose by N-acyl-Derythro-sphingosylphosphorylcholine. The function of the SM related to membrane signaling and protein trafficking are relied on the interactions of the SM, cations, cholesterol and proteins. In this report, the interaction of three different nature SMs, cations and cholesterol at air/aqueous interfaces studied by high-resolution broadband sum frequency vibrational spectroscopy, respectively. Our results shed lights on understanding the relationship between SMs monolayer, cholesterol and Cations.

  4. Broadband cavity-enhanced absorption spectroscopy in the ultraviolet spectral region for measurements of nitrogen dioxide and formaldehyde

    Science.gov (United States)

    Washenfelder, R. A.; Attwood, A. R.; Flores, J. M.; Zarzana, K. J.; Rudich, Y.; Brown, S. S.

    2016-01-01

    Formaldehyde (CH2O) is the most abundant aldehyde in the atmosphere, and it strongly affects photochemistry through its photolysis. We describe simultaneous measurements of CH2O and nitrogen dioxide (NO2) using broadband cavity-enhanced absorption spectroscopy in the ultraviolet spectral region. The light source consists of a continuous-wave diode laser focused into a Xenon bulb to produce a plasma that emits high-intensity, broadband light. The plasma discharge is optically filtered and coupled into a 1 m optical cavity. The reflectivity of the cavity mirrors is 0.99930 ± 0.00003 (1- reflectivity = 700 ppm loss) at 338 nm, as determined from the known Rayleigh scattering of He and zero air. This mirror reflectivity corresponds to an effective path length of 1.43 km within the 1 m cell. We measure the cavity output over the 315-350 nm spectral region using a grating monochromator and charge-coupled device array detector. We use published reference spectra with spectral fitting software to simultaneously retrieve CH2O and NO2 concentrations. Independent measurements of NO2 standard additions by broadband cavity-enhanced absorption spectroscopy and cavity ring-down spectroscopy agree within 2 % (slope for linear fit = 1.02 ± 0.03 with r2 = 0.998). Standard additions of CH2O measured by broadband cavity-enhanced absorption spectroscopy and calculated based on flow dilution are also well correlated, with r2 = 0.9998. During constant mixed additions of NO2 and CH2O, the 30 s measurement precisions (1σ) of the current configuration were 140 and 210 pptv, respectively. The current 1 min detection limit for extinction measurements at 315-350 nm provides sufficient sensitivity for measurement of trace gases in laboratory experiments and ground-based field experiments. Additionally, the instrument provides highly accurate, spectroscopically based trace gas detection that may complement higher precision techniques based on non-absolute detection methods. In addition to

  5. Insights into the Structural Changes Occurring upon Photoconversion in the Orange Carotenoid Protein from Broadband Two-Dimensional Electronic Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    De Re, Eleonora; Schlau-Cohen, Gabriela S.; Leverenz, Ryan L.; Huxter, Vanessa M.; Oliver, Thomas A. A.; Mathies, Richard A.; Fleming, Graham R.

    2014-05-22

    Carotenoids play an essential role in photoprotection, interacting with other pigments to safely dissipate excess absorbed energy as heat. In cyanobacteria, the short time scale photoprotective mechanisms involve the photoactive orange carotenoid protein (OCP), which binds a single carbonyl carotenoid. Blue-green light induces the photoswitching of OCP from its ground state form (OCPO) to a metastable photoproduct (OCPR). OCPR can bind to the phycobilisome antenna and induce fluorescence quenching. The photoswitching is accompanied by structural and functional changes at the level of the protein and of the bound carotenoid. In this study, we use broadband two-dimensional electronic spectroscopy to look at the differences in excited state dynamics of the carotenoid in the two forms of OCP. Our results provide insight into the origin of the pronounced vibrational lineshape and oscillatory dynamics observed in linear absorption and 2D electronic spectroscopy of OCPO and the large inhomogeneous broadening in OCPR, with consequences for the chemical function of the two forms.

  6. Multiplexed measurements by time resolved spectroscopy using colloidal CdSe/ZnS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, U.; Jimenez de Aberasturi, D.; Malinowski, R.; Amin, F.; Parak, W. J.; Heimbrodt, W., E-mail: Wolfram.Heimbrodt@physik.uni-marburg.de [Department of Physics and Materials Sciences Center, Philipps-University of Marburg, Renthof 5, D-35032 Marburg (Germany)

    2014-01-27

    Multiplexed measurements of analytes in parallel is a topical demand in bioanalysis and bioimaging. An interesting alternative to commonly performed spectral multiplexing is lifetime multiplexing. In this Letter, we present a proof of principle of single-color lifetime multiplexing by coupling the same fluorophore to different nanoparticles. The effective lifetime of the fluorophores can be tuned by more than one order of magnitude due to resonance energy transfer from donor states. Measurements have been done on a model systems consisting of ATTO-590 dye molecules linked to either gold particles or to CdSe/ZnS core shell quantum dots. Both systems show the same luminescence spectrum of ATTO-590 dye emission in continuous wave excitation, but can be distinguished by means of time resolved measurements. The dye molecules bound to gold particles exhibit a mono-exponential decay with a lifetime of 4.5 ns, whereas the dye molecules bound to CdSe/ZnS dots show a nonexponential decay with a slow component of about 135 ns due to the energy transfer from the quantum dots. We demonstrate the fundamental possibility to determine the mixing ratio for dyes with equal luminescence spectra but very different transients. This opens up a pathway independent of the standard optical multiplexing with many different fluorophores emitting from the near ultraviolet to the near infrared spectral region.

  7. Broad-band dielectric spectroscopy of tetragonal PLZT x/40/60

    Czech Academy of Sciences Publication Activity Database

    Buixaderas, Elena; Noujni, Dmitri; Veljko, Sergiy; Savinov, Maxim; Vaněk, Přemysl; Kamba, Stanislav; Petzelt, Jan; Kosec, M.

    2006-01-01

    Roč. 79, 6-7 (2006), s. 415-426 ISSN 0141-1594 R&D Projects: GA ČR(CZ) GA202/06/0403; GA ČR GA202/04/0993 Institutional research plan: CEZ:AV0Z10100520 Keywords : ferroelectrics * relaxors * dielectric behaviour * lattice dynamics dielectric spectroscopy * IR spectroscopy * THz spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.830, year: 2006

  8. Broadband pump-probe spectroscopy with sub-10-fs resolution for probing ultrafast internal conversion and coherent phonons in carotenoids

    International Nuclear Information System (INIS)

    Polli, D.; Antognazza, M.R.; Brida, D.; Lanzani, G.; Cerullo, G.; De Silvestri, S.

    2008-01-01

    We use pump-probe spectroscopy with broadband detection to study electronic energy relaxation and coherent vibrational dynamics in carotenoids. A fast optical multichannel analyzer combined with a non-collinear optical parametric amplifier allows simultaneous acquisition of the differential transmission dynamics on the 500-700 nm wavelength range with sub-10-fs temporal resolution. The broad spectral coverage enables on the one hand a detailed study of the ultrafast bright-to-dark state internal conversion process; on the other hand, the tracking of the motion of the vibrational wavepacket launched on the ground state multidimensional potential energy surface. We present results on all-trans β-carotene and on a long-chain polyene in solution. The developed experimental setup enables the straightforward acquisition and analysis of coherent vibrational dynamics, highlighting time-frequency domain features with extreme resolution

  9. SUZAKU BROADBAND SPECTROSCOPY OF SWIFT J1753.5-0127 IN THE LOW-HARD STATE

    International Nuclear Information System (INIS)

    Reynolds, Mark T.; Miller, Jon M.; Homan, Jeroen; Miniutti, Giovanni

    2010-01-01

    We present Suzaku observations of the Galactic black hole candidate Swift J1753.5-0127 in the low-hard state (LHS). The broadband coverage of Suzaku enables us to detect the source over the energy range 0.6-250 keV. The broadband spectrum (2-250 keV) is found to be consistent with a simple power-law (Γ ∼ 1.63). In agreement with previous observations of this system, a significant excess of soft X-ray flux is detected consistent with the presence of a cool accretion disk. Estimates of the disk inner radius infer a value consistent with the innermost stable circular orbit (ISCO; R in ∼ g , for certain values of, e.g., N H , i), although we cannot conclusively rule out the presence of an accretion disk truncated at larger radii (R in ∼ 10-50R g ). A weak, relativistically broadened iron line is also detected, in addition to disk reflection at higher energy. However, the iron-K line profile favors an inner radius larger than the ISCO (R in ∼ 10-20R g ). The implications of these observations for models of the accretion flow in the LHS are discussed.

  10. High-speed combustion diagnostics in a rapid compression machine by broadband supercontinuum absorption spectroscopy.

    Science.gov (United States)

    Werblinski, Thomas; Fendt, Peter; Zigan, Lars; Will, Stefan

    2017-05-20

    The first results under fired internal combustion engine conditions based on a supercontinuum absorption spectrometer are presented and discussed. Temperature, pressure, and water mole fraction are inferred simultaneously from broadband H 2 O absorbance spectra ranging from 1340 nm to 1440 nm. The auto-ignition combustion process is monitored for two premixed n-heptane/air mixtures with 10 kHz in a rapid compression machine. Pressure and temperature levels during combustion exceed 65 bar and 1900 K, respectively. To allow for combustion measurements, the robustness of the spectrometer against beam steering has been improved compared to its previous version. Additionally, the detectable wavelength range has been extended further into the infrared region to allow for the acquisition of distinct high-temperature water transitions located in the P-branch above 1410 nm. Based on a theoretical study, line-of-sight (LOS) effects introduced by temperature stratification on the broadband fitting algorithm in the complete range from 1340 nm to 1440 nm are discussed. In this context, the recorded spectra during combustion were evaluated only within a narrower spectral region exhibiting almost no interference from low-temperature molecules (here, P-branch from 1410 nm to 1440 nm). It is shown that this strategy mitigates almost all of the LOS effects introduced by cold molecules and the evaluation of the spectrum in the entirely recorded wavelength range at engine combustion conditions.

  11. Development of a multiplexing fingerprint and high wavenumber Raman spectroscopy technique for real-time in vivo tissue Raman measurements at endoscopy

    Science.gov (United States)

    Bergholt, Mads Sylvest; Zheng, Wei; Huang, Zhiwei

    2013-03-01

    We report on the development of a novel multiplexing Raman spectroscopy technique using a single laser light together with a volume phase holographic (VPH) grating that simultaneously acquires both fingerprint (FP) and high wavenumber (HW) tissue Raman spectra at endoscopy. We utilize a customized VPH dual-transmission grating, which disperses the incident Raman scattered light vertically onto two separate segments (i.e., -150 to 1950 cm-1 1750 to 3600 cm-1) of a charge-coupled device camera. We demonstrate that the multiplexing Raman technique can acquire high quality in vivo tissue Raman spectra ranging from 800 to 3600 cm-1 within 1.0 s with a spectral resolution of 3 to 6 cm-1 during clinical endoscopy. The rapid multiplexing Raman spectroscopy technique covering both FP and HW ranges developed in this work has potential for improving in vivo tissue diagnosis and characterization at endoscopy.

  12. Broadband Access

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Broadband Access. Worldwide market for broadband access $30 Billion! Over 200 million broadband subscribers worldwide! Various Competing Broadband access. Digital Subscriber line; Wireless; Optical Fiber.

  13. High-resolution gamma-ray spectroscopy with a microwave-multiplexed transition-edge sensor array

    Energy Technology Data Exchange (ETDEWEB)

    Noroozian, Omid [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, Colorado 80309 (United States); Mates, John A. B.; Bennett, Douglas A.; Brevik, Justus A.; Fowler, Joseph W.; Gao, Jiansong; Hilton, Gene C.; Horansky, Robert D.; Irwin, Kent D.; Schmidt, Daniel R.; Vale, Leila R.; Ullom, Joel N. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States); Kang, Zhao [Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States)

    2013-11-11

    We demonstrate very high resolution photon spectroscopy with a microwave-multiplexed two-pixel transition-edge sensor (TES) array. We measured a {sup 153}Gd photon source and achieved an energy resolution of 63 eV full-width-at-half-maximum at 97 keV and an equivalent readout system noise of 86 pA/√(Hz) at the TES. The readout circuit consists of superconducting microwave resonators coupled to radio-frequency superconducting-quantum-interference-devices and transduces changes in input current to changes in phase of a microwave signal. We use flux-ramp modulation to linearize the response and evade low-frequency noise. This demonstration establishes one path for the readout of cryogenic X-ray and gamma-ray sensor arrays with more than 10{sup 3} elements and spectral resolving powers R=λ/Δλ>10{sup 3}.

  14. Broadband high-resolution two-photon spectroscopy with laser frequency combs

    OpenAIRE

    Hipke, Arthur; Meek, Samuel A.; Ideguchi, Takuro; Hänsch, Theodor W.; Picqué, Nathalie

    2013-01-01

    Two-photon excitation spectroscopy with broad spectral span is demonstrated at Doppler-limited resolution. We describe first Fourier transform two-photon spectroscopy of an atomic sample with two mode-locked laser oscillators in a dual-comb technique. Each transition is uniquely identified by the modulation imparted by the interfering comb excitations. The temporal modulation of the spontaneous two-photon fluorescence is monitored with a single photodetector, and the spectrum is revealed by a...

  15. Highly doped semiconductor plasmonic nanoantenna arrays for polarization selective broadband surface-enhanced infrared absorption spectroscopy of vanillin

    Science.gov (United States)

    Barho, Franziska B.; Gonzalez-Posada, Fernando; Milla, Maria-Jose; Bomers, Mario; Cerutti, Laurent; Tournié, Eric; Taliercio, Thierry

    2017-11-01

    Tailored plasmonic nanoantennas are needed for diverse applications, among those sensing. Surface-enhanced infrared absorption (SEIRA) spectroscopy using adapted nanoantenna substrates is an efficient technique for the selective detection of molecules by their vibrational spectra, even in small quantity. Highly doped semiconductors have been proposed as innovative materials for plasmonics, especially for more flexibility concerning the targeted spectral range. Here, we report on rectangular-shaped, highly Si-doped InAsSb nanoantennas sustaining polarization switchable longitudinal and transverse plasmonic resonances in the mid-infrared. For small array periodicities, the highest reflectance intensity is obtained. Large periodicities can be used to combine localized surface plasmon resonances (SPR) with array resonances, as shown in electromagnetic calculations. The nanoantenna arrays can be efficiently used for broadband SEIRA spectroscopy, exploiting the spectral overlap between the large longitudinal or transverse plasmonic resonances and narrow infrared active absorption features of an analyte molecule. We demonstrate an increase of the vibrational line intensity up to a factor of 5.7 of infrared-active absorption features of vanillin in the fingerprint spectral region, yielding enhancement factors of three to four orders of magnitude. Moreover, an optimized readout for SPR sensing is proposed based on slightly overlapping longitudinal and transverse localized SPR.

  16. Highly doped semiconductor plasmonic nanoantenna arrays for polarization selective broadband surface-enhanced infrared absorption spectroscopy of vanillin

    Directory of Open Access Journals (Sweden)

    Barho Franziska B.

    2017-11-01

    Full Text Available Tailored plasmonic nanoantennas are needed for diverse applications, among those sensing. Surface-enhanced infrared absorption (SEIRA spectroscopy using adapted nanoantenna substrates is an efficient technique for the selective detection of molecules by their vibrational spectra, even in small quantity. Highly doped semiconductors have been proposed as innovative materials for plasmonics, especially for more flexibility concerning the targeted spectral range. Here, we report on rectangular-shaped, highly Si-doped InAsSb nanoantennas sustaining polarization switchable longitudinal and transverse plasmonic resonances in the mid-infrared. For small array periodicities, the highest reflectance intensity is obtained. Large periodicities can be used to combine localized surface plasmon resonances (SPR with array resonances, as shown in electromagnetic calculations. The nanoantenna arrays can be efficiently used for broadband SEIRA spectroscopy, exploiting the spectral overlap between the large longitudinal or transverse plasmonic resonances and narrow infrared active absorption features of an analyte molecule. We demonstrate an increase of the vibrational line intensity up to a factor of 5.7 of infrared-active absorption features of vanillin in the fingerprint spectral region, yielding enhancement factors of three to four orders of magnitude. Moreover, an optimized readout for SPR sensing is proposed based on slightly overlapping longitudinal and transverse localized SPR.

  17. BROADBAND X-RAY IMAGING AND SPECTROSCOPY OF THE CRAB NEBULA AND PULSAR WITH NuSTAR

    International Nuclear Information System (INIS)

    Madsen, Kristin K.; Harrison, Fiona; Grefenstette, Brian W.; Reynolds, Stephen; An, Hongjun; Boggs, Steven; Craig, William W.; Zoglauer, Andreas; Christensen, Finn E.; Fryer, Chris L.; Hailey, Charles J.; Nynka, Melania; Markwardt, Craig; Zhang, William; Stern, Daniel

    2015-01-01

    We present broadband (3-78 keV) NuSTAR X-ray imaging and spectroscopy of the Crab nebula and pulsar. We show that while the phase-averaged and spatially integrated nebula + pulsar spectrum is a power law in this energy band, spatially resolved spectroscopy of the nebula finds a break at ∼9 keV in the spectral photon index of the torus structure with a steepening characterized by ΔΓ ∼ 0.25. We also confirm a previously reported steepening in the pulsed spectrum, and quantify it with a broken power law with break energy at ∼12 keV and ΔΓ ∼ 0.27. We present spectral maps of the inner 100'' of the remnant and measure the size of the nebula as a function of energy in seven bands. These results find that the rate of shrinkage with energy of the torus size can be fitted by a power law with an index of γ = 0.094 ± 0.018, consistent with the predictions of Kennel and Coroniti. The change in size is more rapid in the NW direction, coinciding with the counter-jet where we find the index to be a factor of two larger. NuSTAR observed the Crab during the latter part of a γ-ray flare, but found no increase in flux in the 3-78 keV energy band

  18. Coherent cavity-enhanced dual-comb spectroscopy

    OpenAIRE

    Fleisher, Adam J.; Long, David A.; Reed, Zachary D.; Hodges, Joseph T.; Plusquellic, David F.

    2016-01-01

    Dual-comb spectroscopy allows for the rapid, multiplexed acquisition of high-resolution spectra without the need for moving parts or low-resolution dispersive optics. This method of broadband spectroscopy is most often accomplished via tight phase locking of two mode-locked lasers or via sophisticated signal processing algorithms, and therefore, long integration times of phase coherent signals are difficult to achieve. Here we demonstrate an alternative approach to dual-comb spectroscopy usin...

  19. Exhaled breath profiling using broadband quantum cascade laser-based spectroscopy in healthy children and children with asthma and cystic fibrosis.

    Science.gov (United States)

    van Mastrigt, E; Reyes-Reyes, A; Brand, K; Bhattacharya, N; Urbach, H P; Stubbs, A P; de Jongste, J C; Pijnenburg, M W

    2016-04-08

    Exhaled breath analysis is a potential non-invasive tool for diagnosing and monitoring airway diseases. Gas chromatography-mass spectrometry and electrochemical sensor arrays are the main techniques to detect volatile organic compounds (VOC) in exhaled breath. We developed a broadband quantum cascade laser spectroscopy technique for VOC detection and identification. The objective of this study was to assess the repeatability of exhaled breath profiling with broadband quantum cascade laser-based spectroscopy and to explore the clinical applicability by comparing exhaled breath samples from healthy children with those from children with asthma or cystic fibrosis (CF). Healthy children and children with stable asthma or stable CF, aged 6-18 years, were included. Two to four exhaled breath samples were collected in Tedlar bags and analyzed by quantum cascade laser spectroscopy to detect VOCs with an absorption profile in the wavenumber region between 832 and 1262.55 cm(-1). We included 35 healthy children, 39 children with asthma and 15 with CF. Exhaled breath VOC profiles showed poor repeatability (Spearman's rho  =  0.36 to 0.46) and agreement of the complete profiles. However, we were able to discriminate healthy children from children with stable asthma or stable CF and identified VOCs that were responsible for this discrimination. Broadband quantum cascade laser-based spectroscopy detected differences in VOC profiles in exhaled breath samples between healthy children and children with asthma or CF. The combination of a relatively easy and fast method and the possibility of molecule identification makes broadband quantum cascade laser-based spectroscopy attractive to investigate the diagnostic and prognostic potential of volatiles in exhaled breath.

  20. High-resolution broadband terahertz spectroscopy via electronic heterodyne detection of photonically generated terahertz frequency comb.

    Science.gov (United States)

    Pavelyev, D G; Skryl, A S; Bakunov, M I

    2014-10-01

    We report an alternative approach to the terahertz frequency-comb spectroscopy (TFCS) based on nonlinear mixing of a photonically generated terahertz pulse train with a continuous wave signal from an electronic synthesizer. A superlattice is used as a nonlinear mixer. Unlike the standard TFCS technique, this approach does not require a complex double-laser system but retains the advantages of TFCS-high spectral resolution and wide bandwidth.

  1. High-performance broad-band spectroscopy for breast cancer risk assessment

    Science.gov (United States)

    Pawluczyk, Olga; Blackmore, Kristina; Dick, Samantha; Lilge, Lothar

    2005-09-01

    Medical diagnostics and screening are becoming increasingly demanding applications for spectroscopy. Although for many years the demand was satisfied with traditional spectrometers, analysis of complex biological samples has created a need for instruments capable of detecting small differences between samples. One such application is the measurement of absorbance of broad spectrum illumination by breast tissue, in order to quantify the breast tissue density. Studies have shown that breast cancer risk is closely associated with the measurement of radiographic breast density measurement. Using signal attenuation in transillumination spectroscopy in the 550-1100nm spectral range to measure breast density, has the potential to reduce the frequency of ionizing radiation, or making the test accessible to younger women; lower the cost and make the procedure more comfortable for the patient. In order to determine breast density, small spectral variances over a total attenuation of up to 8 OD have to be detected with the spectrophotometer. For this, a high performance system has been developed. The system uses Volume Phase Holographic (VPH) transmission grating, a 2D detector array for simultaneous registration of the whole spectrum with high signal to noise ratio, dedicated optical system specifically optimized for spectroscopic applications and many other improvements. The signal to noise ratio exceeding 50,000 for a single data acquisition eliminates the need for nitrogen cooled detectors and provides sufficient information to predict breast tissue density. Current studies employing transillumination breast spectroscopy (TIBS) relating to breast cancer risk assessment and monitoring are described.

  2. Broadband Ftmw Spectroscopy of the Urea-Argon and Thiourea-Argon Complexes

    Science.gov (United States)

    Medcraft, Chris; Bittner, Dror M.; Cooper, Graham A.; Mullaney, John C.; Walker, Nick

    2017-06-01

    The rotational spectra complexes of argon-urea, argon-thiourea and water-thiourea have been measured by chirped-pulse Fourier transform microwave spectroscopy from 2-18.5 GHz. The sample was produced via laser vaporisation of a rod containing copper and the organic sample as a stream of argon was passed over the surface and subsequently expanded into the vacuum chamber cooling the sample. Argon was found to bind to π system of the carbonyl bond for both the urea and thiourea complexes.

  3. Broadband strip-line ferromagnetic resonance spectroscopy of soft magnetic CoFeTaZr patterned thin films

    Science.gov (United States)

    Gupta, S.; Kumar, D.; Jin, T. L.; Nongjai, R.; Asokan, K.; Ghosh, A.; Aparnadevi, M.; Suri, P.; Piramanayagam, S. N.

    2018-05-01

    In this paper, magnetic and magnetization dynamic properties of compositionally patterned Co46Fe40Ta9Zr5 thin films are investigated. A combination of self-assembly and ion-implantation was employed to locally alter the composition of Co46Fe40Ta9Zr5 thin film in a periodic manner. 20 keV O+ and 60 keV N+ ions were implanted at different doses in order to modify the magnetization dynamic properties of the samples in a controlled fashion. Magnetic hysteresis loop measurements revealed significant changes in the coercivity for higher influences of 5 × 1016 ions per cm2. In particular, N+ implantation was observed to induce two phase formation with high and low coercivities. Broadband strip-line ferromagnetic resonance spectroscopy over wide range of frequency (8 - 20 GHz) was used to study the magnetization dynamics as a function of ion-beam dosage. With higher fluences, damping constant showed a continuous increase from 0.0103 to 0.0430. Such control of magnetic properties at nano-scale using this method is believed to be useful for spintronics and microwave device applications.

  4. Near-infrared incoherent broadband cavity enhanced absorption spectroscopy (NIR-IBBCEAS) for detection and quantification of natural gas components.

    Science.gov (United States)

    Prakash, Neeraj; Ramachandran, Arun; Varma, Ravi; Chen, Jun; Mazzoleni, Claudio; Du, Ke

    2018-06-28

    The principle of near-infrared incoherent broadband cavity enhanced absorption spectroscopy was employed to develop a novel instrument for detecting natural gas leaks as well as for testing the quality of natural gas mixtures. The instrument utilizes the absorption features of methane, butane, ethane, and propane in the wavelength region of 1100 nm to 1250 nm. The absorption cross-section spectrum in this region for methane was adopted from the HITRAN database, and those for the other three gases were measured in the laboratory. A singular-value decomposition (SVD) based analysis scheme was employed for quantifying methane, butane, ethane, and propane by performing a linear least-square fit. The developed instrument achieved a detection limit of 460 ppm, 141 ppm, 175 ppm and 173 ppm for methane, butane, ethane, and propane, respectively, with a measurement time of 1 second and a cavity length of 0.59 m. These detection limits are less than 1% of the Lower Explosive Limit (LEL) for each gas. The sensitivity can be further enhanced by changing the experimental parameters (such as cavity length, lamp power etc.) and using longer averaging intervals. The detection system is a low-cost and portable instrument suitable for performing field monitorings. The results obtained on the gas mixture emphasize the instrument's potential for deployment at industrial facilities dealing with natural gas, where potential leaks pose a threat to public safety.

  5. Hyperbolic-cosine waveguide tapers and oversize rectangular waveguide for reduced broadband insertion loss in W-band electron paramagnetic resonance spectroscopy. II. Broadband characterization

    Energy Technology Data Exchange (ETDEWEB)

    Sidabras, Jason W.; Anderson, James R.; Mainali, Laxman; Hyde, James S. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States); Strangeway, Robert A. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States); Department of Electrical Engineering and Computer Science, Milwaukee School of Engineering, Milwaukee, Wisconsin 53201 (United States); Mett, Richard R. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States); Department of Chemistry and Physics, Milwaukee School of Engineering, Milwaukee, Wisconsin 53201 (United States)

    2016-03-15

    Experimental results have been reported on an oversize rectangular waveguide assembly operating nominally at 94 GHz. It was formed using commercially available WR28 waveguide as well as a pair of specially designed tapers with a hyperbolic-cosine shape from WR28 to WR10 waveguide [R. R. Mett et al., Rev. Sci. Instrum. 82, 074704 (2011)]. The oversize section reduces broadband insertion loss for an Electron Paramagnetic Resonance (EPR) probe placed in a 3.36 T magnet. Hyperbolic-cosine tapers minimize reflection of the main mode and the excitation of unwanted propagating waveguide modes. Oversize waveguide is distinguished from corrugated waveguide, overmoded waveguide, or quasi-optic techniques by minimal coupling to higher-order modes. Only the TE{sub 10} mode of the parent WR10 waveguide is propagated. In the present work, a new oversize assembly with a gradual 90° twist was implemented. Microwave power measurements show that the twisted oversize waveguide assembly reduces the power loss in the observe and pump arms of a W-band bridge by an average of 2.35 dB and 2.41 dB, respectively, over a measured 1.25 GHz bandwidth relative to a straight length of WR10 waveguide. Network analyzer measurements confirm a decrease in insertion loss of 2.37 dB over a 4 GHz bandwidth and show minimal amplitude distortion of approximately 0.15 dB. Continuous wave EPR experiments confirm these results. The measured phase variations of the twisted oversize waveguide assembly, relative to an ideal distortionless transmission line, are reduced by a factor of two compared to a straight length of WR10 waveguide. Oversize waveguide with proper transitions is demonstrated as an effective way to increase incident power and the return signal for broadband EPR experiments. Detailed performance characteristics, including continuous wave experiment using 1 μM 2,2,6,6-tetramethylpiperidine-1-oxyl in aqueous solution, provided here serve as a benchmark for other broadband low-loss probes in

  6. Hyperbolic-cosine waveguide tapers and oversize rectangular waveguide for reduced broadband insertion loss in W-band electron paramagnetic resonance spectroscopy. II. Broadband characterization

    International Nuclear Information System (INIS)

    Sidabras, Jason W.; Anderson, James R.; Mainali, Laxman; Hyde, James S.; Strangeway, Robert A.; Mett, Richard R.

    2016-01-01

    Experimental results have been reported on an oversize rectangular waveguide assembly operating nominally at 94 GHz. It was formed using commercially available WR28 waveguide as well as a pair of specially designed tapers with a hyperbolic-cosine shape from WR28 to WR10 waveguide [R. R. Mett et al., Rev. Sci. Instrum. 82, 074704 (2011)]. The oversize section reduces broadband insertion loss for an Electron Paramagnetic Resonance (EPR) probe placed in a 3.36 T magnet. Hyperbolic-cosine tapers minimize reflection of the main mode and the excitation of unwanted propagating waveguide modes. Oversize waveguide is distinguished from corrugated waveguide, overmoded waveguide, or quasi-optic techniques by minimal coupling to higher-order modes. Only the TE 10 mode of the parent WR10 waveguide is propagated. In the present work, a new oversize assembly with a gradual 90° twist was implemented. Microwave power measurements show that the twisted oversize waveguide assembly reduces the power loss in the observe and pump arms of a W-band bridge by an average of 2.35 dB and 2.41 dB, respectively, over a measured 1.25 GHz bandwidth relative to a straight length of WR10 waveguide. Network analyzer measurements confirm a decrease in insertion loss of 2.37 dB over a 4 GHz bandwidth and show minimal amplitude distortion of approximately 0.15 dB. Continuous wave EPR experiments confirm these results. The measured phase variations of the twisted oversize waveguide assembly, relative to an ideal distortionless transmission line, are reduced by a factor of two compared to a straight length of WR10 waveguide. Oversize waveguide with proper transitions is demonstrated as an effective way to increase incident power and the return signal for broadband EPR experiments. Detailed performance characteristics, including continuous wave experiment using 1 μM 2,2,6,6-tetramethylpiperidine-1-oxyl in aqueous solution, provided here serve as a benchmark for other broadband low-loss probes in

  7. Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS): A rapid test for enteric coating thickness and integrity of controlled release pellet formulations.

    Science.gov (United States)

    Alfarsi, Anas; Dillon, Amy; McSweeney, Seán; Krüse, Jacob; Griffin, Brendan; Devine, Ken; Sherry, Patricia; Henken, Stephan; Fitzpatrick, Stephen; Fitzpatrick, Dara

    2018-04-12

    There are no rapid dissolution based tests for determining coating thickness, integrity and drug concentration in controlled release pellets either during production or post-production. The manufacture of pellets requires several coating steps depending on the formulation. The sub-coating and enteric coating steps typically take up to six hours each followed by additional drying steps. Post production regulatory dissolution testing also takes up to six hours to determine if the batch can be released for commercial sale. The thickness of the enteric coating is a key factor that determines the release rate of the drug in the gastro-intestinal tract. Also, the amount of drug per unit mass decreases with increasing thickness of the enteric coating. In this study, the coating process is tracked from start to finish on an hourly basis by taking samples of pellets during production and testing those using BARDS (Broadband Acoustic Resonance Dissolution Spectroscopy). BARDS offers a rapid approach to characterising enteric coatings with measurements based on reproducible changes in the compressibility of a solvent due to the evolution of air during dissolution. This is monitored acoustically via associated changes in the frequency of induced acoustic resonances. A steady state acoustic lag time is associated with the disintegration of the enteric coatings in basic solution. This lag time is pH dependent and is indicative of the rate at which the coating layer dissolves. BARDS represents a possible future surrogate test for conventional USP dissolution testing as its data correlates directly with the thickness of the enteric coating, its integrity and also with the drug loading as validated by HPLC. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Contactless, probeless and non-titrimetric determination of acid-base reactions using broadband acoustic resonance dissolution spectroscopy (BARDS).

    Science.gov (United States)

    Ahmed, M Rizwan; McSweeney, Sean; Krüse, Jacob; Vos, Bastiaan; Fitzpatrick, Dara

    2018-02-12

    pH determination is a routine measurement in scientific laboratories worldwide. Most major advances in pH measurement were made in the 19th and early 20th century. pH measurements are critical for the determination of acid base reactions. This study demonstrates how an acid-base reaction can be monitored without the use of a pH probe, indicator and titres of reagent. The stoichiometric reaction between carbonate and HCl acid yields specific quantities of CO 2 , which causes reproducible changes to the compressibility of the solvent. This in turn slows down the speed of sound in solution which is induced by a magnetic follower gently tapping the inner wall of the vessel. As a consequence the frequencies of the acoustic resonances in the vessel are reduced. This approach is called Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS) which harnesses this phenomenon for many applications. The acid-carbonate experiments have also been validated using H 2 SO 4 acid and using both potassium and sodium counterions for the carbonate. This method can be used to interrogate strong acid-base reactions in a rapid and non-invasive manner using carbonate as the base. The data demonstrate the first example of a reactant also acting as an indicator. The applicability of the method to weak acids has yet to be determined. A novel conclusion from the study is that a person with a well-trained ear is capable of determining the concentration and pH of a strong acid just by listening. This brings pH measurement into the realm of human perception.

  9. Theory of sum-frequency generation spectroscopy of adsorbed molecules using the density matrix method-broadband vibrational sum-frequency generation and applications

    International Nuclear Information System (INIS)

    Bonn, M; Ueba, H; Wolf, M

    2005-01-01

    A generalized theory of frequency- and time-resolved vibrational sum-frequency generation (SFG) spectroscopy of adsorbates at surfaces is presented using the density matrix formalism. Our theoretical treatment is specifically aimed at addressing issues that accompany the relatively novel SFG approach using broadband infrared pulses. The ultrashort duration of these pulses makes them ideally suited for time-resolved investigations, for which we present a complete theoretical treatment. A second key characteristic of these pulses is their large bandwidth and high intensity, which allow for highly non-linear effects, including vibrational ladder climbing of surface vibrations. We derive general expressions relating the density matrix to SFG spectra, and apply these expressions to specific experimental results by solving the coupled optical Bloch equations of the density matrix elements. Thus, we can theoretically reproduce recent experimentally demonstrated hot band SFG spectra using femtosecond broadband infrared excitation of carbon monoxide (CO) on a Ru(001) surface

  10. Toward broadband mechanical spectroscopy

    DEFF Research Database (Denmark)

    Hecksher, Tina; Torchinsky, Darius; Klieber, Christoph

    2017-01-01

    Diverse material classes exhibit qualitatively similar behavior when made viscous upon cooling toward the glass transition, suggesting a common theoretical basis. We used seven different measurement methods to determine the mechanical relaxation kinetics of a prototype molecular glass former over...

  11. Systematic errors in the determination of the spectroscopic g-factor in broadband ferromagnetic resonance spectroscopy: A proposed solution

    Science.gov (United States)

    Gonzalez-Fuentes, C.; Dumas, R. K.; García, C.

    2018-01-01

    A theoretical and experimental study of the influence of small offsets of the magnetic field (δH) on the measurement accuracy of the spectroscopic g-factor (g) and saturation magnetization (Ms) obtained by broadband ferromagnetic resonance (FMR) measurements is presented. The random nature of δH generates systematic and opposite sign deviations of the values of g and Ms with respect to their true values. A δH on the order of a few Oe leads to a ˜10% error of g and Ms for a typical range of frequencies employed in broadband FMR experiments. We propose a simple experimental methodology to significantly minimize the effect of δH on the fitted values of g and Ms, eliminating their apparent dependence in the range of frequencies employed. Our method was successfully tested using broadband FMR measurements on a 5 nm thick Ni80Fe20 film for frequencies ranging between 3 and 17 GHz.

  12. Laser Spectroscopy and Frequency Combs

    International Nuclear Information System (INIS)

    Hänsch, Theodor W; Picqué, Nathalie

    2013-01-01

    The spectrum of a frequency comb, commonly generated by a mode-locked femtosecond laser consists of several hundred thousand precisely evenly spaced spectral lines. Such laser frequency combs have revolutionized the art measuring the frequency of light, and they provide the long-missing clockwork for optical atomic clocks. The invention of the frequency comb technique has been motivated by precision laser spectroscopy of the simple hydrogen atom. The availability of commercial instruments is facilitating the evolution of new applications far beyond the original purpose. Laser combs are becoming powerful instruments for broadband molecular spectroscopy by dramatically improving the resolution and recording speed of Fourier spectrometers and by creating new opportunities for highly multiplexed nonlinear spectroscopy, such as two-photon spectroscopy or coherent Raman spectroscopy. Other emerging applications of frequency combs range from fundamental research in astronomy, chemistry, or attosecond science to telecommunications and satellite navigation

  13. Multiplex measuring systems in physics

    International Nuclear Information System (INIS)

    Soroko, L.M.

    1980-01-01

    The principles of operation of multiplex devices used in different spheres of physics are discussed. The ''multiplex'' notion means that the data output of the device is an integral image of the functional dependence under investigation, but not its readings as in usual instruments. The analysis of the present state of developments of the multiplex systems in optics, nuclear magnetic resonance spectroscopy, in time-of-flight spectrometers for slow and fast neutrons, as well as elementary particle detectors, is given. The construction algorithms for the digital codes are presented, the history of development of the multiplex measuring principle is given [ru

  14. A versatile setup for ultrafast broadband optical spectroscopy of coherent collective modes in strongly correlated quantum systems

    Directory of Open Access Journals (Sweden)

    Edoardo Baldini

    2016-11-01

    Full Text Available A femtosecond pump-probe setup is described that is optimised for broadband transient reflectivity experiments on solid samples over a wide temperature range. By combining high temporal resolution and a broad detection window, this apparatus can investigate the interplay between coherent collective modes and high-energy electronic excitations, which is a distinctive characteristic of correlated electron systems. Using a single-shot readout array detector at frame rates of 10 kHz allows resolving coherent oscillations with amplitudes <10−4. We demonstrate its operation on the charge-transfer insulator La2CuO4, revealing coherent phonons with frequencies up to 13 THz and providing access into their Raman matrix elements.

  15. Analogue multiplexer

    International Nuclear Information System (INIS)

    Gorshkov, V.A.; Kuznetsov, A.N.

    1980-01-01

    In systems of signal recording from several parallel spectrometric channels one can considerably reduce the total apparatus volume using a special unit - an analog multiplexer. A description of the multiplexer in the CAMAC system on the base of fast linear gating circuits which allows one analog-to-code converter to attend four spectrometric channels is given. On the example of the 4-channel spectrometer the logics of interaction of the multiple with analog-to-digital coxernver and signal recorder is shown. Electrical and functional multiplexer flow-sheets are given and its main characteristics are presented

  16. Ultra-broadband 2D electronic spectroscopy of carotenoid-bacteriochlorophyll interactions in the LH1 complex of a purple bacterium

    Energy Technology Data Exchange (ETDEWEB)

    Maiuri, Margherita [CNR-IFN, Dipartimento di Fisica, Politecnico di Milano, P.zza L. da Vinci 32, Milano 20133 (Italy); Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544 (United States); Réhault, Julien; Polli, Dario; Cerullo, Giulio, E-mail: giulio.cerullo@polimi.it [CNR-IFN, Dipartimento di Fisica, Politecnico di Milano, P.zza L. da Vinci 32, Milano 20133 (Italy); Carey, Anne-Marie; Hacking, Kirsty; Cogdell, Richard J. [Glasgow Biomedical Research Centre, IBLS, University of Glasgow, 126 Place, Glasgow G12 8TA, Scotland (United Kingdom); Garavelli, Marco [Dipartimento di Chimica “G. Ciamician,” Università di Bologna, Via Selmi 2, IT-40126 Bologna (Italy); CNRS, Institut de Chimie de Lyon, École Normale Supérieure de Lyon, Université de Lyon, 46 Allée d’Italie, F-69364 Lyon Cedex 07 (France); Lüer, Larry [Madrid Institute for Advanced Studies, IMDEA Nanociencia, Madrid (Spain)

    2015-06-07

    We investigate the excitation energy transfer (EET) pathways in the photosynthetic light harvesting 1 (LH1) complex of purple bacterium Rhodospirillum rubrum with ultra-broadband two-dimensional electronic spectroscopy (2DES). We employ a 2DES apparatus in the partially collinear geometry, using a passive birefringent interferometer to generate the phase-locked pump pulse pair. This scheme easily lends itself to two-color operation, by coupling a sub-10 fs visible pulse with a sub-15-fs near-infrared pulse. This unique pulse combination allows us to simultaneously track with extremely high temporal resolution both the dynamics of the photoexcited carotenoid spirilloxanthin (Spx) in the visible range and the EET between the Spx and the B890 bacterio-chlorophyll (BChl), whose Q{sub x} and Q{sub y} transitions peak at 585 and 881 nm, respectively, in the near-infrared. Global analysis of the one-color and two-color 2DES maps unravels different relaxation mechanisms in the LH1 complex: (i) the initial events of the internal conversion process within the Spx, (ii) the parallel EET from the first bright state S{sub 2} of the Spx towards the Q{sub x} state of the B890, and (iii) the internal conversion from Q{sub x} to Q{sub y} within the B890.

  17. Broad-band conductivity and dielectric spectroscopy of composites of multiwalled carbon nanotubes and poly(ethylene terephthalate) around their low percolation threshold

    Science.gov (United States)

    Nuzhnyy, D.; Savinov, M.; Bovtun, V.; Kempa, M.; Petzelt, J.; Mayoral, B.; McNally, T.

    2013-02-01

    Composites of multiwalled carbon nanotubes with poly(ethylene terephthalate) (PET-MWCNT) with up to 3 vol% MWCNTs were prepared and characterized by broad-band AC conductivity and dielectric spectroscopy up to the infrared range using several techniques. A very low electrical percolation threshold of 0.07 vol% MWCNTs was revealed from the low-frequency conductivity plateau as well as from DC conductivity, whose values show the same critical power dependence on MWCNT concentration with the exponent t = 4.3. Above the plateau, the AC conductivity increases with frequency up to the THz range, where it becomes overlapped with the absorption of vibrational modes. The temperature dependence down to ˜5 K has shown semiconductor behaviour with a concentration-independent but weakly temperature-dependent small activation energy of ˜3 meV. The behaviour is compatible with the previously suggested fluctuation-induced tunnelling conductivity model through a thin (˜1 nm) polymer contact layer among the adjacent MWCNTs within percolated clusters. At higher frequencies, deviations from the simple universal conductivity behaviour are observed, indicating some distribution of energy barriers for an electron hopping mechanism.

  18. Up-regulation of cerebral cytochrome-c-oxidase and hemodynamics by transcranial infrared laser stimulation: A broadband near-infrared spectroscopy study.

    Science.gov (United States)

    Wang, Xinlong; Tian, Fenghua; Reddy, Divya D; Nalawade, Sahil S; Barrett, Douglas W; Gonzalez-Lima, Francisco; Liu, Hanli

    2017-12-01

    Transcranial infrared laser stimulation (TILS) is a noninvasive form of brain photobiomulation. Cytochrome-c-oxidase (CCO), the terminal enzyme in the mitochondrial electron transport chain, is hypothesized to be the primary intracellular photoacceptor. We hypothesized that TILS up-regulates cerebral CCO and causes hemodynamic changes. We delivered 1064-nm laser stimulation to the forehead of healthy participants ( n = 11), while broadband near-infrared spectroscopy was utilized to acquire light reflectance from the TILS-treated cortical region before, during, and after TILS. Placebo experiments were also performed for accurate comparison. Time course of spectroscopic readings were analyzed and fitted to the modified Beer-Lambert law. With respect to the placebo readings, we observed (1) significant increases in cerebral concentrations of oxidized CCO (Δ[CCO]; >0.08 µM; p 0.8 µM; p 0.5 µM; p < 0.01) during and after TILS, and (2) linear interplays between Δ[CCO] versus Δ[HbO] and between Δ[CCO] versus Δ[HbT]. Ratios of Δ[CCO]/Δ[HbO] and Δ[CCO]/Δ[HbT] were introduced as TILS-induced metabolic-hemodynamic coupling indices to quantify the coupling strength between TILS-enhanced cerebral metabolism and blood oxygen supply. This study provides the first demonstration that TILS causes up-regulation of oxidized CCO in the human brain, and contributes important insight into the physiological mechanisms.

  19. Ultrafast photo-initiated molecular quantum dynamics in the DNA dinucleotide d(ApG) revealed by broadband transient absorption spectroscopy.

    Science.gov (United States)

    Stuhldreier, Mayra C; Temps, Friedrich

    2013-01-01

    The ultrafast photo-initiated quantum dynamics of the adenine-guanine dinucleotide d(ApG) in aqueous solution (pH 7) has been studied by femtosecond time-resolved spectroscopy after excitation at lambda = 260 nm. The results reveal a hierarchy of processes on time scales from tau 100 ps. Characteristic spectro-temporal signatures are observed indicating the transformation of the molecules in the electronic relaxation from the photo-excited state to a long-lived exciplex. In particular, broadband UV/VIS excited-state absorption (ESA) measurements detected a distinctive absorption by the excited dinucleotide around lambda = 335 nm, approximately 0.5 eV to the blue compared to the maximum of the broad and unstructured ESA spectrum after excitation of an equimolar mixture of the mononucleotides dAMP and dGMP. A similar feature has been identified as signature of the excimer in the dynamics of the adenine dinucleotide d(ApA). The lifetime of the d(ApG) exciplex was found to be tau = 124 +/- 4 ps both from the ESA decay time and from the ground-state recovery time, far longer than the sub-picosecond lifetimes of excited dAMP or dGMP. Fluorescence-time profiles measured by the up-conversion technique indicate that the exciplex state is reached around approximately 6 ps after excitation. Very weak residual fluorescence at longer times red-shifted to the emission from the photo-excited state shows that the exciplex is almost optically dark, but still has enough oscillator strength to give rise to the dual fluorescence of the dinucleotide in the static fluorescence spectrum.

  20. Trans-cranial infrared laser stimulation induces hemodynamic and metabolic response measured by broadband near infrared spectroscopy in vivo on human forehead (Conference Presentation)

    Science.gov (United States)

    Wang, Xinlong; Nalawade, Sahil Sunil; Reddy, Divya Dhandapani; Tian, Fenghua; Gonzalez-Lima, F.; Liu, Hanli

    2017-02-01

    Transcranial infrared laser stimulation (TILS) uses infrared light (lasers or LEDs) for nondestructive and non-thermal photobiomodulation on the human brain. Although TILS has shown its beneficial effects to a variety of neurological and psychological conditions, its physiological mechanism remains unknown. Cytochrome-c-oxidase (CCO), the last enzyme in the electron transportation chain, is proposed to be the primary photoacceptor of this infrared laser. In this study, we wish to validate this proposed mechanism. We applied 8 minutes in vivo TILS on the right forehead of 11 human participants with a 1064-nm laser. Broad-band near infrared spectroscopy (bb-NIRS) from 740-900nm was also employed near the TILS site to monitor hemodynamic and metabolic responses during the stimulation and 5-minute recovery period. For rigorous comparison, we also performed similar 8-min bb-NIR measurements under placebo conditions. A multi-linear regression analysis based on the modified Beer-Lambert law was performed to estimate concentration changes of oxy-hemoglobin (Δ[HbO]), deoxy-hemoglobin (Δ[Hb]), and cytochrome-c-oxidase (Δ[CCO]). We found that TILS induced significant increases of [CCO], [HbO] and a decrease of [Hb] with dose-dependent manner as compared with placebo treatments. Furthermore, strong linear relationships or interplays between [CCO] versus [HbO] and [CCO] versus [Hb] induced by TILS were observed in vivo for the first time. These relationships have clearly revealed close coupling/relationship between the hemodynamic oxygen supply and blood volume versus up-regulation of CCO induced by photobiomodulation. Our results demonstrate the tremendous potential of bb-NIRS as a non-invasive in vivo means to study photobiomodulation mechanisms and perform treatment evaluations of TILS.

  1. Two-beam ultrabroadband coherent anti-Stokes Raman spectroscopy for high resolution gas-phase multiplex imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bohlin, Alexis; Kliewer, Christopher J., E-mail: cjkliew@sandia.gov [Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550 (United States)

    2014-01-20

    We propose and develop a method for wideband coherent anti-Stokes Raman spectroscopy (CARS) in the gas phase and demonstrate the single-shot measurement of N{sub 2}, H{sub 2}, CO{sub 2}, O{sub 2}, and CH{sub 4}. Pure-rotational and vibrational O-, Q-, and S- branch spectra are collected simultaneously, with high spectral and spatial resolution, and within a single-laser-shot. The relative intensity of the rotational and vibrational signals can be tuned arbitrarily using polarization techniques. The ultrashort 7 fs pump and Stokes pulses are automatically overlapped temporally and spatially using a two-beam CARS technique, and the crossed probe beam allows for excellent spatial sectioning of the probed location.

  2. Two-beam ultrabroadband coherent anti-Stokes Raman spectroscopy for high resolution gas-phase multiplex imaging

    International Nuclear Information System (INIS)

    Bohlin, Alexis; Kliewer, Christopher J.

    2014-01-01

    We propose and develop a method for wideband coherent anti-Stokes Raman spectroscopy (CARS) in the gas phase and demonstrate the single-shot measurement of N 2 , H 2 , CO 2 , O 2 , and CH 4 . Pure-rotational and vibrational O-, Q-, and S- branch spectra are collected simultaneously, with high spectral and spatial resolution, and within a single-laser-shot. The relative intensity of the rotational and vibrational signals can be tuned arbitrarily using polarization techniques. The ultrashort 7 fs pump and Stokes pulses are automatically overlapped temporally and spatially using a two-beam CARS technique, and the crossed probe beam allows for excellent spatial sectioning of the probed location

  3. Microscopic resolution broadband dielectric spectroscopy

    International Nuclear Information System (INIS)

    Mukherjee, S; Watson, P; Prance, R J

    2011-01-01

    Results are presented for a non-contact measurement system capable of micron level spatial resolution. It utilises the novel electric potential sensor (EPS) technology, invented at Sussex, to image the electric field above a simple composite dielectric material. EP sensors may be regarded as analogous to a magnetometer and require no adjustments or offsets during either setup or use. The sample consists of a standard glass/epoxy FR4 circuit board, with linear defects machined into the surface by a PCB milling machine. The sample is excited with an a.c. signal over a range of frequencies from 10 kHz to 10 MHz, from the reverse side, by placing it on a conducting sheet connected to the source. The single sensor is raster scanned over the surface at a constant working distance, consistent with the spatial resolution, in order to build up an image of the electric field, with respect to the reference potential. The results demonstrate that both the surface defects and the internal dielectric variations within the composite may be imaged in this way, with good contrast being observed between the glass mat and the epoxy resin.

  4. Microscopic resolution broadband dielectric spectroscopy

    Science.gov (United States)

    Mukherjee, S.; Watson, P.; Prance, R. J.

    2011-08-01

    Results are presented for a non-contact measurement system capable of micron level spatial resolution. It utilises the novel electric potential sensor (EPS) technology, invented at Sussex, to image the electric field above a simple composite dielectric material. EP sensors may be regarded as analogous to a magnetometer and require no adjustments or offsets during either setup or use. The sample consists of a standard glass/epoxy FR4 circuit board, with linear defects machined into the surface by a PCB milling machine. The sample is excited with an a.c. signal over a range of frequencies from 10 kHz to 10 MHz, from the reverse side, by placing it on a conducting sheet connected to the source. The single sensor is raster scanned over the surface at a constant working distance, consistent with the spatial resolution, in order to build up an image of the electric field, with respect to the reference potential. The results demonstrate that both the surface defects and the internal dielectric variations within the composite may be imaged in this way, with good contrast being observed between the glass mat and the epoxy resin.

  5. Adoption of Broadband Services

    DEFF Research Database (Denmark)

    Falch, Morten

    2008-01-01

    Broadband is seen as a key infrastructure for developing the information society. For this reason many Governments are actively engaged in stimulating investments in broadband infrastructures and use of broadband services. This chapter compares a wide range of broadband strategies in the most suc....... Many countries have provided active support for stimulating diffusion of broadband and national variants of this type of policies in different countries are important for an explanation of national differences in adoption of broadband....

  6. Testbed for Multi-Wavelength Optical Code Division Multiplexing Based on Passive Linear Unitary Filters

    National Research Council Canada - National Science Library

    Yablonovitch, Eli

    2000-01-01

    .... The equipment purchased under this grant has permitted UCLA to purchase a number of broad-band optical components, including especially some unique code division multiplexing filters that permitted...

  7. Design of high-power, broadband 180o pulses and mixing sequences for fast MAS solid state chemical shift correlation NMR spectroscopy

    International Nuclear Information System (INIS)

    Herbst, Christian; Herbst, Jirada; Kirschstein, Anika; Leppert, Joerg; Ohlenschlaeger, Oliver; Goerlach, Matthias; Ramachandran, Ramadurai

    2009-01-01

    An approach for the design of high-power, broadband 180 o pulses and mixing sequences for generating dipolar and scalar coupling mediated 13 C- 13 C chemical shift correlation spectra of isotopically labelled biological systems at fast magic-angle spinning frequencies without 1 H decoupling during mixing is presented. Considering RF field strengths in the range of 100-120 kHz, as typically available in MAS probes employed at high spinning speeds, and limited B 1 field inhomogeneities, the Fourier coefficients defining the phase modulation profile of the RF pulses were optimised numerically to obtain broadband inversion and refocussing pulses and mixing sequences. Experimental measurements were carried out to assess the performance characteristics of the mixing sequences reported here

  8. Carcinoma multiplex

    International Nuclear Information System (INIS)

    Shah, S. A.; Riaz, U.; Zahoor, I.; Jalil, A.; Zubair, M.

    2013-01-01

    Multiple primaries in a single patient are uncommon, though not very rare. The existence of such cancers in two un-related, non-paired organs is even more un-common. Here, we present a case of 55 years old male who presented to us with a mucoepidermoid carcinoma of the parotid gland and was operated. Later on, he presented with a large cystic swelling in the pelvis which turned out to be pseudomyxoma peritonei. A review of slides and immunohistochemistry indicated it to be adenocarcinoma colon. He presented again with recurrent mucoepidermoid carcinoma of the parotid which was operated successfully with the use of myocutaneous flap for wound closure. He is currently undergoing chemotherapy. In order to establish a separate mono-clonal etiology of both tumours, immunohistochemistry was performed. To the best of our knowledge, carcinoma multiplex in the colon and the parotid has never been reported before. (author)

  9. Multiplexing schemes for an achromatic programmable diffractive lens

    Energy Technology Data Exchange (ETDEWEB)

    Millan, M S; Perez-Cabre, E; Oton, J [Technical University of Catalonia, Dep. Optics and Optometry, Terrassa-Barcelona, 08222 (Spain)], E-mail: millan@oo.upc.edu

    2008-11-01

    A multiplexed programmable diffractive lens, displayed on a pixelated liquid crystal device under broadband illumination, is proposed to compensate for the severe chromatic aberration that affects diffractive elements. The proposed lens is based on multiplexing a set of sublenses with a common focal length for different wavelengths. We consider different types of integration of the optical information (spatial only, temporal only and hybrid spatial-temporal) combined with a proper selection of the spectral bandwidth. The properties and limits of the achromatic programmable multiplexed lens are described. Experimental results are presented and discussed.

  10. Multiplexing schemes for an achromatic programmable diffractive lens

    International Nuclear Information System (INIS)

    Millan, M S; Perez-Cabre, E; Oton, J

    2008-01-01

    A multiplexed programmable diffractive lens, displayed on a pixelated liquid crystal device under broadband illumination, is proposed to compensate for the severe chromatic aberration that affects diffractive elements. The proposed lens is based on multiplexing a set of sublenses with a common focal length for different wavelengths. We consider different types of integration of the optical information (spatial only, temporal only and hybrid spatial-temporal) combined with a proper selection of the spectral bandwidth. The properties and limits of the achromatic programmable multiplexed lens are described. Experimental results are presented and discussed.

  11. Super-Eddington accretion on to the neutron star NGC 7793 P13: Broad-band X-ray spectroscopy and ultraluminous X-ray sources

    Science.gov (United States)

    Walton, D. J.; Fürst, F.; Harrison, F. A.; Stern, D.; Bachetti, M.; Barret, D.; Brightman, M.; Fabian, A. C.; Middleton, M. J.; Ptak, A.; Tao, L.

    2018-02-01

    We present a detailed, broad-band X-ray spectral analysis of the ultraluminous X-ray source (ULX) pulsar NGC 7793 P13, a known super-Eddington source, utilizing data from the XMM-Newton, NuSTAR and Chandra observatories. The broad-band XMM-Newton+NuSTAR spectrum of P13 is qualitatively similar to the rest of the ULX sample with broad-band coverage, suggesting that additional ULXs in the known population may host neutron star accretors. Through time-averaged, phase-resolved and multi-epoch studies, we find that two non-pulsed thermal blackbody components with temperatures ∼0.5 and 1.5 keV are required to fit the data below 10 keV, in addition to a third continuum component which extends to higher energies and is associated with the pulsed emission from the accretion column. The characteristic radii of the thermal components appear to be comparable, and are too large to be associated with the neutron star itself, so the need for two components likely indicates the accretion flow outside the magnetosphere is complex. We suggest a scenario in which the thick inner disc expected for super-Eddington accretion begins to form, but is terminated by the neutron star's magnetic field soon after its onset, implying a limit of B ≲ 6 × 1012 G for the dipolar component of the central neutron star's magnetic field. Evidence of similar termination of the disc in other sources may offer a further means of identifying additional neutron star ULXs. Finally, we examine the spectrum exhibited by P13 during one of its unusual 'off' states. These data require both a hard power-law component, suggesting residual accretion on to the neutron star, and emission from a thermal plasma, which we argue is likely associated with the P13 system.

  12. Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1968-01-01

    This booklet discusses spectroscopy, the study of absorption of radiation by matter, including X-ray, gamma-ray, microwave, mass spectroscopy, as well as others. Spectroscopy has produced more fundamental information to the study of the detailed structure of matter than any other tools.

  13. Spectroscopy

    CERN Document Server

    Walker, S

    1976-01-01

    The three volumes of Spectroscopy constitute the one comprehensive text available on the principles, practice and applications of spectroscopy. By giving full accounts of those spectroscopic techniques only recently introduced into student courses - such as Mössbauer spectroscopy and photoelectron spectroscopy - in addition to those techniques long recognised as being essential in chemistry teaching - sucha as e.s.r. and infrared spectroscopy - the book caters for the complete requirements of undergraduate students and at the same time provides a sound introduction to special topics for graduate students.

  14. Broadband Radiometric LED Measurements

    OpenAIRE

    Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

    2016-01-01

    At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(��) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irr...

  15. Broad-band conductivity and dielectric spectroscopy of composites of multiwalled carbon nanotubes and poly(ethylene terephthalate) around their low percolation threshold

    Czech Academy of Sciences Publication Activity Database

    Nuzhnyy, Dmitry; Savinov, Maxim; Bovtun, Viktor; Kempa, Martin; Petzelt, Jan; Mayoral, B.; McNally, T.

    2013-01-01

    Roč. 24, č. 5 (2013), "055707-1"-"055707-9" ISSN 0957-4484 R&D Projects: GA ČR GAP204/12/0232; GA MŠk LD12025 Institutional support: RVO:68378271 Keywords : THz and dielectric spectroscopy * multiwalled carbon nanotubes * electrical percolation threshold * fluctuation-induced tunneling conductivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.672, year: 2013 http://iopscience.iop.org/0957-4484/24/5/055707/

  16. Broad-band dielectric spectroscopy of Ba.sub.2./sub.NaNb.sub.5./sub.O.sub.15./sub. single crystal

    Czech Academy of Sciences Publication Activity Database

    Buixaderas, Elena; Porokhonskyy, Viktor; Pashkin, Alexej; Savinov, Maxim; Petzelt, Jan

    2002-01-01

    Roč. 30, - (2002), s. 319-329 ISSN 1434-6028 R&D Projects: GA ČR GA202/01/0612; GA AV ČR IAA1010213 Institutional research plan: CEZ:AV0Z1010914 Keywords : incommensurate ferroelectrics * IR and time-domain THz spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.741, year: 2002

  17. Spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules.......This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules....

  18. Broadband Faraday isolator.

    Science.gov (United States)

    Berent, Michał; Rangelov, Andon A; Vitanov, Nikolay V

    2013-01-01

    Driving on an analogy with the technique of composite pulses in quantum physics, we theoretically propose a broadband Faraday rotator and thus a broadband optical isolator, which is composed of sequences of ordinary Faraday rotators and achromatic quarter-wave plates rotated at the predetermined angles.

  19. spectroscopy

    African Journals Online (AJOL)

    Aghomotsegin

    2015-10-14

    Oct 14, 2015 ... characterized by using phenotypic, API and Fourier transform infrared (FTIR) spectroscopy methods. One hundred and fifty-seven (157) strains were isolated from 13 cheese samples, and identification test was performed for 83 strains. At the end of the study, a total of 22 Lactococcus sp., 36 Enterecoccus ...

  20. Topology optimized mode multiplexing in silicon-on-insulator photonic wire waveguides

    DEFF Research Database (Denmark)

    Frellsen, Louise Floor; Ding, Yunhong; Sigmund, Ole

    2016-01-01

    We design and experimentally verify a topology optimized low-loss and broadband two-mode (de-)multiplexer, which is (de-)multiplexing the fundamental and the first-order transverse-electric modes in a silicon photonic wire. The device has a footprint of 2.6 μm x 4.22 μm and exhibits a loss 14 d...

  1. Ultra-broadband photonic internet

    Science.gov (United States)

    Romaniuk, Ryszard S.

    2011-06-01

    In this paper, there is presented a review of our today's understanding of the ultimately broadband photonic Internet. A simple calculation is presented showing the estimate of the throughput of the core photonic network branches. Optoelectronic components, circuits, systems and signals, together with analogous electronic entities and common software layers, are building blocks of the contemporary Internet. Participation of photonics in development of the physical layer in the future Internet will probably increase. The photonics leads now to a better usage of the available bandwidth (increase of the spectral efficiency measured in Bit/s/Hz), increase in the transmission rate (from Gbps, via Tbps up to probably Pbps), increase in the transmission distance without signal regeneration (in distortion compensated active optical cables), increase in energy/power efficiency measured in W/Gbps, etc. Photonics may lead, in the future, to fully transparent optical networks and, thus, to essential increase in bandwidth and network reliability. It is expected that photonics (with biochemistry, electronics and mechatronics) may build psychological and physiological interface for humans to the future global network. The following optical signal multiplexing methods were considered, which are possible without O/E/O conversion: TDM-OTDM, FDM-CO-OFDM, OCDM-OCDMA, WDM-DWDM.

  2. Identifying Broadband Rotational Spectra with Neural Networks

    Science.gov (United States)

    Zaleski, Daniel P.; Prozument, Kirill

    2017-06-01

    A typical broadband rotational spectrum may contain several thousand observable transitions, spanning many species. Identifying the individual spectra, particularly when the dynamic range reaches 1,000:1 or even 10,000:1, can be challenging. One approach is to apply automated fitting routines. In this approach, combinations of 3 transitions can be created to form a "triple", which allows fitting of the A, B, and C rotational constants in a Watson-type Hamiltonian. On a standard desktop computer, with a target molecule of interest, a typical AUTOFIT routine takes 2-12 hours depending on the spectral density. A new approach is to utilize machine learning to train a computer to recognize the patterns (frequency spacing and relative intensities) inherit in rotational spectra and to identify the individual spectra in a raw broadband rotational spectrum. Here, recurrent neural networks have been trained to identify different types of rotational spectra and classify them accordingly. Furthermore, early results in applying convolutional neural networks for spectral object recognition in broadband rotational spectra appear promising. Perez et al. "Broadband Fourier transform rotational spectroscopy for structure determination: The water heptamer." Chem. Phys. Lett., 2013, 571, 1-15. Seifert et al. "AUTOFIT, an Automated Fitting Tool for Broadband Rotational Spectra, and Applications to 1-Hexanal." J. Mol. Spectrosc., 2015, 312, 13-21. Bishop. "Neural networks for pattern recognition." Oxford university press, 1995.

  3. Simultaneous broadband observations and high-resolution X-ray spectroscopy of the transitional millisecond pulsar PSR J1023+0038

    Science.gov (United States)

    Coti Zelati, F.; Campana, S.; Braito, V.; Baglio, M. C.; D'Avanzo, P.; Rea, N.; Torres, D. F.

    2018-03-01

    We report on the first simultaneous XMM-Newton, NuSTAR, and Swift observations of the transitional millisecond pulsar PSR J1023+0038 in the X-ray active state. Our multi-wavelength campaign allowed us to investigate with unprecedented detail possible spectral variability over a broad energy range in the X-rays, as well as correlations and lags among emissions in different bands. The soft and hard X-ray emissions are significantly correlated, with no lags between the two bands. On the other hand, the X-ray emission does not correlate with the UV emission. We refine our model for the observed mode switching in terms of rapid transitions between a weak propeller regime and a rotation-powered radio pulsar state, and report on a detailed high-resolution X-ray spectroscopy using all XMM-Newton Reflection Grating Spectrometer data acquired since 2013. We discuss our results in the context of the recent discoveries on the system and of the state of the art simulations on transitional millisecond pulsars, and show how the properties of the narrow emission lines in the soft X-ray spectrum are consistent with an origin within the accretion disc.

  4. Integrated photonics : compact multiplexing

    NARCIS (Netherlands)

    Pile, D.; Chen, H.; Uden, van R.G.H.; Okonkwo, C.M.; Koonen, A.M.J.

    2015-01-01

    Spatial multiplexers (SMUXs) for mode division multiplexing often involve multiple strategies for mode-selective excitation and the minimization of insertion and other losses. Haoshuo Chen, Roy van Uden, Chigo Okonkwo and Ton Koonen, working at the COBRA Institute at the Eindhoven University of

  5. Dynamic Optically Multiplexed Imaging

    Science.gov (United States)

    2015-07-29

    Dynamic Optically Multiplexed Imaging Yaron Rachlin, Vinay Shah, R. Hamilton Shepard, and Tina Shih Lincoln Laboratory, Massachusetts Institute of...V. Shah, and T. Shih “Design Architectures for Optically Multiplexed Imaging,” in submission 9 R. Gupta , P. Indyk, E. Price, and Y. Rachlin

  6. Broadband Electromagnetic Technology

    Science.gov (United States)

    2011-06-23

    The objectives of this project are to continue the enhancements to the combined Broadband Electromagnetic and Full Encirclement Unit (BEM-FEU) technologies and to evaluate the systems capability in the laboratory and the field. The BEM instrument ...

  7. Coherent cavity-enhanced dual-comb spectroscopy.

    Science.gov (United States)

    Fleisher, Adam J; Long, David A; Reed, Zachary D; Hodges, Joseph T; Plusquellic, David F

    2016-05-16

    Dual-comb spectroscopy allows for the rapid, multiplexed acquisition of high-resolution spectra without the need for moving parts or low-resolution dispersive optics. This method of broadband spectroscopy is most often accomplished via tight phase locking of two mode-locked lasers or via sophisticated signal processing algorithms, and therefore, long integration times of phase coherent signals are difficult to achieve. Here we demonstrate an alternative approach to dual-comb spectroscopy using two phase modulator combs originating from a single continuous-wave laser capable of > 2 hours of coherent real-time averaging. The dual combs were generated by driving the phase modulators with step-recovery diodes where each comb consisted of > 250 teeth with 203 MHz spacing and spanned > 50 GHz region in the near-infrared. The step-recovery diodes are passive devices that provide low-phase-noise harmonics for efficient coupling into an enhancement cavity at picowatt optical powers. With this approach, we demonstrate the sensitivity to simultaneously monitor ambient levels of CO2, CO, HDO, and H2O in a single spectral region at a maximum acquisition rate of 150 kHz. Robust, compact, low-cost and widely tunable dual-comb systems could enable a network of distributed multiplexed optical sensors.

  8. Broadband radiometric LED measurements

    Science.gov (United States)

    Eppeldauer, G. P.; Cooksey, C. C.; Yoon, H. W.; Hanssen, L. M.; Podobedov, V. B.; Vest, R. E.; Arp, U.; Miller, C. C.

    2016-09-01

    At present, broadband radiometric LED measurements with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

  9. Changes in the geometries of C₂H₂ and C₂H₄ on coordination to CuCl revealed by broadband rotational spectroscopy and ab-initio calculations.

    Science.gov (United States)

    Stephens, Susanna L; Bittner, Dror M; Mikhailov, Victor A; Mizukami, Wataru; Tew, David P; Walker, Nicholas R; Legon, Anthony C

    2014-10-06

    The molecular geometries of isolated complexes in which a single molecule of C2H4 or C2H2 is bound to CuCl have been determined through pure rotational spectroscopy and ab-initio calculations. The C2H2···CuCl and C2H4···CuCl complexes are generated through laser vaporization of a copper rod in the presence of a gas sample undergoing supersonic expansion and containing C2H2 (or C2H4), CCl4, and Ar. Results are presented for five isotopologues of C2H2···CuCl and six isotopologues of C2H4···CuCl. Both of these complexes adopt C(2v), T-shaped geometries in which the hydrocarbon binds to the copper atom through its π electrons such that the metal is equidistant from all H atoms. The linear and planar geometries of free C2H2 and C2H4, respectively, are observed to distort significantly on attachment to the CuCl unit, and the various changes are quantified. The ∠(*-C-H) parameter in C2H2 (where * indicates the midpoint of the C≡C bond) is measured to be 192.4(7)° in the r0 geometry of the complex representing a significant change from the linear geometry of the free molecule. This distortion of the linear geometry of C2H2 involves the hydrogen atoms moving away from the copper atom within the complex. Ab-initio calculations at the CCSD(T)(F12*)/AVTZ level predict a dihedral ∠(HCCCu) angle of 96.05° in C2H4···CuCl, and the experimental results are consistent with such a distortion from planarity. The bonds connecting the carbon atoms within each of C2H2 and C2H4, respectively, extend by 0.027 and 0.029 Å relative to the bond lengths in the isolated molecules. Force constants, k(σ), and nuclear quadrupole coupling constants, χ(aa)(Cu), [χ(bb)(Cu) - χ(cc)(Cu)], χ(aa)(Cl), and [χ(bb)(Cl) - χ(cc)(Cl)], are independently determined for all isotopologues of C2H2···CuCl studied and for four isotopologues of C2H4···CuCl.

  10. Multiplex PageRank.

    Science.gov (United States)

    Halu, Arda; Mondragón, Raúl J; Panzarasa, Pietro; Bianconi, Ginestra

    2013-01-01

    Many complex systems can be described as multiplex networks in which the same nodes can interact with one another in different layers, thus forming a set of interacting and co-evolving networks. Examples of such multiplex systems are social networks where people are involved in different types of relationships and interact through various forms of communication media. The ranking of nodes in multiplex networks is one of the most pressing and challenging tasks that research on complex networks is currently facing. When pairs of nodes can be connected through multiple links and in multiple layers, the ranking of nodes should necessarily reflect the importance of nodes in one layer as well as their importance in other interdependent layers. In this paper, we draw on the idea of biased random walks to define the Multiplex PageRank centrality measure in which the effects of the interplay between networks on the centrality of nodes are directly taken into account. In particular, depending on the intensity of the interaction between layers, we define the Additive, Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show how each version reflects the extent to which the importance of a node in one layer affects the importance the node can gain in another layer. We discuss these measures and apply them to an online multiplex social network. Findings indicate that taking the multiplex nature of the network into account helps uncover the emergence of rankings of nodes that differ from the rankings obtained from one single layer. Results provide support in favor of the salience of multiplex centrality measures, like Multiplex PageRank, for assessing the prominence of nodes embedded in multiple interacting networks, and for shedding a new light on structural properties that would otherwise remain undetected if each of the interacting networks were analyzed in isolation.

  11. Multiplex PageRank.

    Directory of Open Access Journals (Sweden)

    Arda Halu

    Full Text Available Many complex systems can be described as multiplex networks in which the same nodes can interact with one another in different layers, thus forming a set of interacting and co-evolving networks. Examples of such multiplex systems are social networks where people are involved in different types of relationships and interact through various forms of communication media. The ranking of nodes in multiplex networks is one of the most pressing and challenging tasks that research on complex networks is currently facing. When pairs of nodes can be connected through multiple links and in multiple layers, the ranking of nodes should necessarily reflect the importance of nodes in one layer as well as their importance in other interdependent layers. In this paper, we draw on the idea of biased random walks to define the Multiplex PageRank centrality measure in which the effects of the interplay between networks on the centrality of nodes are directly taken into account. In particular, depending on the intensity of the interaction between layers, we define the Additive, Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show how each version reflects the extent to which the importance of a node in one layer affects the importance the node can gain in another layer. We discuss these measures and apply them to an online multiplex social network. Findings indicate that taking the multiplex nature of the network into account helps uncover the emergence of rankings of nodes that differ from the rankings obtained from one single layer. Results provide support in favor of the salience of multiplex centrality measures, like Multiplex PageRank, for assessing the prominence of nodes embedded in multiple interacting networks, and for shedding a new light on structural properties that would otherwise remain undetected if each of the interacting networks were analyzed in isolation.

  12. Broadband luminescence in liquid-solid transition

    CERN Document Server

    Achilov, M F; Trunilina, O V

    2002-01-01

    Broadband luminescence (BBL) intensity behavior in liquid-solid transition in polyethyleneglycol-600 has been established. Oscillation of BBL intensity observed in liquid-polycrystal transition are not found to observed in liquid-amorphous solid transition. It is shown that application of the theory of electron state tails to interpretation of BBL spectral properties in liquids demands restriction. BBL spectroscopy may be applied for optimization of preparation of polymers with determined properties. (author)

  13. Multiplex gas chromatography

    Science.gov (United States)

    Valentin, Jose R.

    1990-01-01

    The principles of the multiplex gas chromatography (GC) technique, which is a possible candidate for chemical analysis of planetary atmospheres, are discussed. Particular attention is given to the chemical modulators developed by present investigators for multiplex GC, namely, the thermal-desorption, thermal-decomposition, and catalytic modulators, as well as to mechanical modulators. The basic technique of multiplex GC using chemical modulators and a mechanical modulator is demonstrated. It is shown that, with the chemical modulators, only one gas stream consisting of the carrier in combination with the components is being analyzed, resulting in a simplified instrument that requires relatively few consumables. The mechanical modulator demonstrated a direct application of multiplex GC for the analysis of gases in atmosphere of Titan at very low pressures.

  14. Multiplexed Engineering in Biology.

    Science.gov (United States)

    Rogers, Jameson K; Church, George M

    2016-03-01

    Biotechnology is the manufacturing technology of the future. However, engineering biology is complex, and many possible genetic designs must be evaluated to find cells that produce high levels of a desired drug or chemical. Recent advances have enabled the design and construction of billions of genetic variants per day, but evaluation capacity remains limited to thousands of variants per day. Here we evaluate biological engineering through the lens of the design–build–test cycle framework and highlight the role that multiplexing has had in transforming the design and build steps. We describe a multiplexed solution to the ‘test’ step that is enabled by new research. Achieving a multiplexed test step will permit a fully multiplexed engineering cycle and boost the throughput of biobased product development by up to a millionfold.

  15. Bilevel alarm monitoring multiplexer

    International Nuclear Information System (INIS)

    Johnson, C.S.

    1977-06-01

    This report describes the operation of the Bilevel Alarm Monitoring Multiplexer used in the Adaptive Intrusion Data System (AIDS) to transfer and control alarm signals being sent to the Nova 2 computer, the Memory Controlled Data Processor, and its own integral Display Panel. The multiplexer can handle 48 alarm channels and format the alarms into binary formats compatible with the destination of the alarm data

  16. Direct UV-written broadband directional broadband planar waveguide couplers

    DEFF Research Database (Denmark)

    Olivero, Massimo; Svalgaard, Mikael

    2005-01-01

    We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation.......We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation....

  17. Preliminary Assessment of Microwave Readout Multiplexing Factor

    Energy Technology Data Exchange (ETDEWEB)

    Croce, Mark Philip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Koehler, Katrina Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rabin, Michael W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bennett, D. A. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Mates, J. A. B. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Gard, J. D. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Becker, D. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Schmidt, D. R. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Ullom, J. N. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States)

    2017-01-23

    Ultra-high resolution microcalorimeter gamma spectroscopy is a new non-destructive assay technology for measurement of plutonium isotopic composition, with the potential to reduce total measurement uncertainty to a level competitive with destructive analysis methods [1-4]. Achieving this level of performance in practical applications requires not only the energy resolution now routinely achieved with transition-edge sensor microcalorimeter arrays (an order of magnitude better than for germanium detectors) but also high throughput. Microcalorimeter gamma spectrometers have not yet achieved detection efficiency and count rate capability that is comparable to germanium detectors, largely because of limits from existing readout technology. Microcalorimeter detectors must be operated at low temperature to achieve their exceptional energy resolution. Although the typical 100 mK operating temperatures can be achieved with reliable, cryogen-free systems, the cryogenic complexity and heat load from individual readout channels for large sensor arrays is prohibitive. Multiplexing is required for practical systems. The most mature multiplexing technology at present is time-division multiplexing (TDM) [3, 5-6]. In TDM, the sensor outputs are switched by applying bias current to one SQUID amplifier at a time. Transition-edge sensor (TES) microcalorimeter arrays as large as 256 pixels have been developed for X-ray and gamma-ray spectroscopy using TDM technology. Due to bandwidth limits and noise scaling, TDM is limited to a maximum multiplexing factor of approximately 32-40 sensors on one readout line [8]. Increasing the size of microcalorimeter arrays above the kilopixel scale, required to match the throughput of germanium detectors, requires the development of a new readout technology with a much higher multiplexing factor.

  18. Chemical recognition with broadband THz spectroscopy

    DEFF Research Database (Denmark)

    Fischer, Bernd M.; Helm, Hanspeter; Jepsen, Peter Uhd

    2004-01-01

    THz science is developing rapidly in Europe as well as the rest of the world. There is a strong interest in the exploitation of optical technologies in the THz frequency range in virtually all fields of basic and applied sciences of physics, chemistry, biology as well as medicine. Commercial...... interest in this field has also been growing, spurred by the potential of tHz tools in quality control and the biotechnology sector. We will review some contrast mechanisms, which form the basis for real-world applications of THz technology, in particular in the fields of applied chemistry...... and biotechnology. Whereas narrow bandwidth THz technology may become important for e.g. real-time imaging at larger standoff distances, we will concentrate on broad bandwidth THz technologies for spectroscopic identification of various substances. It has recently been established that the 0.1-5 THz spectral range...

  19. Broadband Internet and Income Inequality

    OpenAIRE

    HOUNGBONON , Georges Vivien; Liang , Julienne

    2017-01-01

    Policy makers are aiming for a large coverage of high-speed broadband Internet. However , there is still a lack of evidence about its effects on income distribution. In this paper, we investigate the effects of fixed broadband Internet on mean income and income inequality using a unique town-level data on broadband adoption and quality in France. We find that broadband adoption and quality raise mean income and lower income inequality. These results are robust to initial conditions, and yield...

  20. AIRTV: Broadband Direct to Aircraft

    Science.gov (United States)

    Sorbello, R.; Stone, R.; Bennett, S. B.; Bertenyi, E.

    2002-01-01

    over the poles. The system consists of a constellation of 4 geostationary satellites covering the earth and delivering its signals to the aircraft at S band (2.52 -2.67 GHz). The S-band spectrum is ideal for this application since it is allocated on a primary basis by the ITU for global broadcast service. The AirTV service is expected to begin in 2004 and should be unencumbered by adjacent satellite interference due to near completion of the ITU coordination process. Each satellite will deliver four 20 Mbps QPSK data streams consisting of multiplexed compressed digital video channels and IP data over the full global beam coverage. The 80 Mbps capacity of each satellite will provide approximately 60 video channels while still allocating 40 Mbits to data services. The combined constellation capacity of 320 Mbits will significantly exceed the capacity of any similar existing or currently planned global satellite system. In addition, the simplicity of the 4-satellite approach is the most cost effective means to deliver high bandwidth globally. Return links, which are required for internet service, will be provided through the existing Inmarsat Aero-H system already onboard virtually all long haul aircraft and will provide return data rates from the aircraft as high as 432 kbps. integrated receiver/decoder (IRD) assembly. The phased array antenna, a key technology element, is being developed by AirTV's strategic partner, CMC Electronics. This antenna is a scaled version of CMC's Inmarsat Aero H antenna and is capable of scanning to 5 degrees above the horizon. Wide angle scanning up to 85 degrees from zenith is necessary for aircraft traversing the northernmost latitudes on transoceanic routes. AirTV has designed both the satellite coverage and aircraft antenna performance to ensure that high signal quality is maintained along all non-polar airline routes. AirTV will be the future of aeronautical broadband delivery. It has been designed specifically for global services and

  1. Broadband waveguided light sources

    NARCIS (Netherlands)

    Pollnau, Markus

    In recent years, broadband fiber interferometers have become very popular as basic instruments used in optical low-coherence reflectometry for diagnostics of fiber and integrated optics devices or in optical coherence tomography (OCT) for imaging applications in the biomedical field. The

  2. Advanced broadband baffle materials

    International Nuclear Information System (INIS)

    Seals, R.D.

    1991-01-01

    In this paper broadband performance characteristics of robust, light-weight, diffuse-absorptive baffle surfaces fabricated from sputter-deposited beryllium on cross-rolled Be ingot sheet material and on Be foam, plasma sprayed beryllium, plasma sprayed boron-on-beryllium, and chemical vapor deposited boron carbide on graphite are described and compared to Martin Black. An overview of the Optics Manufacturing Operations Development and Integration Laboratory (MODIL) Advanced Optical Baffle Program will be discussed

  3. Coherence Multiplex System Topologies

    NARCIS (Netherlands)

    Meijerink, Arjan; Taniman, R.O.; Heideman, G.H.L.M.; van Etten, Wim

    2007-01-01

    Coherence multiplexing is a potentially inexpensive form of optical code-division multiple access, which is particularly suitable for short-range applications with moderate bandwidth requirements, such as access networks, LANs, or interconnects. Various topologies are known for constructing an

  4. Microprocessorized message multiplexer

    International Nuclear Information System (INIS)

    Ejzman, S.; Guglielmi, L.; Jaeger, J.J.

    1980-07-01

    The 'Microprocessorized Message Multiplexer' is an elementary development tool used to create and debug the software of a target microprocessor (User Module: UM). It connects together four devices: a terminal, a cassette recorder, the target microprocessor and a host computer where macro and editor for the M 6800 microprocessor are resident [fr

  5. Multiplex editing system

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a multiplex editing system. The system allows multiple editing of nucleic acid sequences such as genomic sequences, such as knockins of genes of interest in a genome, knockouts of genomic sequences and/or allele replacement. Also provided herein are a method...... for editing nucleic acids and a cell comprising a stably integrated endonuclease....

  6. Broadband Radio Service (BRS) and Educational Broadband Service (EBS) Transmitters

    Data.gov (United States)

    Department of Homeland Security — The Broadband Radio Service (BRS), formerly known as the Multipoint Distribution Service (MDS)/Multichannel Multipoint Distribution Service (MMDS), is a commercial...

  7. Extracting information from multiplex networks

    Science.gov (United States)

    Iacovacci, Jacopo; Bianconi, Ginestra

    2016-06-01

    Multiplex networks are generalized network structures that are able to describe networks in which the same set of nodes are connected by links that have different connotations. Multiplex networks are ubiquitous since they describe social, financial, engineering, and biological networks as well. Extending our ability to analyze complex networks to multiplex network structures increases greatly the level of information that is possible to extract from big data. For these reasons, characterizing the centrality of nodes in multiplex networks and finding new ways to solve challenging inference problems defined on multiplex networks are fundamental questions of network science. In this paper, we discuss the relevance of the Multiplex PageRank algorithm for measuring the centrality of nodes in multilayer networks and we characterize the utility of the recently introduced indicator function Θ ˜ S for describing their mesoscale organization and community structure. As working examples for studying these measures, we consider three multiplex network datasets coming for social science.

  8. Design and fabrication of three-dimensional polymer mode multiplexer based on asymmetric waveguide couplers

    Science.gov (United States)

    He, Guobing; Gao, Yang; Xu, Yan; Ji, Lanting; Sun, Xiaoqiang; Wang, Xibin; Yi, Yunji; Chen, Changming; Wang, Fei; Zhang, Daming; Wu, Yuanda

    2018-05-01

    A polymer mode multiplexer based on asymmetric couplers is theoretically designed and experimentally demonstrated. The proposed X-junction coupler is formed by waveguides overlapped with different crossing angles in the vertical direction. A beam propagation method is adopted to optimize the dimensional parameters of the mode multiplexer to convert LP01 mode of two lower waveguides to LP11a and LP21a mode of the upper waveguide. The ultraviolet lithography and wet chemical etching are used in the fabrication process. A conversion ratio over 98% for both LP11a and LP21a mode in the wavelength range from 1530 to 1570 nm are experimentally demonstrated. This mode multiplexer has potential in broadband mode-division multiplexing transmission systems.

  9. Handheld Broadband Electromagnetic UXO Sensor

    National Research Council Canada - National Science Library

    Won, I. J; San Filipo, William A; Marqusee, Jeffrey; Andrews, Anne; Robitaille, George; Fairbanks, Jeffrey; Overbay, Larry

    2005-01-01

    The broadband electromagnetic sensor improvement and demonstration undertaken in this project took the prototype GEM-3 and evolved it into an operational sensor with increased bandwidth and dynamic...

  10. Dynamic Time Multiplexing Fabrication of Holographic Polymer Dispersed Liquid Crystals for Increased Wavelength Sensitivity

    Science.gov (United States)

    Fontecchio, Adam K. (Inventor); Rai, Kashma (Inventor)

    2017-01-01

    Described herein is a new holographic polymer dispersed liquid crystal (HPDLC) medium with broadband reflective properties, and a new technique for fabrication of broadband HPDLC mediums. The new technique involves dynamic variation of the holography setup during HPDLC formation, enabling the broadening of the HPDLC medium's wavelength response. Dynamic variation of the holography setup may include the rotation and/or translation of one or more motorized stages, allowing for time and spatial, or angular, multiplexing through variation of the incident angles of one or more laser beams on a pre-polymer mixture during manufacture. An HPDLC medium manufactured using these techniques exhibits improved optical response by reflecting a broadband spectrum of wavelengths. A new broadband holographic polymer dispersed liquid crystal thin film polymeric mirror stack with electrically-switchable beam steering capability is disclosed. XXXX Described herein is a new holographic polymer dispersed liquid crystal (HPDLC) medium with broadband reflective properties, and a new technique for fabrication of broadband 10 HPDLC mediums. The new technique involves dynamic variation of the holography setup during HPDLC formation, enabling the broadening of the HPDLC medium's wavelength response. Dynamic variation of the holography setup may include the rotation and/or translation of one or more 15 motorized stages, allowing for time and spatial, or angular, multiplexing through variation of the incident angles of one or more laser beams on a pre-polymer mixture during manufacture. An HPDLC medium manufactured using these techniques exhibits improved optical response by reflecting 20 a broadband spectrum of wavelengths. A new broadband holographic polymer dispersed liquid crystal thin film polymeric mirror stack with electrically switchable beam steering capability is disclosed.

  11. Demonstration of Time Domain Multiplexed Readout for Magnetically Coupled Calorimeters

    Science.gov (United States)

    Porst, J.-P.; Adams, J. S.; Balvin, M.; Bandler, S.; Beyer, J.; Busch, S. E.; Drung, D.; Seidel, G. M.; Smith, S. J.; Stevenson, T. R.

    2012-01-01

    Magnetically coupled calorimeters (MCC) have extremely high potential for x-ray applications due to the inherent high energy resolution capability and being non-dissipative. Although very high energy-resolution has been demonstrated, until now there has been no demonstration of multiplexed read-out. We report on the first realization of a time domain multiplexed (TDM) read-out. While this has many similarities with TDM of transition-edge-sensors (TES), for MGGs the energy resolution is limited by the SQUID read-out noise and requires the well established scheme to be altered in order to minimize degradation due to noise aliasing effects. In cur approach, each pixel is read out by a single first stage SQUID (SQ1) that is operated in open loop. The outputs of the SQ1 s are low-pass filtered with an array of low cross-talk inductors, then fed into a single-stage SQUID TD multiplexer. The multiplexer is addressed from room temperature and read out through a single amplifier channel. We present results achieved with a new detector platform. Noise performance is presented and compared to expectations. We have demonstrated multiplexed X-ray spectroscopy at 5.9keV with delta_FWHM=10eV. In an optimized setup, we show it is possible to multiplex 32 detectors without significantly degrading the Intrinsic detector resolution.

  12. An Assessment of Emerging Wireless Broadband Technologies

    National Research Council Canada - National Science Library

    Fountanas, Leonidas

    2001-01-01

    ... technologies in providing broadband services today, emerging wireless broadband technologies are expected to significantly increase their market share over the next years, Deploying a wireless network...

  13. Functional Multiplex PageRank

    Science.gov (United States)

    Iacovacci, Jacopo; Rahmede, Christoph; Arenas, Alex; Bianconi, Ginestra

    2016-10-01

    Recently it has been recognized that many complex social, technological and biological networks have a multilayer nature and can be described by multiplex networks. Multiplex networks are formed by a set of nodes connected by links having different connotations forming the different layers of the multiplex. Characterizing the centrality of the nodes in a multiplex network is a challenging task since the centrality of the node naturally depends on the importance associated to links of a certain type. Here we propose to assign to each node of a multiplex network a centrality called Functional Multiplex PageRank that is a function of the weights given to every different pattern of connections (multilinks) existent in the multiplex network between any two nodes. Since multilinks distinguish all the possible ways in which the links in different layers can overlap, the Functional Multiplex PageRank can describe important non-linear effects when large relevance or small relevance is assigned to multilinks with overlap. Here we apply the Functional Page Rank to the multiplex airport networks, to the neuronal network of the nematode C. elegans, and to social collaboration and citation networks between scientists. This analysis reveals important differences existing between the most central nodes of these networks, and the correlations between their so-called pattern to success.

  14. Broadband unidirectional ultrasound propagation

    Science.gov (United States)

    Sinha, Dipen N.; Pantea, Cristian

    2017-12-12

    A passive, linear arrangement of a sonic crystal-based apparatus and method including a 1D sonic crystal, a nonlinear medium, and an acoustic low-pass filter, for permitting unidirectional broadband ultrasound propagation as a collimated beam for underwater, air or other fluid communication, are described. The signal to be transmitted is first used to modulate a high-frequency ultrasonic carrier wave which is directed into the sonic crystal side of the apparatus. The apparatus processes the modulated signal, whereby the original low-frequency signal exits the apparatus as a collimated beam on the side of the apparatus opposite the sonic crystal. The sonic crystal provides a bandpass acoustic filter through which the modulated high-frequency ultrasonic signal passes, and the nonlinear medium demodulates the modulated signal and recovers the low-frequency sound beam. The low-pass filter removes remaining high-frequency components, and contributes to the unidirectional property of the apparatus.

  15. Magnetization pinning in conducting films demonstrated using broadband ferromagnetic resonance

    Science.gov (United States)

    Kostylev, M.; Stashkevich, A. A.; Adeyeye, A. O.; Shakespeare, C.; Kostylev, N.; Ross, N.; Kennewell, K.; Magaraggia, R.; Roussigné, Y.; Stamps, R. L.

    2010-11-01

    The broadband microstrip ferromagnetic resonance (FMR), cavity FMR, and Brillouin light scattering spectroscopy techniques have been applied for detection and characterization of a magnetic inhomogeneity in a film sample. In the case of a 100 nm thick permalloy film, an additional magnetically depleted top sublayer has been detected due to pinning effect it produces on the magnetization in the bulk of the film. The pinning results in appearance of an exchange standing spin wave mode in the broadband FMR absorption spectrum, whose amplitudes are different depending on whether the film or the film substrate faces the microstrip transducer. Comparison of the experimental amplitudes for this mode with results of our theory for both film placements revealed that the depleted layer is located at the film surface facing away from the film substrate. Subsequent broadband FMR characterization of a large number of other presumably single-layer films with thicknesses in the range 30-100 nm showed the same result.

  16. A simple electron multiplexer

    International Nuclear Information System (INIS)

    Dobrzynski, L; Akjouj, A; Djafari-Rouhani, B; Al-Wahsh, H; Zielinski, P

    2003-01-01

    We present a simple multiplexing device made of two atomic chains coupled by two other transition metal atoms. We show that this simple atomic device can transfer electrons at a given energy from one wire to the other, leaving all other electron states unaffected. Closed-form relations between the transmission coefficients and the inter-atomic distances are given to optimize the desired directional electron ejection. Such devices can be adsorbed on insulating substrates and characterized by current surface technologies. (letter to the editor)

  17. Multiplex Recurrence Networks

    Science.gov (United States)

    Eroglu, Deniz; Marwan, Norbert

    2017-04-01

    The complex nature of a variety of phenomena in physical, biological, or earth sciences is driven by a large number of degrees of freedom which are strongly interconnected. Although the evolution of such systems is described by multivariate time series (MTS), so far research mostly focuses on analyzing these components one by one. Recurrence based analyses are powerful methods to understand the underlying dynamics of a dynamical system and have been used for many successful applications including examples from earth science, economics, or chemical reactions. The backbone of these techniques is creating the phase space of the system. However, increasing the dimension of a system requires increasing the length of the time series in order get significant and reliable results. This requirement is one of the challenges in many disciplines, in particular in palaeoclimate, thus, it is not easy to create a phase space from measured MTS due to the limited number of available obervations (samples). To overcome this problem, we suggest to create recurrence networks from each component of the system and combine them into a multiplex network structure, the multiplex recurrence network (MRN). We test the MRN by using prototypical mathematical models and demonstrate its use by studying high-dimensional palaeoclimate dynamics derived from pollen data from the Bear Lake (Utah, US). By using the MRN, we can distinguish typical climate transition events, e.g., such between Marine Isotope Stages.

  18. Visible Wavelength Division Multiplex System for use as a Instructional Lab System for Higher Education

    OpenAIRE

    Fischer, Ulrich H. P.; Schmidt, Michael; Volmer, Tino; Weigl, Bjoern; Just, Jens-Uwe

    2007-01-01

    The demand for high-speed digital communication such as data, video, and the broadband Internet increases, the required throughput of the modules in communications systems will also increase. In this paper we present an instruction system, which works on the basis of a wavelength division multiplex (WDM) system in the visible spectrum. It is specialised for the academic training at universities to demonstrate the principles of the WDM techniques. It works platform independent in combination w...

  19. Broadband accelerator control network

    International Nuclear Information System (INIS)

    Skelly, J.; Clifford, T.; Frankel, R.

    1983-01-01

    A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AG) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz bandwidth Digital Control channel using CSMA-CA protocol is provided for digital data transmission, with 8 access nodes available over the length of the RELWAY. Each node consists of an rf modem and a microprocessor-based store-and-forward message handler which interfaces the RELWAY to a branch line implemented in GPIB. A gateway to the RELWAY control channel for the (preexisting) AGS Computerized Accelerator Operating system has been constructed using an LSI-11/23 microprocessor as a device in a GPIB branch line. A multilayer communications protocol has been defined for the Digital Control Channel, based on the ISO Open Systems Interconnect layered model, and a RELWAY Device Language defined as the required universal language for device control on this channel

  20. Multiplex families with epilepsy

    Science.gov (United States)

    Afawi, Zaid; Oliver, Karen L.; Kivity, Sara; Mazarib, Aziz; Blatt, Ilan; Neufeld, Miriam Y.; Helbig, Katherine L.; Goldberg-Stern, Hadassa; Misk, Adel J.; Straussberg, Rachel; Walid, Simri; Mahajnah, Muhammad; Lerman-Sagie, Tally; Ben-Zeev, Bruria; Kahana, Esther; Masalha, Rafik; Kramer, Uri; Ekstein, Dana; Shorer, Zamir; Wallace, Robyn H.; Mangelsdorf, Marie; MacPherson, James N.; Carvill, Gemma L.; Mefford, Heather C.; Jackson, Graeme D.; Scheffer, Ingrid E.; Bahlo, Melanie; Gecz, Jozef; Heron, Sarah E.; Corbett, Mark; Mulley, John C.; Dibbens, Leanne M.; Korczyn, Amos D.

    2016-01-01

    Objective: To analyze the clinical syndromes and inheritance patterns of multiplex families with epilepsy toward the ultimate aim of uncovering the underlying molecular genetic basis. Methods: Following the referral of families with 2 or more relatives with epilepsy, individuals were classified into epilepsy syndromes. Families were classified into syndromes where at least 2 family members had a specific diagnosis. Pedigrees were analyzed and molecular genetic studies were performed as appropriate. Results: A total of 211 families were ascertained over an 11-year period in Israel. A total of 169 were classified into broad familial epilepsy syndrome groups: 61 generalized, 22 focal, 24 febrile seizure syndromes, 33 special syndromes, and 29 mixed. A total of 42 families remained unclassified. Pathogenic variants were identified in 49/211 families (23%). The majority were found in established epilepsy genes (e.g., SCN1A, KCNQ2, CSTB), but in 11 families, this cohort contributed to the initial discovery (e.g., KCNT1, PCDH19, TBC1D24). We expand the phenotypic spectrum of established epilepsy genes by reporting a familial LAMC3 homozygous variant, where the predominant phenotype was epilepsy with myoclonic-atonic seizures, and a pathogenic SCN1A variant in a family where in 5 siblings the phenotype was broadly consistent with Dravet syndrome, a disorder that usually occurs sporadically. Conclusion: A total of 80% of families were successfully classified, with pathogenic variants identified in 23%. The successful characterization of familial electroclinical and inheritance patterns has highlighted the value of studying multiplex families and their contribution towards uncovering the genetic basis of the epilepsies. PMID:26802095

  1. Polarization-multiplexing ghost imaging

    Science.gov (United States)

    Dongfeng, Shi; Jiamin, Zhang; Jian, Huang; Yingjian, Wang; Kee, Yuan; Kaifa, Cao; Chenbo, Xie; Dong, Liu; Wenyue, Zhu

    2018-03-01

    A novel technique for polarization-multiplexing ghost imaging is proposed to simultaneously obtain multiple polarimetric information by a single detector. Here, polarization-division multiplexing speckles are employed for object illumination. The light reflected from the objects is detected by a single-pixel detector. An iterative reconstruction method is used to restore the fused image containing the different polarimetric information by using the weighted sum of the multiplexed speckles based on the correlation coefficients obtained from the detected intensities. Next, clear images of the different polarimetric information are recovered by demultiplexing the fused image. The results clearly demonstrate that the proposed method is effective.

  2. Signal multiplexing scheme for LINAC

    International Nuclear Information System (INIS)

    Sujo, C.I.; Mohan, Shyam; Joshi, Gopal; Singh, S.K.; Karande, Jitendra

    2004-01-01

    For the proper operation of the LINAC some signals, RF (radio frequency) as well as LF (low frequency) have to be available at the Master Control Station (MCS). These signals are needed to control, calibrate and characterize the RF fields in the resonators. This can be achieved by proper multiplexing of various signals locally and then routing the selected signals to the MCS. A multiplexing scheme has been designed and implemented, which will allow the signals from the selected cavity to the MCS. High isolation between channels and low insertion loss for a given signal are important issues while selecting the multiplexing scheme. (author)

  3. Driving demand for broadband networks and services

    CERN Document Server

    Katz, Raul L

    2014-01-01

    This book examines the reasons why various groups around the world choose not to adopt broadband services and evaluates strategies to stimulate the demand that will lead to increased broadband use. It introduces readers to the benefits of higher adoption rates while examining the progress that developed and emerging countries have made in stimulating broadband demand. By relying on concepts such as a supply and demand gap, broadband price elasticity, and demand promotion, this book explains differences between the fixed and mobile broadband demand gap, introducing the notions of substitution and complementarity between both platforms. Building on these concepts, ‘Driving Demand for Broadband Networks and Services’ offers a set of best practices and recommendations aimed at promoting broadband demand.  The broadband demand gap is defined as individuals and households that could buy a broadband subscription because they live in areas served by telecommunications carriers but do not do so because of either ...

  4. Percolation in real multiplex networks

    Science.gov (United States)

    Bianconi, Ginestra; Radicchi, Filippo

    2016-12-01

    We present an exact mathematical framework able to describe site-percolation transitions in real multiplex networks. Specifically, we consider the average percolation diagram valid over an infinite number of random configurations where nodes are present in the system with given probability. The approach relies on the locally treelike ansatz, so that it is expected to accurately reproduce the true percolation diagram of sparse multiplex networks with negligible number of short loops. The performance of our theory is tested in social, biological, and transportation multiplex graphs. When compared against previously introduced methods, we observe improvements in the prediction of the percolation diagrams in all networks analyzed. Results from our method confirm previous claims about the robustness of real multiplex networks, in the sense that the average connectedness of the system does not exhibit any significant abrupt change as its individual components are randomly destroyed.

  5. Multiplexed Colorimetric Solid-Phase Extraction

    Science.gov (United States)

    Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.

    2009-01-01

    Multiplexed colorimetric solid-phase extraction (MC-SPE) is an extension of colorimetric solid-phase extraction (C-SPE) an analytical platform that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water. In CSPE, analytes are extracted and complexed on the surface of an extraction membrane impregnated with a colorimetric reagent. The analytes are then quantified directly on the membrane surface using a handheld diffuse reflectance spectrophotometer. Importantly, the use of solid-phase extraction membranes as the matrix for impregnation of the colorimetric reagents creates a concentration factor that enables the detection of low concentrations of analytes in small sample volumes. In extending C-SPE to a multiplexed format, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple sample syringes have been designed, enabling the simultaneous determination of multiple analytes. Separate, single analyte membranes, placed in a readout cartridge create unique, analyte-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. In a demonstration, MC-SPE was used to measure the pH of a sample and quantitate Ag(I) and Ni(II).

  6. Observations involving broadband impedance modelling

    Energy Technology Data Exchange (ETDEWEB)

    Berg, J S [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1996-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impedance. This paper discusses three aspects of broadband impedance modelling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f. cavity. The last is a discussion of requirements for the mathematical form of an impedance which follow from the general properties of impedances. (author)

  7. Observations involving broadband impedance modelling

    International Nuclear Information System (INIS)

    Berg, J.S.

    1995-08-01

    Results for single- and multi-bunch instabilities can be significantly affected by the precise model that is used for the broadband impendance. This paper discusses three aspects of broadband impendance modeling. The first is an observation of the effect that a seemingly minor change in an impedance model has on the single-bunch mode coupling threshold. The second is a successful attempt to construct a model for the high-frequency tails of an r.f cavity. The last is a discussion of requirements for the mathematical form of an impendance which follow from the general properties of impendances

  8. Achieving universal access to broadband

    DEFF Research Database (Denmark)

    Falch, Morten; Henten, Anders

    2009-01-01

    The paper discusses appropriate policy measures for achieving universal access to broadband services in Europe. Access can be delivered by means of many different technology solutions described in the paper. This means a greater degree of competition and affects the kind of policy measures...

  9. Thermally multiplexed polymerase chain reaction.

    Science.gov (United States)

    Phaneuf, Christopher R; Pak, Nikita; Saunders, D Curtis; Holst, Gregory L; Birjiniuk, Joav; Nagpal, Nikita; Culpepper, Stephen; Popler, Emily; Shane, Andi L; Jerris, Robert; Forest, Craig R

    2015-07-01

    Amplification of multiple unique genetic targets using the polymerase chain reaction (PCR) is commonly required in molecular biology laboratories. Such reactions are typically performed either serially or by multiplex PCR. Serial reactions are time consuming, and multiplex PCR, while powerful and widely used, can be prone to amplification bias, PCR drift, and primer-primer interactions. We present a new thermocycling method, termed thermal multiplexing, in which a single heat source is uniformly distributed and selectively modulated for independent temperature control of an array of PCR reactions. Thermal multiplexing allows amplification of multiple targets simultaneously-each reaction segregated and performed at optimal conditions. We demonstrate the method using a microfluidic system consisting of an infrared laser thermocycler, a polymer microchip featuring 1 μl, oil-encapsulated reactions, and closed-loop pulse-width modulation control. Heat transfer modeling is used to characterize thermal performance limitations of the system. We validate the model and perform two reactions simultaneously with widely varying annealing temperatures (48 °C and 68 °C), demonstrating excellent amplification. In addition, to demonstrate microfluidic infrared PCR using clinical specimens, we successfully amplified and detected both influenza A and B from human nasopharyngeal swabs. Thermal multiplexing is scalable and applicable to challenges such as pathogen detection where patients presenting non-specific symptoms need to be efficiently screened across a viral or bacterial panel.

  10. A SURVEY ON WAVELENGTH DIVISION MULTIPLEXING (WDM NETWORKS

    Directory of Open Access Journals (Sweden)

    G. Ramesh

    2010-03-01

    Full Text Available Communication networks have emerged as a source of empowerment in today’s society. At the global level, the Internet is becoming the backbone of the modern economy. The new generations in developed countries cannot even conceive of a world without broadband access to the Internet. The inability of the current Internet infrastructure to cope with the wide variety and ever growing number of users, emerging networked applications, usage patterns and business models is increasingly being recognized worldwide. The dynamic growth of Internet traffic and its bursty nature requires high transmission rate. With the advances and the progress in Wavelength Division Multiplexing (WDM technology, the amount of raw bandwidth available in fiber links has increased to high magnitude. This paper presents a survey on WDM networks from its development to the current status. Also an analysis on buffer size in optical networks for real time traffic was performed.

  11. Laguerre Gaussian beam multiplexing through turbulence

    CSIR Research Space (South Africa)

    Trichili, A

    2014-08-17

    Full Text Available We analyze the effect of atmospheric turbulence on the propagation of multiplexed Laguerre Gaussian modes. We present a method to multiplex Laguerre Gaussian modes using digital holograms and decompose the resulting field after encountering a...

  12. Spatial analysis of various multiplex cinema types

    Directory of Open Access Journals (Sweden)

    Young-Seo Park

    2016-03-01

    Full Text Available This study identifies the spatial characteristics and relationships of each used space according to the multiplex type. In this study, multiplexes are classified according to screen rooms and circulation systems, and each used space is quantitatively analyzed. The multiplex type based on screen rooms and moving line systems influences the relationship and characteristics of each used space in various ways. In particular, the structure of the used space of multiplexes has a significant effect on profit generation and audience convenience.

  13. On-chip mode division multiplexing technologies

    DEFF Research Database (Denmark)

    Ding, Yunhong; Frellsen, Louise Floor; Guan, Xiaowei

    2016-01-01

    Space division multiplexing (SDM) is currently widely investigated in order to provide enhanced capacity thanks to the utilization of space as a new degree of multiplexing freedom in both optical fiber communication and on-chip interconnects. Basic components allowing the processing of spatial...... photonic integrated circuit mode (de) multiplexer for few-mode fibers (FMFs)....

  14. Frequency-division multiplexer and demultiplexer for terahertz wireless links.

    Science.gov (United States)

    Ma, Jianjun; Karl, Nicholas J; Bretin, Sara; Ducournau, Guillaume; Mittleman, Daniel M

    2017-09-28

    The development of components for terahertz wireless communications networks has become an active and growing research field. However, in most cases these components have been studied using a continuous or broadband-pulsed terahertz source, not using a modulated data stream. This limitation may mask important aspects of the performance of the device in a realistic system configuration. We report the characterization of one such device, a frequency multiplexer, using modulated data at rates up to 10 gigabits per second. We also demonstrate simultaneous error-free transmission of two signals at different carrier frequencies, with an aggregate data rate of 50 gigabits per second. We observe that the far-field spatial variation of the bit error rate is different from that of the emitted power, due to a small nonuniformity in the angular detection sensitivity. This is likely to be a common feature of any terahertz communication system in which signals propagate as diffracting beams not omnidirectional broadcasts.There is growing interest in the development of components to facilitate wireless communications in the terahertz but the characterization of these systems involve an unmodulated input. Here the authors demonstrate multiplexing and demultiplexing of data streams in the terahertz range using a real data link.

  15. A broadband electromagnetic UT system

    International Nuclear Information System (INIS)

    Repplinger, W.; Salzburger, H.J.

    1985-01-01

    An ultrasonic testing system based on contactless electromagnetic acoustic (E.M.A.) transduction has been developed by which broadband ultrasonic pulses are excited. This system overcomes disadvantages of usual E.M.A. transducers with meanderlike coil configuration, namely the excitation of narrowband pulses and the symmetrical radiation pattern. By dividing up a meanderlike coil into single elements and a time-delayed firing of the elements, whereby the time delay is given by the distance of the elements and the phase velocity of the wave propagating along the surface, the ultrasonic pulse radiated in one preferred direction becomes broadband by constructive interference. The signals radiated in the opposite direction do no more interfere. Its amplitude is smaller than that of the other direction, so that the transducer becomes uni-directional. This technique can be applied for the excitation of all dispersionless waves (bulk waves and guided waves)

  16. Visible light broadband perfect absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Jia, X. L.; Meng, Q. X.; Yuan, C. X.; Zhou, Z. X.; Wang, X. O., E-mail: wxo@hit.edu.cn [School of Science, Harbin Institute of Technology, Harbin 150001 (China)

    2016-03-15

    The visible light broadband perfect absorbers based on the silver (Ag) nano elliptical disks and holes array are studied using finite difference time domain simulations. The semiconducting indium silicon dioxide thin film is introduced as the space layer in this sandwiched structure. Utilizing the asymmetrical geometry of the structures, polarization sensitivity for transverse electric wave (TE)/transverse magnetic wave (TM) and left circular polarization wave (LCP)/right circular polarization wave (RCP) of the broadband absorption are gained. The absorbers with Ag nano disks and holes array show several peaks absorbance of 100% by numerical simulation. These simple and flexible perfect absorbers are particularly desirable for various potential applications including the solar energy absorber.

  17. Integrated Broadband Quantum Cascade Laser

    Science.gov (United States)

    Mansour, Kamjou (Inventor); Soibel, Alexander (Inventor)

    2016-01-01

    A broadband, integrated quantum cascade laser is disclosed, comprising ridge waveguide quantum cascade lasers formed by applying standard semiconductor process techniques to a monolithic structure of alternating layers of claddings and active region layers. The resulting ridge waveguide quantum cascade lasers may be individually controlled by independent voltage potentials, resulting in control of the overall spectrum of the integrated quantum cascade laser source. Other embodiments are described and claimed.

  18. Analysis of the Proposed Ghana Broadband Strategy

    DEFF Research Database (Denmark)

    Williams, Idongesit; Botwe, Yvonne

    This project studied the Ghana Broadband Strategy with the aim of evaluating the recommendations in the strategy side by side the broadband development in Ghana. The researchers conducted interviews both officially and unofficially with ICT stakeholders, made observations, studied Government...... intervention policies recommended in the Ghana broadband policy is used to evaluate the broadband market to find out whether the strategy consolidates with the Strengths and opportunities of the market and whether it corrects the anomalies that necessitate the weaknesses and threats to the market....... The strategy did address some threats and weaknesses of the broadband market. It also consolidated on some strengths and opportunities of the broadband market. The researchers also discovered that a market can actually grow without a policy. But a market will grow faster if a well implemented policy is guiding...

  19. Principles of broadband switching and networking

    CERN Document Server

    Liew, Soung C

    2010-01-01

    An authoritative introduction to the roles of switching and transmission in broadband integrated services networks Principles of Broadband Switching and Networking explains the design and analysis of switch architectures suitable for broadband integrated services networks, emphasizing packet-switched interconnection networks with distributed routing algorithms. The text examines the mathematical properties of these networks, rather than specific implementation technologies. Although the pedagogical explanations in this book are in the context of switches, many of the fundamenta

  20. Centrality in earthquake multiplex networks

    Science.gov (United States)

    Lotfi, Nastaran; Darooneh, Amir Hossein; Rodrigues, Francisco A.

    2018-06-01

    Seismic time series has been mapped as a complex network, where a geographical region is divided into square cells that represent the nodes and connections are defined according to the sequence of earthquakes. In this paper, we map a seismic time series to a temporal network, described by a multiplex network, and characterize the evolution of the network structure in terms of the eigenvector centrality measure. We generalize previous works that considered the single layer representation of earthquake networks. Our results suggest that the multiplex representation captures better earthquake activity than methods based on single layer networks. We also verify that the regions with highest seismological activities in Iran and California can be identified from the network centrality analysis. The temporal modeling of seismic data provided here may open new possibilities for a better comprehension of the physics of earthquakes.

  1. Tuchola County Broadband Network (TCBN)

    DEFF Research Database (Denmark)

    Zabludowski, Antoni; Dubalski, B.; Zabludowski, Lukasz

    2012-01-01

    In the paper the designing project (plan) of Tuchola City broadband IP optical network has been presented. The extended version of network plan constitute technical part of network Feasibility Study, that it is expected to be implemented in Tuchola and be financed from European Regional Development...... Funds. The network plan presented in the paper contains both topological structure of fiber optic network as well as the active equipment for the network. In the project described in the paper it has been suggested to use Modular Cable System - MCS for passive infrastructure and Metro Ethernet...

  2. Understanding broadband over power line

    CERN Document Server

    Held, Gilbert

    2006-01-01

    Understanding Broadband over Power Line explores all aspects of the emerging technology that enables electric utilities to provide support for high-speed data communications via their power infrastructure. This book examines the two methods used to connect consumers and businesses to the Internet through the utility infrastructure: the existing electrical wiring of a home or office; and a wireless local area network (WLAN) access point.Written in a practical style that can be understood by network engineers and non-technologists alike, this volume offers tutorials on electric utility infrastru

  3. Achieving Universal Access to Broadband

    Directory of Open Access Journals (Sweden)

    Morten FALCH

    2009-01-01

    Full Text Available The paper discusses appropriate policy measures for achieving universal access to broadband services in Europe. Access can be delivered by means of many different technology solutions described in the paper. This means a greater degree of competition and affects the kind of policy measures to be applied. The paper concludes that other policy measure than the classical universal service obligation are in play, and discusses various policy measures taking the Lisbon process as a point of departure. Available policy measures listed in the paper include, universal service obligation, harmonization, demand stimulation, public support for extending the infrastructure, public private partnerships (PPP, and others.

  4. Dual THz comb spectroscopy

    Science.gov (United States)

    Yasui, Takeshi

    2017-08-01

    Optical frequency combs are innovative tools for broadband spectroscopy because a series of comb modes can serve as frequency markers that are traceable to a microwave frequency standard. However, a mode distribution that is too discrete limits the spectral sampling interval to the mode frequency spacing even though individual mode linewidth is sufficiently narrow. Here, using a combination of a spectral interleaving and dual-comb spectroscopy in the terahertz (THz) region, we achieved a spectral sampling interval equal to the mode linewidth rather than the mode spacing. The spectrally interleaved THz comb was realized by sweeping the laser repetition frequency and interleaving additional frequency marks. In low-pressure gas spectroscopy, we achieved an improved spectral sampling density of 2.5 MHz and enhanced spectral accuracy of 8.39 × 10-7 in the THz region. The proposed method is a powerful tool for simultaneously achieving high resolution, high accuracy, and broad spectral coverage in THz spectroscopy.

  5. Broadband Wireline Provider Service Summary; BBRI_wirelineSum12

    Data.gov (United States)

    University of Rhode Island Geospatial Extension Program — This dataset represents the availability of broadband Internet access in Rhode Island via all wireline technologies assessed by Broadband Rhode Island. Broadband...

  6. Consideration for wavelength multiplexing versus time multiplexing in optical transport network

    DEFF Research Database (Denmark)

    Limal, Emmanuel; Stubkjær, Kristian Elmholdt

    1999-01-01

    We compare optical wavelength multiplexing and time multiplexing techniquesfor optical transport network by studying the space switch sizes of OXCs andtheir interfaces as a function of the fraction of add/drop traffic....

  7. Strain measurement using multiplexed fiber optic sensors

    International Nuclear Information System (INIS)

    Kwon, Il Bum; Kim, Chi Yeop; Yoon, Dong Jin; Lee, Seung Seok

    2003-01-01

    FBG(Fiber Bragg grating) sensor, which is one of the fiber optic sensors for the application of smart structures, can not only measure one specific point but also multiple points by multiplexing techniques. We have proposed a novel multiplexing technique of FBG sensor by the intensity modulation of light source. This technique is applicable to WDM(Wavelength Division Multiplexing) technique and number of sensors in this system can be increased by using this technique with WDM technique.

  8. 75 FR 10464 - Broadband Technology Opportunities Program

    Science.gov (United States)

    2010-03-08

    ... window for Public Computer Center (PCC) and Sustainable Broadband Adoption (SBA) projects. DATES: All...; Extension of Application Closing Deadline for Comprehensive Community Infrastructure (CCI) Projects. SUMMARY... Infrastructure (CCI) projects under the Broadband Technology Opportunities Program (BTOP) is extended until 5:00...

  9. Broadband for all closing the infrastructure gap

    CSIR Research Space (South Africa)

    Roux, K

    2015-10-01

    Full Text Available than just addressing the infrastructure issue. The CSIR is mapping the country’s broadband infrastructure to understand where the largest gaps are, is developing models for how those gaps in broadband infrastructure can be closed. In this presentation...

  10. Frequency multiplexing for readout of spin qubits

    Energy Technology Data Exchange (ETDEWEB)

    Hornibrook, J. M.; Colless, J. I.; Mahoney, A. C.; Croot, X. G.; Blanvillain, S.; Reilly, D. J., E-mail: david.reilly@sydney.edu.au [ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Lu, H.; Gossard, A. C. [Materials Department, University of California, Santa Barbara, California 93106 (United States)

    2014-03-10

    We demonstrate a low loss, chip-level frequency multiplexing scheme for readout of scaled-up spin qubit devices. By integrating separate bias tees and resonator circuits on-chip for each readout channel, we realise dispersive gate-sensing in combination with charge detection based on two radio frequency quantum point contacts. We apply this approach to perform multiplexed readout of a double quantum dot in the few-electron regime and further demonstrate operation of a 10-channel multiplexing device. Limitations for scaling spin qubit readout to large numbers of multiplexed channels are discussed.

  11. Customer Churn Prediction for Broadband Internet Services

    Science.gov (United States)

    Huang, B. Q.; Kechadi, M.-T.; Buckley, B.

    Although churn prediction has been an area of research in the voice branch of telecommunications services, more focused studies on the huge growth area of Broadband Internet services are limited. Therefore, this paper presents a new set of features for broadband Internet customer churn prediction, based on Henley segments, the broadband usage, dial types, the spend of dial-up, line-information, bill and payment information, account information. Then the four prediction techniques (Logistic Regressions, Decision Trees, Multilayer Perceptron Neural Networks and Support Vector Machines) are applied in customer churn, based on the new features. Finally, the evaluation of new features and a comparative analysis of the predictors are made for broadband customer churn prediction. The experimental results show that the new features with these four modelling techniques are efficient for customer churn prediction in the broadband service field.

  12. Steatocystoma multiplex hos 39-årig kvinde

    DEFF Research Database (Denmark)

    Duffy, Jonas Raymond; Siersen, Hans Erik; Bonde, Christian T

    2011-01-01

    -coloured cystic lesions on the chest, abdomen, axillae and back. The patient's clinical presentations and history were compatible with steatocystoma multiplex. Various treatment options for steatocystoma multiplex and steatocystoma multiplex suppurativum have been published and include oral antibiotics...

  13. Novel signal multiplexing methods for integration of services in in-building broadband multimode fibre networks

    NARCIS (Netherlands)

    Koonen, A.M.J.

    2004-01-01

    Many different services with widely ranging signal characteristics are to be supported in in-building networks: fast data transport (e.g. Gbit Ethernet), video, high-Q audio, and control signals. These services may use wired or wireless connection to the end user. In order to support them in

  14. Broad-Band Spectroscopy of Hercules X-1 with Suzaku

    Science.gov (United States)

    Asami, Fumi; Enoto, Teruaki; Iwakiri, Wataru; Yamada, Shin'ya; Tamagawa, Toru; Mihara, Tatehiro; Nagase, Fumiaki

    2014-01-01

    Hercules X-1 was observed with Suzaku in the main-on state from 2005 to 2010. The 0.4- 100 keV wide-band spectra obtained in four observations showed a broad hump around 4-9 keV in addition to narrow Fe lines at 6.4 and 6.7 keV. The hump was seen in all the four observations regardless of the selection of the continuum models. Thus it is considered a stable and intrinsic spectral feature in Her X-1. The broad hump lacked a sharp structure like an absorption edge. Thus it was represented by two different spectral models: an ionized partial covering or an additional broad line at 6.5 keV. The former required a persistently existing ionized absorber, whose origin was unclear. In the latter case, the Gaussian fitting of the 6.5-keV line needs a large width of sigma = 1.0-1.5 keV and a large equivalent width of 400-900 eV. If the broad line originates from Fe fluorescence of accreting matter, its large width may be explained by the Doppler broadening in the accretion flow. However, the large equivalent width may be inconsistent with a simple accretion geometry.

  15. An alarm multiplexer communication system

    International Nuclear Information System (INIS)

    Herrera, G.V.

    1986-01-01

    A low cost Alarm Multiplexer Communication System (AMCS) has been developed to perform the security sensor monitoring and control functions and to provide remote relay control capability for integrated security systems. AMCS has a distributed multiplexer/repeater architecture with up to four dual communication loops and dual control computers that guarantee total system operation under any single point failure condition. Each AMCS can control up to 4096 sensors and 2048 remote relays. AMCS reports alarm status information to and is controlled by either one or two Host computers. This allows for independent operation of primary and backup security command centers. AMCS communicates with the Host computers over an asynchronous serial communication link and has a message protocol which allows AMCS to fully recover from lost messages or large blocks of data communication errors. This paper describes the AMCS theory of operation, AMCS fault modes, and AMCS system design methodology. Also, cost and timing information is presented. AMCS is being used and considered for several DOE and DOD facilities

  16. Broadband and scalable mobile satellite communication system for future access networks

    Science.gov (United States)

    Ohata, Kohei; Kobayashi, Kiyoshi; Nakahira, Katsuya; Ueba, Masazumi

    2005-07-01

    Due to the recent market trends, NTT has begun research into next generation satellite communication systems, such as broadband and scalable mobile communication systems. One service application objective is to provide broadband Internet access for transportation systems, temporal broadband access networks and telemetries to remote areas. While these are niche markets the total amount of capacity should be significant. We set a 1-Gb/s total transmission capacity as our goal. Our key concern is the system cost, which means that the system should be unified system with diversified services and not tailored for each application. As satellites account for a large portion of the total system cost, we set the target satellite size as a small, one-ton class dry mass with a 2-kW class payload power. In addition to the payload power and weight, the mobile satellite's frequency band is extremely limited. Therefore, we need to develop innovative technologies that will reduce the weight and maximize spectrum and power efficiency. Another challenge is the need for the system to handle up to 50 dB and a wide data rate range of other applications. This paper describes the key communication system technologies; the frequency reuse strategy, multiplexing scheme, resource allocation scheme, and QoS management algorithm to ensure excellent spectrum efficiency and support a variety of services and quality requirements in the mobile environment.

  17. Advent of broadband public-switched communications

    Science.gov (United States)

    Casey, John J.

    1992-02-01

    Advances in data communications infrastructure, display technology, and man-machine interfaces have changed business applications and the requirements of public network data transport. These changes have created opportunities for a new generation of public broadband services to more efficiently extend high speed communications capabilities beyond the customer premises. This paper provides a view of the technology and market evolution of these public broadband data communications services, and suggests early customer networked applications that justify the deployment of a public switched broadband network infrastructure.

  18. Reconfigurable Signal Processing and Hardware Architecture for Broadband Wireless Communications

    Directory of Open Access Journals (Sweden)

    Liang Ying-Chang

    2005-01-01

    Full Text Available This paper proposes a broadband wireless transceiver which can be reconfigured to any type of cyclic-prefix (CP -based communication systems, including orthogonal frequency-division multiplexing (OFDM, single-carrier cyclic-prefix (SCCP system, multicarrier (MC code-division multiple access (MC-CDMA, MC direct-sequence CDMA (MC-DS-CDMA, CP-based CDMA (CP-CDMA, and CP-based direct-sequence CDMA (CP-DS-CDMA. A hardware platform is proposed and the reusable common blocks in such a transceiver are identified. The emphasis is on the equalizer design for mobile receivers. It is found that after block despreading operation, MC-DS-CDMA and CP-DS-CDMA have the same equalization blocks as OFDM and SCCP systems, respectively, therefore hardware and software sharing is possible for these systems. An attempt has also been made to map the functional reconfigurable transceiver onto the proposed hardware platform. The different functional entities which will be required to perform the reconfiguration and realize the transceiver are explained.

  19. 47 CFR 27.1305 - Shared wireless broadband network.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Shared wireless broadband network. 27.1305... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

  20. 47 CFR 90.1405 - Shared wireless broadband network.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Shared wireless broadband network. 90.1405... broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private Partnership must be designed to meet requirements associated with a nationwide, public safety broadband network. At...

  1. Analysis of United States' Broadband Policy

    National Research Council Canada - National Science Library

    Uzarski, Joel S

    2007-01-01

    .... With every month that passes, the United States fails to close the gap in the digital divide both inside its borders as well as among the other countries that lead the world in broadband penetration...

  2. Energy efficiency in future wireless broadband networks

    CSIR Research Space (South Africa)

    Masonta, MT

    2012-10-01

    Full Text Available greener economy and environment. In this research, we investigate the concept of green radio communications in wireless networks and discuss approaches for energy efficient solutions in wireless broadband network deployments. These solutions include...

  3. Analyzing Broadband Divide in the Farming Sector

    DEFF Research Database (Denmark)

    Jensen, Michael; Gutierrez Lopez, Jose Manuel; Pedersen, Jens Myrup

    2013-01-01

    , upstream and downstream connection. The main constraint is that farms are naturally located in rural areas where the required access broadband data rates are not available. This paper studies the broadband divide in relation to the Danish agricultural sector. Results show how there is an important......Agriculture industry has been evolving for centuries. Currently, the technological development of Internet oriented farming tools allows to increase the productivity and efficiency of this sector. Many of the already available tools and applications require high bandwidth in both directions...... difference between the broadband availability for farms and the rest of the households/buildings the country. This divide may be slowing down the potential technological development of the farming industry, in order to keep their competitiveness in the market. Therefore, broadband development in rural areas...

  4. Catalyzing Broadband Internet in Africa | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... generates a 1.4% increase in gross domestic product (GDP) in low-income countries. ... Africa offers a good example of the potential benefits and challenges of ... the policy challenges related to providing affordable broadband services; ...

  5. Nanophotonic Design for Broadband Light Management

    Energy Technology Data Exchange (ETDEWEB)

    Kosten, Emily; Callahan, Dennis; Horowitz, Kelsey; Pala, Ragip; Atwater, Harry

    2014-10-13

    We describe nanophotonic design approaches for broadband light management including i) crossed-trapezoidal Si structures ii) Si photonic crystal superlattices, and iii) tapered and inhomogeneous diameter III-V/Si nanowire arrays.

  6. An ultra-broadband multilayered graphene absorber

    KAUST Repository

    Amin, Muhammad; Farhat, Mohamed; Bagci, Hakan

    2013-01-01

    An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon

  7. Wireless Broadband Access and Accounting Schemes

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, we propose two wireless broadband access and accounting schemes. In both schemes, the accounting system adopts RADIUS protocol, but the access system adopts SSH and SSL protocols respectively.

  8. Experimental demonstration of a broadband two-mode multi/demultiplexer based on asymmetric Y-junctions

    Science.gov (United States)

    Li, Haiqin; Wang, Pengjun; Yang, Tianjun; Dai, Tingge; Wang, Gencheng; Li, Shiqi; Chen, Weiwei; Yang, Jianyi

    2018-03-01

    A broadband two-mode multi/demultiplexer using asymmetric Y-junctions is designed and experimentally demonstrated on a silicon-on-insulator platform for on-chip mode-division multiplexing applications. Within a bandwidth from 1513 to 1619 nm, the fabricated device, which consists of a two-mode multiplexer, a multimode straight waveguide, and a two-mode demultiplexer, exhibits demultiplexing crosstalk of less than -9.1 dB. The demultiplexing crosstalk as low as -42.1 dB, lower than -12.8 dB over the C band can be obtained. The measured insertion loss varies from 0.40 to 0.56 dB at a wavelength of 1550 nm. A transmission experiment of 10 Gbit/s electrical signals carried on TE0 and TE1 modes is successfully achieved with open and clear eye diagrams.

  9. Broadband and Unbundling Regulations in OECD Countries

    OpenAIRE

    Wallsten, Scott

    2006-01-01

    Broadband penetration and available speeds vary widely across OECD countries. Policymakers around the world, and especially in countries like the U.S. that lag in the rankings, are searching for policies to narrow those gaps. Relatively little empirical work tests possible reasons for these differences. In this paper I test the impacts of regulations and demographics on broadband development in a panel dataset across countries. In addition to adding to the meager empirical literature on broad...

  10. Broadband electromagnetic environments simulator (EMES)

    International Nuclear Information System (INIS)

    Pollard, N.

    1977-01-01

    A new test facility has been developed by Sandia Laboratories for determining the effects of electromagnetic environments on systems and components. The facility is capable of producing uniform, vertically polarized, continuous wave (CW) and pulsed fields over the frequency range of dc to 10 GHz. This broadband capability addresses the electromagnetic radiation (EMR) threat and is ideally suited to computer controlled sweeping and data acquisition. EMES is also capable of producing uniform transient fields having the wave shape and magnitude characteristic of a nuclear electromagnetic pulse (EMP) and near lightning. The design consists of a truncated, triplate, rectangular coaxial transmission line. The spacing between the flat center conductor and the ground planes is 4 meters. The line is terminated in its characteristic impedance of 50 ohms. At frequencies below the first resonance of the facility it behaves as a typical coaxial system. Above resonance, a wall of electromagnetic absorbing material provides a nonreflecting termination. Thus, EMES essentially combines the elements of a transmission line and an anechoic chamber. It will not radiate electromagnetic energy into the surrounding area because it is a shielded transmission line

  11. Broadband direct RF digitization receivers

    CERN Document Server

    Jamin, Olivier

    2014-01-01

    This book discusses the trade-offs involved in designing direct RF digitization receivers for the radio frequency and digital signal processing domains.  A system-level framework is developed, quantifying the relevant impairments of the signal processing chain, through a comprehensive system-level analysis.  Special focus is given to noise analysis (thermal noise, quantization noise, saturation noise, signal-dependent noise), broadband non-linear distortion analysis, including the impact of the sampling strategy (low-pass, band-pass), analysis of time-interleaved ADC channel mismatches, sampling clock purity and digital channel selection. The system-level framework described is applied to the design of a cable multi-channel RF direct digitization receiver. An optimum RF signal conditioning, and some algorithms (automatic gain control loop, RF front-end amplitude equalization control loop) are used to relax the requirements of a 2.7GHz 11-bit ADC. A two-chip implementation is presented, using BiCMOS and 65nm...

  12. A broadband accelerator control network

    International Nuclear Information System (INIS)

    Skelly, J.; Clifford, T.; Frankel, R.

    1983-01-01

    A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AGS) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz bandwidth Digital Control Channel using CSMA-CA protocol is provided for digital data transmission, with 8 access nodes available over the length of the RELWAY. Each node consists of an rf modem and a microprocessor-based store-and-forward message handler which interfaces the RELWAY to a branch line implemented in GPIB. A gateway to the RELWAY control channel for the (preexisting) AGS Computerized Accelerator Operating System has been constructed using an LSI-11/23 microprocessor as a device in a GPIB branch line. A multilayer communications protocol has been defined for the Digital Control Channel, based on the ISO Open Systems Interconnect layered model, and a RELWAY Device Language defined as the required universal language for device control on this channel

  13. Cooperative epidemics on multiplex networks

    Science.gov (United States)

    Azimi-Tafreshi, N.

    2016-04-01

    The spread of one disease, in some cases, can stimulate the spreading of another infectious disease. Here, we treat analytically a symmetric coinfection model for spreading of two diseases on a two-layer multiplex network. We allow layer overlapping, but we assume that each layer is random and locally loopless. Infection with one of the diseases increases the probability of getting infected with the other. Using the generating function method, we calculate exactly the fraction of individuals infected with both diseases (so-called coinfected clusters) in the stationary state, as well as the epidemic spreading thresholds and the phase diagram of the model. With increasing cooperation, we observe a tricritical point and the type of transition changes from continuous to hybrid. Finally, we compare the coinfected clusters in the case of cooperating diseases with the so-called "viable" clusters in networks with dependencies.

  14. Multi-client quantum key distribution using wavelength division multiplexing

    International Nuclear Information System (INIS)

    Grice, Warren P.; Bennink, Ryan S.; Earl, Dennis Duncan; Evans, Philip G.; Humble, Travis S.; Pooser, Raphael C.; Schaake, Jason; Williams, Brian P.

    2011-01-01

    Quantum Key Distribution (QKD) exploits the rules of quantum mechanics to generate and securely distribute a random sequence of bits to two spatially separated clients. Typically a QKD system can support only a single pair of clients at a time, and so a separate quantum link is required for every pair of users. We overcome this limitation with the design and characterization of a multi-client entangled-photon QKD system with the capacity for up to 100 clients simultaneously. The time-bin entangled QKD system includes a broadband down-conversion source with two unique features that enable the multi-user capability. First, the photons are emitted across a very large portion of the telecom spectrum. Second, and more importantly, the photons are strongly correlated in their energy degree of freedom. Using standard wavelength division multiplexing (WDM) hardware, the photons can be routed to different parties on a quantum communication network, while the strong spectral correlations ensure that each client is linked only to the client receiving the conjugate wavelength. In this way, a single down-conversion source can support dozens of channels simultaneously--and to the extent that the WDM hardware can send different spectral channels to different clients, the system can support multiple client pairings. We will describe the design and characterization of the down-conversion source, as well as the client stations, which must be tunable across the emission spectrum.

  15. Broadband infrared absorption enhancement by electroless-deposited silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Gritti Claudia

    2016-07-01

    Full Text Available Decorating semiconductor surfaces with plasmonic nanoparticles (NPs is considered a viable solution for enhancing the absorptive properties of photovoltaic and photodetecting devices. We propose to deposit silver NPs on top of a semiconductor wafer by a cheap and fast electroless plating technique. Optical characterization confirms that the random array of electroless-deposited NPs improves absorption by up to 20% in a broadband of near-infrared frequencies from the bandgap edge to 2000 nm. Due to the small filling fraction of particles, the reflection in the visible range is practically unchanged, which points to the possible applications of such deposition method for harvesting photons in nanophotonics and photovoltaics. The broadband absorption is a consequence of the resonant behavior of particles with different shapes and sizes, which strongly localize the incident light at the interface of a high-index semiconductor substrate. Our hypothesis is substantiated by examining the plasmonic response of the electroless-deposited NPs using both electron energy loss spectroscopy and numerical calculations.

  16. Broadband in schools: towards a definition and model of broadband for South African schools

    CSIR Research Space (South Africa)

    Ford, Merryl

    2017-05-01

    Full Text Available South Africa is about to provide broadband internet connectivity to all schools in the country via the implementation of the national broadband policy. The challenge is to ensure a balance between the schools’ demand-side usage and supply...

  17. Broad-band beam buncher

    International Nuclear Information System (INIS)

    Goldberg, D.A.; Flood, W.S.; Arthur, A.A.; Voelker, F.

    1986-01-01

    This patent describes a broad-band beam buncher. This beam buncher consists of: a housing adapted to be eacuated, an electron gun in the housing for producing a beam of electrons, buncher means in the housing forming a buncher cavity which has an entrance opening for receiving the electron beam and an exit opening through which the electron beam passes out of the buncher cavity, a drift tube electrode in the buncher cavity and disposed between the entrance opening and the exit opening with first and second gaps between the drift tube electrode and the entrance and exit openings, the drift tube electrode which has a first drift space through which the electron beam passes in traveling between the entrance and exit openings, modulating means for supplying an ultrahigh frequeny modulating signal to the drift tube electrode for producing velocity modulation of the electrons in the electron beam as the electrons pass through the buncher cavity and the drift tube electrode between the entrance opening and the exit opening, drift space means in the housing forming a second drift space for receiving the velocity modulated electron beam from the exit opening, the velocity modulated electron beam being bunched as it passes along the second drift space, the drift space means has a discharge opening through which the electron beam is discharged from the second drift space after being bunched therein, the modulating means containing a signal source for producing an ultrahigh frequency signal, a transmission line connected between the signal source and the drift tube electrode, and terminating means connected to the drift tube electrode for terminating the transmission line in approximately its characteristic impedance to afford a broad response band with minimum 6 variations therein

  18. Immunization of Epidemics in Multiplex Networks

    Science.gov (United States)

    Zhao, Dawei; Wang, Lianhai; Li, Shudong; Wang, Zhen; Wang, Lin; Gao, Bo

    2014-01-01

    Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted) immunization and layer node-based random (targeted) immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER) random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF) networks. PMID:25401755

  19. 16-channel analog store and multiplexer unit

    Energy Technology Data Exchange (ETDEWEB)

    Brossard, M; Kulka, Z [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire

    1979-03-15

    A 16-channel analog store and multiplexer unit is described. The unit enables storing and selection of analog information which is then digitally encoded by single ADC. This solution becomes economically attractive particularly in multidetector pulse height analysis systems.

  20. Packaged mode multiplexer based on silicon photonics

    NARCIS (Netherlands)

    Chen, H.; Koonen, A.M.J.; Snyder, B.; Raz, O.; Boom, van den H.P.A.; Chen, X.

    2012-01-01

    A silicon photonics based mode multiplexer is proposed. Four chirped grating couplers structure can support all 6 channels in a two-mode fiber and realize LP01 and LP11 mode selective exciting. The packaged device is tested.

  1. Immunization of epidemics in multiplex networks.

    Science.gov (United States)

    Zhao, Dawei; Wang, Lianhai; Li, Shudong; Wang, Zhen; Wang, Lin; Gao, Bo

    2014-01-01

    Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted) immunization and layer node-based random (targeted) immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER) random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF) networks.

  2. Immunization of epidemics in multiplex networks.

    Directory of Open Access Journals (Sweden)

    Dawei Zhao

    Full Text Available Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted immunization and layer node-based random (targeted immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF networks.

  3. Broadband quantitative NQR for authentication of vitamins and dietary supplements

    Science.gov (United States)

    Chen, Cheng; Zhang, Fengchao; Bhunia, Swarup; Mandal, Soumyajit

    2017-05-01

    We describe hardware, pulse sequences, and algorithms for nuclear quadrupole resonance (NQR) spectroscopy of medicines and dietary supplements. Medicine and food safety is a pressing problem that has drawn more and more attention. NQR is an ideal technique for authenticating these substances because it is a non-invasive method for chemical identification. We have recently developed a broadband NQR front-end that can excite and detect 14N NQR signals over a wide frequency range; its operating frequency can be rapidly set by software, while sensitivity is comparable to conventional narrowband front-ends over the entire range. This front-end improves the accuracy of authentication by enabling multiple-frequency experiments. We have also developed calibration and signal processing techniques to convert measured NQR signal amplitudes into nuclear spin densities, thus enabling its use as a quantitative technique. Experimental results from several samples are used to illustrate the proposed methods.

  4. Is European Broadband Ready for Smart Grid?

    DEFF Research Database (Denmark)

    Balachandran, Kartheepan; Pedersen, Jens Myrup

    2014-01-01

    In this short paper we compare the communication requirements for three Smart Grid scenarios with the availability of broadband and mobile communication networks in Europe. We show that only in the most demanding case - where data is collected and transmitted every second - a standard GSM/GPRS co....../GPRS connection is not enough. Whereas in the less demanding scenarios it is almost all of the European households that can be covered by a standard broadband technology for use with Smart Grid.......In this short paper we compare the communication requirements for three Smart Grid scenarios with the availability of broadband and mobile communication networks in Europe. We show that only in the most demanding case - where data is collected and transmitted every second - a standard GSM...

  5. Magnetically levitated autoparametric broadband vibration energy harvesting

    International Nuclear Information System (INIS)

    Kurmann, L.; Jia, Y.; Manoli, Y.; Woias, P.

    2016-01-01

    Some of the lingering challenges within the current paradigm of vibration energy harvesting (VEH) involve narrow operational frequency range and the inevitable non-resonant response from broadband noise excitations. Such VEHs are only suitable for limited applications with fixed sinusoidal vibration, and fail to capture a large spectrum of the real world vibration. Various arraying designs, frequency tuning schemes and nonlinear vibratory approaches have only yielded modest enhancements. To fundamentally address this, the paper proposes and explores the potentials in using highly nonlinear magnetic spring force to activate an autoparametric oscillator, in order to realize an inherently broadband resonant system. Analytical and numerical modelling illustrate that high spring nonlinearity derived from magnetic levitation helps to promote the 2:1 internal frequency matching required to activate parametric resonance. At the right internal parameters, the resulting system can intrinsically exhibit semi-resonant response regardless of the bandwidth of the input vibration, including broadband white noise excitation. (paper)

  6. Service Differentiation in Residential Broadband Networks

    DEFF Research Database (Denmark)

    Sigurdsson, Halldór Matthias

    2004-01-01

    As broadband gains widespread adoption with residential users, revenue generating voice- and video-services have not yet taken off. This slow uptake is often attributed to lack of Quality of Service management in residential broadband networks. To resolve this and induce service variety, network...... access providers are implementing service differentiation in their networks where voice and video gets prioritised before data. This paper discusses the role of network access providers in multipurpose packet based networks and the available migration strategies for supporting multimedia services...... in digital subscriber line (DSL) based residential broadband networks. Four possible implementation scenarios and their technical characteristics and effects are described. To conclude, the paper discusses how network access providers can be induced to open their networks for third party service providers....

  7. Policy factors affecting broadband development in Poland

    DEFF Research Database (Denmark)

    Henten, Anders; Windekilde, Iwona Maria

    2014-01-01

    of telecommunications network development in Poland than other countries in the European Union is the reason that the circumstances and also the effects of the implementation of some solutions of the EU regulation model are different in Poland than in the most developed EU countries. The aim of the paper is to examine...... and discuss broadband access development in Poland and the policy factors influencing this development as well as to examine national strategies used to stimulate service and infrastructure competition in Poland. There are, indeed, many other factors affecting broadband development such as the income level....../distribution in the country and the infrastructural point of departure. The paper, therefore, analyses the implications of the policy initiatives in light of these basic conditions and the broader context of factors influencing broadband development. In the paper, different kinds of policy initiatives are examined...

  8. Note: A flexible light emitting diode-based broadband transient-absorption spectrometer

    Science.gov (United States)

    Gottlieb, Sean M.; Corley, Scott C.; Madsen, Dorte; Larsen, Delmar S.

    2012-05-01

    This Note presents a simple and flexible ns-to-ms transient absorption spectrometer based on pulsed light emitting diode (LED) technology that can be incorporated into existing ultrafast transient absorption spectrometers or operate as a stand-alone instrument with fixed-wavelength laser sources. The LED probe pulses from this instrument exhibit excellent stability (˜0.5%) and are capable of producing high signal-to-noise long-time (>100 ns) transient absorption signals either in a broadband multiplexed (spanning 250 nm) or in tunable narrowband (20 ns) operation. The utility of the instrument is demonstrated by measuring the photoinduced ns-to-ms photodynamics of the red/green absorbing fourth GMP phosphodiesterase/adenylyl cyclase/FhlA domain of the NpR6012 locus of the nitrogen-fixing cyanobacterium Nostoc punctiforme.

  9. Participation in the broadband society in Denmark

    DEFF Research Database (Denmark)

    Falch, Morten; Henten, Anders; Skouby, Knud Erik

    2009-01-01

    passed the threshold set by the EU with respect to the relevance of initiating a discussion on the implementation of a universal service obligation on broadband. As documented in the paper, there are groups among primarily the elderly and the unemployed who do not have Internet access. Their own......The purpose of the paper is to provide an empirical overview of broadband developments in Denmark. The overview includes sections on coverage and penetration, connection speeds, retail prices, competition, interconnection prices, and residential access to Internet. The documentation shows...

  10. Silicon Chip-to-Chip Mode-Division Multiplexing

    DEFF Research Database (Denmark)

    Baumann, Jan Markus; Porto da Silva, Edson; Ding, Yunhong

    2018-01-01

    A chip-to-chip mode-division multiplexing connection is demonstrated using a pair of multiplexers/demultiplexers fabricated on the silicon-on-insulator platform. Successful mode multiplexing and demultiplexing is experimentally demonstrated, using the LP01, LP11a and LP11b modes.......A chip-to-chip mode-division multiplexing connection is demonstrated using a pair of multiplexers/demultiplexers fabricated on the silicon-on-insulator platform. Successful mode multiplexing and demultiplexing is experimentally demonstrated, using the LP01, LP11a and LP11b modes....

  11. VT Wireline Broadband Availability by Census Block - 06-2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  12. VT Public Locations of Broadband Data - 06-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  13. VT Public Locations of Broadband Data - 12-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  14. VT Public Locations of Broadband Data - 06-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  15. VT Cable Broadband Availability by Census Block - 06-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  16. VT Total Broadband Availability by Census Block - 12-2012

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  17. VT Cable Broadband Availability by Census Block - 12-2012

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  18. VT Detailed Broadband Availability by Census Block -12-2012

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  19. VT Detailed Broadband Availability by Census Block - 06-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  20. VT Detailed Broadband Availability by Census Block -12-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  1. VT Detailed Broadband Availability by Census Block - 06-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  2. VT Wireline Broadband Availability by Census Block - 12-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  3. VT Wireless Broadband Availability by Census Block - 06-2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  4. VT Total Broadband Availability by Census Block - 06-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  5. VT Wireline Broadband Availability by Census Block - 06-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  6. VT Wireless Broadband Availability by Census Block - 12-2012

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  7. VT Total Broadband Availability by Census Block - 12-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  8. VT Cable Broadband Availability by Census Block - 12-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  9. VT Wireless Broadband Availability by Census Block - 06-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  10. VT Detailed Broadband Availability by Census Block - 12-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  11. VT Total Broadband Availability by Census Block - 06-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  12. VT DSL Broadband Availability by Census Block - 06-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  13. VT Wireline Broadband Availability by Census Block - 12-2012

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  14. VT DSL Broadband Availability by Census Block - 06-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201006 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2010. This...

  15. VT Wireless Broadband Availability by Census Block - 06-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  16. 7 CFR 1738.11 - Availability of broadband service.

    Science.gov (United States)

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE RURAL BROADBAND ACCESS LOANS AND LOAN GUARANTEES Loan Purposes and Basic Policies... given to loans to finance service to eligible rural communities in which broadband service is not...

  17. VT Wireless Broadband Availability by Census Block - 12-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  18. VT Public Locations of Broadband Data - 12-2012

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  19. VT DSL Broadband Availability by Census Block - 06-2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  20. VT Cable Broadband Availability by Census Block - 06-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  1. VT Wireline Broadband Availability by Census Block - 12-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  2. VT Cable Broadband Availability by Census Block - 06-2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  3. VT Wireless Broadband Availability by Census Block - 12-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  4. VT DSL Broadband Availability by Census Block - 12-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  5. VT Wireline Broadband Availability by Census Block - 06-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201106 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2011. This...

  6. VT Public Locations of Broadband Data - 12-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  7. VT Cable Broadband Availability by Census Block - 12-2011

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201112 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2011. This...

  8. VT Total Broadband Availability by Census Block - 12-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  9. VT Detailed Broadband Availability by Census Block - 06-2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  10. VT DSL Broadband Availability by Census Block - 12-2012

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201212 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2012. This...

  11. VT DSL Broadband Availability by Census Block - 12-2010

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201012 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 12/31/2010. This...

  12. VT Public Locations of Broadband Data - 06-2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  13. Semiconductor Quantum Dash Broadband Emitters: Modeling and Experiments

    KAUST Repository

    Khan, Mohammed Zahed Mustafa

    2013-01-01

    multi-disciplinary field applications such as biomedical imaging and sensing, general lighting and internet and mobile phone connectivity. In general, most commercial broadband light sources relies on complex systems for broadband light generation which

  14. VT Total Broadband Availability by Census Block - 06-2013

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The VTBB201306 VT Broadband Availability Dataset represents wireline and wireless 'broadband service' availability in VT as of 6/30/2013. This...

  15. Performance analysis of OFDM modulation on indoor broadband PLC channels

    Science.gov (United States)

    Antonio Cortés, José; Díez, Luis; Cañete, Francisco Javier; Sánchez-Martínez, Juan José; Entrambasaguas, José Tomás

    2011-12-01

    Indoor broadband power-line communications is a suitable technology for home networking applications. In this context, orthogonal frequency-division multiplexing (OFDM) is the most widespread modulation technique. It has recently been adopted by the ITU-T Recommendation G.9960 and is also used by most of the commercial systems, whose number of carriers has gone from about 100 to a few thousands in less than a decade. However, indoor power-line channels are frequency-selective and exhibit periodic time variations. Hence, increasing the number of carriers does not always improves the performance, since it reduces the distortion because of the frequency selectivity, but increases the one caused by the channel time variation. In addition, the long impulse response of power-line channels obliges to use an insufficient cyclic prefix. Increasing its value reduces the distortion, but also the symbol rate. Therefore, there are optimum values for both modulation parameters. This article evaluates the performance of an OFDM system as a function of the number of carriers and the cyclic prefix length, determining their most appropriate values for the indoor power-line scenario. This task must be accomplished by means of time-consuming simulations employing a linear time-varying filtering, since no consensus on a tractable statistical channel model has been reached yet. However, this study presents a simpler procedure in which the distortion because of the frequency selectivity is computed using a time-invariant channel response, and an analytical expression is derived for the one caused by the channel time variation.

  16. Super-multiplex vibrational imaging

    Science.gov (United States)

    Wei, Lu; Chen, Zhixing; Shi, Lixue; Long, Rong; Anzalone, Andrew V.; Zhang, Luyuan; Hu, Fanghao; Yuste, Rafael; Cornish, Virginia W.; Min, Wei

    2017-04-01

    potential of this 24-colour (super-multiplex) optical imaging approach for elucidating intricate interactions in complex biological systems.

  17. Turbulence mitigation scheme based on multiple-user detection in an orbital-angular-momentum multiplexed system

    Science.gov (United States)

    Zou, Li; Wang, Le; Zhao, Sheng-Mei; Chen, Han-Wu

    2016-11-01

    Atmospheric turbulence (AT) induced crosstalk can significantly impair the performance of a free-space optical (FSO) communication link using orbital angular momentum (OAM) multiplexing. In this paper, we propose a multiple-user detection (MUD) turbulence mitigation scheme in an OAM-multiplexed FSO communication link. First, we present a MUD equivalent communication model for an OAM-multiplexed FSO communication link under AT. In the equivalent model, each input bit stream represents one user’s information. The deformed OAM spatial modes caused by AT, instead of the pure OAM spatial modes, are used as information carriers, and the overlapping between the deformed OAM spatial modes are computed as the correlation coefficients between the users. Then, we present a turbulence mitigation scheme based on MUD idea to enhance AT tolerance of the OAM-multiplexed FSO communication link. In the proposed scheme, the crosstalk caused by AT is used as a useful component to deduce users’ information. The numerical results show that the performance of the OAM-multiplexed communication link has greatly improved by the proposed scheme. When the turbulence strength is 1 × 10-15 m-2/3, the transmission distance is 1000 m and the channel signal-to-noise ratio (SNR) is 26 dB, the bit-error-rate (BER) performance of four spatial multiplexed OAM modes lm = +1,+2,+3,+4 are all close to 10-5, and there is a 2-3 fold increase in the BER performance in comparison with those results without the proposed scheme. In addition, the proposed scheme is more effective for an OAM-multiplexed FSO communication link with a larger OAM mode topological charge interval. The proposed scheme is a promising direction for compensating the interference caused by AT in the OAM-multiplexed FSO communication link. Project supported by the National Natural Science Foundation of China (Grant Nos. 61271238 and 61475075), the Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network

  18. Broadband luminescent materials in waveguide geometry

    NARCIS (Netherlands)

    Pollnau, Markus

    In recent years, broadband fiber interferometers have become very popular as basic instruments used in optical low-coherence reflectometry for diagnostics of fiber and integrated optics devices or in optical coherence tomography (OCT) for imaging applications in the biomedical field. The

  19. BROADBAND TRAVELLING WAVE SEMICONDUCTOR OPTICAL AMPLIFIER

    DEFF Research Database (Denmark)

    2010-01-01

    Broadband travelling wave semiconductor optical amplifier (100, 200, 300, 400, 800) for amplification of light, wherein the amplifier (100, 200, 300, 400, 800) comprises a waveguide region (101, 201, 301, 401, 801) for providing confinement of the light in transverse directions and adapted...

  20. WIRELESS FIDELITY (Wi-Fi) BROADBAND NETWORK ...

    African Journals Online (AJOL)

    ES Obe

    broadband speed and coverage, while Wi-Fi can be integrated with WiMAX networks to provide Internet ... Microwave Access (WiMAX), IEEE 802.11 standards. 1.0 INTRODUCTION .... These 2G systems provided circuit- switched data ...

  1. 77 FR 36903 - Accelerating Broadband Infrastructure Deployment

    Science.gov (United States)

    2012-06-20

    ... the Nation's global competitiveness in the 21st century, driving job creation, promoting innovation, and expanding markets for American businesses. Broadband access also affords public safety agencies... infrastructure has been deployed in a vast majority of communities across the country, today too many areas still...

  2. 75 FR 27984 - Broadband Technology Opportunities Program

    Science.gov (United States)

    2010-05-19

    ... applications, including: streaming video (surveillance, remote monitoring); digital imaging; automatic vehicle location; computer-aided dispatching; electronic mail; mapping and GPS; remote database access; report... entities to deploy public safety broadband systems using the 700 MHz spectrum licensed to the PSST.\\13\\ The...

  3. 75 FR 29516 - Broadband Researchers' Data Workshop

    Science.gov (United States)

    2010-05-26

    ... foundation for long-term economic stability and prosperity.\\1\\ The increased availability and use of... telecommunications policies pertaining to the Nation's economic and technological advancement. In order to achieve... stakeholders to develop and implement economic and regulatory policies that foster broadband deployment and...

  4. Electromagnetically induced transparency with broadband laser pulses

    International Nuclear Information System (INIS)

    Yavuz, D. D.

    2007-01-01

    We suggest a scheme to slow and stop broadband laser pulses inside an atomic medium using electromagnetically induced transparency. Extending the suggestion of Harris et al. [Phys. Rev. Lett. 70, 552 (1993)], the key idea is to use matched Fourier components for the probe and coupling laser beams

  5. Design of broadband dispersion flattened fiber for DWDM system: Performance analysis using various modulation formats

    Science.gov (United States)

    Goel, Aditya; Pandey, Gaurav

    2018-05-01

    In this paper, unique design of an optimal broadband optical dispersion flattened fiber (DFF) is proposed, which is capable of supporting the data rate of the order of Tb/s. The analysis of the single mode fiber for the design of the proposed DFF has been carried out by employing the quadratic Finite Element Method (FEM) with generalized refractive index (R. I.) profile. The minimization of the dispersion with respect to various profile parameters within the specified wavelength band is the essential optimization criteria. Computations show that a DFF can be designed where the overall dispersion can be restricted within ± 1 ps/km-nm over the entire spectral span ranging from 1290 to 1540 nm (250 nm) exhibiting a very small maximum value of dispersion slope (± 0.02 ps / (nm2-km)) in particular. The detailed performance analysis of the proposed DFF with different modulation techniques has been carried out in order to critically evaluate the performance of the DFF with respect to various significant parameters. The results suggest an excellent design of broadband optical waveguide capable of supporting high-speed data rate (40 Tb/s) through the single DFF, ideally suitable for the long haul dense wavelength division multiplexing (DWDM) optical transmission systems.

  6. Social contagions on correlated multiplex networks

    Science.gov (United States)

    Wang, Wei; Cai, Meng; Zheng, Muhua

    2018-06-01

    The existence of interlayer degree correlations has been disclosed by abundant multiplex network analysis. However, how they impose on the dynamics of social contagions are remain largely unknown. In this paper, we propose a non-Markovian social contagion model in multiplex networks with inter-layer degree correlations to delineate the behavior spreading, and develop an edge-based compartmental (EBC) theory to describe the model. We find that multiplex networks promote the final behavior adoption size. Remarkably, it can be observed that the growth pattern of the final behavior adoption size, versus the behavioral information transmission probability, changes from discontinuous to continuous once decreasing the behavior adoption threshold in one layer. We finally unravel that the inter-layer degree correlations play a role on the final behavior adoption size but have no effects on the growth pattern, which is coincidence with our prediction by using the suggested theory.

  7. Optimization of a coherent synchrotron radiation source in the Tera-hertz range for high-resolution spectroscopy of molecules of astrophysical interest

    International Nuclear Information System (INIS)

    Barros, J.

    2012-01-01

    Fourier Transform spectroscopy is the most used multiplex tool for high-resolution measurements in the infrared range. Its extension to the Tera-hertz domain is of great interest for spectroscopic studies of interstellar molecules. This application is however hampered by the lack of dedicated, broadband sources with a sufficient intensity and stability. In this work, Coherent Synchrotron Radiation (CSR) was used as a source for molecular spectroscopy at high resolution on the AILES infrared and Tera-hertz beamline of SOLEIL synchrotron. The beamline being optimized for far-infrared, we could characterize the properties of CSR and compare them to the incoherent synchrotron radiation. A double detection system allowed to correct the effect of the source-related instabilities, hence to significantly increase the signal-to-noise ratio. Pure rotational spectra were measured using these developments. The case of the propynal molecule, for which a refined set of rotational and centrifugal distortion constants was calculated, proves the complementarity between CSR and the classical microwave or infrared sources. (author)

  8. Multiplexed image storage by electromagnetically induced transparency in a solid

    Science.gov (United States)

    Heinze, G.; Rentzsch, N.; Halfmann, T.

    2012-11-01

    We report on frequency- and angle-multiplexed image storage by electromagnetically induced transparency (EIT) in a Pr3+:Y2SiO5 crystal. Frequency multiplexing by EIT relies on simultaneous storage of light pulses in atomic coherences, driven in different frequency ensembles of the inhomogeneously broadened solid medium. Angular multiplexing by EIT relies on phase matching of the driving laser beams, which permits simultaneous storage of light pulses propagating under different angles into the crystal. We apply the multiplexing techniques to increase the storage capacity of the EIT-driven optical memory, in particular to implement multiplexed storage of larger two-dimensional amounts of data (images). We demonstrate selective storage and readout of images by frequency-multiplexed EIT and angular-multiplexed EIT, as well as the potential to combine both multiplexing approaches towards further enhanced storage capacities.

  9. Performance modeling, loss networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi

    2009-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of understanding the phenomenon of statistical multiplexing. The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the important ideas of Palm distributions associated with traffic models and their role in performance measures. Also presented are recent ideas of large buffer, and many sources asymptotics that play an important role in understanding statistical multiplexing. I

  10. Digital holograms for laser mode multiplexing

    CSIR Research Space (South Africa)

    Mhlanga, T

    2014-10-02

    Full Text Available multiplexing Thandeka Mhlangaa, b, Abderrahmen Trichilic, Angela Dudleya, Darryl Naidooa, b, Mourad Zghalc and Andrew Forbesa, b aCSIR National Laser Centre, P.O. Box 395, Pretoria 0001, South Africa bSchool of Physics, University of KwaZulu-Natal, Private Bag... problems. In this context, we demonstrate a method of multiplexing laser modes using spatial light modulators (SLMs). In our proposed technique, we use Laguerre Gaussian (LG) modes, which form a complete basis set; hence multi-mode masks can be created...

  11. Simple Multiplexing Hand-Held Control Unit

    Science.gov (United States)

    Hannaford, Blake

    1989-01-01

    Multiplexer consists of series of resistors, each shunted by single-pole, single-throw switch. User operates switches by pressing buttons or squeezing triggers. Prototype includes three switches operated successfully in over 200 hours of system operations. Number of switches accommodated determined by signal-to-noise ratio of current source, noise induced in control unit and cable, and number of bits in output of analog-to-digital converter. Because many computer-contolled robots have extra analog-to-digital channels, such multiplexer added at little extra cost.

  12. Cooperative spreading processes in multiplex networks.

    Science.gov (United States)

    Wei, Xiang; Chen, Shihua; Wu, Xiaoqun; Ning, Di; Lu, Jun-An

    2016-06-01

    This study is concerned with the dynamic behaviors of epidemic spreading in multiplex networks. A model composed of two interacting complex networks is proposed to describe cooperative spreading processes, wherein the virus spreading in one layer can penetrate into the other to promote the spreading process. The global epidemic threshold of the model is smaller than the epidemic thresholds of the corresponding isolated networks. Thus, global epidemic onset arises in the interacting networks even though an epidemic onset does not arise in each isolated network. Simulations verify the analysis results and indicate that cooperative spreading processes in multiplex networks enhance the final infection fraction.

  13. Advanced combinational microfluidic multiplexer for fuel cell reactors

    International Nuclear Information System (INIS)

    Lee, D W; Kim, Y; Cho, Y-H; Doh, I

    2013-01-01

    An advanced combinational microfluidic multiplexer capable to address multiple fluidic channels for fuel cell reactors is proposed. Using only 4 control lines and two different levels of control pressures, the proposed multiplexer addresses up to 19 fluidic channels, at least two times larger than the previous microfluidic multiplexers. The present multiplexer providing high control efficiency and simple structure for channel addressing would be used in the application areas of the integrated microfluidic systems such as fuel cell reactors and dynamic pressure generators

  14. Management of broadband technology and innovation policy, deployment, and use

    CERN Document Server

    Choudrie, Jyoti

    2013-01-01

    When one considers broadband, the Internet immediately springs to mind. However, broadband is impacting society in many ways. For instance, broadband networks can be used to deliver healthcare or community related services to individuals who don't have computers, have distance as an issue to contend with, or don't use the internet. Broadband can support better management of scarce energy resources with the advent of smart grids, enables improved teleworking capacity and opens up a world of new entertainment possibilities. Yet scholarly examinations of broadband technology have so far examin

  15. Electron spectroscopy

    International Nuclear Information System (INIS)

    Hegde, M.S.

    1979-01-01

    An introduction to the various techniques in electron spectroscopy is presented. These techniques include: (1) UV Photoelectron spectroscopy, (2) X-ray Photoelectron spectroscopy, (3) Auger electron spectroscopy, (4) Electron energy loss spectroscopy, (5) Penning ionization spectroscopy and (6) Ion neutralization spectroscopy. The radiations used in each technique, the basis of the technique and the special information obtained in structure determination in atoms and molecules by each technique are summarised. (A.K.)

  16. Local government broadband policies for areas with limited Internet access

    Directory of Open Access Journals (Sweden)

    Yoshio Arai

    2014-03-01

    Full Text Available Despite their wide diffusion in developed countries, broadband services are still limited in areas where providing them is not profitable for private telecom carriers. To address this, many local governments in Japan have implemented broadband deployment projects subsidized by the national government. In this paper, we discuss local government broadband policies based on survey data collected from municipalities throughout the country. With the support of national promotion policies, broadband services were rapidly introduced to most local municipalities in Japan during the 2000s. Local government deployment policies helped to reduce the number of areas with no broadband access. A business model based on the Indefeasible Right of Use (IRU contract between a private telecom carrier and a local government has been developed in recent years. Even local governments without the technical capacity to operate a broadband business can introduce broadband services into their territory using the IRU business model.

  17. Time-multiplexed amplification in a hybrid-less and coil-less Josephson parametric converter

    Science.gov (United States)

    Abdo, Baleegh; Chavez-Garcia, Jose M.; Brink, Markus; Keefe, George; Chow, Jerry M.

    2017-02-01

    Josephson parametric converters (JPCs) are superconducting devices capable of performing nondegenerate, three-wave mixing in the microwave domain without losses. One drawback limiting their use in scalable quantum architectures is the large footprint of the auxiliary circuit needed for their operation, in particular, the use of off-chip, bulky, broadband hybrids and magnetic coils. Here, we realize a JPC that eliminates the need for these bulky components. The pump drive and flux bias are applied in the Hybrid-Less, Coil-Less (HLCL) device through an on-chip, lossless, three-port power divider and an on-chip flux line, respectively. We show that the HLCL design considerably simplifies the circuit and reduces the footprint of the device while maintaining a comparable performance to state-of-the-art JPCs. Furthermore, we exploit the tunable bandwidth property of the JPC and the added capability of applying alternating currents to the flux line in order to switch the resonance frequencies of the device, hence demonstrating time-multiplexed amplification of microwave tones that are separated by more than the dynamical bandwidth of the amplifier. Such a measurement technique can potentially serve to perform a time-multiplexed, high-fidelity readout of superconducting qubits.

  18. Moving through a multiplex holographic scene

    Science.gov (United States)

    Mrongovius, Martina

    2013-02-01

    This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

  19. Prototype data terminal-multiplexer/demultiplexer

    Science.gov (United States)

    Leck, D. E.; Goodwin, J. E.

    1972-01-01

    The design and operation of a quad redundant data terminal and a multiplexer/demultiplexer (MDU) is described. The most unique feature is the design of the quad redundant data terminal. This is one of the few designs where the unit is fail/op, fail/op, fail/safe. Laboratory tests confirm that the unit will operate satisfactorily with the failure of three out of four channels. Although the design utilizes state-of-the-art technology, the waveform error checks, the voting techniques, and the parity bit checks are believed to be used in unique configurations. Correct word selection routines are also novel. The MDU design, while not redundant, utilizes, the latest state-of-the-art advantages of light coupler and interested amplifiers. Much of the technology employed was an evolution of prior NASA contracts related to the Addressable Time Division Data System. A good example of the earlier technology development was the development of a low level analog multiplexer, a high level analog multiplexer, and a digital multiplexer. A list of all drawings is included for reference and all schematic, block and timing diagrams are incorporated.

  20. Silicon Photonic Integrated Circuit Mode Multiplexer

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ou, Haiyan; Xu, Jing

    2013-01-01

    We propose and demonstrate a novel silicon photonic integrated circuit enabling multiplexing of orthogonal modes in a few-mode fiber (FMF). By selectively launching light to four vertical grating couplers, all six orthogonal spatial and polarization modes supported by the FMF are successfully...

  1. Coherence-Multiplexed Optical RF Feeder Networks

    NARCIS (Netherlands)

    Meijerink, Arjan; Taniman, R.O.; van Etten, Wim

    2007-01-01

    An optical RF feeding system for wireless access is proposed, in which the radio access points are distinguished by means of coherence multiplexing (CM). CM is a rather unknown and potentially inexpensive optical code division multiple access technique, which is particularly suitable for relatively

  2. Multiple routes transmitted epidemics on multiplex networks

    International Nuclear Information System (INIS)

    Zhao, Dawei; Li, Lixiang; Peng, Haipeng; Luo, Qun; Yang, Yixian

    2014-01-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  3. Beyond Multiplexing Gain in Large MIMO Systems

    DEFF Research Database (Denmark)

    Cakmak, Burak; Müller, Ralf R.; Fleury, Bernard Henri

    growth (multiplexing gain). Even when the channel entries are i.i.d. the deviation from the linear growth is significant. We also find an additive property of the deviation for a concatenated MIMO system. Finally, we quantify the deviation of the large SNR capacity from the exact capacity and find...

  4. Multiple routes transmitted epidemics on multiplex networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dawei [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Shandong Provincial Key Laboratory of Computer Network, Shandong Computer Science Center, Jinan 250014 (China); Li, Lixiang [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng, E-mail: penghaipeng@bupt.edu.cn [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Luo, Qun; Yang, Yixian [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2014-02-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  5. Microwave multiplex readout for superconducting sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ferri, E., E-mail: elena.ferri@mib.infn.it [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Becker, D.; Bennett, D. [NIST, Boulder, CO (United States); Faverzani, M. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Fowler, J.; Gard, J. [NIST, Boulder, CO (United States); Giachero, A. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Hays-Wehle, J.; Hilton, G. [NIST, Boulder, CO (United States); Maino, M. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Mates, J. [NIST, Boulder, CO (United States); Puiu, A.; Nucciotti, A. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Reintsema, C.; Schmidt, D.; Swetz, D.; Ullom, J.; Vale, L. [NIST, Boulder, CO (United States)

    2016-07-11

    The absolute neutrino mass scale is still an outstanding challenge in both particle physics and cosmology. The calorimetric measurement of the energy released in a nuclear beta decay is a powerful tool to determine the effective electron-neutrino mass. In the last years, the progress on low temperature detector technologies has allowed to design large scale experiments aiming at pushing down the sensitivity on the neutrino mass below 1 eV. Even with outstanding performances in both energy (~ eV on keV) and time resolution (~ 1 μs) on the single channel, a large number of detectors working in parallel is required to reach a sub-eV sensitivity. Microwave frequency domain readout is the best available technique to readout large array of low temperature detectors, such as Transition Edge Sensors (TESs) or Microwave Kinetic Inductance Detectors (MKIDs). In this way a multiplex factor of the order of thousands can be reached, limited only by the bandwidth of the available commercial fast digitizers. This microwave multiplexing system will be used to readout the HOLMES detectors, an array of 1000 microcalorimeters based on TES sensors in which the {sup 163}Ho will be implanted. HOLMES is a new experiment for measuring the electron neutrino mass by means of the electron capture (EC) decay of {sup 163}Ho. We present here the microwave frequency multiplex which will be used in the HOLMES experiment and the microwave frequency multiplex used to readout the MKID detectors developed in Milan as well.

  6. Determinants of public cooperation in multiplex networks

    Science.gov (United States)

    Battiston, Federico; Perc, Matjaž; Latora, Vito

    2017-07-01

    Synergies between evolutionary game theory and statistical physics have significantly improved our understanding of public cooperation in structured populations. Multiplex networks, in particular, provide the theoretical framework within network science that allows us to mathematically describe the rich structure of interactions characterizing human societies. While research has shown that multiplex networks may enhance the resilience of cooperation, the interplay between the overlap in the structure of the layers and the control parameters of the corresponding games has not yet been investigated. With this aim, we consider here the public goods game on a multiplex network, and we unveil the role of the number of layers and the overlap of links, as well as the impact of different synergy factors in different layers, on the onset of cooperation. We show that enhanced public cooperation emerges only when a significant edge overlap is combined with at least one layer being able to sustain some cooperation by means of a sufficiently high synergy factor. In the absence of either of these conditions, the evolution of cooperation in multiplex networks is determined by the bounds of traditional network reciprocity with no enhanced resilience. These results caution against overly optimistic predictions that the presence of multiple social domains may in itself promote cooperation, and they help us better understand the complexity behind prosocial behavior in layered social systems.

  7. Broadband standard dipole antenna for antenna calibration

    Science.gov (United States)

    Koike, Kunimasa; Sugiura, Akira; Morikawa, Takao

    1995-06-01

    Antenna calibration of EMI antennas is mostly performed by the standard antenna method at an open-field test site using a specially designed dipole antenna as a reference. In order to develop broadband standard antennas, the antenna factors of shortened dipples are theoretically investigated. First, the effects of the dipole length are analyzed using the induced emf method. Then, baluns and loads are examined to determine their influence on the antenna factors. It is found that transformer-type baluns are very effective for improving the height dependence of the antenna factors. Resistive loads are also useful for flattening the frequency dependence. Based on these studies, a specification is developed for a broadband standard antenna operating in the 30 to 150 MHz frequency range.

  8. An ultra-broadband multilayered graphene absorber

    KAUST Repository

    Amin, Muhammad

    2013-01-01

    An ultra-broadband multilayered graphene absorber operating at terahertz (THz) frequencies is proposed. The absorber design makes use of three mechanisms: (i) The graphene layers are asymmetrically patterned to support higher order surface plasmon modes that destructively interfere with the dipolar mode and generate electromagnetically induced absorption. (ii) The patterned graphene layers biased at different gate voltages backedup with dielectric substrates are stacked on top of each other. The resulting absorber is polarization dependent but has an ultra-broadband of operation. (iii) Graphene\\'s damping factor is increased by lowering its electron mobility to 1000cm 2=Vs. Indeed, numerical experiments demonstrate that with only three layers, bandwidth of 90% absorption can be extended upto 7THz, which is drastically larger than only few THz of bandwidth that can be achieved with existing metallic/graphene absorbers. © 2013 Optical Society of America.

  9. Broadband phase-preserved optical elevator

    OpenAIRE

    Luo, Yuan; Han, Tiancheng; Zhang, Baile; Qiu, Cheng-Wei; Barbastathis, George

    2011-01-01

    Phase-preserved optical elevator is an optical device to lift up an entire plane virtually without distortion in light path or phase. Using transformation optics, we have predicted and observed the realization of such a broadband phase-preserved optical elevator, made of a natural homogeneous birefringent crystal without resorting to absorptive and narrowband metamaterials involving time-consuming nano-fabrication. In our demonstration, the optical elevator is designed to lift a sheet upwards...

  10. Switched Broadband Services For The Home

    Science.gov (United States)

    Sawyer, Don M.

    1990-01-01

    In considering the deployment of fiber optics to the residence, two critical questions arise: what are the leading services that could be offered to justify the required investment; and what is the nature of the business that would offer these services to the consumer ? This talk will address these two questions together with the related issue of how the "financial engine" of today's television distribution infrastructure - TV advertising - would be affected by an open access system based on fiber optics coupled with broadband switching. On the business side, the talk concludes that the potential for open ended capacity expansion, fair competition between service providers, and new interactive services inherent in an open access, switched broadband system are the critical items in differentiating it from existing video and TV distribution systems. On the question of broadband services, the talk will highlight several new opportunities together with some findings from recent market research conducted by BNR. The talk will show that there are variations on existing services plus many new services that could be offered and which have real consumer appeal. The postulated open access system discussed here is visualized as having ultimately 1,000 to 2,000 video channels available to the consumer. Although this may appear to hopelessly fragment the TV audience and destroy the current TV advertising infrastructure, the technology of open access, switched broadband will present many new advertising techniques, which have the potential to be far more effective than those available today. Some of these techniques will be described in this talk.

  11. Broadband S-band class E HPA

    NARCIS (Netherlands)

    Wanum, M.; van Dijk, R.; de Hek, A.P.; van Vliet, Frank Edward

    2009-01-01

    A broadband class E High Power Amplifier (HPA) is presented. This HPA is designed to operate at S-band (2.75 to 3.75 GHz). A power added efficiency of 50% is obtained for the two stage amplifier with an output power of 35.5 dBm on a chip area of 5.25 times 2.8 mm2.

  12. Diagonalizing sensing matrix of broadband RSE

    International Nuclear Information System (INIS)

    Sato, Shuichi; Kokeyama, Keiko; Kawazoe, Fumiko; Somiya, Kentaro; Kawamura, Seiji

    2006-01-01

    For a broadband-operated RSE interferometer, a simple and smart length sensing and control scheme was newly proposed. The sensing matrix could be diagonal, owing to a simple allocation of two RF modulations and to a macroscopic displacement of cavity mirrors, which cause a detuning of the RF modulation sidebands. In this article, the idea of the sensing scheme and an optimization of the relevant parameters will be described

  13. Gamma Spectroscopy

    NARCIS (Netherlands)

    Niemantsverdriet, J.W.; Butz, Tilman; Ertl, G.; Knözinger, H.; Schüth, F.

    2008-01-01

    No abstract. The sections in this article are 1 Introduction 2 Mössbauer Spectroscopy 3 Time-Differential Perturbed Angular Correlations (TDPAC) 4 Conclusions and Outlook Keywords: Mössbauer spectroscopy; gamma spectroscopy; perturbed angular correlation; TDPAC

  14. Broadband electromagnetic analysis of compacted kaolin

    International Nuclear Information System (INIS)

    Bore, Thierry; Scheuermann, Alexander; Wagner, Norman; Cai, Caifang

    2017-01-01

    The mechanical compaction of soil influences not only the mechanical strength and compressibility but also the hydraulic behavior in terms of hydraulic conductivity and soil suction. At the same time, electric and dielectric parameters are increasingly used to characterize soil and to relate them with mechanic and hydraulic parameters. In the presented study electromagnetic soil properties and suction were measured under defined conditions of standardized compaction tests. The impact of external mechanical stress conditions of nearly pure kaolinite was analyzed on soil suction and broadband electromagnetic soil properties. An experimental procedure was developed and validated to simultaneously determine mechanical, hydraulic and broadband (1 MHz–3 GHz) electromagnetic properties of the porous material. The frequency dependent electromagnetic properties were modeled with a classical mixture equation (advanced Lichtenecker and Rother model, ALRM) and a hydraulic-mechanical-electromagnetic coupling approach was introduced considering water saturation, soil structure (bulk density, porosity), soil suction (pore size distribution, water sorption) as well as electrical conductivity of the aqueous pore solution. Moreover, the relaxation behavior was analyzed with a generalized fractional relaxation model concerning a high-frequency water process and two interface processes extended with an apparent direct current conductivity contribution. The different modeling approaches provide a satisfactory agreement with experimental data for the real part. These results show the potential of broadband electromagnetic approaches for quantitative estimation of the hydraulic state of the soil during densification. (paper)

  15. Design and fabrication of broadband rugate filter

    International Nuclear Information System (INIS)

    Zhang Jun-Chao; Fang Ming; Shao Yu-Chuan; Jin Yun-Xia; He Hong-Bo

    2012-01-01

    The design and the deposition of a rugate filter for broadband applications are discussed. The bandwidth is extended by increasing the rugate period continuously with depth. The width and the smoothness of the reflection band with the distribution of the periods are investigated. The improvement of the steepness of the stopband edges and the suppression of the side lobes in the transmission zone are realized by adding two apodized rugate structures with fixed periods at the external broadband rugate filter interfaces. The rapidly alternating deposition technology is used to fabricate a rugate filter sample. The measured transmission spectrum with a reflection bandwidth of approximately 505 nm is close to that of the designed broadband rugate filter except a transmittance peak in the stopband. Based on the analysis of the cross-sectional scanning electron microscopic image of the sample, it is found that the transmission peak is most likely to be caused by the instability of the deposition rate. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  16. Design of broadband single polarized antenna

    Science.gov (United States)

    Shin, Phoo Kho; Aziz, Mohamad Zoinol Abidin Abd.; Ahmad, Badrul Hisham; Ramli, Mohamad Hafize Bin; Fauzi, Noor Azamiah Md; Malek, Mohd Fareq Abd

    2015-05-01

    In practical wireless communication application, bandwidth enhancement becomes one of the major design considerations. At the same time, circular polarized (CP) antenna received much attention for the applications of modern wireless communication system when compared to linear polarized (LP) antenna. This is because CP antenna can reduce the multipath effect. Hence, broadband antenna with operating frequency at 2.4GHz for WLAN application is proposed. The proposed antenna is done by using L-probe amendment with rectangular patch. The rectangular patch and copper ground plane is separated with 10mm air gap. This approach is used to enhance the bandwidth and the gain of the proposed antenna. The bandwidth of the designed antenna is more than 200MHz which meet broadband application. The return loss for the antenna is below -10dB to achieved 90% matching efficiency. The position of L-probe feed is altered in order to obtained different polarizations. The broadband antenna had been designed and simulated by using Computer Simulation Technology (CST) software. In this paper, the comparison for single polarized antenna with the design of non-inverted patch and inverted patch is discussed. The characteristics of the S-parameter, axial ratio, gain, surface current for each designed antenna are analyzed.

  17. A novel IPTV program multiplex access system to EPON

    Science.gov (United States)

    Xu, Xian; Liu, Deming; He, Wei; Lu, Xi

    2007-11-01

    With the rapid development of high speed networks, such as Ethernet Passive Optical Network (EPON), traffic patterns in access networks have evolved from traditional text-oriented service to the mixed text-, voice- and video- based services, leading to so called "Triple Play". For supporting IPTV service in EPON access network infrastructure, in this article we propose a novel IPTV program multiplex access system to EPON, which enables multiple IPTV program source servers to seamlessly access to IPTV service access port of optical line terminal (OLT) in EPON. There are two multiplex schemes, namely static multiplex scheme and dynamic multiplex scheme, in implementing the program multiplexing. Static multiplex scheme is to multiplex all the IPTV programs and forward them to the OLT, regardless of the need of end-users. While dynamic multiplex scheme can dynamically multiplex and forward IPTV programs according to what the end-users actually demand and those watched by no end-user would not be multiplexed. By comparing these two schemes, a reduced traffic of EPON can be achieved by using dynamic multiplex scheme, especially when most end-users are watching the same few IPTV programs. Both schemes are implemented in our system, with their hardware and software designs described.

  18. Single-component supported lipid bilayers probed using broadband nonlinear optics.

    Science.gov (United States)

    Olenick, Laura L; Chase, Hilary M; Fu, Li; Zhang, Yun; McGeachy, Alicia C; Dogangun, Merve; Walter, Stephanie R; Wang, Hong-Fei; Geiger, Franz M

    2018-01-31

    Broadband SFG spectroscopy is shown to offer considerable advantages over scanning systems in terms of signal-to-noise ratios when probing well-formed single-component supported lipid bilayers formed from zwitterionic lipids with PC headgroups. The SFG spectra obtained from bilayers formed from DOPC, POPC, DLPC, DMPC, DPPC and DSPC show a common peak at ∼2980 cm -1 , which is subject to interference between the C-H and the O-H stretches from the aqueous phase, while membranes having transition temperatures above the laboratory temperature produce SFG spectra with at least two additional peaks, one at ∼2920 cm -1 and another at ∼2880 cm -1 . The results validate spectroscopic and structural data from SFG experiments utilizing asymmetric bilayers in which one leaflet differs from the other in the extent of deuteration. Differences in H 2 O-D 2 O exchange experiments reveal that the lineshapes of the broadband SFG spectra are significantly influenced by interference from OH oscillators in the aqueous phase, even when those oscillators are not probed by the incident infrared light in our broadband setup. In the absence of spectral interference from the OH stretches of the solvent, the alkyl chain terminal methyl group of the bilayer is found to be tilted at an angle of 15° to 35° from the surface normal.

  19. Enhanced Solar-to-Hydrogen Generation with Broadband Epsilon-Near-Zero Nanostructured Photocatalysts

    KAUST Repository

    Tian, Yi

    2017-05-08

    The direct conversion of solar energy into fuels or feedstock is an attractive approach to address increasing demand of renewable energy sources. Photocatalytic systems relying on the direct photoexcitation of metals have been explored to this end, a strategy that exploits the decay of plasmonic resonances into hot carriers. An efficient hot carrier generation and collection requires, ideally, their generation to be enclosed within few tens of nanometers at the metal interface, but it is challenging to achieve this across the broadband solar spectrum. Here the authors demonstrate a new photocatalyst for hydrogen evolution based on metal epsilon-near-zero metamaterials. The authors have designed these to achieve broadband strong light confinement at the metal interface across the entire solar spectrum. Using electron energy loss spectroscopy, the authors prove that hot carriers are generated in a broadband fashion within 10 nm in this system. The resulting photocatalyst achieves a hydrogen production rate of 9.5 µmol h-1  cm-2 that exceeds, by a factor of 3.2, that of the best previously reported plasmonic-based photocatalysts for the dissociation of H2 with 50 h stable operation.

  20. Spin and wavelength multiplexed nonlinear metasurface holography

    Science.gov (United States)

    Ye, Weimin; Zeuner, Franziska; Li, Xin; Reineke, Bernhard; He, Shan; Qiu, Cheng-Wei; Liu, Juan; Wang, Yongtian; Zhang, Shuang; Zentgraf, Thomas

    2016-06-01

    Metasurfaces, as the ultrathin version of metamaterials, have caught growing attention due to their superior capability in controlling the phase, amplitude and polarization states of light. Among various types of metasurfaces, geometric metasurface that encodes a geometric or Pancharatnam-Berry phase into the orientation angle of the constituent meta-atoms has shown great potential in controlling light in both linear and nonlinear optical regimes. The robust and dispersionless nature of the geometric phase simplifies the wave manipulation tremendously. Benefitting from the continuous phase control, metasurface holography has exhibited advantages over conventional depth controlled holography with discretized phase levels. Here we report on spin and wavelength multiplexed nonlinear metasurface holography, which allows construction of multiple target holographic images carried independently by the fundamental and harmonic generation waves of different spins. The nonlinear holograms provide independent, nondispersive and crosstalk-free post-selective channels for holographic multiplexing and multidimensional optical data storages, anti-counterfeiting, and optical encryption.

  1. Multiplexing Short Primers for Viral Family PCR

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, S N; Hiddessen, A L; Hara, C A; Williams, P L; Wagner, M; Colston, B W

    2008-06-26

    We describe a Multiplex Primer Prediction (MPP) algorithm to build multiplex compatible primer sets for large, diverse, and unalignable sets of target sequences. The MPP algorithm is scalable to larger target sets than other available software, and it does not require a multiple sequence alignment. We applied it to questions in viral detection, and demonstrated that there are no universally conserved priming sequences among viruses and that it could require an unfeasibly large number of primers ({approx}3700 18-mers or {approx}2000 10-mers) to generate amplicons from all sequenced viruses. We then designed primer sets separately for each viral family, and for several diverse species such as foot-and-mouth disease virus, hemagglutinin and neuraminidase segments of influenza A virus, Norwalk virus, and HIV-1.

  2. Rail-based Broadband Synthetic Aperture Ocean Measurement System

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Enables collection of broadband acoustic scattering databases where acoustic sources and receivers can be translated on a precise linear path under program...

  3. Handheld, Broadband Electromagnetic UXO Sensor: Cost & Performance Report

    National Research Council Canada - National Science Library

    Won, I. J; SanFilipo, Bill; Oren, Alex

    2006-01-01

    The broadband electromagnetic sensor improvement and demonstration undertaken in this project took the prototype GEM-3 and evolved it into an operational sensor with increased bandwidth and dynamic...

  4. Wireless Multiplexed Surface Acoustic Wave Sensors Project

    Science.gov (United States)

    Youngquist, Robert C.

    2014-01-01

    Wireless Surface Acoustic Wave (SAW) Sensor is a new technology for obtaining multiple, real-time measurements under extreme environmental conditions. This project plans to develop a wireless multiplexed sensor system that uses SAW sensors, with no batteries or semiconductors, that are passive and rugged, can operate down to cryogenic temperatures and up to hundreds of degrees C, and can be used to sense a wide variety of parameters over reasonable distances (meters).

  5. Multiplex congruence network of natural numbers.

    Science.gov (United States)

    Yan, Xiao-Yong; Wang, Wen-Xu; Chen, Guan-Rong; Shi, Ding-Hua

    2016-03-31

    Congruence theory has many applications in physical, social, biological and technological systems. Congruence arithmetic has been a fundamental tool for data security and computer algebra. However, much less attention was devoted to the topological features of congruence relations among natural numbers. Here, we explore the congruence relations in the setting of a multiplex network and unveil some unique and outstanding properties of the multiplex congruence network. Analytical results show that every layer therein is a sparse and heterogeneous subnetwork with a scale-free topology. Counterintuitively, every layer has an extremely strong controllability in spite of its scale-free structure that is usually difficult to control. Another amazing feature is that the controllability is robust against targeted attacks to critical nodes but vulnerable to random failures, which also differs from ordinary scale-free networks. The multi-chain structure with a small number of chain roots arising from each layer accounts for the strong controllability and the abnormal feature. The multiplex congruence network offers a graphical solution to the simultaneous congruences problem, which may have implication in cryptography based on simultaneous congruences. Our work also gains insight into the design of networks integrating advantages of both heterogeneous and homogeneous networks without inheriting their limitations.

  6. Epidemics in partially overlapped multiplex networks.

    Directory of Open Access Journals (Sweden)

    Camila Buono

    Full Text Available Many real networks exhibit a layered structure in which links in each layer reflect the function of nodes on different environments. These multiple types of links are usually represented by a multiplex network in which each layer has a different topology. In real-world networks, however, not all nodes are present on every layer. To generate a more realistic scenario, we use a generalized multiplex network and assume that only a fraction [Formula: see text] of the nodes are shared by the layers. We develop a theoretical framework for a branching process to describe the spread of an epidemic on these partially overlapped multiplex networks. This allows us to obtain the fraction of infected individuals as a function of the effective probability that the disease will be transmitted [Formula: see text]. We also theoretically determine the dependence of the epidemic threshold on the fraction [Formula: see text] of shared nodes in a system composed of two layers. We find that in the limit of [Formula: see text] the threshold is dominated by the layer with the smaller isolated threshold. Although a system of two completely isolated networks is nearly indistinguishable from a system of two networks that share just a few nodes, we find that the presence of these few shared nodes causes the epidemic threshold of the isolated network with the lower propagating capacity to change discontinuously and to acquire the threshold of the other network.

  7. Emerging technology: applications of Raman spectroscopy for prostate cancer.

    Science.gov (United States)

    Kast, Rachel E; Tucker, Stephanie C; Killian, Kevin; Trexler, Micaela; Honn, Kenneth V; Auner, Gregory W

    2014-09-01

    There is a need in prostate cancer diagnostics and research for a label-free imaging methodology that is nondestructive, rapid, objective, and uninfluenced by water. Raman spectroscopy provides a molecular signature, which can be scaled from micron-level regions of interest in cells to macroscopic areas of tissue. It can be used for applications ranging from in vivo or in vitro diagnostics to basic science laboratory testing. This work describes the fundamentals of Raman spectroscopy and complementary techniques including surface enhanced Raman scattering, resonance Raman spectroscopy, coherent anti-Stokes Raman spectroscopy, confocal Raman spectroscopy, stimulated Raman scattering, and spatially offset Raman spectroscopy. Clinical applications of Raman spectroscopy to prostate cancer will be discussed, including screening, biopsy, margin assessment, and monitoring of treatment efficacy. Laboratory applications including cell identification, culture monitoring, therapeutics development, and live imaging of cellular processes are discussed. Potential future avenues of research are described, with emphasis on multiplexing Raman spectroscopy with other modalities.

  8. Resource Management in Broadband Communication Networks

    DEFF Research Database (Denmark)

    Hansen, Mads Stenhuus

    2003-01-01

    . The first part gives a brief description of some of the existing protocols for routing and controlling resources, such as RSVP, OSPF, BGP, PNNI, etc. The remaining part concerns the following two fundamentally different approaches to resource management etc.: - Software agents - Simulated ants......This thesis - Resource Management in Broadband Communication Networks - deals with different ways of optimizing the available resources of data- or telecommunication networks. Especially topics like optimal routing, load balancing and fast recovery of routes in case of link failures are covered...

  9. Designing Broadband Access Networks with Triple Redundancy

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Riaz, Muhammad Tahir; Knudsen, Thomas Phillip

    2005-01-01

    An architecture is proposed for designing broadband access networks, which offer triple redundancy to the end users, resulting in networks providing connectivity even in case of any two independent node or line failures. Two physically independent connections are offered by fiber, and the last...... provided by some wireless solution. Based on experience with planning Fiber To The Home, the architecture is designed to meet a number of demands, making it practicable and useful in realworld network planning. The proposed wired topology is planar, and suitable for being fitted onto the road network...

  10. Broadband Planar 5:1 Impedence Transformer

    Science.gov (United States)

    Ehsan, Negar; Hsieh, Wen-Ting; Moseley, Samuel H.; Wollack, Edward J.

    2015-01-01

    This paper presents a broadband Guanella-type planar impedance transformer that transforms so 50 omega to 10 omega with a 10 dB bandwidth of 1-14GHz. The transformer is designed on a flexible 50 micrometer thick polyimide substrate in microstrip and parallel-plate transmission line topologies, and is Inspired by the traditional 4:1 Guanella transformer. Back-to-back transformers were designed and fabricated for characterization in a 50 omega system. Simulated and measured results are in excellent agreement.

  11. A compact broadband nonsynchronous noncommensurate impedance transformer

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Kim, Kseniya; Narenda, Kumar

    2012-01-01

    Nonsynchronous noncommensurate impedance transformers consist of a combination of high‐ and low‐impedance transmission lines. High‐impedance lines have narrow tracks in strip and microstrip technology, which allows for high flexibility and miniaturization of the layout in comparison...... to the traditional tapered line transformers. This flexibility of the broadband nonsynchronous noncommensurate impedance transformers is experimentally demonstrated in this article allowing the length reduction by almost three times. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1832–1835, 2012; View...

  12. Optimizing UV Index determination from broadband irradiances

    Science.gov (United States)

    Tereszchuk, Keith A.; Rochon, Yves J.; McLinden, Chris A.; Vaillancourt, Paul A.

    2018-03-01

    A study was undertaken to improve upon the prognosticative capability of Environment and Climate Change Canada's (ECCC) UV Index forecast model. An aspect of that work, and the topic of this communication, was to investigate the use of the four UV broadband surface irradiance fields generated by ECCC's Global Environmental Multiscale (GEM) numerical prediction model to determine the UV Index. The basis of the investigation involves the creation of a suite of routines which employ high-spectral-resolution radiative transfer code developed to calculate UV Index fields from GEM forecasts. These routines employ a modified version of the Cloud-J v7.4 radiative transfer model, which integrates GEM output to produce high-spectral-resolution surface irradiance fields. The output generated using the high-resolution radiative transfer code served to verify and calibrate GEM broadband surface irradiances under clear-sky conditions and their use in providing the UV Index. A subsequent comparison of irradiances and UV Index under cloudy conditions was also performed. Linear correlation agreement of surface irradiances from the two models for each of the two higher UV bands covering 310.70-330.0 and 330.03-400.00 nm is typically greater than 95 % for clear-sky conditions with associated root-mean-square relative errors of 6.4 and 4.0 %. However, underestimations of clear-sky GEM irradiances were found on the order of ˜ 30-50 % for the 294.12-310.70 nm band and by a factor of ˜ 30 for the 280.11-294.12 nm band. This underestimation can be significant for UV Index determination but would not impact weather forecasting. Corresponding empirical adjustments were applied to the broadband irradiances now giving a correlation coefficient of unity. From these, a least-squares fitting was derived for the calculation of the UV Index. The resultant differences in UV indices from the high-spectral-resolution irradiances and the resultant GEM broadband irradiances are typically within 0

  13. Source of broadband Jovian Kilometric radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jones, D.; Leblanc, Y.

    1987-02-01

    Broadband Jovian Kilometric radiation was observed by Voyagers 1 and 2 to be beamed away from the zenomagnetic equatorial plane. Two theories were proposed for the equatorial shadow zone. One suggested that Io plasma torus forms an obstacle to radiation produced on auroral field lines. The other theory proposed that the source is located on the outer flanks of the torus, the beaming being inherent to the emission mechanism. Results are presented which indicate that the latter is consistent with the observations and it would appear that the emission is produced by linear mode conversion of electrostatic upper hybrid to electromagnetic waves in plasma density gradients.

  14. Source of broadband Jovian Kilometric radiation

    International Nuclear Information System (INIS)

    Jones, D.; Leblanc, Y.

    1987-01-01

    Broadband Jovian Kilometric radiation was observed by Voyagers 1 and 2 to be beamed away from the zenomagnetic equatorial plane. Two theories were proposed for the equatorial shadow zone. One suggested that Io plasma torus forms an obstacle to radiation produced on auroral field lines. The other theory proposed that the source is located on the outer flanks of the torus, the beaming being inherent to the emission mechanism. Results are presented which indicate that the latter is consistent with the observations and it would appear that the emission is produced by linear mode conversion of electrostatic upper hybrid to electromagnetic waves in plasma density gradients

  15. Hyperbolic metamaterials: Nonlocal response regularizes broadband supersingularity

    DEFF Research Database (Denmark)

    Yan, Wei; Wubs, Martijn; Mortensen, N. Asger

    2012-01-01

    We study metamaterials known as hyperbolic media that in the usual local-response approximation exhibit hyperbolic dispersion and an associated broadband singularity in the density of states. Instead, from the more microscopic hydrodynamic Drude theory we derive qualitatively different optical...... properties of these metamaterials, due to the free-electron nonlocal optical response of their metal constituents. We demonstrate that nonlocal response gives rise to a large-wavevector cutoff in the dispersion that is inversely proportional to the Fermi velocity of the electron gas, but also for small...

  16. Peramalan Pengguna Broadband di Indonesia [Forecasting of Broadband Users in Indonesia

    Directory of Open Access Journals (Sweden)

    Azwar Aziz

    2016-07-01

    Full Text Available Negara Indonesia memiliki peluang yang sangat besar untuk merealisasikan potensi pitalebar, mengingat Indonesia memiliki jumlah penduduk 253 juta orang dan pengguna internet 88,1 juta orang pada tahun 2014. Di sisi lain sektor komunikasi (salah satunya termasuk telekomunikasi merupakan satu-satunya sektor yang secara konsisten memberikan kontribusi pertumbuhan terhadap Pendapatan Domestik Bruto (PDB sebesar dua angka (double digit. Kemudian peran penting pemerintah adalah selalu mengantisipasi dalam membuat regulasi telekomunikasi, salah satu nya untuk mempercepat penggelaran prasarana pitalebar, seperti menerbitkan Peraturan Presiden RI. Nomor 96 Tahun 2014 tentang Rencana Pitalebar Indonesia 2014 – 2019.  Secara riil pembangunan jaringan pitalebar di Indonesia masih dilakukan di kota-kota besar, mengingat pengguna telekomunikasi sebagian besar berada di kota-kota besar. Selain itu perangkat hanset atau handphone, ketersediaan di pasaran masih terbatas dan harganya masih mahal. Kajian ini menggunakan metodologi penelitian kuantitatif dengan menghitung peramalan dan kualitatif, dengan melakukan observasi atau pengamatan langsung ke lapangan kepada perusahaan Telkom, Telkomsel, XL Axiata dan Indosat. Selanjutnya hasil penelitian ini diperoleh lima faktor yang mempengaruhi penggunaan pitalebar yaitu jumlah penduduk, produk domestik bruto, pendapatan per kapita, laju pertumbuhan ekonomi dan inflasi, dan laju penetrasi. Selain itu, hasil pitalebar menunjukkan pengguna pitalebar lima tahun kedepan selalu meningkat.*****Indonesia has a tremendous opportunity to implement the potential of broadband, as Indonesia has a population of 253 million people and 88.1 million Internet users in 2014. On the other hand, the communication sector (one of them including telecommunications is the only sector that is consistently contributed to the growth of Gross Domestic Product (GDP as many as two numbers (double-digit. Then the important role of government is

  17. Signal-to-noise ratios of multiplexing spectrometers in high backgrounds

    Science.gov (United States)

    Knacke, R. F.

    1978-01-01

    Signal-to-noise ratios and the amount of multiplexing gain achieved with a Michelson spectrometer during detector and background noise are studied. Noise caused by the warm background is found in 10 and 20-micron atmospheric windows in high resolution Fourier spectroscopy. An equation is derived for the signal-to-noise ratio based on the number of channels, total time to obtain the complete spectrum, the signal power in one spectral element, and the detector noise equivalent power in the presence of negligible background. Similar expressions are derived for backgrounds yielding a noise equivalent power to a spectral element, and backgrounds having flat spectra in the frequency range under investigation.

  18. Demonstration of hybrid orbital angular momentum multiplexing and time-division multiplexing passive optical network.

    Science.gov (United States)

    Wang, Andong; Zhu, Long; Liu, Jun; Du, Cheng; Mo, Qi; Wang, Jian

    2015-11-16

    Mode-division multiplexing passive optical network (MDM-PON) is a promising scheme for next-generation access networks to further increase fiber transmission capacity. In this paper, we demonstrate the proof-of-concept experiment of hybrid mode-division multiplexing (MDM) and time-division multiplexing (TDM) PON architecture by exploiting orbital angular momentum (OAM) modes. Bidirectional transmissions with 2.5-Gbaud 4-level pulse amplitude modulation (PAM-4) downstream and 2-Gbaud on-off keying (OOK) upstream are demonstrated in the experiment. The observed optical signal-to-noise ratio (OSNR) penalties for downstream and upstream transmissions at a bit-error rate (BER) of 2 × 10(-3) are less than 2.0 dB and 3.0 dB, respectively.

  19. Quantitative terahertz time-domain spectroscopy and analysis in chemistry and biology

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd

    2005-01-01

    I will describe how Terahertz Time-Domain Spectroscopy (THz-TDS) can be used for quantitative, broadband spectroscopy in the far-infrared spectral region. Thz-TDS is sensitive to long-range, non-covalent interactions in the condensed phase, for instance intermolecular hydrogen bonding in molecula...

  20. Reflective afocal broadband adaptive optics scanning ophthalmoscope

    Science.gov (United States)

    Dubra, Alfredo; Sulai, Yusufu

    2011-01-01

    A broadband adaptive optics scanning ophthalmoscope (BAOSO) consisting of four afocal telescopes, formed by pairs of off-axis spherical mirrors in a non-planar arrangement, is presented. The non-planar folding of the telescopes is used to simultaneously reduce pupil and image plane astigmatism. The former improves the adaptive optics performance by reducing the root-mean-square (RMS) of the wavefront and the beam wandering due to optical scanning. The latter provides diffraction limited performance over a 3 diopter (D) vergence range. This vergence range allows for the use of any broadband light source(s) in the 450-850 nm wavelength range to simultaneously image any combination of retinal layers. Imaging modalities that could benefit from such a large vergence range are optical coherence tomography (OCT), multi- and hyper-spectral imaging, single- and multi-photon fluorescence. The benefits of the non-planar telescopes in the BAOSO are illustrated by resolving the human foveal photoreceptor mosaic in reflectance using two different superluminescent diodes with 680 and 796 nm peak wavelengths, reaching the eye with a vergence of 0.76 D relative to each other. PMID:21698035

  1. Asymmetric quantum well broadband thyristor laser

    Science.gov (United States)

    Liu, Zhen; Wang, Jiaqi; Yu, Hongyan; Zhou, Xuliang; Chen, Weixi; Li, Zhaosong; Wang, Wei; Ding, Ying; Pan, Jiaoqing

    2017-11-01

    A broadband thyristor laser based on InGaAs/GaAs asymmetric quantum well (AQW) is fabricated by metal organic chemical vapor deposition (MOCVD). The 3-μm-wide Fabry-Perot (FP) ridge-waveguide laser shows an S-shape I-V characteristic and exhibits a flat-topped broadband optical spectrum coverage of ~27 nm (Δ-10 dB) at a center wavelength of ~1090 nm with a total output power of 137 mW under pulsed operation. The AQW structure was carefully designed to establish multiple energy states within, in order to broaden the gain spectrum. An obvious blue shift emission, which is not generally acquired in QW laser diodes, is observed in the broadening process of the optical spectrum as the injection current increases. This blue shift spectrum broadening is considered to result from the prominent band-filling effect enhanced by the multiple energy states of the AQW structure, as well as the optical feedback effect contributed by the thyristor laser structure. Project supported by the National Natural Science Foundation of China (Nos. 61604144, 61504137). Zhen Liu and Jiaqi Wang contributed equally to this work.

  2. Broadband impedance of the NESTOR storage ring

    International Nuclear Information System (INIS)

    Androsov, V.P.; Gladkikh, P.I.; Gvozd, A.M.; Karnaukhov, I.M.; Telegin, Yu.N.

    2011-01-01

    The contributions from lossy and inductive vacuum chamber components to the broadband impedance of the NESTOR storage ring are obtained by using both low-frequency analytical approaches and computer simulations. As was expected considering the small ring circumference (15.44m), the main contributions both to the longitudinal impedance Z || /n and the loss factor k loss come from the RF-cavity. Cavity impedance was also estimated with CST Microwave Studio (CST Studio Suite TM 2006) by simulating coaxial wire method commonly used for impedance measurements. Both estimates agree well. Finally, we performed the simulations of a number of inductive elements with CST Particle Studio 2010 by using wake field solver. We have also evaluated the bunch length in NESTOR taking the conservative estimate of 3 Ohm for the ring broadband impedance and have found that the bunch length s z = 0.5 cm could be obtained in steady state operation mode for the designed bunch current of 10 mA and RF-voltage of 250 kV.

  3. A Design of Double Broadband MIMO Antenna

    Directory of Open Access Journals (Sweden)

    Yanfeng Geng

    2015-01-01

    Full Text Available The MIMO antenna applied to LTE mobile system should be miniaturization and can work in the current communication frequency band; isolation between each antenna unit also should be good so as to reduce loss of radio wave energy and improve the antenna performance of the MIMO system. This paper puts forward the design scheme of a broadband MIMO double antenna. And the design of antenna unit and debugging and related technical measures, such as bending antenna bracket, are both presented; the integration design of high isolation of ultra broadband MIMO antenna is realized on the plate with the volume of 100 × 52 × 0.8 mm3; antenna working bands are 698 MHz~960 MHz and 1710 MHz~2700 MHz; in the whole spectrum, the 10 dB of port isolation can be basically achieved; in low frequency band, the isolation degree of antenna port can reach 12 dB.

  4. Broadband acoustic properties of a murine skull.

    Science.gov (United States)

    Estrada, Héctor; Rebling, Johannes; Turner, Jake; Razansky, Daniel

    2016-03-07

    It has been well recognized that the presence of a skull imposes harsh restrictions on the use of ultrasound and optoacoustic techniques in the study, treatment and modulation of the brain function. We propose a rigorous modeling and experimental methodology for estimating the insertion loss and the elastic constants of the skull over a wide range of frequencies and incidence angles. A point-source-like excitation of ultrawideband acoustic radiation was induced via the absorption of nanosecond duration laser pulses by a 20 μm diameter microsphere. The acoustic waves transmitted through the skull are recorded by a broadband, spherically focused ultrasound transducer. A coregistered pulse-echo ultrasound scan is subsequently performed to provide accurate skull geometry to be fed into an acoustic transmission model represented in an angular spectrum domain. The modeling predictions were validated by measurements taken from a glass cover-slip and ex vivo adult mouse skulls. The flexible semi-analytical formulation of the model allows for seamless extension to other transducer geometries and diverse experimental scenarios involving broadband acoustic transmission through locally flat solid structures. It is anticipated that accurate quantification and modeling of the skull transmission effects would ultimately allow for skull aberration correction in a broad variety of applications employing transcranial detection or transmission of high frequency ultrasound.

  5. Comparison of multiplex reverse transcription-PCR-enzyme ...

    African Journals Online (AJOL)

    Comparison of multiplex reverse transcription-PCR-enzyme hybridization assay with immunofluorescence techniques for the detection of four viral respiratory pathogens in pediatric community acquired pneumonia.

  6. Optical broadband in-home networks for converged service delivery

    NARCIS (Netherlands)

    Shi, Y.

    2013-01-01

    Broadband access networks, and in particular fibre-to-the-home (FTTH) networks, are offering abundantly available bandwidth in the local loop with high quality of services. Under such broadband connectivity conditions, in-home networks should not represent the bottleneck for high capacity service

  7. Radio-over-fibre technology for broadband wireless communication systems

    NARCIS (Netherlands)

    Ng'Oma, A.

    2005-01-01

    Wireless coverage of the end-user domain, be it outdoors or indoors (in-building), is poised to become an essential part of broadband communication networks. In order to offer integrated broadband services (combining voice, data, video, multimedia services, and new value added services), these

  8. Broadband Liner Optimization for the Source Diagnostic Test Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.

    2012-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

  9. Techno-economic evaluation of broadband access technologies

    DEFF Research Database (Denmark)

    Sigurdsson, Halldór Matthias; Skouby, Knud Erik

    2005-01-01

    Broadband for all is an essential element in the EU policy concerning the future of ICT-based society. The overall purpose of this paper is to present a model for evaluation of different broadband access technologies and to present some preliminary results based on the model that has been carried...

  10. Silicon graphene waveguide tunable broadband microwave photonics phase shifter.

    Science.gov (United States)

    Capmany, José; Domenech, David; Muñoz, Pascual

    2014-04-07

    We propose the use of silicon graphene waveguides to implement a tunable broadband microwave photonics phase shifter based on integrated ring cavities. Numerical computation results show the feasibility for broadband operation over 40 GHz bandwidth and full 360° radiofrequency phase-shift with a modest voltage excursion of 0.12 volt.

  11. The role of public initiatives facilitating investments in broadband infrastructures

    DEFF Research Database (Denmark)

    Falch, Morten; Tadayoni, Reza; Henten, Anders

    2015-01-01

    This paper discusses the role of a developmental approach to broadband policy. The policy approaches made in Denmark and Sweden are compared, and the scope for public intervention at the broadband market is discussed. The paper includes a case study on public intervention in the rural areas of th...

  12. Supercurrent Spectroscopy of Andreev States

    Directory of Open Access Journals (Sweden)

    L. Bretheau

    2013-12-01

    Full Text Available We measure the excitation spectrum of a superconducting atomic contact. In addition to the usual continuum above the superconducting gap, the single-particle excitation spectrum contains discrete, spin-degenerate Andreev levels inside the gap. Quasiparticle excitations are induced by a broadband on-chip microwave source and detected by measuring changes in the supercurrent flowing through the atomic contact. Since microwave photons excite quasiparticles in pairs, two types of transitions are observed: Andreev transitions, which consist of putting two quasiparticles in an Andreev level, and transitions to odd states with a single quasiparticle in an Andreev level and the other one in the continuum. In contrast to absorption spectroscopy, supercurrent spectroscopy allows detection of long-lived odd states.

  13. Analisis Perkembangan Internet Broadband di Daerah Perbatasan Sulawesi Utara

    Directory of Open Access Journals (Sweden)

    Riva'atul Adaniah Wahab

    2016-12-01

    Full Text Available Adopsi teknologi internet broadband dapat memberikan dampak ekonomi bagi masyarakat perbatasan. Karenanya pemerataan pembangunan internet broadband di wilayah  ini harus segera diwujudkan. Penelitian deskriptif kuantitatif ini dilaksanakan di wilayah perbatasan Provinsi Sulawesi Utara untuk mengetahui kondisi aspek supply dan demand perkembangan internet broadband di wilayah tersebut. Berdasarkan hasil penelitian, dapat disimpulkan bahwa dari aspek supply, kondisi infrastruktur masih sangat kurang, ketersediaan layanan internet broadband berkualitas tinggi dengan tarif rendah juga masih sulit diwujudkan. Dari aspek demand, stigma atau persepsi masyarakat bahwa internet tidak penting menjadi salah satu faktor penyebab tidak memiliki akses internet. Adapun hambatan yang paling dominan adalah ketidakpahaman dalam penggunaan internet. Faktor ini juga menjadi mendasari literasi internet broadband masyarakat pada level 0 yaitu  tidak peduli akan pentinya internet. Menanggapai kondisi ini, penyusunan dan penetapan kebijakan serta regulasi seperti QoS layanan, tarif interkoneksi, infrastructure sharing dibuat untuk menyediakan internet broadband berkualitas tinggi dengan harga murah. Selain itu distribusi perangkat mobile berharga murah (smartphone juga perlu didorong dengan penerapan TKDN untuk produksi perangkat. Tidak kalah pentingnya adalah peningkatan literasi internet broadband masyarakat melalui sosialisasi atau pelatihan baik formal maupun nonformal. Abstract   Adoption of internet broadband internet can provide the economic impact for border communities. Hence equitable development of internet broadband in the region should be immediately implemented. This quantitative descriptive study was conducted in the border region of North Sulawesi to determine the condition of supply and demand aspects of the development of internet broadband. Based on the results, it can be concluded that from the aspect of supply, the condition of the

  14. 76 FR 71982 - Advancing Regulatory Science for Highly Multiplexed Microbiology/Medical Countermeasure Devices...

    Science.gov (United States)

    2011-11-21

    ... Multiplexed Microbiology Devices: Their clinical application and public health/clinical needs; inclusion of...] Advancing Regulatory Science for Highly Multiplexed Microbiology/ Medical Countermeasure Devices; Public... Multiplexed Microbiology/ Medical Countermeasure Devices'' that published in the Federal Register of August 8...

  15. Chaos-assisted broadband momentum transformation in optical microresonators.

    Science.gov (United States)

    Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

    2017-10-20

    The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  16. Chaos-assisted broadband momentum transformation in optical microresonators

    Science.gov (United States)

    Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

    2017-10-01

    The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks.

  17. Molecular spectroscopy

    International Nuclear Information System (INIS)

    Kokh, Eh.; Zonntag, B.

    1981-01-01

    The latest investigation results on molecular spectroscopy with application of synchrotron radiation in the region of vacuum ultraviolet are generalized. Some results on investigation of excited, superexcited and ionized molecule states with the use of adsorption spectroscopy, photoelectron spectroscopy, by fluorescent and mass-spectrometric methods are considered [ru

  18. Atom spectroscopy

    International Nuclear Information System (INIS)

    Kodling, K.

    1981-01-01

    Experiments on atom photoabsorption spectroscopy using synchrotron radiation in the 10-1000 eV range are reviewed. Properties of the necessary synchrotron radiation and the experiment on absorption spectroscopy are briefly described. Comparison with other spectroscopy methods is conducted. Some data on measuring photoabsorption, photoelectron emission and atom mass spectra are presented [ru

  19. Vibrational spectroscopy

    Science.gov (United States)

    Umesh P. Agarwal; Rajai Atalla

    2010-01-01

    Vibrational spectroscopy is an important tool in modern chemistry. In the past two decades, thanks to significant improvements in instrumentation and the development of new interpretive tools, it has become increasingly important for studies of lignin. This chapter presents the three important instrumental methods-Raman spectroscopy, infrared (IR) spectroscopy, and...

  20. Multiplexed Western Blotting Using Microchip Electrophoresis.

    Science.gov (United States)

    Jin, Shi; Furtaw, Michael D; Chen, Huaxian; Lamb, Don T; Ferguson, Stephen A; Arvin, Natalie E; Dawod, Mohamed; Kennedy, Robert T

    2016-07-05

    Western blotting is a commonly used protein assay that combines the selectivity of electrophoretic separation and immunoassay. The technique is limited by long time, manual operation with mediocre reproducibility, and large sample consumption, typically 10-20 μg per assay. Western blots are also usually used to measure only one protein per assay with an additional housekeeping protein for normalization. Measurement of multiple proteins is possible; however, it requires stripping membranes of antibody and then reprobing with a second antibody. Miniaturized alternatives to Western blot based on microfluidic or capillary electrophoresis have been developed that enable higher-throughput, automation, and greater mass sensitivity. In one approach, proteins are separated by electrophoresis on a microchip that is dragged along a polyvinylidene fluoride membrane so that as proteins exit the chip they are captured on the membrane for immunoassay. In this work, we improve this method to allow multiplexed protein detection. Multiple injections made from the same sample can be deposited in separate tracks so that each is probed with a different antibody. To further enhance multiplexing capability, the electrophoresis channel dimensions were optimized for resolution while keeping separation and blotting times to less than 8 min. Using a 15 μm deep × 50 μm wide × 8.6 cm long channel, it is possible to achieve baseline resolution of proteins that differ by 5% in molecular weight, e.g., ERK1 (44 kDa) from ERK2 (42 kDa). This resolution allows similar proteins detected by cross-reactive antibodies in a single track. We demonstrate detection of 11 proteins from 9 injections from a single Jurkat cell lysate sample consisting of 400 ng of total protein using this procedure. Thus, multiplexed Western blots are possible without cumbersome stripping and reprobing steps.

  1. Multiplex serology of paraneoplastic antineuronal antibodies.

    Science.gov (United States)

    Maat, Peter; Brouwer, Eric; Hulsenboom, Esther; VanDuijn, Martijn; Schreurs, Marco W J; Hooijkaas, Herbert; Smitt, Peter A E Sillevis

    2013-05-31

    Paraneoplastic neurological syndromes (PNS) are devastating neurological disorders secondary to cancer, associated with onconeural autoantibodies. Such antibodies are directed against neuronal antigens aberrantly expressed by the tumor. The detection of onconeural antibodies in a patient is extremely important in diagnosing a neurological syndrome as paraneoplastic (70% is not yet known to have cancer) and in directing the search for the underlying neoplasm. At present six onconeural antibodies are considered 'well characterized' and recognize the antigens HuD, CDR62 (Yo), amphiphysin, CRMP-5 (CV2), NOVA-1 (Ri), and Ma2. The gold standard of detection is the characteristic immunohistochemical staining pattern on brain tissue sections combined with confirmation by immunoblotting using recombinant purified proteins. Since all six onconeural antibodies are usually analyzed simultaneously and objective cut-off values for these analyses are warranted, we developed a multiplex assay based on Luminex technology. Reaction of serial dilutions of six onconeural standard sera with microsphere-bound antigens showed lower limits of detection than with Western blotting. Using the six standard sera at a dilution of 1:200, the average within-run coefficient of variation (CV) was 4% (range 1.9-7.3%). The average between-run within-day CV was 5.1% (range 2.9-6.7%) while the average between-day CV was 8.1% (range 2.8-11.6%). The shelf-life of the antigen coupled microspheres was at least two months. The sensitivity of the multiplex assay ranged from 83% (Ri) to 100% (Yo, amphiphysin, CV2) and the specificity from 96% (CV2) to 100% (Ri). In conclusion, Luminex-based multiplex serology is highly reproducible with high sensitivity and specificity for the detection of onconeural antibodies. Conventional immunoblotting for diagnosis of onconeural antibodies in the setting of a routine laboratory may be replaced by this novel, robust technology. Copyright © 2013 Elsevier B.V. All rights

  2. Wavelength division multiplexing a practical engineering guide

    CERN Document Server

    Grobe, Klaus

    2013-01-01

    In this book, Optical Wavelength Division Multiplexing (WDM) is approached from a strictly practical and application-oriented point of view. Based on the characteristics and constraints of modern fiber-optic components, transport systems and fibers, the text provides relevant rules of thumb and practical hints for technology selection, WDM system and link dimensioning, and also for network-related aspects such as wavelength assignment and resilience mechanisms. Actual 10/40 Gb/s WDM systems are considered, and a preview of the upcoming 100 Gb/s systems and technologies for even higher bit rate

  3. Performance modeling, stochastic networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi R

    2013-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of introducing an appropriate mathematical framework for modeling and analysis as well as understanding the phenomenon of statistical multiplexing. The models, techniques, and results presented form the core of traffic engineering methods used to design, control and allocate resources in communication networks.The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the importan

  4. Subcarrier multiplexing optical quantum key distribution

    International Nuclear Information System (INIS)

    Ortigosa-Blanch, A.; Capmany, J.

    2006-01-01

    We present the physical principles of a quantum key distribution system that opens the possibility of parallel quantum key distribution and, therefore, of a substantial improvement in the bit rate of such systems. Quantum mechanics allows for multiple measurements at different frequencies and thus we exploit this concept by extending the concept of frequency coding to the case where more than one radio-frequency subcarrier is used for independently encoding the bits onto an optical carrier. Taking advantage of subcarrier multiplexing techniques we demonstrate that the bit rate can be greatly improved as parallel key distribution is enabled

  5. Broadband Optical Access Technologies to Converge towards a Broadband Society in Europe

    Science.gov (United States)

    Coudreuse, Jean-Pierre; Pautonnier, Sophie; Lavillonnière, Eric; Didierjean, Sylvain; Hilt, Benoît; Kida, Toshimichi; Oshima, Kazuyoshi

    This paper provides insights on the status of broadband optical access market and technologies in Europe and on the expected trends for the next generation optical access networks. The final target for most operators, cities or any other player is of course FTTH (Fibre To The Home) deployment although we can expect intermediate steps with copper or wireless technologies. Among the two candidate architectures for FTTH, PON (Passive Optical Network) is by far the most attractive and cost effective solution. We also demonstrate that Ethernet based optical access network is very adequate to all-IP networks without any incidence on the level of quality of service. Finally, we provide feedback from a FTTH pilot network in Colmar (France) based on Gigabit Ethernet PON technology. The interest of this pilot lies on the level of functionality required for broadband optical access networks but also on the development of new home network configurations.

  6. Terahertz spectroscopy

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd

    2009-01-01

    In this presentation I will review methods for spectroscopy in the THz range, with special emphasis on the practical implementation of the technique known ad THz time-domain spectroscopy (THz-TDS). THz-TDS has revived the old field of far-infrared spectroscopy, and enabled a wealth of new...... activities that promise commercial potential for spectroscopic applications in the THz range. This will be illustrated with examples of spectroscopy of liquids inside their bottles as well as sensitive, quantitative spectroscopy in waveguides....

  7. High efficiency and broadband acoustic diodes

    Science.gov (United States)

    Fu, Congyi; Wang, Bohan; Zhao, Tianfei; Chen, C. Q.

    2018-01-01

    Energy transmission efficiency and working bandwidth are the two major factors limiting the application of current acoustic diodes (ADs). This letter presents a design of high efficiency and broadband acoustic diodes composed of a nonlinear frequency converter and a linear wave filter. The converter consists of two masses connected by a bilinear spring with asymmetric tension and compression stiffness. The wave filter is a linear mass-spring lattice (sonic crystal). Both numerical simulation and experiment show that the energy transmission efficiency of the acoustic diode can be improved by as much as two orders of magnitude, reaching about 61%. Moreover, the primary working band width of the AD is about two times of the cut-off frequency of the sonic crystal filter. The cut-off frequency dependent working band of the AD implies that the developed AD can be scaled up or down from macro-scale to micro- and nano-scale.

  8. Frequency Doubling Broadband Light in Multiple Crystals

    International Nuclear Information System (INIS)

    Alford, William J.; Smith, Arlee V.

    2000-01-01

    The authors compare frequency doubling of broadband light in a single nonlinear crystal with doubling in five crystals with intercrystal temporal walk off compensation, and with doubling in five crystals adjusted for offset phase matching frequencies. Using a plane-wave, dispersive numerical model of frequency doubling they study the bandwidth of the second harmonic and the conversion efficiency as functions of crystal length and fundamental irradiance. For low irradiance the offset phase matching arrangement has lower efficiency than a single crystal of the same total length but gives a broader second harmonic bandwidth. The walk off compensated arrangement gives both higher conversion efficiency and broader bandwidth than a single crystal. At high irradiance, both multicrystal arrangements improve on the single crystal efficiency while maintaining broad bandwidth

  9. Broadband plasmon induced transparency in terahertz metamaterials

    KAUST Repository

    Zhu, Zhihua

    2013-04-25

    Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena and an enhanced nonlinear effect. However, the transparency mode is normally localized in a narrow frequency band, which thus restricts many of its applications. Here we present the simulation, implementation, and measurement of a broadband PIT metamaterial functioning in the terahertz regime. By integrating four U-shape resonators around a central bar resonator, a broad transparency window across a frequency range greater than 0.40 THz is obtained, with a central resonance frequency located at 1.01 THz. Such PIT metamaterials are promising candidates for designing slow light devices, highly sensitive sensors, and nonlinear elements operating over a broad frequency range. © 2013 IOP Publishing Ltd.

  10. Piezoelectric energy harvesting from broadband random vibrations

    International Nuclear Information System (INIS)

    Adhikari, S; Friswell, M I; Inman, D J

    2009-01-01

    Energy harvesting for the purpose of powering low power electronic sensor systems has received explosive attention in the last few years. Most works using deterministic approaches focusing on using the piezoelectric effect to harvest ambient vibration energy have concentrated on cantilever beams at resonance using harmonic excitation. Here, using a stochastic approach, we focus on using a stack configuration and harvesting broadband vibration energy, a more practically available ambient source. It is assumed that the ambient base excitation is stationary Gaussian white noise, which has a constant power-spectral density across the frequency range considered. The mean power acquired from a piezoelectric vibration-based energy harvester subjected to random base excitation is derived using the theory of random vibrations. Two cases, namely the harvesting circuit with and without an inductor, have been considered. Exact closed-form expressions involving non-dimensional parameters of the electromechanical system have been given and illustrated using numerical examples

  11. Piezoelectric energy harvesting from broadband random vibrations

    Science.gov (United States)

    Adhikari, S.; Friswell, M. I.; Inman, D. J.

    2009-11-01

    Energy harvesting for the purpose of powering low power electronic sensor systems has received explosive attention in the last few years. Most works using deterministic approaches focusing on using the piezoelectric effect to harvest ambient vibration energy have concentrated on cantilever beams at resonance using harmonic excitation. Here, using a stochastic approach, we focus on using a stack configuration and harvesting broadband vibration energy, a more practically available ambient source. It is assumed that the ambient base excitation is stationary Gaussian white noise, which has a constant power-spectral density across the frequency range considered. The mean power acquired from a piezoelectric vibration-based energy harvester subjected to random base excitation is derived using the theory of random vibrations. Two cases, namely the harvesting circuit with and without an inductor, have been considered. Exact closed-form expressions involving non-dimensional parameters of the electromechanical system have been given and illustrated using numerical examples.

  12. Techno-Economics of Residential Broadband Deployment

    DEFF Research Database (Denmark)

    Sigurdsson, Halldor Matthias

    2007-01-01

    on account of their existing telecom network (”the raw copper”), and typically they will prefer an xDSL-based strategy (various types of Digital Subscriber Line-technology: ADSL, VDSL, etc.), where the rate of speed of data connections are increased gradually to 10-50 Mbit/s or even more, in order to gain...... broadband deployment strategy is depending on a complexed set of parameters, and there is a demand for precise techno-economic cost models estimating financial feasibility. The existing cost models do not consider the dynamic developments in the market caused by competition. The PhD thesis has a profound...... the general principles from the Danish LRAIC-model (Long Run Average Incremental Cost) and divides Denmark in 4 geografical profiles. Considering the existing copper-infrastructure the most advantageous strategies for the players of each of these profiles are identified. The importance of the time horizon...

  13. Broadband plasmon induced transparency in terahertz metamaterials

    International Nuclear Information System (INIS)

    Zhu Zhihua; Yang Xu; Gu Jianqiang; Jiang Jun; Tian Zhen; Han Jiaguang; Zhang Weili; Yue Weisheng; Tonouchi, Masayoshi

    2013-01-01

    Plasmon induced transparency (PIT) could be realized in metamaterials via interference between different resonance modes. Within the sharp transparency window, the high dispersion of the medium may lead to remarkable slow light phenomena and an enhanced nonlinear effect. However, the transparency mode is normally localized in a narrow frequency band, which thus restricts many of its applications. Here we present the simulation, implementation, and measurement of a broadband PIT metamaterial functioning in the terahertz regime. By integrating four U-shape resonators around a central bar resonator, a broad transparency window across a frequency range greater than 0.40 THz is obtained, with a central resonance frequency located at 1.01 THz. Such PIT metamaterials are promising candidates for designing slow light devices, highly sensitive sensors, and nonlinear elements operating over a broad frequency range. (paper)

  14. QCD on the Cell Broadband Engine

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Nils [Department of Physics, University of Regensburg, 93040 Regensburg (Germany)

    2008-07-01

    We evaluate IBM's Enhanced Cell Broadband Engine (BE) as a possible building block of a new generation of lattice QCD machines. The Enhanced Cell BE will provide full support of double precision floating-point arithmetics, including IEEE-compliant rounding. We have developed a performance model and applied it to relevant lattice QCD kernels. The performance estimates are supported by micro- and application-benchmarks that have been obtained on currently available Cell BE-based computers, such as IBM QS20 blades and PlayStation 3. The results are encouraging and show that this processor is an interesting option for lattice QCD applications. For a massively parallel machine on the basis of the Cell BE, an application-optimized network needs to be developed.

  15. QCD on the Cell Broadband Engine

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Nils [Department of Physics, University of Regensburg, 93040 Regensburg (Germany)

    2008-07-01

    We evaluate IBM's Enhanced Cell Broadband Engine (BE) as a possible building block of a new generation of lattice QCD machines. The Enhanced Cell BE will provide full support of double precision floating-point arithmetics, including IEEE-compliant rounding. We have developed a performance model and applied it to relevant lattice QCD kernels. The performance estimates are supported by micro- and application-benchmarks that have been obtained on currently available Cell BE-based computers, such as IBM QS20 blades and PlayStation 3. The results are encouraging and show that this processor is an interesting option for lattice QCD applications. For a massively parallel machine on the basis of the Cell BE, an application-optimized network needs to be developed.

  16. Terahertz broadband polarization converter based on metamaterials

    Science.gov (United States)

    Li, Yonghua; Zhao, Guozhong

    2018-01-01

    Based on the metamaterial composed of symmetrical split resonant ring, a broadband reflective terahertz polarization converter is proposed. The numerical simulation shows that it can rotate the polarization direction of linear polarized wave 90° in the range of 0.7-1.8THz and the polarization conversion ratio is over 90%. The reflection coefficient of the two electric field components in the diagonal direction is the same and the phase difference is 180° ,which leads to the cross-polarization rotation.In order to further study the physical mechanism of high polarization conversion, we analyze the surface current distribution of the resonant ring. The polarization converter has potential applications in terahertz wave plate and metamaterial antenna design.

  17. Patient portals and broadband internet inequality.

    Science.gov (United States)

    Perzynski, Adam T; Roach, Mary Joan; Shick, Sarah; Callahan, Bill; Gunzler, Douglas; Cebul, Randall; Kaelber, David C; Huml, Anne; Thornton, John Daryl; Einstadter, Douglas

    2017-09-01

    Patient portals have shown potential for increasing health care quality and efficiency. Internet access and other factors influencing patient portal use could worsen health disparities. Observational study of adults with 1 or more visits to the outpatient clinics of an urban public health care system from 2012 to 2015. We used mixed effects logistic regression to evaluate the association between broadband internet access and (1) patient portal initiation (whether a patient logged in at least 1 time) and (2) messaging, controlling for demographic and neighborhood characteristics. There were 243 248 adults with 1 or more visits during 2012-2015 and 70 835 (29.1%) initiated portal use. Portal initiation was 34.1% for whites, 23.4% for blacks, and 23.8% for Hispanics, and was lower for Medicaid (26.5%), Medicare (23.4%), and uninsured patients (17.4%) than commercially insured patients (39.3%). In multivariate analysis, both initiation of portal use (odds ratio [OR] = 1.24 per quintile, 95% confidence interval [CI], 1.23-1.24, P  internet access. The majority of adults with outpatient visits to a large urban health care system did not use the patient portal, and initiation of use was lower for racial and ethnic minorities, persons of lower socioeconomic status, and those without neighborhood broadband internet access. These results suggest the emergence of a digital divide in patient portal use. Given the scale of investment in patient portals and other internet-dependent health information technologies, efforts are urgently needed to address this growing inequality. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  18. Preliminary study of visual effect of multiplex hologram

    Science.gov (United States)

    Fu, Huaiping; Xiong, Bingheng; Yang, Hong; Zhang, Xueguo

    2004-06-01

    The process of any movement of real object can be recorded and displayed by a multiplex holographic stereogram. An embossing multiplex holographic stereogram and a multiplex rainbow holographic stereogram have been made by us, the multiplex rainbow holographic stereogram reconstructs the dynamic 2D line drawing of speech organs, the embossing multiplex holographic stereogram reconstructs the process of an old man drinking water. In this paper, we studied the visual result of an embossing multiplex holographic stereogram made with 80 films of 2-D pictures. Forty-eight persons of aged from 13 to 67 were asked to see the hologram and then to answer some questions about the feeling of viewing. The results indicate that this kind of holograms could be accepted by human visual sense organ without any problem. This paper also discusses visual effect of the multiplex holography stereograms base on visual perceptual psychology. It is open out that the planar multiplex holograms can be recorded and present the movement of real animal and object. Not only have the human visual perceptual constancy for shape, just as that size, color, etc... but also have visual perceptual constancy for binocular parallax.

  19. Topology-optimized silicon photonic wire mode (de)multiplexer

    DEFF Research Database (Denmark)

    Frellsen, Louise Floor; Frandsen, Lars Hagedorn; Ding, Yunhong

    2015-01-01

    We have designed and for the first time experimentally verified a topology optimized mode (de)multiplexer, which demultiplexes the fundamental and the first order mode of a double mode photonic wire to two separate single mode waveguides (and multiplexes vice versa). The device has a footprint...

  20. Computerized multiplexing and processing of in-core signals

    International Nuclear Information System (INIS)

    Meyer, J.

    1982-09-01

    After a presentation of the in-core instrumentation the main objectives of electric connection multiplexing are given. The conclusion of a study led to choose the multiplexing solution for the reactor building/electric building connections and to associate an information order management system based on the utilization of microprocessors. Finally, the control system (processors, organization, communication, language) is presented [fr

  1. Multiplexing and data processing of in-core signals

    International Nuclear Information System (INIS)

    Meyer, M.

    1983-01-01

    The application of multiplexing and signal processing techniques used for reactor operation and utilisation of data from the in-core instrumentation system is described. After a brief recall about in-core instrumentation, the aims, the advantages of multiplexing are presented. One of the aims of this realization is to show the compatibity between the technologies used with a PWR environment [fr

  2. Explaining HIV Risk Multiplexity: A Social Network Analysis.

    Science.gov (United States)

    Felsher, Marisa; Koku, Emmanuel

    2018-04-21

    Risk multiplexity (i.e., overlap in drug-use, needle exchange and sexual relations) is a known risk factor for HIV. However, little is known about predictors of multiplexity. This study uses egocentric data from the Colorado Springs study to examine how individual, behavioral and social network factors influence engagement in multiplex risk behavior. Analyses revealed that compared to Whites, Hispanics were significantly more likely to engage in risk multiplexity and Blacks less so. Respondents who were similar to each other (e.g., in terms of race) had significantly higher odds of being in risk multiplex relationships, and respondents' risk perceptions and network size were significantly associated with engaging in multiplex risk behaviors. Findings from interaction analysis showed the effect of knowing someone with HIV on the odds of multiplexity depends partly on whether respondents' know their HIV status. Findings suggest that demographics, HIV behaviors and network factors impact engagement in multiplex risk behaviors, highlighting the need for multi-level interventions aimed at reducing HIV risk behavior.

  3. Dual-excitation upconverting nanoparticle and quantum dot aptasensor for multiplexed food pathogen detection.

    Science.gov (United States)

    Kurt, Hasan; Yüce, Meral; Hussain, Babar; Budak, Hikmet

    2016-07-15

    In this report, a dual-excitation sensing method was developed using aptamer-functionalized quantum dots and upconverting nanoparticles, exhibiting Stokes and anti-Stokes type excitation profiles, respectively. Conjugation of the aptamer-functionalized luminescent nanoparticles with the magnetic beads, comprising short DNA sequences that were partially complementary to the aptamer sequences, enabled facile separation of the analyte-free conjugates for fluorescent measurement. UV-Visible spectroscopy, Circular Dichroism spectroscopy, Dynamic Light Scattering and Polyacrylamide Gel Electrophoresis techniques were used to characterize the aptamer probes developed. The target-specific luminescent conjugates were applied for multiplex detection of model food pathogens, Salmonella typhimurium, and Staphylococcus aureus, in which the fluorescent emission spectra were obtained under UV excitation at 325nm for quantum dots and NIR excitation at 980nm for upconverting nanoparticles, respectively. The dual-excitation strategy was aimed to minimize cross-talk between the luminescent signals for multiplexed detection, and yielded limit of detection values of 16 and 28cfumL(-1) for Staphylococcus aureus, and Salmonella typhimurium, respectively. By employing a greater number of quantum dots and upconverting nanoparticles with non-overlapping fluorescent emissions, the proposed methodology might be exploited further to detect several analytes, simultaneously. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Data multiplexing in radio interferometric calibration

    Science.gov (United States)

    Yatawatta, Sarod; Diblen, Faruk; Spreeuw, Hanno; Koopmans, L. V. E.

    2018-03-01

    New and upcoming radio interferometers will produce unprecedented amount of data that demand extremely powerful computers for processing. This is a limiting factor due to the large computational power and energy costs involved. Such limitations restrict several key data processing steps in radio interferometry. One such step is calibration where systematic errors in the data are determined and corrected. Accurate calibration is an essential component in reaching many scientific goals in radio astronomy and the use of consensus optimization that exploits the continuity of systematic errors across frequency significantly improves calibration accuracy. In order to reach full consensus, data at all frequencies need to be calibrated simultaneously. In the SKA regime, this can become intractable if the available compute agents do not have the resources to process data from all frequency channels simultaneously. In this paper, we propose a multiplexing scheme that is based on the alternating direction method of multipliers with cyclic updates. With this scheme, it is possible to simultaneously calibrate the full data set using far fewer compute agents than the number of frequencies at which data are available. We give simulation results to show the feasibility of the proposed multiplexing scheme in simultaneously calibrating a full data set when a limited number of compute agents are available.

  5. Multiplexed microsatellite recovery using massively parallel sequencing

    Science.gov (United States)

    Jennings, T.N.; Knaus, B.J.; Mullins, T.D.; Haig, S.M.; Cronn, R.C.

    2011-01-01

    Conservation and management of natural populations requires accurate and inexpensive genotyping methods. Traditional microsatellite, or simple sequence repeat (SSR), marker analysis remains a popular genotyping method because of the comparatively low cost of marker development, ease of analysis and high power of genotype discrimination. With the availability of massively parallel sequencing (MPS), it is now possible to sequence microsatellite-enriched genomic libraries in multiplex pools. To test this approach, we prepared seven microsatellite-enriched, barcoded genomic libraries from diverse taxa (two conifer trees, five birds) and sequenced these on one lane of the Illumina Genome Analyzer using paired-end 80-bp reads. In this experiment, we screened 6.1 million sequences and identified 356958 unique microreads that contained di- or trinucleotide microsatellites. Examination of four species shows that our conversion rate from raw sequences to polymorphic markers compares favourably to Sanger- and 454-based methods. The advantage of multiplexed MPS is that the staggering capacity of modern microread sequencing is spread across many libraries; this reduces sample preparation and sequencing costs to less than $400 (USD) per species. This price is sufficiently low that microsatellite libraries could be prepared and sequenced for all 1373 organisms listed as 'threatened' and 'endangered' in the United States for under $0.5M (USD).

  6. Multiplexed electrospray scaling for liquid fuel injection

    International Nuclear Information System (INIS)

    Waits, C Mike; Hanrahan, Brendan; Lee, Ivan

    2010-01-01

    Evaporation and space-charge requirements are evaluated to understand the effect of device scaling and fuel preheating for a liquid fuel injector using a multiplexed electrospray (MES) configuration in compact combustion applications. This work reveals the influence of the droplet diameter, droplet velocity and droplet surface temperature as well as the surrounding gas temperature on the size and performance of microfabricated MES. Measurements from MES devices are used in the model to accurately account for the droplet diameter versus flow rate relationship, the minimum droplet diameter and the relevant droplet velocities. A maximum extractor electrode to ground electrode distance of 3.1 mm required to overcome space-charge forces is found to be independent of voltage or droplet velocity for large levels of multiplexing. This maximum distance also becomes the required evaporation length scale which imposes minimum fuel pre-heating requirements for large flow densities. Required fuel preheating is therefore evaluated for both ethanol and 1-butanol with combustor parameters relevant to fuel reformation, thermoelectric conversion, thermophotovoltaic conversion and thermionic conversion

  7. Non-identical multiplexing promotes chimera states

    Science.gov (United States)

    Ghosh, Saptarshi; Zakharova, Anna; Jalan, Sarika

    2018-01-01

    We present the emergence of chimeras, a state referring to coexistence of partly coherent, partly incoherent dynamics in networks of identical oscillators, in a multiplex network consisting of two non-identical layers which are interconnected. We demonstrate that the parameter range displaying the chimera state in the homogeneous first layer of the multiplex networks can be tuned by changing the link density or connection architecture of the same nodes in the second layer. We focus on the impact of the interconnected second layer on the enlargement or shrinking of the coupling regime for which chimeras are displayed in the homogeneous first layer. We find that a denser homogeneous second layer promotes chimera in a sparse first layer, where chimeras do not occur in isolation. Furthermore, while a dense connection density is required for the second layer if it is homogeneous, this is not true if the second layer is inhomogeneous. We demonstrate that a sparse inhomogeneous second layer which is common in real-world complex systems can promote chimera states in a sparse homogeneous first layer.

  8. Link prediction in multiplex online social networks

    Science.gov (United States)

    Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

    2017-02-01

    Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

  9. A micro-controlled universal message multiplexer

    International Nuclear Information System (INIS)

    Fontaine, G.; Guglielmi, L.; Jaeger, J.J.; Szafran, S.

    1981-01-01

    Based on the Motorola 6800, this multiplexer is designed to provide a microprocessor development tool in the specific environment of a high energy physics laboratory. The basic philosophy of this device is to allow communication of a target (prototype) processor with a host computer under control of a human operator. The host can be an experimental on-line computer or any remote machine with a time-sharing network. It is thus possible to speed up design and debugging of a physics application program by taking advantage of the sophisticated resources usually available in a computer centre (powerful editor, large disk space, source management via ''Patchy'' etc...). In addition to the classical cross-macroassembler, a loader is available on the host for down-line loading binary code, via the multiplexer, into the prototype memory. Such a scheme is easiextended to the communication of any host interactive processing program with a data acquisition microprocessor, and provides the latter with a convenient and easily portable extension of its computing power. A typical application of this mode is described in a separate paper

  10. Metropolitan area networks: a corner stone in the broadband era

    Science.gov (United States)

    Ghanem, Adel

    1991-02-01

    Deployment of Broadband ISDN is being influenced by both a market pull and a technology push. New broadband service opportunities exist in the business and residential sectors of the market place. It is envisioned that some customers will need connections directly to broadband switches because of the high bandwidth needed for their applications. At the same time Metropolitan Area Network (MAN) systems will serve those customers with bandwidth requirements less than or equal to 150 Mbps. A given MAN will have a geographical domain to serve where it will carry out the switching tasks within this domain. While MANs couldbe designed using differentarchitecturalconcepts the setofservices expected tobeprovidedby MANs could be equivalent to thelist ofservices thatwillbe supported by the targetbroadband network. This paperpositions MANs as a major building block for Broadband networks. It also examines the evolution process ofMANs as a needed step to assure the successful deployment of these new broadband services. 2. BISDN - OVERVIEW Broadband ISDN (BISDN) is being driven into existence by both a market pull as well as a technology push. Opportunities for new valueadded services are the prime market pull for future broadband networks. These services opportunities extend beyond simple voice and low speed data applications and cover both the residential and the business sectors of the market. It is noted for instance that business customers have growing needs for sophisticated telecommunication vehicles to support their

  11. Broadband availability in metropolitan and non-metropolitan Pennsylvania

    Directory of Open Access Journals (Sweden)

    Lawrence E. Wood

    2016-09-01

    Full Text Available Over the past few years having a broadband connection has become essential for many Internet activities. As broadband increases in importance, it becomes imperative to assess how its use and availability may vary, especially in relation to issues such as geographic location. For rural areas in particular, the availability of broadband service is especially important. This research assesses broadband service availability in rural areas of Pennsylvania, USA. In particular, it examines the extent to which Digital Subscriber Line (DSL and broadband cable modem services are being deployed throughout rural Pennsylvania. It compares this deployment with the availability of such services in the state’s urban and metropolitan areas. The results of this research suggest that there is a “digital divide” in terms of broadband availability between rural and urban areas of Pennsylvania. However, this “divide” is perhaps not as wide as might be expected. Thus, as broadband is becoming increasingly available in rural areas of the U.S. and throughout much of the rest of the world, this research concludes that while research must remain vigilant in terms of assessing advanced telecommunications availability in rural areas, future research should also be sure to focus on how such technologies can be used to promote economic and social concerns, including in relation to building online networks and diminishing social and professional isolation in rural areas.

  12. Multiplex PCR identification of Taenia spp. in rodents and carnivores.

    Science.gov (United States)

    Al-Sabi, Mohammad N S; Kapel, Christian M O

    2011-11-01

    The genus Taenia includes several species of veterinary and public health importance, but diagnosis of the etiological agent in definitive and intermediate hosts often relies on labor intensive and few specific morphometric criteria, especially in immature worms and underdeveloped metacestodes. In the present study, a multiplex PCR, based on five primers targeting the 18S rDNA and ITS2 sequences, produced a species-specific banding patterns for a range of Taenia spp. Species typing by the multiplex PCR was compared to morphological identification and sequencing of cox1 and/or 12S rDNA genes. As compared to sequencing, the multiplex PCR identified 31 of 32 Taenia metacestodes from rodents, whereas only 14 cysts were specifically identified by morphology. Likewise, the multiplex PCR identified 108 of 130 adult worms, while only 57 were identified to species by morphology. The tested multiplex PCR system may potentially be used for studies of Taenia spp. transmitted between rodents and carnivores.

  13. Broadband high-resolution multi-species CARS in gas-filled hollow-core photonic crystal fiber.

    Science.gov (United States)

    Trabold, Barbara M; Hupfer, Robert J R; Abdolvand, Amir; St J Russell, Philip

    2017-09-01

    We report the use of coherent anti-Stokes Raman spectroscopy (CARS) in gas-filled hollow-core photonic crystal fiber (HC-PCF) for trace gas detection. The long optical path-lengths yield a 60 dB increase in the signal level compared with free-space arrangements. This enables a relatively weak supercontinuum (SC) to be used as Stokes seed, along with a ns pump pulse, paving the way for broadband (>4000  cm -1 ) single-shot CARS with an unprecedented resolution of ∼100  MHz. A kagomé-style HC-PCF provides broadband guidance, and, by operating close to the pressure-tunable zero dispersion wavelength, we can ensure simultaneous phase-matching of all gas species. We demonstrate simultaneous measurement of the concentrations of multiple trace gases in a gas sample introduced into the core of the HC-PCF.

  14. Broadband infrared beam splitter for spaceborne interferometric infrared sounder.

    Science.gov (United States)

    Yu, Tianyan; Liu, Dingquan; Qin, Yang

    2014-10-01

    A broadband infrared beam splitter (BS) on ZnSe substrate used for the spaceborne interferometric infrared sounder (SIIRS) is studied in the spectral range of 4.44-15 μm. Both broadband antireflection coating and broadband beam-splitter coating in this BS are designed and tested. To optimize the optical properties and the stability of the BS, suitable infrared materials were selected, and improved deposition techniques were applied. The designed structures matched experimental data well, and the properties of the BS met the application specification of SIIRS.

  15. An integrated processor for photonic quantum states using a broadband light–matter interface

    International Nuclear Information System (INIS)

    Saglamyurek, E; Sinclair, N; Slater, J A; Heshami, K; Oblak, D; Tittel, W

    2014-01-01

    Faithful storage and coherent manipulation of quantum optical pulses are key for long distance quantum communications and quantum computing. Combining these functions in a light–matter interface that can be integrated on-chip with other photonic quantum technologies, e.g. sources of entangled photons, is an important step towards these applications. To date there have only been a few demonstrations of coherent pulse manipulation utilizing optical storage devices compatible with quantum states, and that only in atomic gas media (making integration difficult) and with limited capabilities. Here we describe how a broadband waveguide quantum memory based on the atomic frequency comb (AFC) protocol can be used as a programmable processor for essentially arbitrary spectral and temporal manipulations of individual quantum optical pulses. Using weak coherent optical pulses at the few photon level, we experimentally demonstrate sequencing, time-to-frequency multiplexing and demultiplexing, splitting, interfering, temporal and spectral filtering, compressing and stretching as well as selective delaying. Our integrated light–matter interface offers high-rate, robust and easily configurable manipulation of quantum optical pulses and brings fully practical optical quantum devices one step closer to reality. Furthermore, as the AFC protocol is suitable for storage of intense light pulses, our processor may also find applications in classical communications. (paper)

  16. Simultaneous multiplexed materials characterization using a high-precision hard X-ray micro-slit array

    International Nuclear Information System (INIS)

    Zhang, Fan; Allen, Andrew J.; Levine, Lyle E.; Mancini, Derrick C.; Ilavsky, Jan

    2015-01-01

    A novel measurement scheme that allows multiplexed simultaneous measurements from multiple nearby sample volumes is reported. The needs both for increased experimental throughput and for in operando characterization of functional materials under increasingly realistic experimental conditions have emerged as major challenges across the whole of crystallography. A novel measurement scheme that allows multiplexed simultaneous measurements from multiple nearby sample volumes is presented. This new approach enables better measurement statistics or direct probing of heterogeneous structure, dynamics or elemental composition. To illustrate, the submicrometer precision that optical lithography provides has been exploited to create a multiplexed form of ultra-small-angle scattering based X-ray photon correlation spectroscopy (USAXS-XPCS) using micro-slit arrays fabricated by photolithography. Multiplexed USAXS-XPCS is applied to follow the equilibrium dynamics of a simple colloidal suspension. While the dependence of the relaxation time on momentum transfer, and its relationship with the diffusion constant and the static structure factor, follow previous findings, this measurements-in-parallel approach reduces the statistical uncertainties of this photon-starved technique to below those associated with the instrument resolution. More importantly, we note the potential of the multiplexed scheme to elucidate the response of different components of a heterogeneous sample under identical experimental conditions in simultaneous measurements. In the context of the X-ray synchrotron community, this scheme is, in principle, applicable to all in-line synchrotron techniques. Indeed, it has the potential to open a new paradigm for in operando characterization of heterogeneous functional materials, a situation that will be even further enhanced by the ongoing development of multi-bend achromat storage ring designs as the next evolution of large-scale X-ray synchrotron facilities around

  17. Investigation into constant envelope orthogonal frequency division multiplexing for polarization-division multiplexing coherent optical communication

    Science.gov (United States)

    Li, Yupeng; Ding, Ding

    2017-09-01

    Benefiting from the high spectral efficiency and low peak-to-average power ratio, constant envelope orthogonal frequency division multiplexing (OFDM) is a promising technique in coherent optical communication. Polarization-division multiplexing (PDM) has been employed as an effective way to double the transmission capacity in the commercial 100 Gb/s PDM-QPSK system. We investigated constant envelope OFDM together with PDM. Simulation results show that the acceptable maximum launch power into the fiber improves 10 and 6 dB for 80- and 320-km transmission, respectively (compared with the conventional PDM OFDM system). The maximum reachable distance of the constant envelope OFDM system is able to reach 800 km, and even 1200 km is reachable if an ideal erbium doped fiber amplifier is employed.

  18. Modern spectroscopy

    CERN Document Server

    Hollas, J Michael

    2013-01-01

    The latest edition of this highly acclaimed title introduces the reader to a wide range of spectroscopies, and includes both the background theory and applications to structure determination and chemical analysis.  It covers rotational, vibrational, electronic, photoelectron and Auger spectroscopy, as well as EXAFs and the theory of lasers and laser spectroscopy. A  revised and updated edition of a successful, clearly written book Includes the latest developments in modern laser techniques, such as cavity ring-down spectroscopy and femtosecond lasers Provides numerous worked examples, calculations and questions at the end of chapters.

  19. Broadband back grating design for thin film solar cells

    KAUST Repository

    Janjua, Bilal; Jabbour, Ghassan E.

    2013-01-01

    In this paper, design based on tapered circular grating structure was studied, to provide broadband enhancement in thin film amorphous silicon solar cells. In comparison to planar structure an absorption enhancement of ~ 7% was realized.

  20. Fixed Broadband Deployment Data: June, 2016 Status V1

    Data.gov (United States)

    Federal Communications Commission — Version 1 reflects data filed by the March 1, 2016 filing deadline and any revisions made before February 10, 2017. All facilities-based broadband providers are...

  1. Broadband Reflective Coating Process for Large FUVOIR Mirrors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — ZeCoat Corporation will develop and demonstrate a set of revolutionary coating processes for making broadband reflective coatings suitable for very large mirrors (4+...

  2. Fixed Broadband Deployment Data: June, 2016 Status V2

    Data.gov (United States)

    Federal Communications Commission — This data contains status reports for June 2016, with revisions accepted through May 2017. All facilities-based broadband providers are required to file data with...

  3. Expressive Communication and Human Development in the New Broadband Environment

    Science.gov (United States)

    Carey, John

    2004-01-01

    An understanding of the structure and functions of expressive communication in face-to-face communication and audiovisual media can inform the development of new educational services for human development across cultures in the emerging broadband environment.

  4. Broadband Wireless Data Acquisition and Control Device, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Mobitrum is proposing to develop a broadband wireless device for real-time data acquisition and monitoring applicable to the field instrumentation and control...

  5. 76 FR 13769 - Rural Broadband Access Loans and Loan Guarantees

    Science.gov (United States)

    2011-03-14

    ... pharmacy work, and savings to health facilities from outsourcing specialized medical procedures. One study... international markets and enables new, small, and home-based businesses to thrive. Broadband access affords...

  6. 78 FR 8353 - Rural Broadband Access Loans and Loan Guarantees

    Science.gov (United States)

    2013-02-06

    ... outsourcing specialized medical procedures. One study of 24 rural hospitals placed the annual cost of not... a key to economic growth. For rural businesses, broadband gives access to national and international...

  7. Prototype data terminal: Multiplexer/demultiplexer

    Science.gov (United States)

    Leck, D. E.; Goodwin, J. E.

    1972-01-01

    The design and operation of a quad redundant data terminal and a multiplexer/demultiplexer (MDU) design are described. The most unique feature is the design of the quad redundant data terminal. This is one of the few designs where the unit is fail/op, fail/op, fail/safe. Laboratory tests confirm that the unit will operate satisfactorily with the failure of three out of four channels. Although the design utilizes state-of-the-art technology. The waveform error checks, the voting techniques, and the parity bit checks are believed to be used in unique configurations. Correct word selection routines are also novel, if not unique. The MDU design, while not redundant, utilizes, the latest state-of-the-art advantages of light couplers and integrated circuit amplifiers.

  8. Mode demultiplexer using angularly multiplexed volume holograms.

    Science.gov (United States)

    Wakayama, Yuta; Okamoto, Atsushi; Kawabata, Kento; Tomita, Akihisa; Sato, Kunihiro

    2013-05-20

    This study proposes a volume holographic demultiplexer (VHDM) for extracting the spatial modes excited in a multimode fiber. A unique feature of the demultiplexer is that it can separate a number of multiplexed modes output from a fiber in different directions by using multi-recorded holograms without beam splitters, which results in a simple configuration as compared with that using phase plates instead of holograms. In this study, an experiment is conducted to demonstrate the basic operations for three LP mode groups to confirm the performance of the proposed VHDM and to estimate the signal-to-crosstalk noise ratio (SNR). As a result, an SNR of greater than 20 dB is obtained.

  9. Broadband and High power Reactive Jamming Resilient Wireless Communication

    Science.gov (United States)

    2017-10-21

    Broadband and High -power Reactive Jamming Resilient Wireless Communication The views, opinions and/or findings contained in this report are those of... available in extremely hostile environments, where FHSS and DSSS are completely defeated by a broadband and high -power reactive jammer. b. Wireless...SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6. AUTHORS

  10. Crosstalk analysis of a broadband data communications system

    Science.gov (United States)

    Crutcher, R. I.; Ewing, P. D.; Hayes, T. W.

    1987-11-01

    A broadband cable system represents a significant resource for data transmission within a facility. Duplication of a broadband network to provide services of varying sensitivity levels within the same area is wasteful of capital resources. The sharing of a network by different data services is financially attractive providing that sensitive data are inaccessible from nonsensitive ports. The use of equipment from two manufacturers introduces a deliberate incompatibility for the purpose of data isolation. This report presents test results obtained by this technique.

  11. Investigating broadband acoustic adsorption using rapid manufacturing

    Science.gov (United States)

    Godbold, O.

    The reduction of nuisance noise and the removal of unwanted sound modes within a room or component enclosure-area can be accomplished through the use of acoustic absorbers. Sound absorption can be achieved through conversion of the kinetic energy associated with pressure waves, into heat energy via viscous dissipation. This occurs within open porous materials, or by utilising resonant effects produced using simple cavity and orifice configurations. The manufacture of traditional porous and resonant absorbers is commonly realised using basic manufacturing techniques. These techniques restrict the geometry of a given resonant construction, and limit the configuration of porous absorbers. The aim of this work is to exploit new and emerging capabilities of Rapid Manufacturing (RM) to produce components with geometrical freedom, and apply it to the development of broadband acoustic absorption. New and novel absorber geometric configurations are identified and their absorption performance is determined. The capabilities and limitations of RM processes in reproducing these configurations are demonstrated. The geometric configuration of RM resonant absorbers is investigated. Cavity modifications aimed at damping the resonant effect by restricting the motion of cavity air, and adding increased viscous resistance are explored. Modifications relating to cavity shape, the addition of internal perforations and increased cavity surface area have all been shown to add acoustic resistance, thereby increasing the bandwidth of absorption. Decreasing the hydraulic radius of the cavity cross section and reducing internal feature dimensions provide improved resistance over conventional configurations..

  12. Broadband spectrally dynamic solid state illumination source

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, David B; Asghar, Ali; Gupta, Shalini; Kang, Hun; Pan, Ming [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Strassburg, Martin [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Georgia State University, Department of Physics and Astronomy, Atlanta, GA 30302-4106 (United States); Summers, Chris; Ferguson, Ian T [Georgia Institute of Technology, School of Materials Science and Engineering, Atlanta, GA 30332 (United States)

    2006-06-15

    Solid state lighting has done well recently in niche markets such as signage and displays, however, no available SSL technologies incorporate all the necessary attributes for general illumination. Development of a novel solid state general illumination source is discussed here. Two LEDs emitting at two distinct wavelengths can be monolithically grown and used to excite two or more phosphors with varied excitation spectra. The combined phosphorescence spectrum can then be controlled by adjusting the relative intensities of the two LED emissions. Preliminary phosphor analysis shows such a scheme to be viable for use in a spectrally dynamic broadband general illumination source. A tunnel junction is envisioned as a means of current spreading in a buried layer for three terminal operation. However, tunnel junction properties in GaN based materials are not well understood, and require further optimization to be practical devices. Preliminary results on GaN tunnel junctions are presented here as well. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Broadband over powerline : advances and applications

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, E.W. [EnerNex Corp., Knoxville, TN (United States)

    2006-07-01

    An overview of the broadband over powerline (BPL) industry was presented with reference to the history of the technology; current trials and deployments; applications; and, technologies currently in service. The presentation offers background information and a history of BPL, an early adopters test lab, BPL deployment map and access BPL stats. A comparison of wireless, hybrid and fiber optic communication technologies was presented along with access BPL systems and a review of how BPL can enhance utility operations. Diagnostic monitoring, operations improvement, system protection, load and DG management, distribution automation, and customer interface were included in an eye chart for operations enhancement. Suggestions on how BPL can reduce distribution line radio interference were presented along with examples of how BPL EMI analysis can find faulty electrical equipment. BPL customer services include Internet access, consumer portal, voice over Internet protocol, video surveillance, video conferencing, and building automation and energy management. BPL technical issues include installation, operation and electromagnetic compatibility. BPL regulations and standard efforts were described. It was concluded that BPL has a variety of applications in the utility sector including power quality, reliability monitoring and improvement. 1 tab., 7 figs.

  14. Broadband Vibration Attenuation Using Hybrid Periodic Rods

    Directory of Open Access Journals (Sweden)

    S. Asiri

    2008-12-01

    Full Text Available This paper presents both theoretically and experimentally a new kind of a broadband vibration isolator. It is a table-like system formed by four parallel hybrid periodic rods connected between two plates. The rods consist of an assembly of periodic cells, each cell being composed of a short rod and piezoelectric inserts. By actively controlling the piezoelectric elements, it is shown that the periodic rods can efficiently attenuate the propagation of vibration from the upper plate to the lower one within critical frequency bands and consequently minimize the effects of transmission of undesirable vibration and sound radiation. In such a system, longitudinal waves can propagate from the vibration source in the upper plate to the lower one along the rods only within specific frequency bands called the "Pass Bands" and wave propagation is efficiently attenuated within other frequency bands called the "Stop Bands". The spectral width of these bands can be tuned according to the nature of the external excitation. The theory governing the operation of this class of vibration isolator is presented and their tunable filtering characteristics are demonstrated experimentally as functions of their design parameters. This concept can be employed in many applications to control the wave propagation and the force transmission of longitudinal vibrations both in the spectral and spatial domains in an attempt to stop/attenuate the propagation of undesirable disturbances.

  15. Silicon Micromachined Sensor for Broadband Vibration Analysis

    Science.gov (United States)

    Gutierrez, Adolfo; Edmans, Daniel; Cormeau, Chris; Seidler, Gernot; Deangelis, Dave; Maby, Edward

    1995-01-01

    The development of a family of silicon based integrated vibration sensors capable of sensing mechanical resonances over a broad range of frequencies with minimal signal processing requirements is presented. Two basic general embodiments of the concept were designed and fabricated. The first design was structured around an array of cantilever beams and fabricated using the ARPA sponsored multi-user MEMS processing system (MUMPS) process at the Microelectronics Center of North Carolina (MCNC). As part of the design process for this first sensor, a comprehensive finite elements analysis of the resonant modes and stress distribution was performed using PATRAN. The dependence of strain distribution and resonant frequency response as a function of Young's modulus in the Poly-Si structural material was studied. Analytical models were also studied. In-house experimental characterization using optical interferometry techniques were performed under controlled low pressure conditions. A second design, intended to operate in a non-resonant mode and capable of broadband frequency response, was proposed and developed around the concept of a cantilever beam integrated with a feedback control loop to produce a null mode vibration sensor. A proprietary process was used to integrat a metal-oxide semiconductor (MOS) sensing device, with actuators and a cantilever beam, as part of a compatible process. Both devices, once incorporated as part of multifunction data acquisition and telemetry systems will constitute a useful system for NASA launch vibration monitoring operations. Satellite and other space structures can benefit from the sensor for mechanical condition monitoring functions.

  16. Broadband Ionospheric Scintillation Measurements from Space

    Science.gov (United States)

    Suszcynsky, D. M.; Light, M. E.; Pigue, M. J.

    2014-12-01

    The U.S. Department of Energy's Radio Frequency Propagation (RFProp) experiment consists of a satellite-based radio receiver suite to study various aspects of trans-ionospheric signal propagation and detection in four frequency bands, 2 - 55 MHz, 125 - 175 MHz, 365 - 415 MHz and 825 - 1100 MHz. In this paper, we present an overview of the RFProp on-orbit research and analysis effort with particular focus on an equatorial scintillation experiment called ESCINT. The 3-year ESCINT project is designed to characterize equatorial ionospheric scintillation in the upper HF and lower VHF portions of the radio spectrum (20 - 150 MHz). Both a 40 MHz continuous wave (CW) signal and 30 - 42 MHz swept frequency signal are transmitted to the satellite receiver suite from the Reagan Test Site at Kwajalein Atoll in the Marshall Islands (8.7° N, 167.7° E) in four separate campaigns centered on the 2014 and 2015 equinoxes. Results from the first campaign conducted from April 22 - May 15, 2014 will be presented including (a) coherence bandwidth measurements over a full range of transmission frequencies and scintillation activity levels, (b) spread-Doppler clutter effects arising from preferential ray paths to the satellite due to refraction off of isolated density irregularities, and (c) supporting ray-trace simulations. The broadband nature of the measurements is found to offer unique insight into both the structure of ionospheric irregularities and their impact on HF/VHF trans-ionospheric radio wave propagation.

  17. Broadband unidirectional invisibility for airborne sound

    Science.gov (United States)

    Kan, Weiwei; Guo, Mengping; Shen, Zhonghua

    2018-05-01

    We present a metafluid-based broadband cloak capable of guiding acoustic waves around obstacles along given directions while maintaining the wavefront undisturbed. The required parameter distribution of the proposed cloak is derived by coordinate transformation and practically implemented by employing the acoustic metafluid formed with periodically arranged slabs in acoustic chambers. The method for independently modulating the effective mass density and bulk modulus of the metafluid is developed by tuning the geometry parameters and the temperature of the acoustic chamber in a specific process. By virtue of this free-modulated method, the range of realizable effective parameters is substantially broadened, and the acoustic impedance of the anisotropic structures can be well matched to the background. The performance of the designed structure is quantitatively evaluated in the frequency range of 3-4 kHz by the averaged invisibility factor. The results show that the proposed cloak is effective in manipulating the acoustic field along the given direction and suppressing the wave scattering from the hidden object.

  18. A Broadband Ultrathin Nonlinear Switching Metamaterial

    Directory of Open Access Journals (Sweden)

    E. Zarnousheh Farahani

    2017-05-01

    Full Text Available In this paper, an ultrathin planar nonlinear metamaterial slab is designed and simulated. Nonlinearity is provided through placing diodes in each metamaterial unit cell. The diodes are auto-biased and activated by an incident wave. The proposed structure represents a broadband switching property between two transmission and reflection states depending on the intensity of the incident wave. High permittivity values are presented creating a near zero effective impedance at low power states, around the second resonant mode of the structure unit cell; as the result, the incident wave is reflected. Increasing the incident power to the level which can activate the loaded diodes in the structure results in elimination of the resonance and consequently a drop in the permittivity values near the permeability one as well as a switch to the transmission state. A full wave as well as a nonlinear simulations are performed. An optimization method based on weed colonization is applied to the unit cell of the metamaterial slab to achieve the maximum switching bandwidth. The structure represents a 24% switching bandwidth of a 10 dB reduction in the reflection coefficient.

  19. Pricing by timing: innovating broadband data plans

    Science.gov (United States)

    Ha, Sangtae; Joe-Wong, Carlee; Sen, Soumya; Chiang, Mung

    2012-01-01

    Wireless Internet usage is doubling every year. Users are using more of high bandwidth data applications, and the heavy usage concentrates on several peak hours in a day, forcing ISPs to overprovision their networks accordingly. In order to remain profitable, ISPs have been using pricing as a congestion management tool. We review many of such pricing schemes in practice today and argue that they do not solve ISPs' problem of growing data traffic. We believe that dynamic, time-dependent usage pricing, which charges users based on when they access the Internet, can incentivize users to spread out their bandwidth consumption more evenly across different times of the day, thus helping ISPs to overcome the problem of peak congestion. Congestion pricing is not a new idea in itself, but the time for its implementation in data networks has finally arrived. Our key contribution lies in developing new analysis and a fully integrated system architecture, called TUBE (Time-dependent Usage-based Broadband price Engineering) that enables ISPs to implement the proposed TDP plan. The theory, simulation, and system implementation of TUBE system is further complemented with consumer surveys conducted in India and the US, along with preparations for a field trial that is currently underway.

  20. Control of Angular Intervals for Angle-Multiplexed Holographic Memory

    Science.gov (United States)

    Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki

    2009-03-01

    In angle-multiplexed holographic memory, the full width at half maximum of the Bragg selectivity curves is dependent on the angle formed between the medium and incident laser beams. This indicates the possibility of high density and high multiplexing number by varying the angular intervals between adjacent holograms. We propose an angular interval scheduling for closely stacking holograms into medium even when the angle range is limited. We obtained bit error rates of the order of 10-4 under the following conditions: medium thickness of 1 mm, laser beam wavelength of 532 nm, and angular multiplexing number of 300.

  1. Opportunities and Challenges of Multiplex Assays: A Machine Learning Perspective.

    Science.gov (United States)

    Chen, Junfang; Schwarz, Emanuel

    2017-01-01

    Multiplex assays that allow the simultaneous measurement of multiple analytes in small sample quantities have developed into a widely used technology. Their implementation spans across multiple assay systems and can provide readouts of similar quality as the respective single-plex measures, albeit at far higher throughput. Multiplex assay systems are therefore an important element for biomarker discovery and development strategies but analysis of the derived data can face substantial challenges that may limit the possibility of identifying meaningful biological markers. This chapter gives an overview of opportunities and challenges of multiplexed biomarker analysis, in particular from the perspective of machine learning aimed at identification of predictive biological signatures.

  2. Experimental demonstration of subcarrier multiplexed quantum key distribution system.

    Science.gov (United States)

    Mora, José; Ruiz-Alba, Antonio; Amaya, Waldimar; Martínez, Alfonso; García-Muñoz, Víctor; Calvo, David; Capmany, José

    2012-06-01

    We provide, to our knowledge, the first experimental demonstration of the feasibility of sending several parallel keys by exploiting the technique of subcarrier multiplexing (SCM) widely employed in microwave photonics. This approach brings several advantages such as high spectral efficiency compatible with the actual secure key rates, the sharing of the optical fainted pulse by all the quantum multiplexed channels reducing the system complexity, and the possibility of upgrading with wavelength division multiplexing in a two-tier scheme, to increase the number of parallel keys. Two independent quantum SCM channels featuring a sifted key rate of 10 Kb/s/channel over a link with quantum bit error rate <2% is reported.

  3. Mobile charge generation dynamics in P3HT: PCBM observed by time-resolved terahertz spectroscopy

    DEFF Research Database (Denmark)

    Cooke, D. G.; Krebs, Frederik C; Jepsen, Peter Uhd

    2012-01-01

    Ultra-broadband time-resolved terahertz spectroscopy is used to examine the sub-ps conductivity dynamics of a conjugated polymer bulk heterojunction film P3HT:PCBM. We directly observe mobile charge generation dynamics on a sub-100 fs time scale.......Ultra-broadband time-resolved terahertz spectroscopy is used to examine the sub-ps conductivity dynamics of a conjugated polymer bulk heterojunction film P3HT:PCBM. We directly observe mobile charge generation dynamics on a sub-100 fs time scale....

  4. Broadband homonuclear TOCSY with amplitude and phase-modulated RF mixing schemes

    International Nuclear Information System (INIS)

    Kirschstein, Anika; Herbst, Christian; Riedel, Kerstin; Carella, Michela; Leppert, Joerg; Ohlenschlaeger, Oliver; Goerlach, Matthias; Ramachandran, Ramadurai

    2008-01-01

    We have explored the design of broadband scalar coupling mediated 13 C- 13 C and cross-relaxation suppressed 1 H- 1 H TOCSY sequences employing phase/amplitude modulated inversion pulses. Considering a variety of supercycles, pulsewidths and a RF field strength of 10 kHz, the Fourier coefficients defining the amplitude and phase modulation profiles of the 180 deg. pulses were optimised numerically so as to obtain efficient magnetisation transfer within the desired range of resonance offsets. The coherence transfer characteristics of the mixing schemes were assessed via numerical simulations and experimental measurements and were compared with commonly used sequences based on rectangular RF pulses. The efficacies of the clean 1 H- 1 H TOCSY sequences were also examined via numerical simulations for application to weakly oriented systems and sequences with efficient, broadband and clean dipolar transfer characteristics were identified. In general, the amplitude and phase modulated TOCSY sequences presented here have moderately better performance characteristics than the sequences currently employed in biomolecular NMR spectroscopy

  5. Eigenmode multiplexing with SLM for volume holographic data storage

    Science.gov (United States)

    Chen, Guanghao; Miller, Bo E.; Takashima, Yuzuru

    2017-08-01

    The cavity supports the orthogonal reference beam families as its eigenmodes while enhancing the reference beam power. Such orthogonal eigenmodes are used as additional degree of freedom to multiplex data pages, consequently increase storage densities for volume Holographic Data Storage Systems (HDSS) when the maximum number of multiplexed data page is limited by geometrical factor. Image bearing holograms are multiplexed by orthogonal phase code multiplexing via Hermite-Gaussian eigenmodes in a Fe:LiNbO3 medium with a 532 nm laser at multiple Bragg angles by using Liquid Crystal on Silicon (LCOS) spatial light modulators (SLMs) in reference arms. Total of nine holograms are recorded with three angular and three eigenmode.

  6. Multiplexing of spatial modes in the mid-IR region

    CSIR Research Space (South Africa)

    Gailele, Lucas M

    2017-02-01

    Full Text Available ceiling in the near future. Communications using orbital angular momentum (OAM) carrying modes offers in finite dimensional states, providing means to increase link capacity by multiplexing spatially overlapping modes in both the azimuthal and radial...

  7. Recent Progress in Space-Division Multiplexed Transmission Technologies

    DEFF Research Database (Denmark)

    Morioka, Toshio

    2013-01-01

    Recent development of transmission technologies based on space-division multiplexing is described with future perspectives including a recent achievement of one Pb/s transmission in a single strand of fiber....

  8. Capacity analysis of spectrum sharing spatial multiplexing MIMO systems

    KAUST Repository

    Yang, Liang; Qaraqe, Khalid A.; Serpedin, Erchin; Alouini, Mohamed-Slim

    2014-01-01

    This paper considers a spectrum sharing (SS) multiple-input multiple-output (MIMO) system operating in a Rayleigh fading environment. First the capacity of a single-user SS spatial multiplexing system is investigated in two scenarios that assume

  9. User Multiplexing in Relay Enhanced LTE-Advanced Networks

    DEFF Research Database (Denmark)

    Teyeb, Oumer Mohammed; Frederiksen, Frank; Redana, Simone

    2010-01-01

    is radio relaying. This uses relay nodes that act as surrogate base stations for mobile users whose radio links with the base stations are not experiencing good enough conditions. In the downlink, the data that is destined for the relayed users may first have to be multiplexed by the base station, sent...... over the wireless backhaul link towards the relay node, and de-multiplexed and forwarded to the individual users by the relay node. The reverse process also has to be undertaken in the uplink. In this paper, we present a novel multiplexing scheme which is able to adapt the addressing and bitmapping...... of user identification to the actual number of users being served by the relay nodes, and thus greatly reduce the multiplexing overhead....

  10. Characteristics of Multiplexed Grooved Nozzles for High Flow Rate Electrospray

    International Nuclear Information System (INIS)

    Kim, Kyoung Tae; Kim, Woo Jin; Kim, Sang Soo

    2007-01-01

    The electrospray operated in the cone-jet mode can generate highly charged micro droplets in an almost uniform size at flow rates. Therefore, the multiplexing system which can retain the characteristics of the cone-jet mode is inevitable for the electrospray application. This experiment reports the multiplexed grooved nozzle system with the extractor. The effects of the grooves and the extractor on the performance of the electrospray were evaluated through experiments. Using the grooved nozzle, the stable cone-jet mode can be achieved at the each groove in the grooved mode. Furthermore, the number of nozzles per unit area is increased by the extractor. The multiplexing density is 12 jets per cm 2 at 30 mm distance from the nozzle tip to the ground plate. The multiplexing system for the high flow rate electrospray is realized with the extractor which can diminish the space charge effect without sacrificing characteristics of the cone-jet mode

  11. Shift-Peristrophic Multiplexing for High Density Holographic Data Storage

    Directory of Open Access Journals (Sweden)

    Zenta Ushiyama

    2014-03-01

    Full Text Available Holographic data storage is a promising technology that provides very large data storage capacity, and the multiplexing method plays a significant role in increasing this capacity. Various multiplexing methods have been previously researched. In the present study, we propose a shift-peristrophic multiplexing technique that uses spherical reference waves, and experimentally verify that this method efficiently increases the data capacity. In the proposed method, a series of holograms is recorded with shift multiplexing, in which the recording material is rotated with its axis perpendicular to the material’s surface. By iterating this procedure, multiplicity is shown to improve. This method achieves more than 1 Tbits/inch2 data density recording. Furthermore, a capacity increase of several TB per disk is expected by maximizing the recording medium performance.

  12. Nanoscale Test Strips for Multiplexed Blood Analysis, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of our nanoscale test strips, or nanostrips, is to provide rapid, low-cost, powerful multiplexed analyses in a diminutive form so that whole body health...

  13. Multiplexed Dosing Assays by Digitally Definable Hydrogel Volumes

    DEFF Research Database (Denmark)

    Faralli, Adele; Melander, Fredrik; Larsen, Esben Kjær Unmack

    2016-01-01

    Stable and low-cost multiplexed drug sensitivity assays using small volumes of cells or tissue are in demand for personalized medicine, including patientspecific combination chemotherapy. Spatially defined projected light photopolymerization of hydrogels with embedded active compounds is introduc...

  14. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

  15. Computing broadband accelerograms using kinematic rupture modeling

    International Nuclear Information System (INIS)

    Ruiz Paredes, J.A.

    2007-05-01

    In order to make the broadband kinematic rupture modeling more realistic with respect to dynamic modeling, physical constraints are added to the rupture parameters. To improve the slip velocity function (SVF) modeling, an evolution of the k -2 source model is proposed, which consists to decompose the slip as a sum of sub-events by band of k. This model yields to SVF close to the solution proposed by Kostrov for a crack, while preserving the spectral characteristics of the radiated wave field, i.e. a w 2 model with spectral amplitudes at high frequency scaled to the coefficient of directivity C d . To better control the directivity effects, a composite source description is combined with a scaling law defining the extent of the nucleation area for each sub-event. The resulting model allows to reduce the apparent coefficient of directivity to a fraction of C d , as well as to reproduce the standard deviation of the new empirical attenuation relationships proposed for Japan. To make source models more realistic, a variable rupture velocity in agreement with the physics of the rupture must be considered. The followed approach that is based on an analytical relation between the fracture energy, the slip and the rupture velocity, leads to higher values of the peak ground acceleration in the vicinity of the fault. Finally, to better account for the interaction of the wave field with the geological medium, a semi-empirical methodology is developed combining a composite source model with empirical Green functions, and is applied to the Yamaguchi, M w 5.9 earthquake. The modeled synthetics reproduce satisfactorily well the observed main characteristics of ground motions. (author)

  16. BROADBAND OBSERVATIONS OF HIGH REDSHIFT BLAZARS

    Energy Technology Data Exchange (ETDEWEB)

    Paliya, Vaidehi S. [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States); Parker, M. L.; Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Stalin, C. S., E-mail: vpaliya@g.clemson.edu [Indian Institute of Astrophysics, Block II, Koramangala, Bangalore-560034 (India)

    2016-07-01

    We present a multi-wavelength study of four high redshift blazars, S5 0014+81 ( z = 3.37), CGRaBS J0225+1846 ( z = 2.69), BZQ J1430+4205 ( z = 4.72), and 3FGL J1656.2−3303 ( z = 2.40) using quasi-simultaneous data from the Swift , Nuclear Spectroscopic Telescope Array ( NuSTAR ) and the Fermi -Large Area Telescope (LAT) and also archival XMM-Newton observations. Other than 3FGL J1656.2−3303, none of the sources were known as γ -ray emitters, and our analysis of ∼7.5 yr of LAT data reveals the first time detection of statistically significant γ -ray emission from CGRaBS J0225+1846. We generate the broadband spectral energy distributions (SED) of all the objects, centering at the epoch of NuSTAR observations and reproduce them using a one-zone leptonic emission model. The optical−UV emission in all the objects can be explained by radiation from the accretion disk, whereas the X-ray to γ -ray windows of the SEDs are found to be dominated by inverse Compton scattering off the broad line region photons. All of them host black holes that are billions of solar masses. Comparing the accretion disk luminosity and the jet power of these sources with a large sample of blazars, we find them to occupy a high disk luminosity–jet power regime. We also investigate the X-ray spectral properties of the sources in detail with a major focus on studying the causes of soft X-ray deficit, a feature generally seen in high redshift radio-loud quasars. We summarize that this feature could be explained based on the intrinsic curvature in the jet emission rather than being due to the external effects predicted in earlier studies, such as host galaxy and/or warm absorption.

  17. Broadband Spectral Investigations of Magnetar Bursts

    Science.gov (United States)

    Kırmızıbayrak, Demet; Şaşmaz Muş, Sinem; Kaneko, Yuki; Göğüş, Ersin

    2017-09-01

    We present our broadband (2-250 keV) time-averaged spectral analysis of 388 bursts from SGR J1550-5418, SGR 1900+14, and SGR 1806-20 detected with the Rossi X-ray Timing Explorer (RXTE) here and as a database in a companion web-catalog. We find that two blackbody functions (BB+BB), the sum of two modified blackbody functions (LB+LB), the sum of a blackbody function and a power-law function (BB+PO), and a power law with a high-energy exponential cutoff (COMPT) all provide acceptable fits at similar levels. We performed numerical simulations to constrain the best fitting model for each burst spectrum and found that 67.6% of burst spectra with well-constrained parameters are better described by the Comptonized model. We also found that 64.7% of these burst spectra are better described with the LB+LB model, which is employed in the spectral analysis of a soft gamma repeater (SGR) for the first time here, than with the BB+BB and BB+PO models. We found a significant positive lower bound trend on photon index, suggesting a decreasing upper bound on hardness, with respect to total flux and fluence. We compare this result with bursts observed from SGR and AXP (anomalous X-ray pulsar) sources and suggest that the relationship is a distinctive characteristic between the two. We confirm a significant anticorrelation between burst emission area and blackbody temperature, and find that it varies between the hot and cool blackbody temperatures differently than previously discussed. We expand on the interpretation of our results in the framework of a strongly magnetized neutron star.

  18. Broadband Spectral Investigations of Magnetar Bursts

    Energy Technology Data Exchange (ETDEWEB)

    Kırmızıbayrak, Demet; Şaşmaz Muş, Sinem; Kaneko, Yuki; Göğüş, Ersin, E-mail: demetk@sabanciuniv.edu [Faculty of Engineering and Natural Sciences, Sabancı University, Orhanlı Tuzla, Istanbul 34956 (Turkey)

    2017-09-01

    We present our broadband (2–250 keV) time-averaged spectral analysis of 388 bursts from SGR J1550−5418, SGR 1900+14, and SGR 1806−20 detected with the Rossi X-ray Timing Explorer ( RXTE ) here and as a database in a companion web-catalog. We find that two blackbody functions (BB+BB), the sum of two modified blackbody functions (LB+LB), the sum of a blackbody function and a power-law function (BB+PO), and a power law with a high-energy exponential cutoff (COMPT) all provide acceptable fits at similar levels. We performed numerical simulations to constrain the best fitting model for each burst spectrum and found that 67.6% of burst spectra with well-constrained parameters are better described by the Comptonized model. We also found that 64.7% of these burst spectra are better described with the LB+LB model, which is employed in the spectral analysis of a soft gamma repeater (SGR) for the first time here, than with the BB+BB and BB+PO models. We found a significant positive lower bound trend on photon index, suggesting a decreasing upper bound on hardness, with respect to total flux and fluence. We compare this result with bursts observed from SGR and AXP (anomalous X-ray pulsar) sources and suggest that the relationship is a distinctive characteristic between the two. We confirm a significant anticorrelation between burst emission area and blackbody temperature, and find that it varies between the hot and cool blackbody temperatures differently than previously discussed. We expand on the interpretation of our results in the framework of a strongly magnetized neutron star.

  19. Specdata: Automated Analysis Software for Broadband Spectra

    Science.gov (United States)

    Oliveira, Jasmine N.; Martin-Drumel, Marie-Aline; McCarthy, Michael C.

    2017-06-01

    With the advancement of chirped-pulse techniques, broadband rotational spectra with a few tens to several hundred GHz of spectral coverage are now routinely recorded. When studying multi-component mixtures that might result, for example, with the use of an electrical discharge, lines of new chemical species are often obscured by those of known compounds, and analysis can be laborious. To address this issue, we have developed SPECdata, an open source, interactive tool which is designed to simplify and greatly accelerate the spectral analysis and discovery. Our software tool combines both automated and manual components that free the user from computation, while giving him/her considerable flexibility to assign, manipulate, interpret and export their analysis. The automated - and key - component of the new software is a database query system that rapidly assigns transitions of known species in an experimental spectrum. For each experiment, the software identifies spectral features, and subsequently assigns them to known molecules within an in-house database (Pickett .cat files, list of frequencies...), or those catalogued in Splatalogue (using automatic on-line queries). With suggested assignments, the control is then handed over to the user who can choose to accept, decline or add additional species. Data visualization, statistical information, and interactive widgets assist the user in making decisions about their data. SPECdata has several other useful features intended to improve the user experience. Exporting a full report of the analysis, or a peak file in which assigned lines are removed are among several options. A user may also save their progress to continue at another time. Additional features of SPECdata help the user to maintain and expand their database for future use. A user-friendly interface allows one to search, upload, edit or update catalog or experiment entries.

  20. Dynamical interplay between awareness and epidemic spreading in multiplex networks

    OpenAIRE

    Granell, Clara; Gomez, Sergio; Arenas, Alex

    2013-01-01

    We present the analysis of the interrelation between two processes accounting for the spreading of an epidemics, and the information awareness to prevent its infection, on top of multiplex networks. This scenario is representative of an epidemic process spreading on a network of persistent real contacts, and a cyclic information awareness process diffusing in the network of virtual social contacts between the same individuals. The topology corresponds to a multiplex network where two diffusiv...

  1. Interferometric crosstalk suppression using polarization multiplexing technique and an SOA

    DEFF Research Database (Denmark)

    Liu, Fenghai; Xueyan, Zheng; Pedersen, Rune Johan Skullerud

    2000-01-01

    Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA.......Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA....

  2. Characterization of highly multiplexed monolithic PET / gamma camera detector modules

    Science.gov (United States)

    Pierce, L. A.; Pedemonte, S.; DeWitt, D.; MacDonald, L.; Hunter, W. C. J.; Van Leemput, K.; Miyaoka, R.

    2018-04-01

    PET detectors use signal multiplexing to reduce the total number of electronics channels needed to cover a given area. Using measured thin-beam calibration data, we tested a principal component based multiplexing scheme for scintillation detectors. The highly-multiplexed detector signal is no longer amenable to standard calibration methodologies. In this study we report results of a prototype multiplexing circuit, and present a new method for calibrating the detector module with multiplexed data. A 50 × 50 × 10 mm3 LYSO scintillation crystal was affixed to a position-sensitive photomultiplier tube with 8 × 8 position-outputs and one channel that is the sum of the other 64. The 65-channel signal was multiplexed in a resistive circuit, with 65:5 or 65:7 multiplexing. A 0.9 mm beam of 511 keV photons was scanned across the face of the crystal in a 1.52 mm grid pattern in order to characterize the detector response. New methods are developed to reject scattered events and perform depth-estimation to characterize the detector response of the calibration data. Photon interaction position estimation of the testing data was performed using a Gaussian Maximum Likelihood estimator and the resolution and scatter-rejection capabilities of the detector were analyzed. We found that using a 7-channel multiplexing scheme (65:7 compression ratio) with 1.67 mm depth bins had the best performance with a beam-contour of 1.2 mm FWHM (from the 0.9 mm beam) near the center of the crystal and 1.9 mm FWHM near the edge of the crystal. The positioned events followed the expected Beer–Lambert depth distribution. The proposed calibration and positioning method exhibited a scattered photon rejection rate that was a 55% improvement over the summed signal energy-windowing method.

  3. Broadband enhancement of local density of states using silicon-compatible hyperbolic metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yu; Inampudi, Sandeep; Capretti, Antonio [Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary' s Street Boston, Massachusetts 02215 (United States); Sugimoto, Hiroshi [Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary' s Street Boston, Massachusetts 02215 (United States); Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Fujii, Minoru [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Dal Negro, Luca, E-mail: dalnegro@bu.edu [Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary' s Street Boston, Massachusetts 02215 (United States); Division of Materials Science and Engineering, Boston University, 15 Saint Mary' s Street, Brookline, Massachusetts 02446 (United States)

    2015-06-15

    Light emitting silicon quantum dots by colloidal synthesis were uniformly spin-coated into a 20 nm-thick film and deposited atop a hyperbolic metamaterial of alternating TiN and SiO{sub 2} sub-wavelength layers. Using steady-state and time-resolved photoluminescence spectroscopy as a function of the emission wavelength in partnership with rigorous electromagnetic modeling of dipolar emission, we demonstrate enhanced Local Density of States and coupling to high-k modes in a broad spectral range. These findings provide an alternative approach for the engineering of novel Si-compatible broadband sources that leverage the control of radiative transitions in hyperbolic metamaterials and the flexibility of the widespread Si platform.

  4. The broadband microwave spectra of the monoterpenoids thymol and carvacrol: Conformational landscape and internal dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, D.; Shubert, V. A. [Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany); The Center for Free-Electron Laser Science, Hamburg (Germany); Giuliano, B. M. [Center for Astrobiology, INTA-CSIC, Torrejón de Ardoz, Madrid (Spain); Schnell, M., E-mail: melanie.schnell@mpsd.mpg.de [Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany); The Center for Free-Electron Laser Science, Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg (Germany)

    2014-07-21

    The rotational spectra of the monoterpenoids thymol and carvacrol are reported in the frequency range 2–8.5 GHz, obtained with broadband Fourier-transform microwave spectroscopy. For carvacrol four different conformations were identified in the cold conditions of the molecular jet, whereas only three conformations were observed for thymol. The rotational constants and other molecular parameters are reported and compared with quantum chemical calculations. For both molecules, line splittings due to methyl group internal rotation were observed and the resulting barrier heights could be determined. The experimental barrier heights, 4.0863(25) kJ/mol for trans-carvacrol-A, 4.4024(16) kJ/mol for trans-carvacrol-B, and 0.3699(11) kJ/mol for trans-thymol-A, are compared with similar molecules.

  5. The broadband microwave spectra of the monoterpenoids thymol and carvacrol: Conformational landscape and internal dynamics

    International Nuclear Information System (INIS)

    Schmitz, D.; Shubert, V. A.; Giuliano, B. M.; Schnell, M.

    2014-01-01

    The rotational spectra of the monoterpenoids thymol and carvacrol are reported in the frequency range 2–8.5 GHz, obtained with broadband Fourier-transform microwave spectroscopy. For carvacrol four different conformations were identified in the cold conditions of the molecular jet, whereas only three conformations were observed for thymol. The rotational constants and other molecular parameters are reported and compared with quantum chemical calculations. For both molecules, line splittings due to methyl group internal rotation were observed and the resulting barrier heights could be determined. The experimental barrier heights, 4.0863(25) kJ/mol for trans-carvacrol-A, 4.4024(16) kJ/mol for trans-carvacrol-B, and 0.3699(11) kJ/mol for trans-thymol-A, are compared with similar molecules

  6. Multicomponent chemical imaging of pharmaceutical solid dosage forms with broadband CARS microscopy.

    Science.gov (United States)

    Hartshorn, Christopher M; Lee, Young Jong; Camp, Charles H; Liu, Zhen; Heddleston, John; Canfield, Nicole; Rhodes, Timothy A; Hight Walker, Angela R; Marsac, Patrick J; Cicerone, Marcus T

    2013-09-03

    We compare a coherent Raman imaging modality, broadband coherent anti-Stokes Raman scattering (BCARS) microscopy, with spontaneous Raman microscopy for quantitative and qualitative assessment of multicomponent pharmaceuticals. Indomethacin was used as a model active pharmaceutical ingredient (API) and was analyzed in a tabulated solid dosage form, embedded within commonly used excipients. In comparison with wide-field spontaneous Raman chemical imaging, BCARS acquired images 10× faster, at higher spatiochemical resolution and with spectra of much higher SNR, eliminating the need for multivariate methods to identify chemical components. The significant increase in spatiochemical resolution allowed identification of an unanticipated API phase that was missed by the spontaneous wide-field method and bulk Raman spectroscopy. We confirmed the presence of the unanticipated API phase using confocal spontaneous Raman, which provided spatiochemical resolution similar to BCARS but at 100× slower acquisition times.

  7. Cavity enhanced eigenmode multiplexing for volume holographic data storage

    Science.gov (United States)

    Miller, Bo E.; Takashima, Yuzuru

    2017-08-01

    Previously, we proposed and experimentally demonstrated enhanced recording speeds by using a resonant optical cavity to semi-passively increase the reference beam power while recording image bearing holograms. In addition to enhancing the reference beam power the cavity supports the orthogonal reference beam families of its eigenmodes, which can be used as a degree of freedom to multiplex data pages and increase storage densities for volume Holographic Data Storage Systems (HDSS). While keeping the increased recording speed of a cavity enhanced reference arm, image bearing holograms are multiplexed by orthogonal phase code multiplexing via Hermite-Gaussian eigenmodes in a Fe:LiNbO3 medium with a 532 nm laser at two Bragg angles for expedited recording of four multiplexed holograms. We experimentally confirmed write rates are enhanced by an average factor of 1.1, and page crosstalk is about 2.5%. This hybrid multiplexing opens up a pathway to increase storage density while minimizing modifications to current angular multiplexing HDSS.

  8. Multiplexing a high-throughput liability assay to leverage efficiencies.

    Science.gov (United States)

    Herbst, John; Anthony, Monique; Stewart, Jeremy; Connors, David; Chen, Taosheng; Banks, Martyn; Petrillo, Edward W; Agler, Michele

    2009-06-01

    In order to identify potential cytochrome P-450 3A4 (drug-metabolizing enzyme) inducers at an early stage of the drug discovery process, a cell-based transactivation high-throughput luciferase reporter assay for the human pregnane X receptor (PXR) in HepG2 cells has been implemented and multiplexed with a viability end point for data interpretation, as part of a Lead Profiling portfolio of assays. As a routine part of Lead Profiling operations, assays are periodically evaluated for utility as well as for potential improvements in technology or process. We used a recent evaluation of our PXR-transactivation assay as a model for the application of Lean Thinking-based process analysis to lab-bench assay optimization and automation. This resulted in the development of a 384-well multiplexed homogeneous assay simultaneously detecting PXR transactivation and HepG2 cell cytotoxicity. In order to multiplex fluorescent and luminescent read-outs, modifications to each assay were necessary, which included optimization of multiple assay parameters such as cell density, plate type, and reagent concentrations. Subsequently, a set of compounds including known cytotoxic compounds and PXR inducers were used to validate the multiplexed assay. Results from the multiplexed assay correlate well with those from the singleplexed assay formats measuring PXR transactivation and viability separately. Implementation of the multiplexed assay for routine compound profiling provides improved data quality, sample conservation, cost savings, and resource efficiencies.

  9. Optimizing diffusion in multiplexes by maximizing layer dissimilarity

    Science.gov (United States)

    Serrano, Alfredo B.; Gómez-Gardeñes, Jesús; Andrade, Roberto F. S.

    2017-05-01

    Diffusion in a multiplex depends on the specific link distribution between the nodes in each layer, but also on the set of the intralayer and interlayer diffusion coefficients. In this work we investigate, in a quantitative way, the efficiency of multiplex diffusion as a function of the topological similarity among multiplex layers. This similarity is measured by the distance between layers, taken among the pairs of layers. Results are presented for a simple two-layer multiplex, where one of the layers is held fixed, while the other one can be rewired in a controlled way in order to increase or decrease the interlayer distance. The results indicate that, for fixed values of all intra- and interlayer diffusion coefficients, a large interlayer distance generally enhances the global multiplex diffusion, providing a topological mechanism to control the global diffusive process. For some sets of networks, we develop an algorithm to identify the most sensitive nodes in the rewirable layer, so that changes in a small set of connections produce a drastic enhancement of the global diffusion of the whole multiplex system.

  10. Link overlap, viability, and mutual percolation in multiplex networks

    International Nuclear Information System (INIS)

    Min, Byungjoon; Lee, Sangchul; Lee, Kyu-Min; Goh, K.-I.

    2015-01-01

    Many real-world complex systems are best modeled by multiplex networks. The multiplexity has proved to have broad impact on the system’s structure and function. Most theoretical studies on multiplex networks to date, however, have largely ignored the effect of the link overlap across layers despite strong empirical evidences for its significance. In this article, we investigate the effect of the link overlap in the viability of multiplex networks, both analytically and numerically. After a short recap of the original multiplex viability study, the distinctive role of overlapping links in viability and mutual connectivity is emphasized and exploited for setting up a proper analytic framework. A rich phase diagram for viability is obtained and greatly diversified patterns of hysteretic behavior in viability are observed in the presence of link overlap. Mutual percolation with link overlap is revisited as a limit of multiplex viability problem, and the controversy between existing results is clarified. The distinctive role of overlapping links is further demonstrated by the different responses of networks under random removals of overlapping and non-overlapping links, respectively, as well as under several link-removal strategies. Our results show that the link overlap facilitates the viability and mutual percolation; at the same time, the presence of link overlap poses a challenge in analytical approaches to the problem

  11. Miniaturized high-temperature superconducting multiplexer with cascaded quadruplet structure

    Science.gov (United States)

    Xu, Zhang; Jingping, Liu; Shaolin, Yan; Lan, Fang; Bo, Zhang; Xinjie, Zhao

    2015-06-01

    In this paper, compact high temperature superconducting (HTS) multiplexers are presented for satellite communication applications. The first multiplexer consists of an input coupling node and three high-order bandpass filters, which is named triplexer. The node is realized by a loop microstrip line instead of conventional T-junction to eliminate the redundant susceptance due to combination of three filters. There are two eight-pole band-pass filters and one ten-pole band-pass filter with cascaded quadruplet structure for realizing high isolation. Moreover, the triplexer is extended to a multiplexer with six channels so as to verify the expansibility of the suggested approach. The triplexer is fabricated using double-sided YBa2Cu3O7 thin films on a 38 × 25 mm2 LaAlO3 substrate. The experimental results, when compared with those ones from the T-junction multiplexer, show that our multiplexer has lower insertion loss, smaller sizes and higher isolation between any two channels. Also, good agreement has been achieved between simulations and measurements, which illustrate the effectiveness of our methods for the design of high performance HTS multiplexers.

  12. Laser spectroscopy

    International Nuclear Information System (INIS)

    Letokhov, V.S.

    1981-01-01

    This article describes recent progress in the application of laser atomic spectroscopy to study parameters of nuclei available in very small quantities; radioactive nuclei, rare isotopes, nuclear isomers, etc, for which study by conventional spectroscopic methods is difficult. (author)

  13. Fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2016-01-01

    Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses the foundati......Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses...

  14. The relationship investigation between factors affecting demand for broadband and the level of satisfaction among broadband customers in the South East Coast of Sabah, Malaysia

    Science.gov (United States)

    Hashim, S. H. A.; Hamid, F. A.; Kiram, J. J.; Sulaiman, J.

    2017-09-01

    This paper aims to investigate the relationship between factors that affecting the demand for broadband and the level of satisfaction. Previous researchers have found that the adoption of broadband is greatly influenced by many factors. Thus, in this study, a self-administered questionnaire was developed to obtain the factors affecting demand for broadband among broadband customers as well as their level of satisfaction. Pearson correlation, one-way analysis of variance (ANOVA) and t-test were used for statistical interpretation of the relationship. This study shows that there are better relationships between several factors over demand for broadband and satisfaction level.

  15. Development of dual-broadband rotational CARS for combustion diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Bood, Joakim

    2000-06-01

    The present thesis concerns development and application of dual-broadband rotational coherent anti-Stokes Raman spectroscopy (DB-RCARS) for temperature and species concentration measurements in combustion processes. Both fundamental development of the technique, including experimental as well as modelling results, and measurements in practical combustion devices were conducted. A code for calculation of rotational CARS spectra of pure acetylene as well as mixtures of acetylene and nitrogen was developed. Using this code, temperatures and relative acetylene to nitrogen concentrations were evaluated from DB-RCARS measurements in pure acetylene and different acetylene/nitrogen mixtures. Moreover, rotational CARS spectra of dimethyl-ether (DME) have been analyzed. A powerful tool for simultaneous temperature and multiple species concentration measurements was developed by combining rotational CARS with vibrational CARS. The concept was demonstrated for measurements of temperature, oxygen, and carbon monoxide concentrations simultaneously in a premixed sooting ethene/air flame. Rotational CARS spectra of nitrogen at very high pressures (0.1-44 MPa) at room temperature were investigated. The experimental spectra were compared with calculated spectra using different Raman linewidth models. The results indicate some shortcomings in the present model, basically the density calculation and neglecting overlapping effects between adjacent spectral lines. A new method for CARS measurements in several spatially separated points simultaneously was developed. By using DB-RCARS the method was demonstrated for quantitative measurements of profiles of temperatures and oxygen concentrations. An atomic filter for rejection of stray light was developed. The filter was shown to efficiently reject stray light from the narrowband laser without affecting the shape of the rotational CARS spectrum or causing any signal losses. Within an interdisciplinary project intended to increase the

  16. Detailed Balance Limit of Efficiency of Broadband-Pumped Lasers.

    Science.gov (United States)

    Nechayev, Sergey; Rotschild, Carmel

    2017-09-13

    Broadband light sources are a wide class of pumping schemes for lasers including LEDs, sunlight and flash lamps. Recently, efficient coupling of broadband light to high-quality micro-cavities has been demonstrated for on-chip applications and low-threshold solar-pumped lasers via cascade energy transfer. However, the conversion of incoherent to coherent light comes with an inherent price of reduced efficiency, which has yet to be assessed. In this paper, we derive the detailed balance limit of efficiency of broadband-pumped lasers and discuss how it is affected by the need to maintain a threshold population inversion and thermodynamically dictated minimal Stokes' shift. We show that lasers' slope efficiency is analogous to the nominal efficiency of solar cells, limited by thermalisation losses and additional unavoidable Stokes' shift. The lasers' power efficiency is analogous to the detailed balance limit of efficiency of solar cells, affected by the cavity mirrors and impedance matching factor, respectively. As an example we analyze the specific case of solar-pumped sensitized Nd 3+ :YAG-like lasers and define the conditions to reach their thermodynamic limit of efficiency. Our work establishes an upper theoretical limit for the efficiency of broadband-pumped lasers. Our general, yet flexible model also provides a way to incorporate other optical and thermodynamic losses and, hence, to estimate the efficiency of non-ideal broadband-pumped lasers.

  17. Broadband set-top box using MAP-CA processor

    Science.gov (United States)

    Bush, John E.; Lee, Woobin; Basoglu, Chris

    2001-12-01

    Advances in broadband access are expected to exert a profound impact in our everyday life. It will be the key to the digital convergence of communication, computer and consumer equipment. A common thread that facilitates this convergence comprises digital media and Internet. To address this market, Equator Technologies, Inc., is developing the Dolphin broadband set-top box reference platform using its MAP-CA Broadband Signal ProcessorT chip. The Dolphin reference platform is a universal media platform for display and presentation of digital contents on end-user entertainment systems. The objective of the Dolphin reference platform is to provide a complete set-top box system based on the MAP-CA processor. It includes all the necessary hardware and software components for the emerging broadcast and the broadband digital media market based on IP protocols. Such reference design requires a broadband Internet access and high-performance digital signal processing. By using the MAP-CA processor, the Dolphin reference platform is completely programmable, allowing various codecs to be implemented in software, such as MPEG-2, MPEG-4, H.263 and proprietary codecs. The software implementation also enables field upgrades to keep pace with evolving technology and industry demands.

  18. Spatial-temporal dynamics of broadband terahertz Bessel beam propagation

    International Nuclear Information System (INIS)

    Semenova, V A; Kulya, M S; Bespalov, V G

    2016-01-01

    The unique properties of narrowband and broadband terahertz Bessel beams have led to a number of their applications in different fields, for example, for the depth of focusing and resolution enhancement in terahertz imaging. However, broadband terahertz Bessel beams can probably be also used for the diffraction minimization in the short-range broadband terahertz communications. For this purpose, the study of spatial-temporal dynamics of the broadband terahertz Bessel beams is needed. Here we present a simulation-based study of the propagating in non-dispersive medium broadband Bessel beams generated by a conical axicon lens. The algorithm based on scalar diffraction theory was used to obtain the spatial amplitude and phase distributions of the Bessel beam in the frequency range from 0.1 to 3 THz at the distances 10-200 mm from the axicon. Bessel beam field is studied for the different spectral components of the initial pulse. The simulation results show that for the given parameters of the axicon lens one can obtain the Gauss-Bessel beam generation in the spectral range from 0.1 to 3 THz. The length of non-diffraction propagation for a different spectral components was measured, and it was shown that for all spectral components of the initial pulse this length is about 130 mm. (paper)

  19. Broadband low-frequency sound isolation by lightweight adaptive metamaterials

    Science.gov (United States)

    Liao, Yunhong; Chen, Yangyang; Huang, Guoliang; Zhou, Xiaoming

    2018-03-01

    Blocking broadband low-frequency airborne noises is highly desirable in lots of engineering applications, while it is extremely difficult to be realized with lightweight materials and/or structures. Recently, a new class of lightweight adaptive metamaterials with hybrid shunting circuits has been proposed, demonstrating super broadband structure-borne bandgaps. In this study, we aim at examining their potentials in broadband sound isolation by establishing an analytical model that rigorously combines the piezoelectric dynamic couplings between adaptive metamaterials and acoustics. Sound transmission loss of the adaptive metamaterial is investigated with respect to both the frequency and angular spectrum to demonstrate their sound-insulation effects. We find that efficient sound isolation can indeed be pursued in the broadband bi-spectrum for not only the case of the small resonator's periodicity where only one mode relevant to the mass-spring resonance exists, but also for the large-periodicity scenario, so that the total weight can be even lighter, in which the multiple plate-resonator coupling modes appear. In the latter case, the negative spring stiffness provided by the piezoelectric stack has been utilized to suppress the resonance-induced high acoustic transmission. Such kinds of adaptive metamaterials could open a new approach for broadband noise isolation with extremely lightweight structures.

  20. Tunable Broadband Nanocarbon Transparent Conductor by Electrochemical Intercalation.

    Science.gov (United States)

    Wan, Jiayu; Xu, Yue; Ozdemir, Burak; Xu, Lisha; Sushkov, Andrei B; Yang, Zhi; Yang, Bao; Drew, Dennis; Barone, Veronica; Hu, Liangbing

    2017-01-24

    Optical transparent and electrical conducting materials with broadband transmission are important for many applications in optoelectronic, telecommunications, and military devices. However, studies of broadband transparent conductors and their controlled modulation are scarce. In this study, we report that reversible transmittance modulation has been achieved with sandwiched nanocarbon thin films (containing carbon nanotubes (CNTs) and reduced graphene oxide (rGO)) via electrochemical alkali-ion intercalation/deintercalation. The transmittance modulation covers a broad range from the visible (450 nm) to the infrared (5 μm), which can be achieved only by rGO rather than pristine graphene films. The large broadband transmittance modulation is understood with DFT calculations, which suggest a decrease in interband transitions in the visible range as well as a reduced reflection in the IR range upon intercalation. We find that a larger interlayer distance in few-layer rGO results in a significant increase in transparency in the infrared region of the spectrum, in agreement with experimental results. Furthermore, a reduced plasma frequency in rGO compared to few-layer graphene is also important to understand the experimental results for broadband transparency in rGO. The broadband transmittance modulation of the CNT/rGO/CNT systems can potentially lead to electrochromic and thermal camouflage applications.

  1. System and method for detection of dispersed broadband signals

    Science.gov (United States)

    Qian, S.; Dunham, M.E.

    1999-06-08

    A system and method for detecting the presence of dispersed broadband signals in real time are disclosed. The present invention utilizes a bank of matched filters for detecting the received dispersed broadband signals. Each matched filter uses a respective robust time template that has been designed to approximate the dispersed broadband signals of interest, and each time template varies across a spectrum of possible dispersed broadband signal time templates. The received dispersed broadband signal x(t) is received by each of the matched filters, and if one or more matches occurs, then the received data is determined to have signal data of interest. This signal data can then be analyzed and/or transmitted to Earth for analysis, as desired. The system and method of the present invention will prove extremely useful in many fields, including satellite communications, plasma physics, and interstellar research. The varying time templates used in the bank of matched filters are determined as follows. The robust time domain template is assumed to take the form w(t)=A(t)cos[l brace]2[phi](t)[r brace]. Since the instantaneous frequency f(t) is known to be equal to the derivative of the phase [phi](t), the trajectory of a joint time-frequency representation of x(t) is used as an approximation of [phi][prime](t). 10 figs.

  2. Bio-inspired heterogeneous composites for broadband vibration mitigation.

    Science.gov (United States)

    Chen, Yanyu; Wang, Lifeng

    2015-12-08

    Structural biological materials have developed heterogeneous and hierarchical architectures that are responsible for the outstanding performance to provide protection against environmental threats including static and dynamic loading. Inspired by this observation, this research aims to develop new material and structural concepts for broadband vibration mitigation. The proposed composite materials possess a two-layered heterogeneous architecture where both layers consist of high-volume platelet-shape reinforcements and low-volume matrix, similar to the well-known "brick and mortar" microstructure of biological composites. Using finite element method, we numerically demonstrated that broadband wave attenuation zones can be achieved by tailoring the geometric features of the heterogeneous architecture. We reveal that the resulting broadband attenuation zones are gained by directly superimposing the attenuation zones in each constituent layer. This mechanism is further confirmed by the investigation into the phonon dispersion relation of each layer. Importantly, the broadband wave attenuation capability will be maintained when the mineral platelet orientation is locally manipulated, yet a contrast between the mineral platelet concentrations of the two constituent layers is essential. The findings of this work will provide new opportunities to design heterogeneous composites for broadband vibration mitigation and impact resistance under mechanically challenging environmental conditions.

  3. A real-time multi-gases detection and concentration measurements based-on time-division multiplexed-lasers

    Science.gov (United States)

    Yazdandoust, Fatemeh; Tatenguem Fankem, Hervé; Milde, Tobias; Jimenez, Alvaro; Sacher, Joachim

    2018-02-01

    We report the development of a platform, based-on a Field-Programmable Gate Arrays (FPGAs) and suitable for Time-Division-Multiplexed DFB lasers. The designed platform is subsequently combined with a spectroscopy setup, for detection and quantification of species in a gas mixture. The experimental results show a detection limit of 460 ppm, an uncertainty of 0.1% and a computation time of less than 1000 clock cycles. The proposed system offers a high level of flexibility and is applicable to arbitrary types of gas-mixtures.

  4. Clostridium perfringens isolate typing by multiplex PCR

    Directory of Open Access Journals (Sweden)

    MR Ahsani

    2010-01-01

    Full Text Available Clostridium perfringens is an important pathogen that provokes numerous different diseases. This bacterium is classified into five different types, each of which capable of causing a different disease. There are various methods for the bacterial identification, many are labor-intensive, time-consuming, expensive and also present low sensitivity and specificity. The aim of this research was to identify the different types of C. perfringens using PCR molecular method. In this study, 130 sheep-dung samples were randomly collected from areas around the city of Kerman, southeastern Iran. After processing and culturing of samples, the produced colonies were morphologically studied, gram stain test was also carried out and the genera of these bacteria were identified through biochemical tests. DNA extracted from isolated bacteria for genotyping was tested by multiplex PCR with specific primers. Based on length of synthesized fragments by PCR, toxin types and bacterial strains were detected. C. perfringens isolated types were divided as follows: 17.39% type A, 21.74% type B, 34.78% type C and 26.09% type D. It should be emphasized that, up to the present moment, C. perfringens type A has not been reported in Iran.

  5. Opinion competition dynamics on multiplex networks

    Science.gov (United States)

    Amato, R.; Kouvaris, N. E.; San Miguel, M.; Díaz-Guilera, A.

    2017-12-01

    Multilayer and multiplex networks represent a good proxy for the description of social phenomena where social structure is important and can have different origins. Here, we propose a model of opinion competition where individuals are organized according to two different structures in two layers. Agents exchange opinions according to the Abrams-Strogatz model in each layer separately and opinions can be copied across layers by the same individual. In each layer a different opinion is dominant, so each layer has a different absorbing state. Consensus in one opinion is not the only possible stable solution because of the interaction between the two layers. A new mean field solution has been found where both opinions coexist. In a finite system there is a long transient time for the dynamical coexistence of both opinions. However, the system ends in a consensus state due to finite size effects. We analyze sparse topologies in the two layers and the existence of positive correlations between them, which enables the coexistence of inter-layer groups of agents sharing the same opinion.

  6. Multiplexed coding in the human basal ganglia

    Science.gov (United States)

    Andres, D. S.; Cerquetti, D.; Merello, M.

    2016-04-01

    A classic controversy in neuroscience is whether information carried by spike trains is encoded by a time averaged measure (e.g. a rate code), or by complex time patterns (i.e. a time code). Here we apply a tool to quantitatively analyze the neural code. We make use of an algorithm based on the calculation of the temporal structure function, which permits to distinguish what scales of a signal are dominated by a complex temporal organization or a randomly generated process. In terms of the neural code, this kind of analysis makes it possible to detect temporal scales at which a time patterns coding scheme or alternatively a rate code are present. Additionally, finding the temporal scale at which the correlation between interspike intervals fades, the length of the basic information unit of the code can be established, and hence the word length of the code can be found. We apply this algorithm to neuronal recordings obtained from the Globus Pallidus pars interna from a human patient with Parkinson’s disease, and show that a time pattern coding and a rate coding scheme co-exist at different temporal scales, offering a new example of multiplexed neuronal coding.

  7. The Multiplex Network of EU Lobby Organizations.

    Science.gov (United States)

    Zeng, An; Battiston, Stefano

    2016-01-01

    The practice of lobbying in the interest of economic or social groups plays an important role in the policy making process of most economies. While no data is available at this stage to examine the success of lobbies in exerting influence on specific policy issues, we perform a first systematic multi-layer network analysis of a large lobby registry. Here we focus on the domains of finance and climate and we combine information on affiliation and client relations from the EU transparency register with information about shareholding and interlocking directorates of firms. We find that the network centrality of lobby organizations has no simple relation with their lobbying budget. Moreover, different layers of the multiplex network provide complementary information to characterize organizations' potential influence. At the aggregate level, it appears that while the domains of finance and climate are separated on the layer of affiliation relations, they become intertwined when economic relations are considered. Because groups of interest differ not only in their budget and network centrality but also in terms of their internal cohesiveness, drawing a map of both connections across and within groups is a precondition to better understand the dynamics of influence on policy making and the forces at play.

  8. Nanoscale Test Strips for Multiplexed Blood Analysis

    Science.gov (United States)

    Chan, Eugene

    2015-01-01

    A critical component of the DNA Medicine Institute's Reusable Handheld Electrolyte and Lab Technology for Humans (rHEALTH) sensor are nanoscale test strips, or nanostrips, that enable multiplexed blood analysis. Nanostrips are conceptually similar to the standard urinalysis test strip, but the strips are shrunk down a billionfold to the microscale. Each nanostrip can have several sensor pads that fluoresce in response to different targets in a sample. The strips carry identification tags that permit differentiation of a specific panel from hundreds of other nanostrip panels during a single measurement session. In Phase I of the project, the company fabricated, tested, and demonstrated functional parathyroid hormone and vitamin D nanostrips for bone metabolism, and thrombin aptamer and immunoglobulin G antibody nanostrips. In Phase II, numerous nanostrips were developed to address key space flight-based medical needs: assessment of bone metabolism, immune response, cardiac status, liver metabolism, and lipid profiles. This unique approach holds genuine promise for space-based portable biodiagnostics and for point-of-care (POC) health monitoring and diagnostics here on Earth.

  9. Manta A New BroadBand OBS

    Science.gov (United States)

    Hello, Y.; Yegikyan, M.; Charvis, P.; Philippe, O.

    2017-12-01

    Manta is a new BroadBand OBS developed at Geoazur and commercialized by Osean. The design is inspired by 3-years autonomy MUG-OBS a Multiparameter Ocean Bottom System which carry a lot of sort of sensor types. As Mug-OBS, Manta-OBS rated 6000m is designed to resist a trawling. All the components are non corrosive such polyethylene, titanium and buoyancy is ensured by syntactic foam. Equipped in standard version with a Trillium compact OBS Manta has an autonomy of 18 months, but can accept on its 4 input channels any kind of signal as low as from an hydrophone or larger from other type of a seismometer or accelerometer. Tri-axial geophones unit (2 Hz or 4.5 Hz ) can replace the seismometer and will expend the lifespan for the instrument. The seismometer is encapsulated in a central well established by four panels of the main structure to protect it from sea current convection and is decoupled from main chassis. An health bulletin is recoverable by acoustic any time to facilitate the installation and during a visit when instrument is deployed. Main parameters for acquisition can be changed by acoustics command from surface at any time. Once at the bottom, release for the main sensor installation is programmed on a timer but controlled by the tilt of the OBS. If the tilt is too important based on programmed limits, sensor will not released automatically, but this can be forced by acoustic command after returning the tilt informations to the boat operator. Manta is equipped with flash light and AIS system for easy location at recovery, and can also send it's position by Iridium satellite in case of an unexpected ascent such caused by a possible trawling if deployed in shallow water. Clock drift calculation is automatically made against GPS time signal once the OBS return at the surface. The recovery of the OBS is initiated by an acoustic command. These new features made Manta a very versatile instrument for monitoring earthquakes.

  10. Broadband unidirectional cloaks based on flat metasurface focusing lenses

    International Nuclear Information System (INIS)

    Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Pang, Yongqiang; Xu, Zhuo; Zhang, Anxue

    2015-01-01

    Bandwidth extension and thickness reduction are now the two key issues of cloaks. In this paper, we propose to achieve broadband, thin uni-directional electromagnetic (EM) cloaks using metasurfaces. To this end, a wideband flat focusing lens is firstly devised based on high-efficiency transmissive metasurfaces. Due to the nearly dispersionless parabolic phase profile along the metasurface in the operating band, incident plane waves can be focused efficiently after passing through the metasurface. Broadband unidirectional EM cloaks were then designed by combining two identical flat lenses. Upon illumination, the incident plane waves are firstly focused by one lens and then are restored by the other lens, avoiding the cloaked region. Both simulation and experiment results verify the broadband unidirectional cloak. The broad bandwidth and small thickness of such cloaks have potential applications in achieving invisibility for electrically large objects. (paper)

  11. Broadband unidirectional cloaks based on flat metasurface focusing lenses

    Science.gov (United States)

    Li, Yongfeng; Zhang, Jieqiu; Qu, Shaobo; Wang, Jiafu; Pang, Yongqiang; Xu, Zhuo; Zhang, Anxue

    2015-08-01

    Bandwidth extension and thickness reduction are now the two key issues of cloaks. In this paper, we propose to achieve broadband, thin uni-directional electromagnetic (EM) cloaks using metasurfaces. To this end, a wideband flat focusing lens is firstly devised based on high-efficiency transmissive metasurfaces. Due to the nearly dispersionless parabolic phase profile along the metasurface in the operating band, incident plane waves can be focused efficiently after passing through the metasurface. Broadband unidirectional EM cloaks were then designed by combining two identical flat lenses. Upon illumination, the incident plane waves are firstly focused by one lens and then are restored by the other lens, avoiding the cloaked region. Both simulation and experiment results verify the broadband unidirectional cloak. The broad bandwidth and small thickness of such cloaks have potential applications in achieving invisibility for electrically large objects.

  12. Broadband and Resonant Approaches to Axion Dark Matter Detection.

    Science.gov (United States)

    Kahn, Yonatan; Safdi, Benjamin R; Thaler, Jesse

    2016-09-30

    When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. We propose a new experiment to detect this axion effective current. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current ring, whose induced magnetic flux can be measured by an external pickup loop inductively coupled to a SQUID magnetometer. We consider both resonant and broadband readout circuits and show that a broadband approach has advantages at small axion masses. We estimate the reach of this design, taking into account the irreducible sources of noise, and demonstrate potential sensitivity to axionlike dark matter with masses in the range of 10^{-14}-10^{-6}  eV. In particular, both the broadband and resonant strategies can probe the QCD axion with a GUT-scale decay constant.

  13. National Broadband strategies – The case of Brazil

    DEFF Research Database (Denmark)

    Falch, Morten; Iaskio, Emerson

    2018-01-01

    as differences in institutional factors. For instance has the government played a leading role in Japan and South Korea, while US and UK have a strong emphasis on market forces and competition. Brazil has chosen their own strategy for broadband development. This strategy is defined within a specific national...... of comparing broadband strategies in different countries. The paper first describes these dimensions, and how the framework relates to other kinds of categorisations. Second it provides a brief overview of how the Brazilian telecom market developed. The subsequent section presents various policy initiatives......). Broadband for all is a widely accepted policy objective in both developed and developing countries. However, the policy strategies for achieving this goal are very different in different countries. These differences are originated in different levels of economic and technological development, as well...

  14. Broadband electromagnetic dipole scattering by coupled multiple nanospheres

    Science.gov (United States)

    Jing, Xufeng; Ye, Qiufeng; Hong, Zhi; Zhu, Dongshuo; Shi, Guohua

    2017-11-01

    With the development of nanotechnology, the ability to manipulate light at the nanoscale is critical to future optical functional devices. The use of high refractive index dielectric single silicon nanoparticle can achieve electromagnetic dipole resonant properties. Compared with single nanosphere, the use of dimer and trimer introduces an additional dimension (gap size) for improving the performance of dielectric optical devices through the coupling between closely connected silicon nanospheres. When changing the gap size between the nanospheres, the interaction between the particles can be from weak to strong. Compared with single nanospheres, dimerized or trimeric nanospheres exhibit more pronounced broadband scattering properties. In addition, by introducing more complex interaction, the trimericed silicon nanospheres exhibit a more significant increase in bandwidth than expected. In addition, the presence of the substrate will also contribute to the increase in the bandwidth of the nanospheres. The broadband response in dielectric nanostructures can be effectively applied to broadband applications such as dielectric nanoantennas or solar cells.

  15. Broadband enhancement of infrared absorption in microbolometers using Ag nanocrystals

    International Nuclear Information System (INIS)

    Hyun, Jerome K.; Ahn, Chi Won; Kim, Woo Choong; Kim, Tae Hyun; Hyun, Moon Seop; Kim, Hee Yeoun; Park, Jae Hong; Lee, Won-Oh

    2015-01-01

    High performance microbolometers are widely sought for thermal imaging applications. In order to increase the performance limits of microbolometers, the responsivity of the device to broadband infrared (IR) radiation needs to be improved. In this work, we report a simple, quick, and cost-effective approach to modestly enhance the broadband IR response of the device by evaporating Ag nanocrystals onto the light entrance surface of the device. When irradiated with IR light, strong fields are built up within the gaps between adjacent Ag nanocrystals. These fields resistively generate heat in the nanocrystals and underlying substrate, which is transduced into an electrical signal via a resistive sensing element in the device. Through this method, we are able to enhance the IR absorption over a broadband spectrum and improve the responsivity of the device by ∼11%

  16. 77 FR 62461 - Implementing Public Safety Broadband Provisions of the Middle Class Tax Relief and Job Creation...

    Science.gov (United States)

    2012-10-15

    ... Wireless Broadband Network,'' ``Special Purpose Bankruptcy Remote Entity,'' ``Upper 700 MHz D Block license... definitions ``700 MHz Public/Private Partnership,'' ``Network Assets Holder,'' ``Network Sharing Agreement...,'' ``Public safety broadband network operator,'' ``Shared Wireless Broadband Network, '' ``Special Purpose...

  17. Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Gonser, U.

    1975-01-01

    This book is addressed to persons interested in learning about what has been done and what can be done with Moessbauer spectroscopy. In an introductory chapter the basic principle is explained and the general parameters governing Moessbauer spectroscopy are tabulated. For the following chapters various disciplines are chosen and the wide applicability of this measuring technique is demonstrated. The second chapter discusses a few representative examples of chemical interesting information being reflected by isomer shifts and quadrupole splittings, particularly with respect to bonding and structural properties. The third chapter deals with some applications of Moessbauer spectroscopy for characterizing magnetic compounds and its use for magnetic structure investigations, particularly by making use of polarized radiation. The fourth chapter describes the use of the Moessbauer spectroscopy for studying iron in biological molecules. As an example of recent applications to mineralogy and geology the results of the studies of lunar samples are reviewed in the fifth chapter. Finally, in the last chapter, work is described on the use of Moessbauer spectroscopy in physical metallurgy, particularly quantitative analyses which have enabled metallurgists to solve many old problems. (orig./FW) [de

  18. On-chip dual comb source for spectroscopy

    OpenAIRE

    Dutt, Avik; Joshi, Chaitanya; Ji, Xingchen; Cardenas, Jaime; Okawachi, Yoshitomo; Luke, Kevin; Gaeta, Alexander L.; Lipson, Michal

    2016-01-01

    Dual-comb spectroscopy is a powerful technique for real-time, broadband optical sampling of molecular spectra which requires no moving components. Recent developments with microresonator-based platforms have enabled frequency combs at the chip scale. However, the need to precisely match the resonance wavelengths of distinct high-quality-factor microcavities has hindered the development of an on-chip dual comb source. Here, we report the first simultaneous generation of two microresonator comb...

  19. Multiplex CARS imaging with spectral notch shaped laser pulses delivered by optical fibers.

    Science.gov (United States)

    Oh, Seung Ryeol; Park, Joo Hyun; Kim, Kyung-Soo; Lee, Jae Yong; Kim, Soohyun

    2017-12-11

    We present an experimental demonstration of single-pulse coherent anti-Stokes Raman spectroscopy (CARS) using a spectrally shaped broadband laser that is delivered by an optical fiber to a sample at its distal end. The optical fiber consists of a fiber Bragg grating component to serve as a narrowband notch filter and a combined large-mode-area fiber to transmit such shaped ultrashort laser pulses without spectral distortion in a long distance. Experimentally, our implementation showed a capability to measure CARS spectra of various samples with molecular vibrations in the fingerprint region. Furthermore, CARS imaging of poly(methyl methacrylate) bead samples was carried out successfully under epi-CARS geometry in which backward-scattered CARS signals were collected into a multimode optical fiber. A compatibility of single-pulse CARS scheme with fiber optics, verified in this study, implies a potential for future realization of compact all-fiber CARS spectroscopic imaging systems.

  20. Comparison of VP broadband tiltmeter and VS vertical pendulum tiltmeter

    Directory of Open Access Journals (Sweden)

    Wugang Ma

    2015-05-01

    Full Text Available Vertical pendulum (VP tiltmeter is a kind of earthquake precursor observation equipment, which is used to record the interaction force associated with astronomical tidal tilts caused. Currently, VP broadband tiltmeter and vertical sensor (VS vertical pendulum tiltmeter are primarily used. In this paper, we compare the two different instruments by using four aspects—mechanical structure, circuitry, zeroing, and bandwidth—based on their working principles and applications. We conclude that VP broadband tiltmeter is more superior compared with VS vertical pendulum tiltmeter because of its higher bandwidth and degree of automation.

  1. Broadband electrical impedance matching for piezoelectric ultrasound transducers.

    Science.gov (United States)

    Huang, Haiying; Paramo, Daniel

    2011-12-01

    This paper presents a systematic method for designing broadband electrical impedance matching networks for piezoelectric ultrasound transducers. The design process involves three steps: 1) determine the equivalent circuit of the unmatched piezoelectric transducer based on its measured admittance; 2) design a set of impedance matching networks using a computerized Smith chart; and 3) establish the simulation model of the matched transducer to evaluate the gain and bandwidth of the impedance matching networks. The effectiveness of the presented approach is demonstrated through the design, implementation, and characterization of impedance matching networks for a broadband acoustic emission sensor. The impedance matching network improved the power of the acquired signal by 9 times.

  2. Broadband sound blocking in phononic crystals with rotationally symmetric inclusions.

    Science.gov (United States)

    Lee, Joong Seok; Yoo, Sungmin; Ahn, Young Kwan; Kim, Yoon Young

    2015-09-01

    This paper investigates the feasibility of broadband sound blocking with rotationally symmetric extensible inclusions introduced in phononic crystals. By varying the size of four equally shaped inclusions gradually, the phononic crystal experiences remarkable changes in its band-stop properties, such as shifting/widening of multiple Bragg bandgaps and evolution to resonance gaps. Necessary extensions of the inclusions to block sound effectively can be determined for given incident frequencies by evaluating power transmission characteristics. By arraying finite dissimilar unit cells, the resulting phononic crystal exhibits broadband sound blocking from combinational effects of multiple Bragg scattering and local resonances even with small-numbered cells.

  3. Measurement uncertainty in broadband radiofrequency radiation level measurements

    Directory of Open Access Journals (Sweden)

    Vulević Branislav D.

    2014-01-01

    Full Text Available For the evaluation of measurement uncertainty in the measurement of broadband radio frequency radiation, in this paper we propose a new approach based on the experience of the authors of the paper with measurements of radiofrequency electric field levels conducted in residential areas of Belgrade and over 35 municipalities in Serbia. The main objective of the paper is to present practical solutions in the evaluation of broadband measurement uncertainty for the in-situ RF radiation levels. [Projekat Ministarstva nauke Republike Srbije, br. III43009

  4. Broadband polymer microstructured THz fiber coupler with downdoped cores

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Rasmussen, Henrik K.; Bang, Ole

    2010-01-01

    We demonstrate a broadband THz directional coupler based on a dual core photonic crystal fiber (PCF) design with mechanically down-doped core regions. For a center frequency of 1.3 THz we demonstrate a bandwidth of 0.65 THz.......We demonstrate a broadband THz directional coupler based on a dual core photonic crystal fiber (PCF) design with mechanically down-doped core regions. For a center frequency of 1.3 THz we demonstrate a bandwidth of 0.65 THz....

  5. Semiconductor Quantum Dash Broadband Emitters: Modeling and Experiments

    KAUST Repository

    Khan, Mohammed Zahed Mustafa

    2013-10-01

    Broadband light emitters operation, which covers multiple wavelengths of the electromagnetic spectrum, has been established as an indispensable element to the human kind, continuously advancing the living standard by serving as sources in important multi-disciplinary field applications such as biomedical imaging and sensing, general lighting and internet and mobile phone connectivity. In general, most commercial broadband light sources relies on complex systems for broadband light generation which are bulky, and energy hungry. \\tRecent demonstration of ultra-broadband emission from semiconductor light sources in the form of superluminescent light emitting diodes (SLDs) has paved way in realization of broadband emitters on a completely novel platform, which offered compactness, cost effectiveness, and comparatively energy efficient, and are already serving as a key component in medical imaging systems. The low power-bandwidth product is inherent in SLDs operating in the amplified spontaneous emission regime. A quantum leap in the advancement of broadband emitters, in which high power and large bandwidth (in tens of nm) are in demand. Recently, the birth of a new class of broadband semiconductor laser diode (LDs) producing multiple wavelength light in stimulated emission regime was demonstrated. This very recent manifestation of a high power-bandwidth-product semiconductor broadband LDs relies on interband optical transitions via quantum confined dot/dash nanostructures and exploiting the natural inhomogeneity of the self-assembled growth technology. This concept is highly interesting and extending the broad spectrum of stimulated emission by novel device design forms the central focus of this dissertation. \\tIn this work, a simple rate equation numerical technique for modeling InAs/InP quantum dash laser incorporating the properties of inhomogeneous broadening effect on lasing spectra was developed and discussed, followed by a comprehensive experimental analysis

  6. Analysis of broadband aerodynamic noise from VS45

    Energy Technology Data Exchange (ETDEWEB)

    Dundabin, P. [Renewable Energy Systems Ltd., Glasgow, Scotland (United Kingdom)

    1997-12-31

    This paper describes the analysis of acoustic data taken from the VS45 at Kaiser-Wilhelm-Koog. The aim was to investigate the dependence of aerodynamic noise on tip speed and angle of attack. In particular, the dependence of noise in individual third octave bands on these variable is examined. The analysis is divided into 3 sections: data selection, data checks and analysis of broadband nacelle noise; analysis of broadband aerodynamic noise and its sensitivity to tip speed and angle of attack. (LN)

  7. Implementation of Scientific Computing Applications on the Cell Broadband Engine

    Directory of Open Access Journals (Sweden)

    Guochun Shi

    2009-01-01

    Full Text Available The Cell Broadband Engine architecture is a revolutionary processor architecture well suited for many scientific codes. This paper reports on an effort to implement several traditional high-performance scientific computing applications on the Cell Broadband Engine processor, including molecular dynamics, quantum chromodynamics and quantum chemistry codes. The paper discusses data and code restructuring strategies necessary to adapt the applications to the intrinsic properties of the Cell processor and demonstrates performance improvements achieved on the Cell architecture. It concludes with the lessons learned and provides practical recommendations on optimization techniques that are believed to be most appropriate.

  8. Optical Spectroscopy

    DEFF Research Database (Denmark)

    Thyrhaug, Erling

    The work presented in this thesis is broadly concerned with how complexation reactions and molecular motion can be characterized with the standard techniques in optical spectroscopy. The thesis aims to show a relatively broad range of methods for probing physico-chemical properties in fluorophore...... information about chemical equilibria, kinetics and molecular motion by monitoring changes in optical properties of the system. The five presented research projects are largely unrelated to each other both in aim and in what property is probed, however they are all connected in that they are fluorophore...... reactions by optical spectroscopy. In project 1 simple steady-state absorption and fluorescence spectroscopy is used to determine the stoichiometries and equilibrium constants in the inclusion complex formation between cyclodextrins and derivatives of the water-insoluble oligo(phenylene vinylene) in aqueous...

  9. Diagnosis of Cutaneous Leishmaniasis by Multiplex PCR

    Directory of Open Access Journals (Sweden)

    M Heiat

    2010-07-01

    Full Text Available Introduction: Annually, more than 14 million people are reported to be infected with Leishmaniasis all over the world. In Iran, this disease is seen in the form of cutaneous and visceral leishmaniasis, of which the cutaneous form is more wide spread. In recent years, cutaneous leishmaniaisis is diagnosed by PCR utilizing specific primers in order to amplify different parasite genes including ribosomal RNA genes, kinetoplast DNA or tandem repeating sequences. The aim of this research was to detect early stage cutaneous leishmaniasis using Multiplex-PCR technique. Methods: In this study, 67 samples were prepared from patients with cutaneous leishmaniasis. DNA was extracted with phenolchloroform. Each specimen was analyzed using two different pairs of PCR primers. The sensitivity of each PCR was optimized on pure Leishmania DNA prior to use for diagnosis. Two standard parasites L. major and L. tropica were used as positive control. Results: DNA amplification fragments were two 115 bp and 683 bp for AB and UL primers, respectively. The sensitivity of two primers was not equal for detection of L. major and L. tropica. The sensivity of PCR with AB primer was 35 cells, while that for UL primer was 40 cells. Conclusion: The results of this study indicate that PCR is a sensitive diagnostic assay for cutaneous leishmaniasis and could be employed as the new standard for routine diagnosis when species identification is not required. However, the ability to identify species is especially important in prognosis of the disease and in deciding appropriate therapy, especially in regions where more than one type of species and disease are seen by clinicians.

  10. VT Fiber Optic Broadband Availability by Census Block - 12-2010

    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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    Data.gov (United States)

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