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Sample records for high concentration linear

  1. A high temperature hybrid photovoltaic-thermal receiver employing spectral beam splitting for linear solar concentrators

    Science.gov (United States)

    Mojiri, Ahmad; Stanley, Cameron; Rosengarten, Gary

    2015-09-01

    Hybrid photovoltaic/thermal (PV-T) solar collectors are capable of delivering heat and electricity concurrently. Implementing such receivers in linear concentrators for high temperature applications need special considerations such as thermal decoupling of the photovoltaic (pv) cells from the thermal receiver. Spectral beam splitting of concentrated light provides an option for achieving this purpose. In this paper we introduce a relatively simple hybrid receiver configuration that spectrally splits the light between a high temperature thermal fluid and silicon pv cells using volumetric light filtering by semi-conductor doped glass and propylene glycol. We analysed the optical performance of this device theoretically using ray tracing and experimentally through the construction and testing of a full scale prototype. The receiver was mounted on a commercial parabolic trough concentrator in an outdoor experiment. The prototype receiver delivered heat and electricity at total thermal efficiency of 44% and electrical efficiency of 3.9% measured relative to the total beam energy incident on the primary mirror.

  2. High-temperature stable absorber coatings for linear concentrating solar thermal power plants; Hochtemperaturstabile Absorberschichten fuer linear konzentrierende solarthermische Kraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Christina

    2009-03-23

    This work describes the development of new absorber coatings for different applications - para-bolic trough and linear Fresnel collectors - and operating conditions - absorber in vacuum or in air. The demand for higher efficiencies of solar thermal power plants using parabolic trough technology results in higher temperatures in the collectors and on the absorber tubes. As heat losses increase strongly with increasing temperatures, the need for a lower emissivity of the absorber coating at constant absorptivity arises. The linear Fresnel application envisions ab-sorber tubes stable in air at high temperatures of about 450 C, which are to date commercially not available. This work comprises the theoretical background, the modeling and the fabrication of absorber tubes including the technology transfer to a production-size inline sputter coater. In annealing tests and accompanying optical measurements, degradation processes have been observed and specified more precisely by material characterization techniques. The simulations provided the capability of different materials used as potential IR-reflector. The highest selectivity can be achieved by applying silver which consequently has been chosen for the application in absorber coatings of the parabolic trough technology. Thin silver films how-ever need to be stabilized when used at high temperatures. Appropriate barrier layers as well as process and layer parameters were identified. A high selectivity was achieved and stability of the absorber coating for 1200 h at 500 C in vacuum has been demonstrated. For the application in air, silver was also analyzed as a potential IR-reflector. Even though the stability could be increased considerably, it nevertheless proved to be insufficient. The main factors influencing stability in a positive way are the use of higher quality polishing, additional barrier layers and adequate process parameters. This knowledge was applied for developing coatings which are stable in air at

  3. Confinement dependent chemotaxis in two-photon polymerized linear migration constructs with highly definable concentration gradients

    DEFF Research Database (Denmark)

    Hjortø, Gertrud Malene; Olsen, Mark Holm; Svane, Inge Marie

    2015-01-01

    Dendritic cell chemotaxis is known to follow chemoattractant concentration gradients through tissue of heterogeneous pore sizes, but the dependence of migration velocity on pore size and gradient steepness is not fully understood. We enabled chemotaxis studies for at least 42 hours at confinement...

  4. High-resolution continuum source electrothermal atomic absorption spectrometry: Linearization of the calibration curves within a broad concentration range

    Energy Technology Data Exchange (ETDEWEB)

    Katskov, Dmitri, E-mail: katskovda@tut.ac.za [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Hlongwane, Miranda [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Heitmann, Uwe [German Aerospace Center, Rose-Luxemburg Str. 2, 10178 Berlin (Germany); Florek, Stefan [ISAS-Leibniz-Institut fuer Analytische Wissenschaften e.V., Albert-Einstein-Str. 9,12489 Berlin (Germany)

    2012-05-15

    The calculation algorithm suggested provides linearization of the calibration curves in high-resolution continuum source electrothermal atomic absorption spectrometry. The algorithm is based on the modification of the function wavelength-integrated absorbance vs. concentration of analyte vapor in the absorption volume. According to the suggested approach, the absorption line is represented by a triangle for low and trapezium for high analyte vapor concentration in the absorption volume. The respective semi-empirical formulas include two linearization parameters, which depend on properties of the absorption line and characteristics of the atomizer and spectrometer. The parameters can be approximately evaluated from the theory and determined in practice from the original broad-range calibration curve. The parameters were found and the proposed calculation algorithm verified in the experiments on direct determination of Ag, Cd, Cu, Fe, Mn and Pb in the solutions within a concentration ranges from 0.15 to 625 {mu}g{center_dot}L{sup -1} using tube, platform tube and filter furnace atomizers. The use of various atomizers, lines, elements and atomization temperatures made possible the simulation of various practical analytical conditions. It was found that the algorithm and optimal linearization parameters made it possible to obtain for each line and atomizer linear approximations of the calibration curves within 3-4 orders of magnitude with correlation coefficients close to 0.999. The algorithm makes possible to employ a single line for the direct element determination over a broad concentration range. The sources of errors and the possibility of a priori theoretical evaluation of the linearization parameters are discussed. - Highlights: Black-Right-Pointing-Pointer New calculation algorithm for HR-CS ET AAS measurements was proposed and applied. Black-Right-Pointing-Pointer The suggested formulas include two parameters to be determined experimentally. Black

  5. Linear concentration system; Sistema de concentracion lineal

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Lugo, J.I; Leon Rovira, N; Aguayo Tellez, H [Instituto Tecnologico y de Estudios Superiores de Monterrey, Monterrey, Nuevo Leon (Mexico)]. E-mails: a00812662@itesm.mx; noel.leon@itesm.mx; haguayo@itesm.mx

    2013-03-15

    Solar linear concentration technologies to generate high temperatures are limited to the ranges of 200 to 500 degrees Celsius. While its performance has been tested through prototypes and pilot plants around the world, there are still areas of opportunity that can be exploited to obtain a linear concentration that achieves temperatures above this range in order to have a better use of the available solar energy. Because of this: It is possible to develop a linear concentration system that can track the sun with minimal movement of the absorber-receiver while maintaining temperatures above 850 degrees Celsius sufficient for industrial processes that require that temperature. The methodology consists of a series of stages (conceptual design, simulation, evaluation, development concept, results and validation) through which concepts are generated that allow design and evaluation of solar concentrator configurations with the help of simulation software. We have designed a linear parabolic concentrating system which comprises a set of mirrors segments with different focal lengths that works within the range of 600 degrees Celsius; however, it is advancing in the development of a double concentration to reach 850 degrees Celsius. [Spanish] Las tecnologias de concentracion lineal solar para generar altas temperaturas se ven limitadas a los rangos de 200 a 500 grados centigrados. Si bien su funcionamiento ha sido probado a traves de prototipos y plantas piloto alrededor del mundo, aun existen areas de oportunidad que pueden ser aprovechadas para obtener un sistema de concentracion lineal que permita alcanzar temperaturas mayores a este rango para asi tener un mejor aprovechamiento de la energia solar disponible. Debido a esto: Es posible desarrollar un sistema de concentracion lineal capaz de seguir la trayectoria del Sol con minimo movimiento del absorbedor-recibidor al mismo tiempo que mantiene temperaturas superiores a los 850 grados centigrados suficientes para

  6. Satellite-derived high resolution PM2.5 concentrations in Yangtze River Delta Region of China using improved linear mixed effects model

    Science.gov (United States)

    Ma, Zongwei; Liu, Yang; Zhao, Qiuyue; Liu, Miaomiao; Zhou, Yuanchun; Bi, Jun

    2016-05-01

    Satellite remotely sensed aerosol optical depth (AOD) provides an effective way to fill the spatial and temporal gaps left by ground PM2.5 monitoring network. Previous studies have established robust advanced statistical models to estimate PM2.5 using AOD data in China. However, their coarse resolutions (˜10 km or greater) of PM2.5 estimations are not enough to support the health effect studies at urban scales. In this study, 3 km AOD data from Moderate Resolution Imaging Spectroradiometer (MODIS) collection 6 products were used to estimate the high resolution PM2.5 concentrations in Yangtze Delta Region of China. We proposed a nested linear mixed effects (LME) model including nested month-, week-, and day-specific random effects of PM2.5-AOD relationships. Validation results show that the LME model only with day-specific random effects (non-nested model) used in previous studies has poor performance in the days without PM2.5-AOD matchups (the R2 of day-of-year-based cross validation (DOY-based CV) is 0.148). The results also show that our nested model cannot improve the performance of non-nested model in the days with PM2.5-AOD matchups (sample-based CV R2 = 0.671 for nested model vs. 0.661 for non-nested model), but can greatly improve the model performance beyond those days (DOY-based CV R2 = 0.339 for nested model vs. 0.148 for non-nested model). To further improve the model performance, we applied the "buffer models" (i.e., models fitted from datasets which ground PM2.5 were matched with the average AOD values within certain radius buffer zones of gridded PM2.5 data) on the 3 km AOD data since the "buffer models" has more days with PM2.5-AOD matchups and can provide more day-specific relationships. The results of this study show that 3 km MODIS C6 AOD data can be used to estimate PM2.5 concentrations and can provide more detailed spatial information for urban scale studies. The application of our nested LME model can greatly improve the accuracy of 3 km PM2

  7. Double curvature mirrors for linear concentrators

    Science.gov (United States)

    Lance, Tamir; Ackler, Harold; Finot, Marc

    2012-10-01

    Skyline Solar's medium concentration photovoltaic system uses quasi-parabolic mirrors and one axis tracking. Improvements in levelized cost of energy can be achieved by effective management of non-uniformity of the flux line on the panels. To reduce non uniformity of the flux line due to mirror to mirror gaps, Skyline developed a dual curvature mirror that stretches the flux line along the panel. Extensive modeling and experiments have been conducted to analyze the impact of this new design and to optimize the design.

  8. Rebuilding sources of linear tracers after atmospheric concentration concentration

    Directory of Open Access Journals (Sweden)

    J.-P. Issartel

    2003-06-01

    Full Text Available The identification of widespread sources of passive tracers out of atmospheric concentration measurements has become an important challenge of modern meteorology. The paper proposes some mathematical tracks to address this reconstruction of the complex space-time geometry of the sources. The methods are based upon the use of retroplumes. The inverse problem is addressed in a deterministic non statistical frame. The information obtained by local measurements is spread by introducing the concept of illumination. The constraint that the source to be rebuilt is non negative is also addressed. The experimental source ETEX1 is rebuilt in order to evaluate an impulse response of the algorithms.

  9. Non-linear absorption for concentrated solar energy transport

    Energy Technology Data Exchange (ETDEWEB)

    Jaramillo, O. A; Del Rio, J.A; Huelsz, G [Centro de Investigacion de Energia, UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    In order to determine the maximum solar energy that can be transported using SiO{sub 2} optical fibers, analysis of non-linear absorption is required. In this work, we model the interaction between solar radiation and the SiO{sub 2} optical fiber core to determine the dependence of the absorption of the radioactive intensity. Using Maxwell's equations we obtain the relation between the refractive index and the electric susceptibility up to second order in terms of the electric field intensity. This is not enough to obtain an explicit expression for the non-linear absorption. Thus, to obtain the non-linear optical response, we develop a microscopic model of an harmonic driven oscillators with damp ing, based on the Drude-Lorentz theory. We solve this model using experimental information for the SiO{sub 2} optical fiber, and we determine the frequency-dependence of the non-linear absorption and the non-linear extinction of SiO{sub 2} optical fibers. Our results estimate that the average value over the solar spectrum for the non-linear extinction coefficient for SiO{sub 2} is k{sub 2}=10{sup -}29m{sup 2}V{sup -}2. With this result we conclude that the non-linear part of the absorption coefficient of SiO{sub 2} optical fibers during the transport of concentrated solar energy achieved by a circular concentrator is negligible, and therefore the use of optical fibers for solar applications is an actual option. [Spanish] Con el objeto de determinar la maxima energia solar que puede transportarse usando fibras opticas de SiO{sub 2} se requiere el analisis de absorcion no linear. En este trabajo modelamos la interaccion entre la radiacion solar y el nucleo de la fibra optica de SiO{sub 2} para determinar la dependencia de la absorcion de la intensidad radioactiva. Mediante el uso de las ecuaciones de Maxwell obtenemos la relacion entre el indice de refraccion y la susceptibilidad electrica hasta el segundo orden en terminos de intensidad del campo electrico. Esto no es

  10. Numerical Study of Concentration Characteristics of Linear Fresnel Reflector System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jin [Kookmin Univ., Seoul (Korea, Republic of); Kim, Jong Kyu; Lee, Sang Nam [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

    2015-12-15

    In this study, we numerically investigated the concentration characteristics of a linear Fresnel reflector system that can drive a solar thermal absorption refrigeration system to be installed in Saudi Arabia. Using an optical modeling program based on the Monte Carlo ray-tracing method, we simulated the concentrated solar flux, concentration efficiency, and concentrated solar energy on four representative days of the year - the vernal equinox, summer solstice, autumnal equinox, and winter solstice. Except the winter solstice, the concentrations were approximately steady from 9 AM to 15 PM, and the concentration efficiencies exceed 70%. Moreover, the maximum solar flux around the solar receiver center changes only within the range of 13.0 - 14.6 kW/m{sup 2}. When we investigated the effects of the receiver installation height, reflector width, and reflector gap, the optimal receiver installation height was found to be 5 m. A smaller reflector width had a greater concentration efficiency. However, the design of the reflector width should be based on the capacity of the refrigeration system because it dominantly affects the concentrated solar energy. The present study was an essential prerequisite for thermal analyses of the solar receiver. Thus, an optical-thermal integration study in the future will assist with the performance prediction and design of the entire system.

  11. Explicit Bounds for Entropy Concentration under Linear Constraints

    CERN Document Server

    Oikonomou, Kostas N

    2011-01-01

    Consider the construction of an object composed of $m$ parts by distributing $n$ units to those parts. For example, say we are assigning $n$ balls to $m$ boxes. Each assignment results in a certain count vector, specifying the number of balls allocated to each box. If only assignments satisfying a set of constraints that are linear in these counts are allowable, and $m$ is fixed while $n$ increases, most assignments that satisfy the constraints result in frequency vectors (normalized counts) whose entropy approaches that of the maximum entropy vector satisfying the constraints. This phenomenon of "entropy concentration" is known in various forms, and is one of the justifications of the maximum entropy method, one of the most powerful tools for solving problems with incomplete information. The appeal of entropy concentration comes from the simplicity of the argument: it is based purely on counting. Existing proofs of the concentration phenomenon are based on limits or asymptotics. Here we present non-asymptoti...

  12. Linear stability analysis of capillary instabilities for concentric cylindrical shells

    CERN Document Server

    Liang, X; Nave, J -C; Johnson, S G

    2010-01-01

    Motivated by complex multi-fluid geometries currently being explored in fibre-device manufacturing, we study capillary instabilities in concentric cylindrical flows of N fluids with arbitrary viscosities, thicknesses, densities, and surface tensions in both the Stokes regime and for the full Navier--Stokes problem. Generalising previous work by Tomotika (N=2), Stone & Brenner (N=3, equal viscosities) and others, we present a full linear stability analysis of the growth modes and rates, reducing the system to a linear generalised eigenproblem in the Stokes case. Furthermore, we demonstrate by Plateau-style geometrical arguments that only axisymmetric instabilities need be considered. We show that the N=3 case is already sufficient to obtain several interesting phenomena: limiting cases of thin shells or low shell viscosity that reduce to N=2 problems, and a system with competing breakup processes at very different length scales. The latter is demonstrated with full 3-dimensional simulations. Many $N > 3$ c...

  13. Rebuilding sources of linear tracers after atmospheric concentration measurements

    Directory of Open Access Journals (Sweden)

    J.-P. Issartel

    2003-01-01

    Full Text Available The identification of widespread sources of passive tracers out of atmospheric concentration measurements has become an important challenge of modern meteorology. The paper proposes some mathematical tracks to address the reconstruction of the complex space-time geometry of the sources of linear tracers. The methods are based upon the use of retroplumes. The inverse problem is addressed in a deterministic non statistical frame. The information obtained by local measurements is spread by introducing the concept of illumination. The constraint that the source is non negative is also addressed. The experimental source ETEX1 is rebuilt in order to evaluate an impulse response of the algorithms.

  14. Energy and environmental analysis of a linear concentrating photovoltaic system

    Science.gov (United States)

    Kerzmann, Tony

    The world is facing an imminent energy supply crisis. In order to sustain and increase our energy supply in an environmentally-conscious manner, it is necessary to advance renewable technologies. Despite this urgency, however, it is paramount to consider the larger environmental effects associated with using renewable energy resources. This research is meant to better understand linear concentrating photovoltaics (LCPVs) from an engineering and environmental standpoint. In order to analyze the LCPV system, a simulation and life cycle assessment (LCA) were developed. The LCPV system serves two major purposes: it produces electricity, and waste heat is collected for heating use. There are three parts to the LCPV simulation. The first part simulates the multijunction cell output so as to calculate the temperature-dependent electricity generation. The second part simulates the cell cooling and waste heat recovery system using a model consisting of heat transfer and fluid flow equations. The waste heat recovery in the LCPV system was linked to a hot water storage system, which was also modeled. Coupling the waste heat recovery simulation and the hot water storage system gives an overall integrated system that is useful for system design, optimization, and acts as a stepping stone for future multijunction cell Photovoltaic/Thermal (PV/T) systems. Finally, all of the LCPV system components were coded in Engineering Equation Solver (EES) and were used in an energy analysis under actual weather and solar conditions for the Phoenix, AZ, region. The life cycle assessment for the LCPV system allowed for an environmental analysis of the system where areas of the highest environmental impact were pinpointed. While conducting the LCA research, each component of the system was analyzed from a resource extraction, production, and use standpoint. The collective production processes of each LCPV system component were gathered into a single inventory of materials and energy flows

  15. New dual asymmetric CEC linear Fresnel concentrator for evacuated tubular receivers

    Science.gov (United States)

    Canavarro, Diogo; Chaves, Julio; Collares-Pereira, Manuel

    2017-06-01

    Linear Fresnel Reflector concentrators (LFR) are a potential solution for low-cost electricity production. Nevertheless in order to become more competitive with other CSP (Concentrated Solar Power) technologies, in particular with the Parabolic Trough concentrator, their overall solar to electricity efficiencies must increase. A possible path to achieve this goal is to increase the concentration factor, hence increasing the working temperatures for higher thermodynamic efficiency (more energy collection) and decrease the total number of rows of the solar field (less parasitic losses and corresponding cost reduction). This paper presents a dual asymmetric CEC-type (Compound Elliptical Concentrator) LFR (Linear Fresnel Concentrator) for evacuated tubular receivers. The concentrator is designed for a high concentration factor, presenting an asymmetric configuration enabling a very compact solution. The CEC-type secondary mirror is introduced to accommodate very high concentration values with a wide enough acceptance-angle (augmenting optical tolerances) for simple mechanical tracking solutions, achieving a higher CAP (Concentration Acceptance Product) in comparison with conventional LFR solutions. The paper presents an optical and thermal analysis of the concentrator using two different locations, Faro (Portugal) and Hurghada (Egypt).

  16. Linear algebra on high-performance computers

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J.J.; Sorensen, D.C.

    1986-01-01

    This paper surveys work recently done at Argonne National Laboratory in an attempt to discover ways to construct numerical software for high-performance computers. The numerical algorithms are taken from several areas of numerical linear algebra. We discuss certain architectural features of advanced-computer architectures that will affect the design of algorithms. The technique of restructuring algorithms in terms of certain modules is reviewed. This technique has proved successful in obtaining a high level of transportability without severe loss of performance on a wide variety of both vector and parallel computers. The module technique is demonstrably effective for dense linear algebra problems. However, in the case of sparse and structured problems it may be difficult to identify general modules that will be as effective. New algorithms have been devised for certain problems in this category. We present examples in three important areas: banded systems, sparse QR factorization, and symmetric eigenvalue problems. 32 refs., 10 figs., 6 tabs.

  17. Explicit bounds for entropy concentration under linear constraints

    NARCIS (Netherlands)

    K.N. Oikonomou (Kostas); P.D. Grünwald (Peter)

    2016-01-01

    textabstractConsider the set of all sequences of n outcomes, each taking one of m values, whose frequency vectors satisfy a set of linear constraints. If m is fixed while n increases, most sequences that satisfy the constraints result in frequency vectors whose entropy approaches that of the maximum

  18. High-efficiency solar concentrator

    Science.gov (United States)

    Lansing, F. L.; Dorman, J.

    1980-01-01

    A new type of solar concentrator is presented using liquid lenses and simple translational tracking mechanism. The concentrator achieves a 100:1 nominal concentration ratio and is compared in performance with a flat-plate collector having two sheets of glazing and non-selective coating. The results of the thermal analysis show that higher temperatures can be obtained with the concentrator than is possible with the non-concentrator flat-plate type. Furthermore, the thermal efficiency far exceeds that of the comparative flat-plate type for all operating conditions.

  19. Thermal performance of a linear Fresnel reflector solar concentrator PV/T energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Gomaa, Mohamed R. [State Engineering University of Armenia (Armenia)], E-Mail: Dmoh_elbehary@yahoo.com

    2011-07-01

    This is a report on an investigation of photovoltaic/thermal (PV/T) collectors. Solar energy conversion efficiency was increased by taking advantage of PV/T collectors and low solar concentration technologies, combined into a PV/T system operated at elevated temperature. The main novelty is the coupling of a linear Fresnel mirror reflecting concentrator with a channel PV/T collector. Concentrator PV/T collectors can function at temperatures over 100 degrees celsius, and thus thermal energy can be made to drive processes such as refrigeration, desalination and steam production. Solar system analytical thermal performance gives efficiency values over 60%. Combined electric and thermal (CET) efficiency is high. A combined electric and heat power for the linear fresnel reflector approach that employs high performance CPV technology to produce both electricity and thermal energy at low to medium temperatures is presented. A well-functioning PV/T system can be designed and constructed with low concentration and a total efficiency of nearly 80% can be attained.

  20. LINEAR AND NONLINEAR DIELECTRIC PROPERTIES OF PARTICULATE COMPOSITES AT FINITE CONCENTRATION

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiao-ming; HU Geng-kai

    2006-01-01

    An analytical method was proposed to calculate effective linear and nonlinear dielectric properties for particulate composites. The method is based on an approximate solution of two-particle interaction problem, and it can be applied to relatively high volume concentration of particles (up to 50%). Nonlinear dielectric property was also examined by means of secant method. It is found that for low applied electric filed the proposed method is close to Stroud and Hui's method and for high applied electric filed it is close to Yu's method.

  1. Breaker concentrations required to improve the permeability of proppant packs damaged by concentrated linear and borate-crosslinked fracturing fluids

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, H. (BJ Services (United States)); Pulsinelli, R.J. (Dowell Schlumberger, Tulsa, OK (United States))

    1992-11-01

    This paper reports on the concentrations of an oxidative breaker required to reduce significantly the proppant-pack permeability damage caused by aqueous hydraulic fracturing fluids. Long-term, proppant-pack permeability testing was used to evaluate linear and borate-crosslinked gels. Results indicate that increasing the breaker concentration can reduce proppant-pack permeability damage very effectively.

  2. High order stiffly stable linear multistep methods

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, C.N.

    1979-01-01

    Stiffly stable linear k-step methods of order k for the initial-value problem are studied. Examples for k = 1, 2, and 3 were discovered by use of Adams-type methods. A large family of stiffly stable linear 7-step methods of order 7 was also found.

  3. Shielding effects in polymer-polymer reactions. V. Concentration dependence of contact formation between star-branched and linear chains.

    Science.gov (United States)

    Nardai, Michael M; Zifferer, Gerhard

    2013-07-19

    By use of the Dissipative Particle Dynamics (DPD) simulation technique mixtures of star-branched (arm number F = 4) and linear chains in athermal (good) solvent are analyzed regarding probabilities for intermolecular contacts of various reactive sites within different polymer coils. The accompanying sterical hindrances are described in the framework of shielding factors in order to investigate reactions and side reactions in radical polymerization and other techniques that involve polymer-polymer coupling. The shielding factors are studied as a function of total concentration from high dilution up to the bulk for different chain lengths of star-shaped and linear chains. Results indicate that their concentration dependence can be described by a power law for systems above the overlap concentration, whereas the chain length dependence vanishes when extrapolating to infinite chain lengths in that concentration range. Also the influence of the ratio of star chains and linear chains is studied for various concentrations.

  4. Roll-to-roll embossing of optical linear Fresnel lens polymer film for solar concentration.

    Science.gov (United States)

    Zhang, XinQuan; Liu, Kui; Shan, Xuechuan; Liu, Yuchan

    2014-12-15

    Roll-to-roll manufacturing has been proven to be a high-throughput and low-cost technology for continuous fabrication of functional optical polymer films. In this paper, we have firstly studied a complete manufacturing cycle of linear Fresnel lens polymer film for solar concentration in the aspects of ultra-precision diamond machining of metal roller mold, roll-to-roll embossing, and measurement on film profile and functionality. A metal roller mold patterned with linear Fresnel lenses is obtained using single point diamond turning technique. The roller mold is installed onto a self-developed roll-to-roll UV embossing system to realize continuous manufacturing of linear Fresnel lens film. Profile measurement of the machined roller mold and the embossed polymer film, which is conducted using a stylus profilometer, shows good agreement between measured facet angles with designed ones. Functionality test is conducted on a solar simulation system with a reference solar cell, and results show that strong light concentration is realized.

  5. Optical analysis and thermal management of 2-cell strings linear concentrating photovoltaic system

    Science.gov (United States)

    Reddy, K. S.; Kamnapure, Nikhilesh R.

    2015-09-01

    This paper presents the optical and thermal analyses for a linear concentrating photovoltaic/thermal collector under different operating conditions. Linear concentrating photovoltaic system (CPV) consists of a highly reflective mirror, a receiver and semi-dual axis tracking mechanism. The CPV receiver embodies two strings of triple-junction cells (100 cells in each string) adhered to a mild steel circular tube mounted at the focal length of trough. This system provides 560 W of electricity and 1580 W of heat which needs to be dissipated by active cooling. The Al2O3/Water nanofluid is used as heat transfer fluid (HTF) flowing through circular receiver for CPV cells cooling. Optical analysis of linear CPV system with 3.35 m2 aperture and geometric concentration ratio (CR) of 35 is carried out using Advanced System Analysis Program (ASAP) an optical simulation tool. Non-uniform intensity distribution model of solar disk is used to model the sun in ASAP. The impact of random errors including slope error (σslope), tracking error (σtrack) and apparent change in sun's width (σsun) on optical performance of collector is shown. The result from the optical simulations shows the optical efficiency (ηo) of 88.32% for 2-cell string CPV concentrator. Thermal analysis of CPV receiver is carried out with conjugate heat transfer modeling in ANSYS FLUENT-14. Numerical simulations of Al2O3/Water nanofluid turbulent forced convection are performed for various parameters such as nanoparticle volume fraction (φ), Reynolds number (Re). The addition of the nanoparticle in water enhances the heat transfer in the ranges of 3.28% - 35.6% for φ = 1% - 6%. Numerical results are compared with literature data which shows the reasonable agreement.

  6. Multiple linear regression models of urban runoff pollutant load and event mean concentration considering rainfall variables.

    Science.gov (United States)

    Maniquiz, Marla C; Lee, Soyoung; Kim, Lee-Hyung

    2010-01-01

    Rainfall is an important factor in estimating the event mean concentration (EMC) which is used to quantify the washed-off pollutant concentrations from non-point sources (NPSs). Pollutant loads could also be calculated using rainfall, catchment area and runoff coefficient. In this study, runoff quantity and quality data gathered from a 28-month monitoring conducted on the road and parking lot sites in Korea were evaluated using multiple linear regression (MLR) to develop equations for estimating pollutant loads and EMCs as a function of rainfall variables. The results revealed that total event rainfall and average rainfall intensity are possible predictors of pollutant loads. Overall, the models are indicators of the high uncertainties of NPSs; perhaps estimation of EMCs and loads could be accurately obtained by means of water quality sampling or a long-term monitoring is needed to gather more data that can be used for the development of estimation models.

  7. Influence of volatile fatty acid concentration stability on anaerobic degradation of linear alkylbenzene sulfonate.

    Science.gov (United States)

    Okada, Dagoberto Y; Delforno, Tiago P; Esteves, Andressa S; Polizel, Juliana; Hirasawa, Julia S; Duarte, Iolanda C S; Varesche, Maria B A

    2013-10-15

    Linear alkylbenzene sulfonate (LAS) is an anionic surfactant used in cleaning products, which is usually found in wastewaters. Despite the greater LAS removal rate related to a lower concentrations of volatile fatty acids (VFA), the influence of different ranges of VFA on LAS degradation is not known. LAS degradation was evaluated in upflow anaerobic sludge blanket (UASB) and expanded granular sludge bed (EGSB) reactors at different ranges of VFA concentrations. The reactors were fed with a synthetic wastewater containing LAS (14 mg/L). A greater LAS removal rate (40-80%) was related to the lower and narrower range of acetic acid concentration (1-22 mg/L) in the EGSB reactor. In the UASB reactor, the acetic acid concentrations presented a wider range (2-45 mg/L), and some low LAS removal rates (around 20-25%) were observed even at low acetic acid concentrations (<10 mg/L). The high recirculation rate in the EGSB reactor improved substrate-biomass contact, which resulted in a narrower range of VFA and greater LAS removal rate.

  8. High performance linear algebra algorithms: An introduction

    DEFF Research Database (Denmark)

    Gustavson, F.G.; Wasniewski, Jerzy

    2006-01-01

    his Mini-Symposium consisted of two back to back sessions, each consisting of five presentations, held on the afternoon of Monday, June 21, 2004. A major theme of both sessions was novel data structures for the matrices of dense linear algebra, DLA. Talks one to four of session one all centered...

  9. Design and development of a high-concentration photovoltaic concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, R C

    1982-04-01

    The design and development of a high concentration photovoltaic concentrator module is discussed. The design concept described herein incorporates a curved groove domed Fresnel lens, a high concentration etched multiple vertical junction (EMVJ) solar cell and a passively cooled direct-bonded copper cell mount all packaged in a plastic module. Two seven inch diameter 1200x domed Fresnel lenses were fabricated using single point diamond turning technology. Testing at both GE and Sandia confirmed optical transmission efficiencies of over 83%. Samples of the latest available EMVJ cells were mounted and installed, with a domed Fresnel lens, into a prototype module. Subsequent testing demonstrated net lens-cell efficiencies of 10 to 13%. As a result of this program, salient conclusions have been formulated as to this technology.

  10. Distributed coupling high efficiency linear accelerator

    Science.gov (United States)

    Tantawi, Sami G.; Neilson, Jeffrey

    2016-07-19

    A microwave circuit for a linear accelerator includes multiple monolithic metallic cell plates stacked upon each other so that the beam axis passes vertically through a central acceleration cavity of each plate. Each plate has a directional coupler with coupling arms. A first coupling slot couples the directional coupler to an adjacent directional coupler of an adjacent cell plate, and a second coupling slot couples the directional coupler to the central acceleration cavity. Each directional coupler also has an iris protrusion spaced from corners joining the arms, a convex rounded corner at a first corner joining the arms, and a corner protrusion at a second corner joining the arms.

  11. Methanogenic activity inhibition by increasing the linear alkylbenzene sulfonate (LAS) concentration.

    Science.gov (United States)

    Souza, Luiza F C; Florencio, Lourdinha; Gavazza, Savia; Kato, Mario T

    2016-07-02

    The effect of the initial concentration of linear alkylbenzene sulfonate (LAS) on specific methanogenic activity (SMA) was investigated in this work. Six anaerobic flasks reactors with 1 L of total volume were inoculated with anaerobic sludge (2 g VSS L(-1)). The reactors were assayed for 42 days, and fed with volatile fatty acids, nutrients, and LAS. The initial LAS concentrations were 0, 10, 30, 50, 75, and 100 mg L(-1) for the treatment flasks T1 (control), T2, T3, T4, T5, and T6, respectively. When compared with T1, T2 exhibited a 30% reduction in maximum SMA and total methane production (TMP). In treatment T3 through T6, the reductions were 44-97% (T3-T6) for SMA, and 30-90% (T3-T6) for TMP. Total LAS removal increased following the increase in the initial LAS concentration (from 36% at T1 to 76% at T6), primarily due to the high degree of sludge adsorption. LAS biodegradation also occurred (32% in all treatments), although this was most likely associated with the formation of non-methane intermediates. Greater removal by adsorption was observed in long-chain homologues, when compared to short-chain homologues (C13 > C10), whereas the opposite occurred for biodegradation (C10 > C13). The C13 homologue was adsorbed to a great extent (in mass) in T4, T5 and T6, and may also have inhibited methane formation in these treatments.

  12. Dye alignment in luminescent solar concentrators: II. Horizontal alignment for energy harvesting in linear polarizers.

    Science.gov (United States)

    Mulder, C L; Reusswig, P D; Beyler, A P; Kim, H; Rotschild, C; Baldo, M A

    2010-04-26

    We describe Linearly Polarized Luminescent Solar Concentrators (LP-LSCs) to replace conventional, purely absorptive, linear polarizers in energy harvesting applications. As a proof of concept, we align 3-(2-Benzothiazolyl)-N,N-diethylumbelliferylamine (Coumarin 6) and 4-dicyanomethyl-6-dimethylaminostiryl-4H-pyran (DCM) dye molecules linearly in the plane of the substrate using a polymerizable liquid crystal host. We show that up to 38% of the photons polarized on the long axis of the dye molecules can be coupled to the edge of the device for an LP-LSC based on Coumarin 6 with an order parameter of 0.52.

  13. Playa: High-Performance Programmable Linear Algebra

    Directory of Open Access Journals (Sweden)

    Victoria E. Howle

    2012-01-01

    Full Text Available This paper introduces Playa, a high-level user interface layer for composing algorithms for complex multiphysics problems out of objects from other Trilinos packages. Among other features, Playa provides very high-performance overloaded operators implemented through an expression template mechanism. In this paper, we give an overview of the central Playa objects from a user's perspective, show application to a sequence of increasingly complex solver algorithms, provide timing results for Playa's overloaded operators and other functions, and briefly survey some of the implementation issues involved.

  14. High-brightness rf linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, R.A.

    1986-01-01

    The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines. (LEW)

  15. High-brightness rf linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, R.A.

    1986-01-01

    The issue of high brightness and its ramifications in linacs driven by radio-frequency fields is discussed. A history of the RF linacs is reviewed briefly. Some current applications are then examined that are driving progress in RF linacs. The physics affecting the brightness of RF linacs is then discussed, followed by the economic feasibility of higher brightness machines. (LEW)

  16. Linear versus non-linear structural information limit in high-resolution transmission electron microscopy.

    Science.gov (United States)

    Van Aert, S; Chen, J H; Van Dyck, D

    2010-10-01

    A widely used performance criterion in high-resolution transmission electron microscopy (HRTEM) is the information limit. It corresponds to the inverse of the maximum spatial object frequency that is linearly transmitted with sufficient intensity from the exit plane of the object to the image plane and is limited due to partial temporal coherence. In practice, the information limit is often measured from a diffractogram or from Young's fringes assuming a weak phase object scattering beyond the inverse of the information limit. However, for an aberration corrected electron microscope, with an information limit in the sub-angstrom range, weak phase objects are no longer applicable since they do not scatter sufficiently in this range. Therefore, one relies on more strongly scattering objects such as crystals of heavy atoms observed along a low index zone axis. In that case, dynamical scattering becomes important such that the non-linear and linear interaction may be equally important. The non-linear interaction may then set the experimental cut-off frequency observed in a diffractogram. The goal of this paper is to quantify both the linear and the non-linear information transfer in terms of closed form analytical expressions. Whereas the cut-off frequency set by the linear transfer can be directly related with the attainable resolution, information from the non-linear transfer can only be extracted using quantitative, model-based methods. In contrast to the historic definition of the information limit depending on microscope parameters only, the expressions derived in this paper explicitly incorporate their dependence on the structure parameters as well. In order to emphasize this dependence and to distinguish from the usual information limit, the expressions derived for the inverse cut-off frequencies will be referred to as the linear and non-linear structural information limit. The present findings confirm the well-known result that partial temporal coherence has

  17. A comparative analysis of configurations of linear Fresnel collectors for concentrating solar power

    OpenAIRE

    Montes, Maria Jesus; Rubbia, C; Abbas Camara, Rubén; Martínez-Val Peñalosa, Jose Maria

    2014-01-01

    Linear Fresnel collector arrays present some relevant advantages in the domain of concentrating solar power because of their simplicity, robustness and low capital cost. However, they also present important drawbacks and limitations, notably their average concentration ratio, which seems to limit significantly the performance of these systems. First, the paper addresses the problem of characterizing the mirror field configuration assuming hourly data of a typical year, in reference to a c...

  18. Producing a highly concentrated coal suspension

    Energy Technology Data Exchange (ETDEWEB)

    Mokudzu, K.; Atsudzima, T.; Kiyedzuka, Y.

    1983-06-03

    Coal from wet and dry grinding is loaded into a mixer with a mixer arm with the acquisition of a highly concentrated suspension. Foamers (for instance, alkylbenzolsulfonate) and foam stabilizers (for instance diethanolamide of lauric acid) are added in a ratio of 10 to (2 to 5). The high fluidity of the suspension is maintained by injecting air into the suspension and an 80 percent concentration of the suspension is achieved.

  19. Scheme for entanglement concentration of unknown W class states via linear optics

    Institute of Scientific and Technical Information of China (English)

    Zhang Li-Hua; Dong Ping; Cao Zhuo-Liang

    2007-01-01

    This paper proposes a scheme for entanglement concentration of unknown triparticle W class states with a certain probability.This protocol is mainly based on the coincidences of single-photon detectors and requires single-photon detectors and linear optical elements.The scheme is feasible within current technology.

  20. Performance of a concentrated photovoltaic energy system with static linear Fresnel lenses

    NARCIS (Netherlands)

    Sonneveld, P.J.; Swinkels, G.L.A.M.; Tuijl, van B.A.J.; Janssen, H.J.J.; Campen, J.B.; Bot, G.P.A.

    2011-01-01

    A new type of greenhouse with linear Fresnel lenses in the cover performing as a concentrated photovoltaic (CPV) system is presented. The CPV system retains all direct solar radiation, while diffuse solar radiation passes through and enters into the greenhouse cultivation system. The removal of all

  1. Daylighting in linear atrium buildings at high latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Matusiak, Barbara

    1998-12-31

    This thesis proposes new criteria for visual comfort based on knowledge of visual perception and a method for estimating the modelling ability of light by using inter-reflection calculations. Simplified calculations are presented for the daylight factor in linear building structures, using the projected solid angle principle, for uniform sky and for CIE overcast sky conditions. The calculations are compared with experimental results. Simple diagrams are created based on calculations of the mean daylight factor in rooms adjacent to a narrow street. These diagrams and presented formulas and tables can be used as a simple design tool. Daylighting strategies for linear atrium buildings at high latitudes are developed and examined. These strategies are divided into three groups: (1) the atrium space and facades as light conductor/reflector, (2) the glass roof as a light conductor, and (3) light reflectors on the neighbouring roof. The atrium space and facade strategies are subdivided into passive and active. The strategies connected to the glazed roof includes different configurations of glazing: horizontal, single pitched, double pitched, and the use of laser cut panels and prismatic panels in the glazed roof. The shapes of reflectors on the neighbouring roof are a flat reflector, a parabolic reflector and a parabolic concentrator. Strategies from all three groups are examined on a physical model of scale 1:20 in the artificial sky of mirror box type. Simulations with artificial sun have also been done. The results from model studies are compared with computer simulations. All the active daylighting systems designed for use in the atrium space or on the atrium facades have a huge potential for use in atrium buildings. From the strategies connected with the glazed roof the negatively sloped glass is found to be the best alternative for glazed roofs at high latitudes. Among the roof reflectors, the flat one performs best. 82 refs., 122 figs., 27 tabs.

  2. Transformation of nitrogen dioxide into ozone and prediction of ozone concentrations using multiple linear regression techniques.

    Science.gov (United States)

    Ghazali, Nurul Adyani; Ramli, Nor Azam; Yahaya, Ahmad Shukri; Yusof, Noor Faizah Fitri M D; Sansuddin, Nurulilyana; Al Madhoun, Wesam Ahmed

    2010-06-01

    Analysis and forecasting of air quality parameters are important topics of atmospheric and environmental research today due to the health impact caused by air pollution. This study examines transformation of nitrogen dioxide (NO(2)) into ozone (O(3)) at urban environment using time series plot. Data on the concentration of environmental pollutants and meteorological variables were employed to predict the concentration of O(3) in the atmosphere. Possibility of employing multiple linear regression models as a tool for prediction of O(3) concentration was tested. Results indicated that the presence of NO(2) and sunshine influence the concentration of O(3) in Malaysia. The influence of the previous hour ozone on the next hour concentrations was also demonstrated.

  3. Dynamics of global atmospheric CO2 concentration from 1850 to 2010: a linear approximation

    Science.gov (United States)

    Wang, W.; Nemani, R.

    2014-09-01

    The increase in anthropogenic CO2 emissions largely followed an exponential path between 1850 and 2010, and the corresponding increases in atmospheric CO2 concentration were almost constantly proportional to the emissions by the so-called "airborne fraction". These observations suggest that the dynamics of atmospheric CO2 concentration through this time period may be properly approximated as a linear system. We demonstrate this hypothesis by deriving a linear box-model to describe carbon exchanges between the atmosphere and the surface reservoirs under the influence of disturbances such as anthropogenic CO2 emissions and global temperature changes. We show that the box model accurately simulates the observed atmospheric CO2 concentrations and growth rates across interannual to multi-decadal time scales. The model also allows us to analytically examine the dynamics of such changes/variations, linking its characteristic disturbance-response functions to bio-geophysically meaningful parameters. In particular, our results suggest that the elevated atmospheric CO2 concentrations have significantly promoted the gross carbon uptake by the terrestrial biosphere. However, such "fertilization" effects are partially offset by enhanced carbon release from surface reservoirs promoted by warmer temperatures. The result of these interactions appears to be a decline in net efficiency in sequestering atmospheric CO2 by ∼30% since 1960s. We believe that the linear modeling framework outlined in this paper provides a convenient tool to diagnose the observed atmospheric CO2 dynamics and monitor their future changes.

  4. A HIGH VELOCITY FEED UNIT DRIVEN BY LINEAR MOTOR

    Institute of Scientific and Technical Information of China (English)

    Zhang Bolin; Chen Yanji; Li Zhiying

    2000-01-01

    In order to realize high speed machining,the special requirements for feed transmission system of the CNC machine tool have to be satisfied.A high velocity feed unit driven by a induction linear motor is developed.The compositions of the high velocity CNC feed unit and main problems in the unit design are discussed.

  5. Cellulase Inhibition by High Concentrations of Monosaccharides

    DEFF Research Database (Denmark)

    Hsieh, Chia-Wen; Cannella, David; Jørgensen, Henning

    2014-01-01

    that low free water availability contributes to cellulase inhibition. Of the hydrolytic enzymes involved, those acting on the cellulose substrate, that is, exo- and endoglucanases, were the most inhibited. The β -glucosidases were shown to be less sensitive to high monosaccharide concentrations except...

  6. Effective Surfactants Blend Concentration Determination for O/W Emulsion Stabilization by Two Nonionic Surfactants by Simple Linear Regression

    National Research Council Canada - National Science Library

    Hassan, A K

    2015-01-01

    ...°. Applying the simple linear regression least squares method statistical analysis to the temperature-conductivity obtained data determines the effective surfactants blend concentration required...

  7. Accelerating R with high performance linear algebra libraries

    Directory of Open Access Journals (Sweden)

    Bogdan Oancea

    2015-09-01

    Full Text Available Linear algebra routines are basic building blocks for the statistical software. In this paper we analyzed how can we improve R performance for matrix computations. We benchmarked few matrix operations using the standard linear algebra libraries included in the R distribution and high performance libraries like OpenBLAS, GotoBLAS and MKL. Our tests showed the best results are obtained with the MKL library, the other two libraries having similar performances, but lower than MKL.

  8. High-dimensional entanglement concentration of twisted photon pairs High-dimensional entanglement concentration

    Science.gov (United States)

    Chen, L. X.; Wu, Q. P.

    2012-10-01

    Recently, Dada et al. reported on the experimental entanglement concentration and violation of generalized Bell inequalities with orbital angular momentum (OAM) [Nat. Phys. 7, 677 (2011)]. Here we demonstrate that the high-dimensional entanglement concentration can be performed in arbitrary OAM subspaces with selectivity. Instead of violating the generalized Bell inequalities, the working principle of present entanglement concentration is visualized by the biphoton OAM Klyshko picture, and its good performance is confirmed and quantified through the experimental Shannon dimensionalities after concentration.

  9. Linear and nonlinear filters under high power microwave conditions

    Directory of Open Access Journals (Sweden)

    F. Brauer

    2009-05-01

    Full Text Available The development of protection circuits against a variety of electromagnetic disturbances is important to assure the immunity of an electronic system. In this paper the behavior of linear and nonlinear filters is measured and simulated with high power microwave (HPM signals to achieve a comprehensive protection against different high power electromagnetic (HPEM threats.

  10. Characterization of a photovoltaic-thermal module for Fresnel linear concentrator

    Energy Technology Data Exchange (ETDEWEB)

    Chemisana, D., E-mail: daniel.chemisana@macs.udl.cat [University of Lleida, c/Pere Cabrera s/n, 25001 Lleida (Spain); Ibanez, M.; Rosell, J.I. [University of Lleida, c/Pere Cabrera s/n, 25001 Lleida (Spain)

    2011-09-15

    Highlights: {yields} A combined domed Fresnel lens - CPC PVT system is designed and characterized. {yields} Electrical and thermal experiments have been performed. {yields} CFD analysis has been used to determine thermal characteristic dimensionless numbers. - Abstract: An advanced solar unit is designed to match the needs of building integration and concentrating photovoltaic/thermal generation. The unit proposed accurately combines three elements: a domed linear Fresnel lens as primary concentrator, a compound parabolic reflector as secondary concentrator and a photovoltaic-thermal module. In this work the photovoltaic-thermal generator is built, analysed and characterized. Models for the electrical and thermal behaviour of the module are developed and validated experimentally. Applying a thermal resistances approach the results from both models are combined. Finally, efficiency electrical and thermal curves are derived from theoretical analysis showing good agreement with experimental measurements.

  11. Modelling acceptance of sunlight in high and low photovoltaic concentration

    Energy Technology Data Exchange (ETDEWEB)

    Leutz, Ralf, E-mail: ralf.leutz@leopil.com [Leutz Optics and Illumination UG (haftungsbeschränkt), Marburg (Germany)

    2014-09-26

    A simple model incorporating linear radiation characteristics, along with the optical trains and geometrical concentration ratios of solar concentrators is presented with performance examples for optical trains of HCPV, LCPV and benchmark flat-plate PV.

  12. CRPC research into linear algebra software for high performance computers

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.; Walker, D.W. [Oak Ridge National Lab., TN (United States). Mathematical Sciences Section; Dongarra, J.J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Computer Science]|[Oak Ridge National Lab., TN (United States). Mathematical Sciences Section; Pozo, R. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Computer Science; Sorensen, D.C. [Rice Univ., Houston, TX (United States). Dept. of Computational and Applied Mathematics

    1994-12-31

    In this paper the authors look at a number of approaches being investigated in the Center for Research on Parallel Computation (CRPC) to develop linear algebra software for high-performance computers. These approaches are exemplified by the LAPACK, templates, and ARPACK projects. LAPACK is a software library for performing dense and banded linear algebra computations, and was designed to run efficiently on high-performance computers. The authors focus on the design of the distributed-memory version of LAPACK, and on an object-oriented interface to LAPACK.

  13. Linear Active Disturbance Rejection Control of Dissolved Oxygen Concentration Based on Benchmark Simulation Model Number 1

    Directory of Open Access Journals (Sweden)

    Xiaoyi Wang

    2015-01-01

    Full Text Available In wastewater treatment plants (WWTPs, the dissolved oxygen is the key variable to be controlled in bioreactors. In this paper, linear active disturbance rejection control (LADRC is utilized to track the dissolved oxygen concentration based on benchmark simulation model number 1 (BSM1. Optimal LADRC parameters tuning approach for wastewater treatment processes is obtained by analyzing and simulations on BSM1. Moreover, by analyzing the estimation capacity of linear extended state observer (LESO in the control of dissolved oxygen, the parameter range of LESO is acquired, which is a valuable guidance for parameter tuning in simulation and even in practice. The simulation results show that LADRC can overcome the disturbance existing in the control of wastewater and improve the tracking accuracy of dissolved oxygen. LADRC provides another practical solution to the control of WWTPs.

  14. Asymptotic expansions for high-contrast linear elasticity

    KAUST Repository

    Poveda, Leonardo A.

    2015-03-01

    We study linear elasticity problems with high contrast in the coefficients using asymptotic limits recently introduced. We derive an asymptotic expansion to solve heterogeneous elasticity problems in terms of the contrast in the coefficients. We study the convergence of the expansion in the H1 norm. © 2015 Elsevier B.V.

  15. Annotated bibliography on high-intensity linear accelerators. [240 citations

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, R.A.; Roybal, E.U.

    1978-01-01

    A technical bibliography covering subjects important to the design of high-intensity beam transport systems and linear accelerators is presented. Space charge and emittance growth are stressed. Subject and author concordances provide cross-reference to detailed citations, which include an abstract and notes on the material. The bibliography resides in a computer database that can be searched for key words and phrases.

  16. Note: A high dynamic range, linear response transimpedance amplifier.

    Science.gov (United States)

    Eckel, S; Sushkov, A O; Lamoreaux, S K

    2012-02-01

    We have built a high dynamic range (nine decade) transimpedance amplifier with a linear response. The amplifier uses junction-gate field effect transistors (JFETs) to switch between three different resistors in the feedback of a low input bias current operational amplifier. This allows for the creation of multiple outputs, each with a linear response and a different transimpedance gain. The overall bandwidth of the transimpedance amplifier is set by the bandwidth of the most sensitive range. For our application, we demonstrate a three-stage amplifier with transimpedance gains of approximately 10(9)Ω, 3 × 10(7)Ω, and 10(4)Ω with a bandwidth of 100 Hz.

  17. Completely monolithic linearly polarized high-power fiber laser oscillator

    Science.gov (United States)

    Belke, Steffen; Becker, Frank; Neumann, Benjamin; Ruppik, Stefan; Hefter, Ulrich

    2014-03-01

    We have demonstrated a linearly polarized cw all-in-fiber oscillator providing 1 kW of output power and a polarization extinction ratio (PER) of up to 21.7 dB. The design of the laser oscillator is simple and consists of an Ytterbium-doped polarization maintaining large mode area (PLMA) fiber and suitable fiber Bragg gratings (FBG) in matching PLMA fibers. The oscillator has nearly diffraction-limited beam quality (M² high power 6+1:1 pump coupler. The slope efficiency of the laser is 75 %. The electro/optical efficiency of the complete laser system is ~30 % and hence in the range of Rofin's cw non-polarized fiber lasers. Choosing an adequate bending diameter for the Yb-doped PLMA fiber, one polarization mode as well as higher order modes are sufficiently supressed1. Resulting in a compact and robust linearly polarized high power single mode laser without external polarizing components. Linearly polarized lasers are well established for one dimensional cutting or welding applications. Using beam shaping optics radially polarized laser light can be generated to be independent from the angle of incident to the processing surface. Furthermore, high power linearly polarized laser light is fundamental for nonlinear frequency conversion of nonlinear materials.

  18. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam

    2011-01-01

    This book provides an in-depth treatment of both linear fiber-optic systems and their key enabling devices. It presents a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers. To the second edition of this book important new aspects of linear fiber-optic transmission technologies are added, such as high level system architectural issues, algorithms for deriving the optimal frequency assignment, directly modulated or externally modulated laser t...

  19. Developing a methodology to predict PM10 concentrations in urban areas using generalized linear models.

    Science.gov (United States)

    Garcia, J M; Teodoro, F; Cerdeira, R; Coelho, L M R; Kumar, Prashant; Carvalho, M G

    2016-09-01

    A methodology to predict PM10 concentrations in urban outdoor environments is developed based on the generalized linear models (GLMs). The methodology is based on the relationship developed between atmospheric concentrations of air pollutants (i.e. CO, NO2, NOx, VOCs, SO2) and meteorological variables (i.e. ambient temperature, relative humidity (RH) and wind speed) for a city (Barreiro) of Portugal. The model uses air pollution and meteorological data from the Portuguese monitoring air quality station networks. The developed GLM considers PM10 concentrations as a dependent variable, and both the gaseous pollutants and meteorological variables as explanatory independent variables. A logarithmic link function was considered with a Poisson probability distribution. Particular attention was given to cases with air temperatures both below and above 25°C. The best performance for modelled results against the measured data was achieved for the model with values of air temperature above 25°C compared with the model considering all ranges of air temperatures and with the model considering only temperature below 25°C. The model was also tested with similar data from another Portuguese city, Oporto, and results found to behave similarly. It is concluded that this model and the methodology could be adopted for other cities to predict PM10 concentrations when these data are not available by measurements from air quality monitoring stations or other acquisition means.

  20. Use of linear regression models to determine influence factors on the concentration levels of radon in occupied houses

    Science.gov (United States)

    Buermeyer, Jonas; Gundlach, Matthias; Grund, Anna-Lisa; Grimm, Volker; Spizyn, Alexander; Breckow, Joachim

    2016-09-01

    This work is part of the analysis of the effects of constructional energy-saving measures to radon concentration levels in dwellings performed on behalf of the German Federal Office for Radiation Protection. In parallel to radon measurements for five buildings, both meteorological data outside the buildings and the indoor climate factors were recorded. In order to access effects of inhabited buildings, the amount of carbon dioxide (CO2) was measured. For a statistical linear regression model, the data of one object was chosen as an example. Three dummy variables were extracted from the process of the CO2 concentration to provide information on the usage and ventilation of the room. The analysis revealed a highly autoregressive model for the radon concentration with additional influence by the natural environmental factors. The autoregression implies a strong dependency on a radon source since it reflects a backward dependency in time. At this point of the investigation, it cannot be determined whether the influence by outside factors affects the source of radon or the habitant’s ventilation behavior resulting in variation of the occurring concentration levels. In any case, the regression analysis might provide further information that would help to distinguish these effects. In the next step, the influence factors will be weighted according to their impact on the concentration levels. This might lead to a model that enables the prediction of radon concentration levels based on the measurement of CO2 in combination with environmental parameters, as well as the development of advices for ventilation.

  1. A High-Swing OTA with wide Linearity for design of self-tunable linear resistor

    Directory of Open Access Journals (Sweden)

    Nikhil Raj

    2015-09-01

    Full Text Available Low power consumption, long battery life and portability are essential requirements of modern health monitoring products. Operational Trans-conductance Amplifier (OTA operating in sub threshold region is an basic building block for low power health monitoring products design. An modified design of OTA which incorporates better linearity and increased output impedance has been discussed in this paper. The proposed OTA uses High-swing improved-Wilson current mirror for low power and low-frequency applications. The achieved linearity is about ± 1.9 volt and unity gain bandwidth (UGB of 342.30 KHz at power supply of 0.9 volt which makes OTA to consume power in range of nanowatts. The proposed lowvoltage OTA implementation in design of self- tunable linear resistor has been presented in this paper. The circuit implementation has been done using standard 0.18 micron technology provided by TSMC on BSIM3v3 level-53 model parameter and verified results through use of ELDO Simulator.

  2. Deviations from sorption linearity on soils of polar and nonpolar organic compounds at low relative concentrations

    Science.gov (United States)

    Chiou, C.T.; Kile, D.E.

    1998-01-01

    A series of single-solute and binary-solute sorption data have been obtained on representative samples of polar compounds (substituted ureas and phenolic compounds) and of nonpolar compounds (e.g., EDB and TCE) on a peat soil and a mineral (Woodburn) soil; the data extend to low relative solute concentrations (C(e)/S(w)). At relatively low C(e)/S(w), both the nonpolar and the polar solutes exhibit nonlinear sorption. The sorption nonlinearity approaches apparent saturation at about C(e)/S(w) = 0.010-0.015 for the nonpolar solutes and at about C(e)/S(w) = 0.10-0.13 for the polar solutes; above these C(e)/S(w) regions, the isotherms are practically linear. The nonlinear sorption capacities are greater for polar solutes than for nonpolar solutes and the peat soil shows a greater effect than the Woodburn soil. The small nonlinear sorption capacity for a nonpolar solute is suppressed indiscriminately by either a nonpolar or a polar cosolute at relatively low C(e)/S(w) of the cosolute. By contrast, the abilities of different cosolutes to suppress the nonlinear capacity of a nominal polar solute differ drastically. For polar solutes, a nonpolar cosolute exhibits a limited suppression even at high cosolute C(e)/S(w); effective suppression occurs when the cosolute is relatively polar and at various C(e)/S(w). These differences suggest that more than a single mechanism is required to account for the nonlinear sorption of both nonpolar and polar compounds at low C(e)/S(w). Mechanistic processes consistent with these observations and with soil surface areas are discussed along with other suggested models. Some important consequences of the nonlinear competitive sorption to the behavior of contaminants in natural systems are discussed.A number of conceptual models was postulated to account for the nonlinear solute sorption on soils of significant soil organic matter. A series of single-solute and binary-route sorption data was obtained representing samples of polar compounds of

  3. Linear and non-linear amplification of high-mode perturbations at the ablation front in HiPER targets

    Energy Technology Data Exchange (ETDEWEB)

    Olazabal-Loume, M; Breil, J; Hallo, L; Ribeyre, X [CELIA, UMR 5107 Universite Bordeaux 1-CNRS-CEA, 351 cours de la Liberation, 33405 Talence (France); Sanz, J, E-mail: olazabal@celia.u-bordeaux1.f [ETSI Aeronauticos, Universidad Politecnica de Madrid, Madrid 28040 (Spain)

    2011-01-15

    The linear and non-linear sensitivity of the 180 kJ baseline HiPER target to high-mode perturbations, i.e. surface roughness, is addressed using two-dimensional simulations and a complementary analysis by linear and non-linear ablative Rayleigh-Taylor models. Simulations provide an assessment of an early non-linear stage leading to a significant deformation of the ablation surface for modes of maximum linear growth factor. A design using a picket prepulse evidences an improvement in the target stability inducing a delay of the non-linear behavior. Perturbation evolution and shape, evidenced by simulations of the non-linear stage, are analyzed with existing self-consistent non-linear theory.

  4. Concentrating partially entangled W-class states on nonlocal atoms using low- Q optical cavity and linear optical elements

    Science.gov (United States)

    Cao, Cong; Chen, Xi; Duan, YuWen; Fan, Ling; Zhang, Ru; Wang, TieJun; Wang, Chuan

    2016-10-01

    Entanglement plays an important role in quantum information science, especially in quantum communications. Here we present an efficient entanglement concentration protocol (ECP) for nonlocal atom systems in the partially entangled W-class states, using the single-photon input-output process regarding low- Q cavity and linear optical elements. Compared with previously published ECPs for the concentration of non-maximally entangled atomic states, our protocol is much simpler and more efficient as it employs the Faraday rotation in cavity quantum electrodynamics (QED) and the parameter-splitting method. The Faraday rotation requires the cavity with low- Q factor and weak coupling to the atom, which makes the requirement for entanglement concentration much less stringent than the previous methods, and achievable with current cavity QED techniques. The parameter-splitting method resorts to linear-optical elements only. This ECP has high efficiency and fidelity in realistic experiments, and some imperfections during the experiment can be avoided efficiently with currently available techniques.

  5. Diverse microbial species survive high ammonia concentrations

    Science.gov (United States)

    Kelly, Laura C.; Cockell, Charles S.; Summers, Stephen

    2012-04-01

    Planetary protection regulations are in place to control the contamination of planets and moons with terrestrial micro-organisms in order to avoid jeopardizing future scientific investigations relating to the search for life. One environmental chemical factor of relevance in extraterrestrial environments, specifically in the moons of the outer solar system, is ammonia (NH3). Ammonia is known to be highly toxic to micro-organisms and may disrupt proton motive force, interfere with cellular redox reactions or cause an increase of cell pH. To test the survival potential of terrestrial micro-organisms exposed to such cold, ammonia-rich environments, and to judge whether current planetary protection regulations are sufficient, soil samples were exposed to concentrations of NH3 from 5 to 35% (v/v) at -80°C and room temperature for periods up to 11 months. Following exposure to 35% NH3, diverse spore-forming taxa survived, including representatives of the Firmicutes (Bacillus, Sporosarcina, Viridibacillus, Paenibacillus, Staphylococcus and Brevibacillus) and Actinobacteria (Streptomyces). Non-spore forming organisms also survived, including Proteobacteria (Pseudomonas) and Actinobacteria (Arthrobacter) that are known to have environmentally resistant resting states. Clostridium spp. were isolated from the exposed soil under anaerobic culture. High NH3 was shown to cause a reduction in viability of spores over time, but spore morphology was not visibly altered. In addition to its implications for planetary protection, these data show that a large number of bacteria, potentially including spore-forming pathogens, but also environmentally resistant non-spore-formers, can survive high ammonia concentrations.

  6. Causal correlation of foliar biochemical concentrations with AVIRIS spectra using forced entry linear regression

    Science.gov (United States)

    Dawson, Terence P.; Curran, Paul J.; Kupiec, John A.

    1995-01-01

    link between wavelengths chosen by stepwise regression and the biochemical of interest, and this in turn has cast doubts on the use of imaging spectrometry for the estimation of foliar biochemical concentrations at sites distant from the training sites. To investigate this problem, an analysis was conducted on the variation in canopy biochemical concentrations and reflectance spectra using forced entry linear regression.

  7. Design of dual-curvature mirror for linear medium concentration photovoltaic systems

    Science.gov (United States)

    Lance, Tamir; Ackler, Harold; Finot, Marc

    2012-01-01

    The impact of mirror shape on energy production in Skyline Solar's reflective trough medium concentration photovoltaic system is reviewed using a combination of commercial and proprietary modeling tools. For linear concentrators, an important parameter for efficiency optimization is the uniformity of the flux line on the photovoltaic cells. A significant source of nonuniformity is the discontinuity of reflected light due to the gap between mirrors along the length of the trough. Standard concentrating solar power trough mirrors have a typical length of 1.5 m with a gap between mirrors of 10 to 20 mm. To reduce nonuniformity of the flux line due to this mirror to mirror gap, Skyline Solar developed a dual curvature mirror that stretches the flux line along the trough axis. Extensive modeling and experiments have been conducted to analyze the impact of this design. The methodology of optimization is presented for the X14 Skyline system architecture, and benefits of up to 3% of energy can be realized at locations with latitude below 30 deg.

  8. Effect of linear alkylbenzene sulfonate (LAS) on human intestinal Caco-2 cells at non cytotoxic concentrations.

    Science.gov (United States)

    Bradai, Mohamed; Han, Junkyu; Omri, Abdelfatteh El; Funamizu, Naoyuki; Sayadi, Sami; Isoda, Hiroko

    2016-08-01

    Linear alkylbenzene sulfonate (LAS) is a cytotoxic synthetic anionic surfactant widely present in the environment due to its large-scale production and intensive use in the detergency field. In this study, we investigated the effect of LAS (CAS No. 25155-30-0) at non cytotoxic concentrations on human intestinal Caco-2 cells using different in vitro bioassays. As results, LAS increased Caco-2 cell proliferation at concentrations ranging from 1 to 15 ppm, more significantly for shorter exposure time (24 h), confirmed using flow cytometry and trypan blue exclusion methods. Moreover, proteomics analysis revealed that this effect was associated with an over-expression of elongation factor 2 and dipeptidyl peptidase 3, and a down-regulation of 14-3-3 protein theta, confirmed at mRNA level using real-time PCR. These findings suggest that LAS at non cytotoxic concentrations, similar to those observed at wastewater treatment plants outlets, increases the growth rate of colon cancer cells, raising thereby its tumor promotion effect potential.

  9. High reliability linear drive device for artificial hearts

    Science.gov (United States)

    Ji, Jinghua; Zhao, Wenxiang; Liu, Guohai; Shen, Yue; Wang, Fangqun

    2012-04-01

    In this paper, a new high reliability linear drive device, termed as stator-permanent-magnet tubular oscillating actuator (SPM-TOA), is proposed for artificial hearts (AHs). The key is to incorporate the concept of two independent phases into this linear AH device, hence achieving high reliability operation. The fault-tolerant teeth are employed to provide the desired decoupling phases in magnetic circuit. Also, as the magnets and the coils are located in the stator, the proposed SPM-TOA takes the definite advantages of robust mover and direct-drive capability. By using the time-stepping finite element method, the electromagnetic characteristics of the proposed SPM-TOA are analyzed, including magnetic field distributions, flux linkages, back- electromotive forces (back-EMFs) self- and mutual inductances, as well as cogging and thrust forces. The results confirm that the proposed SPM-TOA meets the dimension, weight, and force requirements of the AH drive device.

  10. Non-linear high-frequency waves in the magnetosphere

    Indian Academy of Sciences (India)

    S Moolla; R Bharuthram; S V Singh; G S Lakhina

    2003-12-01

    Using fluid theory, a set of equations is derived for non-linear high-frequency waves propagating oblique to an external magnetic field in a three-component plasma consisting of hot electrons, cold electrons and cold ions. For parameters typical of the Earth’s magnetosphere, numerical solutions of the governing equations yield sinusoidal, sawtooth or bipolar wave-forms for the electric field.

  11. High-linearity CMOS RF front-end circuits

    CERN Document Server

    Ding, Yongwang

    2005-01-01

    This monograph presents techniques to improve the performance of linear integrated circuits (IC) in CMOS at high frequencies. Those circuits are primarily used in radio-frequency (RF) front-ends of wireless communication systems, such as low noise amplifiers (LNA) and mixers in a receiver and power amplifiers (PA) in a transmitter. A novel linearization technique is presented. With a small trade-off of gain and power consumption this technique can improve the linearity of the majority of circuits by tens of dB. Particularly, for modern CMOS processes, most of which has device matching better than 1%, the distortion can be compressed by up to 40 dB at the output. A prototype LNA has been fabricated in a 0.25um CMOS process, with a measured +18 dBm IIP3. This technique improves the dynamic range of a receiver RF front-end by 12 dB. A new class of power amplifier (parallel class A&B) is also presented to extend the linear operation range and save the DC power consumption. It has been shown by both simulation...

  12. A wavelet-linear genetic programming model for sodium (Na+) concentration forecasting in rivers

    Science.gov (United States)

    Ravansalar, Masoud; Rajaee, Taher; Zounemat-Kermani, Mohammad

    2016-06-01

    The prediction of water quality parameters in water resources such as rivers is of importance issue that needs to be considered in better management of irrigation systems and water supplies. In this respect, this study proposes a new hybrid wavelet-linear genetic programming (WLGP) model for prediction of monthly sodium (Na+) concentration. The 23-year monthly data used in this study, were measured from the Asi River at the Demirköprü gauging station located in Antakya, Turkey. At first, the measured discharge (Q) and Na+ datasets are initially decomposed into several sub-series using discrete wavelet transform (DWT). Then, these new sub-series are imposed to the ad hoc linear genetic programming (LGP) model as input patterns to predict monthly Na+ one month ahead. The results of the new proposed WLGP model are compared with LGP, WANN and ANN models. Comparison of the models represents the superiority of the WLGP model over the LGP, WANN and ANN models such that the Nash-Sutcliffe efficiencies (NSE) for WLGP, WANN, LGP and ANN models were 0.984, 0.904, 0.484 and 0.351, respectively. The achieved results even points to the superiority of the single LGP model than the ANN model. Continuously, the capability of the proposed WLGP model in terms of prediction of the Na+ peak values is also presented in this study.

  13. Three-dimensional non-linear numerical analysis on the oxygen concentration field in underground coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lanhe [College of Mineral Resources and Geosciences, China University of Mining and Technology, Xuzhou, Jiangsu Province 221008 (China)

    2004-10-15

    The stability of the process of underground coal gasification and its gas compositions depend on, to a large extent, the features of the convection diffusion of the gas and the dynamical conditions of chemical reactions. The dynamic distribution of the gasification agent concentration, in particular, has a great influence on the combustion and gasification reactions. In this paper, the basic features of convection diffusion for the gas produced in underground coal gasification are studied. On the basis of the model experiment, through the analysis of the distribution and patterns of variation for the fluid concentration field in the process of the combustion and gasification of the coal seams within the gasifier, the 3-D non-linear unstable mathematical models on the convection diffusion for oxygen are established. Additionally, the determination method of the major model parameters is explained. In order to curb such pseudo-physical effects as numerical oscillation and surfeit frequently occurred in the solution of the complex mathematical models, the novel finite unit algorithm-the upstream weighted multi-cell balance method is adopted in this paper to solve the numerical models established. The author also analyzed and discussed the simulated calculation results, which show that, except very few points in loosening zone, where the relative calculation error is comparatively high (>20%) resulting from the low oxygen concentration, the relative calculation error of other points falls between 7% and 17%. Therefore, the calculation value and the experiment value take on a good conformity. According to the simulated results, the calculation value of the oxygen concentration is a little bit lower than the experiment one. On top of that, with the prolonging of gasification time, in high temperature zone, the change gradient of oxygen concentration for experiment value is bigger than that of the calculation value. The oxygen concentration is in direct proportion to its

  14. Energy efficient fluid powered linear actuator with variable area and concentric chambers

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Randall F.; Love, Lonnie J.

    2016-11-15

    Hydraulic actuation systems having concentric chambers, variable displacements and energy recovery capabilities include cylinders with pistons disposed inside of barrels. When operating in energy consuming modes, high speed valves pressurize extension chambers or retraction chambers to provide enough force to meet or counteract an opposite load force. When operating in energy recovery modes, high speed valves return a working fluid from extension chambers or retraction chambers, which are pressurized by a load, to an accumulator for later use.

  15. Physical chemistry of highly concentrated emulsions.

    Science.gov (United States)

    Foudazi, Reza; Qavi, Sahar; Masalova, Irina; Malkin, Alexander Ya

    2015-06-01

    This review explores the physics underlying the rheology of highly concentrated emulsions (HCEs) to determine the relationship between elasticity and HCE stability, and to consider whether it is possible to describe all physicochemical properties of HCEs on the basis of a unique physical approach. We define HCEs as emulsions with a volume fraction above the maximum closest packing fraction of monodisperse spheres, φm=0.74, even if droplets are not of polyhedron shape. The solid-like rheological behavior of HCEs is characterized by yield stress and elasticity, properties which depend on droplet polydispersity and which are affected by caging at volume fractions about the jamming concentration, φj. A bimodal size distribution in HCEs diminishes caging and facilitates droplet movement, resulting in HCEs with negligible yield stress and no plateau in storage modulus. Thermodynamic forces automatically move HCEs toward the lowest free energy state, but since interdroplet forces create local minimums - points beyond which free energy temporarily increases before it reaches the global minimum of the system - the free energy of HCEs will settle at a local minimum unless additional energy is added. Several attempts have been undertaken to predict the elasticity of HCEs. In many cases, the elastic modulus of HCEs is higher than the one predicted from classical models, which only take into account spatial repulsion (or simply interfacial energy). Improved models based on free energy calculation should be developed to consider the disjoining pressure and interfacial rheology in addition to spatial repulsion. The disjoining pressure and interfacial viscoelasticity, which result in the deviation of elasticity from the classical model, can be regarded as parameters for quantifying the stability of HCEs. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Determination of Stress Concentration factor in Linearly Elastic Structures with Different Stress-Raisers Using FEM

    Directory of Open Access Journals (Sweden)

    Dheeraj Gunwant

    2016-02-01

    Full Text Available Stress concentration is the localization of stress around stress raisers. Sudden changes in the geometry of structures give rise to stress values that are higher than those obtained by elementary equations of solid mechanics. Therefore the evaluation of stress state at such locations needs specialized techniques such as Finite Element Method (FEM.The finite element method is a numerical procedure that can be used to obtain solution to a large variety of engineering problems such as structural, thermal, heat transfer, electromagnetism and fluid flow. In the present investigation, focus has been kept on the finite element modeling and determination of stress concentration factor (SCF in linearly elastic structures with different stress-raisers such as circular and elliptical holes and double semicircular notch at different locations in a finite plate. The results obtained from FEM are compared with those obtained by analytical relations as given in literature. A commercially available finite element solver ANSYS has been used for the modeling and analysis in the investigation. Throughout the investigation, plane82, which is an eight node two-dimensional element is used for the discretization.

  17. High Efficiency, High Linearity, Switch Mode Power Amplifiers for Varying envelop Signal Applications

    DEFF Research Database (Denmark)

    Tong, Tian; Sira, Daniel; Nielsen, Michael;

    2009-01-01

    using switch-mode power amplifier aided by various linearization techniques can present a feasible way to achieve both high linearity and high power efficiency. In this paper two different implementations of the switch-mode power amplifier a re p resented for varying envelop applications: the RF pulse...

  18. The design of linear algebra libraries for high performance computers

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J.J. [Tennessee Univ., Knoxville, TN (United States). Dept. of Computer Science]|[Oak Ridge National Lab., TN (United States); Walker, D.W. [Oak Ridge National Lab., TN (United States)

    1993-08-01

    This paper discusses the design of linear algebra libraries for high performance computers. Particular emphasis is placed on the development of scalable algorithms for MIMD distributed memory concurrent computers. A brief description of the EISPACK, LINPACK, and LAPACK libraries is given, followed by an outline of ScaLAPACK, which is a distributed memory version of LAPACK currently under development. The importance of block-partitioned algorithms in reducing the frequency of data movement between different levels of hierarchical memory is stressed. The use of such algorithms helps reduce the message startup costs on distributed memory concurrent computers. Other key ideas in our approach are the use of distributed versions of the Level 3 Basic Linear Algebra Subprograms (BLAS) as computational building blocks, and the use of Basic Linear Algebra Communication Subprograms (BLACS) as communication building blocks. Together the distributed BLAS and the BLACS can be used to construct higher-level algorithms, and hide many details of the parallelism from the application developer. The block-cyclic data distribution is described, and adopted as a good way of distributing block-partitioned matrices. Block-partitioned versions of the Cholesky and LU factorizations are presented, and optimization issues associated with the implementation of the LU factorization algorithm on distributed memory concurrent computers are discussed, together with its performance on the Intel Delta system. Finally, approaches to the design of library interfaces are reviewed.

  19. Coherent integrated receiver for highly linear microwave photonic links

    Science.gov (United States)

    Klamkin, Jonathan

    Phase modulation can be used to improve the signal-to-noise ratio and spurfree dynamic range (SFDR) of microwave photonic links because phase modulation is not limited in input modulation swing and is inherently linear using certain electro-optic devices. Traditional interferometer-based phase demodulators have a sinusoidal response therefore a novel approach is required for achieving linear coherent detection at the receive end of a photonic link employing phase modulation. In this work, a balanced receiver with feedback to a reference tracking phase modulator was developed. With sufficient feedback loop gain, the received signal phase is closely tracked and the phase detection falls within the linear regime of the interferometer response. For stable operation at high frequency the delay of the feedback loop must be kept short, therefore a monolithic approach is required to realize a compact receiver architecture. The monolithic photonic integrated circuit (PIC) developed here consists of a high power balanced uni-traveling-carrier photodiode (UTC-PD), a compact 2x2 multimode interference (MMI) coupler, and multi-quantum well reference phase modulators. This PIC is hybrid integrated with an electronic IC that provides transconductance amplification of the feedback signal for increased loop gain. Novel concepts such as charge compensation, partially depleted absorption, and absorption profile modification were incorporated into the design of the waveguide UTCPDs resulting in record output saturation current and linearity. Both general interference surface ridge (SR) MMI couplers and restricted interference deep ridge (DR) MMI couplers were explored, the latter for reducing the loop delay. Current injection tuning was incorporated into the MMI couplers for fine tuning the output power splitting ratio. The quantum well design of the reference phase modulators was optimized for realizing low Vpi, low insertion loss, low absorption modulation, and improved linearity

  20. Stochastic Lipschitz continuity for high dimensional Lasso with multiple linear covariate structures or hidden linear covariates

    CERN Document Server

    Chi, Zhiyi

    2010-01-01

    Two extensions of generalized linear models are considered. In the first one, response variables depend on multiple linear combinations of covariates. In the second one, only response variables are observed while the linear covariates are missing. We derive stochastic Lipschitz continuity results for the loss functions involved in the regression problems and apply them to get bounds on estimation error for Lasso. Multivariate comparison results on Rademacher complexity are obtained as tools to establish the stochastic Lipschitz continuity results.

  1. Cryogenic linear Paul trap for cold highly charged ion experiments.

    Science.gov (United States)

    Schwarz, M; Versolato, O O; Windberger, A; Brunner, F R; Ballance, T; Eberle, S N; Ullrich, J; Schmidt, P O; Hansen, A K; Gingell, A D; Drewsen, M; López-Urrutia, J R Crespo

    2012-08-01

    Storage and cooling of highly charged ions require ultra-high vacuum levels obtainable by means of cryogenic methods. We have developed a linear Paul trap operating at 4 K capable of very long ion storage times of about 30 h. A conservative upper bound of the H(2) partial pressure of about 10(-15) mbar (at 4 K) is obtained from this. External ion injection is possible and optimized optical access for lasers is provided, while exposure to black body radiation is minimized. First results of its operation with atomic and molecular ions are presented. An all-solid state laser system at 313 nm has been set up to provide cold Be(+) ions for sympathetic cooling of highly charged ions.

  2. Cryogenic linear Paul trap for cold highly charged ion experiments

    DEFF Research Database (Denmark)

    Schwarz, Maria; Versolato, Oscar; Windberger, Alexander

    2012-01-01

    Storage and cooling of highly charged ions require ultra-high vacuum levels obtainable by means of cryogenic methods. We have developed a linear Paul trap operating at 4 K capable of very long ion storage times of about 30 h. A conservative upper bound of the H2 partial pressure of about 10−15 mbar...... (at 4 K) is obtained from this. External ion injection is possible and optimized optical access for lasers is provided, while exposure to black body radiation is minimized. First results of its operation with atomic and molecular ions are presented. An all-solid state laser system at 313 nm has been...... set up to provide cold Be+ ions for sympathetic cooling of highly charged ions....

  3. High-concentration-gradient dispersion in porous media : experiments, analysis and approximations

    NARCIS (Netherlands)

    R.J. Schotting; H. Moser; S.M. Hassanizadeh

    1997-01-01

    textabstractVarious experimental and theoretical studies have shown that Fick's law, based on the assumption of a linear relation between solute dispersive mass flux and concentration gradient, is not valid when high concentration gradients are encountered in a porous medium. The value of the macrod

  4. High-Temperature, High-Concentration Solar Thermoelectric Generators

    Science.gov (United States)

    Warren, Emily; Baranowski, Lauryn; Olsen, Michele; Ndione, Paul; Netter, Judy; Goodrich, Alan; Gray, Matthew; Parilla, Philip; Ginley, David; Toberer, Eric

    2014-03-01

    Solar thermoelectric generators (STEGs) powered with concentrated solar energy have potential for use as primary energy converters or as topping-cycles for more conventional concentrated solar power (CSP) technologies. Modeling based on current record modules from JPL suggests thermoelectric efficiencies of 18 % could be experimentally expected with a temperature gradient of 1000 - 100°C. Integrating these state-of-the-art TEGs with a concentrating solar receiver requires simultaneous optimization of optical, thermal, and thermoelectric systems. This talk will discuss the modeling, design, and experimental testing of STEG devices under concentrated sunlight. We have developed a model that combines thermal circuit modeling with optical ray tracing to design selective absorber coatings and cavities to minimize radiation losses from the system. We have fabricated selective absorber coatings and demonstrated that these selective absorber films can minimize blackbody radiation losses at high temperature and are stable after thermal cycling to 1000°C. On-sun testing of STEG devices and thermal simulators is ongoing and preliminary results will be discussed.

  5. Production of high concentrations of yeast

    Energy Technology Data Exchange (ETDEWEB)

    1981-11-10

    A microbe is aerobically cultured using O/sub 2/ or a gas rich in O/sub 2/. The grown cells are washed, concentrated and a portion of the cells used as a seed culture. Thus, Saccharomyces cerevisiae (bakers' yeast) was cultured in a jar fermentor by flow down system maintaining the dissolved O/sub 2/ at 2-5 mg/L; volume of the initial medium containing 30% glucose was 350 mL and the initial washed cell concentration was 50 g dry cells/L. After 12 hours of cultivation, the volume of the medium increased to 750 mL and the cell concentration rose to 102 g dry cells/L; the yield was 49% with respect to glucose. The cells were washed and the cultivation was repeated by use of the washed cells; cell concentration reached 105 g dry cells/L.

  6. Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

    Science.gov (United States)

    Ma, Hongcai; Wu, Lin

    2015-07-10

    We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

  7. VERTICAL LINEAR PROJECT SCHEDULING FOR HIGH-RISE BUILDINGS

    Directory of Open Access Journals (Sweden)

    İlker ÖZDEMİR

    1999-02-01

    Full Text Available In this paper, an application to high-rise buildings of VPM (Vertical Production Method and an example will be given which is composition of two distinct and preferable methods are CPM (Critical Path Method that is prefering against traditional Bar-Charts or schedules especially in big and costly investments and LOB (Line of Balance technique that is suitable for using in linear project planning. Thus, it could be expected that to show the way of the method to designer and manufacturer about subjects which are activity, priority and sequencing of high-rise project, speeds of activity and construction, completion times, to add or take out some terms to schedule at the state of project changing.

  8. Linear and non-linear stability analysis for finite difference discretizations of high-order Boussinesq equations

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Bingham, Harry B.; Madsen, Per A.

    2004-01-01

    This paper considers a method of lines stability analysis for finite difference discretizations of a recently published Boussinesq method for the study of highly non-linear and extremely dispersive water waves. The analysis demonstrates the near-equivalence of classical linear Fourier (von Neumann...

  9. A novel highly parallel algorithm for linearly unmixing hyperspectral images

    Science.gov (United States)

    Guerra, Raúl; López, Sebastián.; Callico, Gustavo M.; López, Jose F.; Sarmiento, Roberto

    2014-10-01

    Endmember extraction and abundances calculation represent critical steps within the process of linearly unmixing a given hyperspectral image because of two main reasons. The first one is due to the need of computing a set of accurate endmembers in order to further obtain confident abundance maps. The second one refers to the huge amount of operations involved in these time-consuming processes. This work proposes an algorithm to estimate the endmembers of a hyperspectral image under analysis and its abundances at the same time. The main advantage of this algorithm is its high parallelization degree and the mathematical simplicity of the operations implemented. This algorithm estimates the endmembers as virtual pixels. In particular, the proposed algorithm performs the descent gradient method to iteratively refine the endmembers and the abundances, reducing the mean square error, according with the linear unmixing model. Some mathematical restrictions must be added so the method converges in a unique and realistic solution. According with the algorithm nature, these restrictions can be easily implemented. The results obtained with synthetic images demonstrate the well behavior of the algorithm proposed. Moreover, the results obtained with the well-known Cuprite dataset also corroborate the benefits of our proposal.

  10. High Accuracy Attitude Control of a Spacecraft Using Feedback Linearization

    Science.gov (United States)

    1992-05-01

    and Spacecraft Body from Gyro Measurements ......... .................................. 119 D.2 An Approximation to Exact Linearization using IPSRU...31 2-4 Attitude Determination and Control System Architecture ................. 33 3-1 Exact Linearization Using Nonlinear Feedback...though basic techniques were adapted from recent references on the use of exact linearization (such as [8] and [27]), the specific control approach

  11. Linear processes in high dimensions: Phase space and critical properties

    Science.gov (United States)

    Mastromatteo, Iacopo; Bacry, Emmanuel; Muzy, Jean-François

    2015-04-01

    In this work we investigate the generic properties of a stochastic linear model in the regime of high dimensionality. We consider in particular the vector autoregressive (VAR) model and the multivariate Hawkes process. We analyze both deterministic and random versions of these models, showing the existence of a stable phase and an unstable phase. We find that along the transition region separating the two regimes the correlations of the process decay slowly, and we characterize the conditions under which these slow correlations are expected to become power laws. We check our findings with numerical simulations showing remarkable agreement with our predictions. We finally argue that real systems with a strong degree of self-interaction are naturally characterized by this type of slow relaxation of the correlations.

  12. Effect of laundry activities on in-stream concentrations of linear alkylbenzene sulfonate in a small rural South African river.

    Science.gov (United States)

    Gordon, A K; Muller, W J; Gysman, N; Marshall, S J; Sparham, C J; O'Connor, S M; Whelan, M J

    2009-07-15

    In many parts of the world clothes are washed near to or in rivers and streams. Little information is available on resulting concentrations of detergent ingredients or on any potential effects caused. In this study, the fate of a commonly used anionic surfactant, linear alkylbenzene sulphonate (LAS) was investigated in a reach of the Balfour River (Eastern Cape Province, South Africa) which was regularly used as a site for laundry activity. Samples of river water were collected upstream of the main washing site and at a number of locations downstream on several occasions in winter and summer. Sediment samples were also collected and analysed. In addition, a household survey was conducted to ascertain the amount of detergent used and the distribution of washing practices. The results of the survey suggested that the use of riverside locations for laundry activities was seasonal. Most washing tended to be done at home during the winter with riverside sites used more frequently during the summer months. The monitoring data showed that LAS concentrations in water were very variable. They were occasionally high in the immediate vicinity of the laundry site (up to 342 microg L(-1)) but were generally very low (effects are expected from LAS emissions at this site.

  13. Linear and non-linear stability analysis for finite difference discretizations of high-order Boussinesq equations

    DEFF Research Database (Denmark)

    Fuhrman, David R.; Bingham, Harry B.; Madsen, Per A.;

    2004-01-01

    This paper considers a method of lines stability analysis for finite difference discretizations of a recently published Boussinesq method for the study of highly non-linear and extremely dispersive water waves. The analysis demonstrates the near-equivalence of classical linear Fourier (von Neumann......) techniques with matrix-based methods for formulations in both one and two horizontal dimensions. The matrix-based method is also extended to show the local de-stabilizing effects of the non-linear terms, as well as the stabilizing effects of numerical dissipation. A comparison of the relative stability...... moderately non-normal, suggesting that the eigenvalues are likely suitable for analysis purposes. Numerical experiments demonstrate excellent agreement with the linear analysis, and good qualitative agreement with the local non-linear analysis. The various methods of analysis combine to provide significant...

  14. An Octave Bandwidth, High PAE, Linear, Class J GaN High Power Amplifier

    Science.gov (United States)

    2012-03-12

    versus the modeled small-signal gain and return loss response of the Class J amplifier using a 45-W CREE GaN HEMT . The amplifier has a gain of 13 to...AFFTC-PA-12055 An Octave Bandwidth, High PAE, Linear, Class J GaN High Power Amplifier Kris Skowronski, Steve Nelson, Rajesh Mongia, Howard...Technical Paper 3. DATES COVERED (From - To) 11/11 – 03/12 (etc.) 4. TITLE AND SUBTITLE An Octave Bandwidth, High PAE, Linear, Class J GaN High

  15. High-resolution diffraction grating interferometric transducer of linear displacements

    Science.gov (United States)

    Shang, Ping; Xia, Haojie; Fei, Yetai

    2016-01-01

    A high-resolution transducer of linear displacements is presented. The system is based on semiconductor laser illumination and a diffraction grating applied as a length master. The theory of the optical method is formulated using Doppler description. The relationship model among the interference strips, measurement errors, grating deflection around the X, Y and Z axes and translation along the Z axis is built. The grating interference strips' direction and space is not changed with movement along the X (direction of grating movement), Y (direction of grating line), Z axis, and the direction and space has a great effect when rotating around the X axis. Moreover the space is little affected by deflection around the Z axis however the direction is changed dramatically. In addition, the strips' position shifted rightward or downwards respectively for deflection around the X or Y axis. Because the emitted beams are separated on the grating plane, the tilt around the X axis error of the stage during motion will lead to the optical path difference of the two beams resulting in phase shift. This study investigates the influence of the tilt around the X axis error. Experiments show that after yaw error compensation, the high-resolution diffraction grating interferometric transducer readings can be significantly improved. The error can be reduced from +/-80 nm to +/-30 nm in maximum.

  16. A non-iterative linear retrieval for infrared high resolution limb sounders

    Directory of Open Access Journals (Sweden)

    L. Millán

    2013-01-01

    Full Text Available Currently most of the high spectral resolution infrared limb sounders use subsets of the recorded spectra (microwindows in their retrieval schemes to reduce the computing time of rerunning the radiative transfer model. A fast linear retrieval scheme is described which allows the whole spectral signature of the target molecule to be used. We determine how close the linearisation point needs to be to the solution in order to fall in the linear regime and also suggest an adjustment to the forward model and Jacobians to propagate the change in pressure and temperature on the gas concentration retrievals. As an example, this technique is implemented for the Michelson Interferometer for Passive Atmospheric Sounding instrument, but it is applicable to any high resolution limb sounder.

  17. Energy performance of a concentrated photovoltaic energy system with static linear Fresnel lenses integrated in a greenhouse

    NARCIS (Netherlands)

    Sonneveld, Piet; Swinkels, Gert-Jan; Tuijl, B.A.J. van; Janssen, H.J.J.; Campen, J.; Bot, G.P.A

    2011-01-01

    A new type of greenhouse with linear Fresnel lenses in the cover performing as a concentrated photovoltaic (CPV) system is presented. The CPV system retains all direct solar radiation, while diffuse solar radiation passes through and enters into the greenhouse cultivation system. The removal of all

  18. Linearized inversion frameworks toward high-resolution seismic imaging

    KAUST Repository

    Aldawood, Ali

    2016-09-01

    internally multiply scattered seismic waves to obtain highly resolved images delineating vertical faults that are otherwise not easily imaged by primaries. Seismic interferometry is conventionally based on the cross-correlation and convolution of seismic traces to transform seismic data from one acquisition geometry to another. The conventional interferometric transformation yields virtual data that suffers from low temporal resolution, wavelet distortion, and correlation/convolution artifacts. I therefore incorporate a least-squares datuming technique to interferometrically transform vertical-seismic-profile surface-related multiples to surface-seismic-profile primaries. This yields redatumed data with high temporal resolution and less artifacts, which are subsequently imaged to obtain highly resolved subsurface images. Tests on synthetic examples demonstrate the efficiency of the proposed techniques, yielding highly resolved migrated sections compared with images obtained by imaging conventionally redatumed data. I further advance the recently developed cost-effective Generalized Interferometric Multiple Imaging procedure, which aims to not only image first but also higher-order multiples as well. I formulate this procedure as a linearized inversion framework and solve it as a least-squares problem. Tests of the least-squares Generalized Interferometric Multiple imaging framework on synthetic datasets and demonstrate that it could provide highly resolved migrated images and delineate vertical fault planes compared with the standard procedure. The results support the assertion that this linearized inversion framework can illuminate subsurface zones that are mainly illuminated by internally scattered energy.

  19. Bayesian Subset Modeling for High-Dimensional Generalized Linear Models

    KAUST Repository

    Liang, Faming

    2013-06-01

    This article presents a new prior setting for high-dimensional generalized linear models, which leads to a Bayesian subset regression (BSR) with the maximum a posteriori model approximately equivalent to the minimum extended Bayesian information criterion model. The consistency of the resulting posterior is established under mild conditions. Further, a variable screening procedure is proposed based on the marginal inclusion probability, which shares the same properties of sure screening and consistency with the existing sure independence screening (SIS) and iterative sure independence screening (ISIS) procedures. However, since the proposed procedure makes use of joint information from all predictors, it generally outperforms SIS and ISIS in real applications. This article also makes extensive comparisons of BSR with the popular penalized likelihood methods, including Lasso, elastic net, SIS, and ISIS. The numerical results indicate that BSR can generally outperform the penalized likelihood methods. The models selected by BSR tend to be sparser and, more importantly, of higher prediction ability. In addition, the performance of the penalized likelihood methods tends to deteriorate as the number of predictors increases, while this is not significant for BSR. Supplementary materials for this article are available online. © 2013 American Statistical Association.

  20. Tracking control of concentration profiles in a fed-batch bioreactor using a linear algebra methodology.

    Science.gov (United States)

    Rómoli, Santiago; Serrano, Mario Emanuel; Ortiz, Oscar Alberto; Vega, Jorge Rubén; Eduardo Scaglia, Gustavo Juan

    2015-07-01

    Based on a linear algebra approach, this paper aims at developing a novel control law able to track reference profiles that were previously-determined in the literature. A main advantage of the proposed strategy is that the control actions are obtained by solving a system of linear equations. The optimal controller parameters are selected through Monte Carlo Randomized Algorithm in order to minimize a proposed cost index. The controller performance is evaluated through several tests, and compared with other controller reported in the literature. Finally, a Monte Carlo Randomized Algorithm is conducted to assess the performance of the proposed controller. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Linear regression of postevacuation serum human chorionic gonadotropin concentrations predicts postmolar gestational trophoblastic neoplasia

    NARCIS (Netherlands)

    Lybol, C.; Sweep, F.C.; Ottevanger, P.B.; Massuger, L.F.A.G.; Thomas, C.M.G.

    2013-01-01

    OBJECTIVE: Currently, human chorionic gonadotropin (hCG) follow-up after evacuation of hydatidiform moles is essential to identify patients requiring chemotherapeutic treatment for gestational trophoblastic neoplasia (GTN). We propose a model based on linear regression of postevacuation serum hCG co

  2. SuperB: a Linear High-Luminosity B Factory

    Energy Technology Data Exchange (ETDEWEB)

    Albert, J.; Bettarini, S.; Biagini, M.; Bonneaud, G.; Cai, Y.; Calderini, G.; Ciuchini, M.; Dubois-Felsmann, G.P.; Ecklund, S.; Forti, F.; Gershon, T.J.; Giorgi, M.A.; Hitlin, D.G.; Leith, D.W.G.S.; Lusiani, A.; MacFarlane, D.B.; Martinez-Vidal, F.; Neri, N.; Novokhatski, A.; Pierini, M.; Piredda, G.; /Caltech /Pisa U. /Pisa, Scuola Normale

    2006-02-08

    This paper is based on the outcome of the activity that has taken place during the recent workshop on ''SuperB in Italy'' held in Frascati on November 11-12, 2005. The workshop was opened by a theoretical introduction of Marco Ciuchini and was structured in two working groups. One focused on the machine and the other on the detector and experimental issues.. The present status on CP is mainly based on the results achieved by BABAR and Belle. Establishment of the indirect CP violation in B sector in 2001 and of the direct CP violation in 2004 thanks to the success of PEP-II and KEKB e{sup +}e{sup -} asymmetric B Factories operating at the center of mass energy corresponding to the mass of the {Upsilon}(4S ). With the two B Factories taking data, the Unitarity Triangle is now beginning to be over constrained by improving the measurements of the sides and now also of the angles {alpha}, and {gamma}. We are also in presence of the very intriguing results about the measurements of sin2{beta} in the time dependent analysis of decay channels via penguin loops, where b {yields} s{bar s}s and b {yields} s{bar d}d. {tau} physics, in particular LFV search, as well as charm and ISR physics are important parts of the scientific program of a SuperB Factory. The physics case together with possible scenarios for the high luminosity SuperB Factory based on the concepts of the Linear Collider and the related experimental issues are discussed.

  3. Miniature High-Force, Long-Stroke SMA Linear Actuators

    Science.gov (United States)

    Cummin, Mark A.; Donakowski, William; Cohen, Howard

    2008-01-01

    Improved long-stroke shape-memory-alloy (SMA) linear actuators are being developed to exert significantly higher forces and operate at higher activation temperatures than do prior SMA actuators. In these actuators, long linear strokes are achieved through the principle of displacement multiplication, according to which there are multiple stages, each intermediate stage being connected by straight SMA wire segments to the next stage so that relative motions of stages are additive toward the final stage, which is the output stage. Prior SMA actuators typically include polymer housings or shells, steel or aluminum stages, and polymer pads between successive stages of displacement-multiplication assemblies. Typical output forces of prior SMA actuators range from 10 to 20 N, and typical strokes range from 0.5 to 1.5 cm. An important disadvantage of prior SMA wire actuators is relatively low cycle speed, which is related to actuation temperature as follows: The SMA wires in prior SMA actuators are typically made of a durable nickel/titanium alloy that has a shape-memory activation temperature of 80 C. An SMA wire can be heated quickly from below to above its activation temperature to obtain a stroke in one direction, but must then be allowed to cool to somewhat below its activation temperature (typically, less than or equal to 60 C in the case of an activation temperature of 80 C) to obtain a stroke in the opposite direction (return stroke). At typical ambient temperatures, cooling times are of the order of several seconds. Cooling times thus limit cycle speeds. Wires made of SMA alloys having significantly higher activation temperatures [denoted ultra-high-temperature (UHT) SMA alloys] cool to the required lower return-stroke temperatures more rapidly, making it possible to increase cycle speeds. The present development is motivated by a need, in some applications (especially aeronautical and space-flight applications) for SMA actuators that exert higher forces, operate

  4. Factors Impeding Enzymatic Wheat Gluten Hydrolysis at High Solid Concentrations

    NARCIS (Netherlands)

    Hardt, N.A.; Janssen, A.E.M.; Boom, R.M.; Goot, van der A.J.

    2014-01-01

    Enzymatic wheat gluten hydrolysis at high solid concentrations is advantageous from an environmental and economic point of view. However, increased wheat gluten concentrations result in a concentration effect with a decreased hydrolysis rate at constant enzyme-to-substrate ratios and a decreased

  5. High resolution inverse scattering in two dimensions using recursive linearization

    CERN Document Server

    Borges, Carlos; Greengard, Leslie

    2016-01-01

    We describe a fast, stable algorithm for the solution of the inverse acoustic scattering problem in two dimensions. Given full aperture far field measurements of the scattered field for multiple angles of incidence, we use Chen's method of recursive linearization to reconstruct an unknown sound speed at resolutions of thousands of square wavelengths in a fully nonlinear regime. Despite the fact that the underlying optimization problem is formally ill-posed and non-convex, recursive linearization requires only the solution of a sequence of linear least squares problems at successively higher frequencies. By seeking a suitably band-limited approximation of the sound speed profile, each least squares calculation is well-conditioned and involves the solution of a large number of forward scattering problems, for which we employ a recently developed, spectrally accurate, fast direct solver. For the largest problems considered, involving 19,600 unknowns, approximately one million partial differential equations were ...

  6. TiO2 dye sensitized solar cell (DSSC): linear relationship of maximum power point and anthocyanin concentration

    Science.gov (United States)

    Ahmadian, Radin

    2010-09-01

    This study investigated the relationship of anthocyanin concentration from different organic fruit species and output voltage and current in a TiO2 dye-sensitized solar cell (DSSC) and hypothesized that fruits with greater anthocyanin concentration produce higher maximum power point (MPP) which would lead to higher current and voltage. Anthocyanin dye solution was made with crushing of a group of fresh fruits with different anthocyanin content in 2 mL of de-ionized water and filtration. Using these test fruit dyes, multiple DSSCs were assembled such that light enters through the TiO2 side of the cell. The full current-voltage (I-V) co-variations were measured using a 500 Ω potentiometer as a variable load. Point-by point current and voltage data pairs were measured at various incremental resistance values. The maximum power point (MPP) generated by the solar cell was defined as a dependent variable and the anthocyanin concentration in the fruit used in the DSSC as the independent variable. A regression model was used to investigate the linear relationship between study variables. Regression analysis showed a significant linear relationship between MPP and anthocyanin concentration with a p-value of 0.007. Fruits like blueberry and black raspberry with the highest anthocyanin content generated higher MPP. In a DSSC, a linear model may predict MPP based on the anthocyanin concentration. This model is the first step to find organic anthocyanin sources in the nature with the highest dye concentration to generate energy.

  7. Minimization of Cogging Force in Fractional-Slot Permanent Magnet Linear Motors with Double-Layer Concentrated Windings

    Directory of Open Access Journals (Sweden)

    Qian Wang

    2016-11-01

    Full Text Available Permanent magnet linear motors (PMLMs with double-layer concentrated windings generally show significant cogging forces due to the introduction of auxiliary teeth for eliminating the end-effect induced phase unbalance, even when the fractional-slot technology is applied. This paper presents a novel approach to reduce the cogging force by adjusting the armature core dimensions in fractional-slot PMLMs with double-layer concentrated windings, together with magnet skewing. It is shown that the proposed technique is capable of reducing the cogging force of the motor in an effective way, with the peak value minimized to less than 0.4% of the rated thrust force in the case study. Such a technique can also be applicable to other linear motors with appropriate changes.

  8. Refractive Secondary Solar Concentrator Demonstrated High-Temperature Operation

    Science.gov (United States)

    Wong, Wayne A.

    2002-01-01

    Space applications that utilize solar thermal energy--such as electric power conversion systems, thermal propulsion systems, and furnaces--require highly efficient solar concentration systems. The NASA Glenn Research Center is developing the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, such as inflatable thin films, the refractive secondary concentrator enables very high system concentration ratios and very high temperatures. Last year, Glenn successfully demonstrated a secondary concentrator throughput efficiency of 87 percent, with a projected efficiency of 93 percent using an antireflective coating. Building on this achievement, Glenn recently successfully demonstrated high-temperature operation of the secondary concentrator when it was used to heat a rhenium receiver to 2330 F. The high-temperature demonstration of the concentrator was conducted in Glenn's 68-ft long Tank 6 thermal vacuum facility equipped with a solar simulator. The facility has a rigid panel primary concentrator that was used to concentrate the light from the solar simulator onto the refractive secondary concentrator. NASA Marshall Space Flight Center provided a rhenium cavity, part of a solar thermal propulsion engine, to serve as the high-temperature receiver. The prototype refractive secondary concentrator, measuring 3.5 in. in diameter and 11.2 in. long, is made of single-crystal sapphire. A water-cooled splash shield absorbs spillage light outside of the 3.5-in. concentrator aperture. Multilayer foil insulation composed of tungsten, molybdenum, and niobium is used to minimize heat loss from the hightemperature receiver. A liquid-cooled canister calorimeter is used to measure the heat loss through the multilayer foil insulation.

  9. Effective Surfactants Blend Concentration Determination for O/W Emulsion Stabilization by Two Nonionic Surfactants by Simple Linear Regression.

    Science.gov (United States)

    Hassan, A K

    2015-01-01

    In this work, O/W emulsion sets were prepared by using different concentrations of two nonionic surfactants. The two surfactants, tween 80(HLB=15.0) and span 80(HLB=4.3) were used in a fixed proportions equal to 0.55:0.45 respectively. HLB value of the surfactants blends were fixed at 10.185. The surfactants blend concentration is starting from 3% up to 19%. For each O/W emulsion set the conductivity was measured at room temperature (25±2°), 40, 50, 60, 70 and 80°. Applying the simple linear regression least squares method statistical analysis to the temperature-conductivity obtained data determines the effective surfactants blend concentration required for preparing the most stable O/W emulsion. These results were confirmed by applying the physical stability centrifugation testing and the phase inversion temperature range measurements. The results indicated that, the relation which represents the most stable O/W emulsion has the strongest direct linear relationship between temperature and conductivity. This relationship is linear up to 80°. This work proves that, the most stable O/W emulsion is determined via the determination of the maximum R² value by applying of the simple linear regression least squares method to the temperature-conductivity obtained data up to 80°, in addition to, the true maximum slope is represented by the equation which has the maximum R² value. Because the conditions would be changed in a more complex formulation, the method of the determination of the effective surfactants blend concentration was verified by applying it for more complex formulations of 2% O/W miconazole nitrate cream and the results indicate its reproducibility.

  10. High-order TVD and TVB linear multistep methods

    NARCIS (Netherlands)

    Ruuth, S.J.; Hundsdorfer, W.

    2004-01-01

    We consider linear multistep methods that possess the TVD (total variation diminishing) or TVB (total variation bounded) properties, or related general monotonicity and boundedness properties. Strict monotonicity or TVD, in terms of arbitrary starting values for the multistep schemes, is only valid

  11. Fabrication and tolerances of optics for high concentration photovoltaics

    OpenAIRE

    Benitez Gimenez, Pablo; Miñano Dominguez, Juan Carlos; Ahmadpanaih, Hamed; Mendes Lopes, Joao; Zamora Herranz, Pablo

    2014-01-01

    High Concentration Photovoltaics (HCPV) require an optical system with high efficiency, low cost and large tolerance. We describe the particularities of the HCPV applications, which constrain the optics design and the manufacturing techonologies.

  12. Maintaining rotational equilibrium during object manipulation: linear behavior of a highly non-linear system

    Science.gov (United States)

    Gao, Fan; Latash, Mark L.

    2010-01-01

    We address issues of simultaneous control of the grasping force and the total moment of forces applied to a handheld object during its manipulation. Six young healthy male subjects grasped an instrumented handle and performed its cyclic motion in the vertical direction. The handle allowed for setting different clockwise (negative) or counterclockwise torques. Three movement frequencies: 1, 1.5 and 2 Hz, and five different torques: −1/3, −1/6, 0, 1/6 and 1/3 Nm, were used. The rotational equilibrium was maintained by two means: (1) Concerted changes of the moments produced by the normal and tangential forces, specifically anti-phase changes of the moments during the tasks with zero external torque and in-phase changes during the non-zero-torque tasks, and (2) Redistribution of the normal forces among individual fingers such that the agonist fingers—the fingers that resist external torque—increased the force in phase with the acceleration, while the forces of the antagonist fingers—those that assist the external torque—especially, the fingers with the large moment arms, the index and little fingers, stayed unchanged. The observed effects agree with the principle of superposition—according to which some complex actions, for example, prehension, can be decomposed into elemental actions controlled independently—and the mechanical advantage hypothesis according to which in moment production the fingers are activated in proportion to their moment arms with respect to the axis of rotation. We would like to emphasize the linearity of the observed relations, which was not prescribed by the task mechanics and seems to be produced by specific neural control mechanisms. PMID:16328302

  13. A concentrator system for BI-CPVT with static linear Fresnel lenses

    NARCIS (Netherlands)

    Swinkels, G.L.A.M.; Sonneveld, P.J.; Tuijl, van B.A.J.; Janssen, H.J.J.; Zwart, de H.F.

    2011-01-01

    A greenhouse with Fresnel lenses in the south facing roof and a receiver for concentrated Photovoltaic with water cooling (CPVT system) will result in electrical and thermal energy output from the solar energy excess entering a greenhouse. The PV system converts about half of the direct radiation

  14. A concentrator system for BI-CPVT with static linear Fresnel lenses

    NARCIS (Netherlands)

    Swinkels, G.L.A.M.; Sonneveld, P.J.; Tuijl, van B.A.J.; Janssen, H.J.J.; Zwart, de H.F.

    2011-01-01

    A greenhouse with Fresnel lenses in the south facing roof and a receiver for concentrated Photovoltaic with water cooling (CPVT system) will result in electrical and thermal energy output from the solar energy excess entering a greenhouse. The PV system converts about half of the direct radiation in

  15. Interrogation of a linearly chirped fiber Bragg grating sensor with high resolution using a linearly chirped optical waveform.

    Science.gov (United States)

    Wang, Yiping; Zhang, Jiejun; Coutinho, Olympio; Yao, Jianping

    2015-11-01

    An approach to the interrogation of a linearly chirped fiber Bragg grating (LCFBG) sensor using a linearly frequency-modulated (or chirped) optical waveform (LFMOW) with a high resolution is proposed and experimentally demonstrated. An LFMOW is generated at a laser diode through linear frequency modulation. The generated LFMOW is then launched into an LCFBG pair consisting of two identical LCFBGs, with one serving as a sensing LCFBG and the other as a reference LCFBG. The reflection of the LFMOW from the two LCFBGs would lead to two time delayed LFMOWs. By beating the LFMOWs at a photodetector, a microwave signal with a beat frequency that is proportional to the time delay difference between the two reflected LFMOWs is generated. By measuring the frequency change of the beat signal, the strain applied to the sensing LCFBG is estimated. The proposed approach is experimentally evaluated. An LCFBG sensor with a resolution of 0.25 με is experimentally demonstrated.

  16. High Resolution Linear Polarimetric Imaging for the Event Horizon Telescope

    CERN Document Server

    Chael, Andrew A; Narayan, Ramesh; Doeleman, Sheperd S; Wardle, John F C; Bouman, Katherine L

    2016-01-01

    Images of the linear polarization of synchrotron radiation around Active Galactic Nuclei (AGN) identify their projected magnetic field lines and provide key data for understanding the physics of accretion and outflow from supermassive black holes. The highest resolution polarimetric images of AGN are produced with Very Long Baseline Interferometry (VLBI). Because VLBI incompletely samples the Fourier transform of the source image, any image reconstruction that fills in unmeasured spatial frequencies will not be unique and reconstruction algorithms are required. In this paper, we explore extensions of the Maximum Entropy Method (MEM) to linear polarimetric VLBI imaging. In contrast to previous work, our polarimetric MEM algorithm combines a Stokes I imager that uses only bispectrum measurements that are immune to atmospheric phase corruption with a joint Stokes Q and U imager that operates on robust polarimetric ratios. We demonstrate the effectiveness of our technique on 7- and 3-mm wavelength quasar observat...

  17. High Momentum Resolution tracking In a Linear Collider

    CERN Document Server

    Ljunggren, M; Oskarsson, A

    2011-01-01

    The work in this thesis has been made within the LCTPC-collaboration, an international collaboration for studying the technical aspects af a possible tracking detector at a linear collider. The collaboration has built a prototype Time Projection Chamber (TPC) for testing the properties of dierent readout structures. A TPC is a tracking detector consisting of a gas lled drift volume placed in a solenoidal magnetic eld where the readout is made using a segmented plane of so called pads. When a char...

  18. Protoplanetary Disk Turbulence Driven by the Streaming Instability: Non-Linear Saturation and Particle Concentration

    CERN Document Server

    Johansen, A; Johansen, Anders; Youdin, Andrew

    2007-01-01

    We present simulations of the non-linear evolution of streaming instabilities in protoplanetary disks. The two components of the disk, gas treated with grid hydrodynamics and solids treated as superparticles, are mutually coupled by drag forces. We find that the initially laminar equilibrium flow spontaneously develops into turbulence in our unstratified local model. Marginally coupled solids (that couple to the gas on a Keplerian time-scale) trigger an upward cascade to large particle clumps with peak overdensities above 100. The clumps evolve dynamically by losing material downstream to the radial drift flow while receiving recycled material from upstream. Smaller, more tightly coupled solids produce weaker turbulence with more transient overdensities on smaller length scales. The net inward radial drift is decreased for marginally coupled particles, whereas the tightly coupled particles migrate faster in the saturated turbulent state. The turbulent diffusion of solid particles, measured by their random wal...

  19. Short-term population-based non-linear concentration-response associations between fine particulate matter and respiratory diseases in Taipei (Taiwan): a spatiotemporal analysis.

    Science.gov (United States)

    Yu, Hwa-Lung; Chien, Lung-Chang

    2016-01-01

    Fine particulate matter respiratory disease remain inconsistent. The short-term, population-based association between the respiratory clinic visits of children and PM2.5 exposure levels were investigated by considering both the spatiotemporal distributions of ambient pollution and clinic visit data. We applied a spatiotemporal structured additive regression model to examine the concentration-response (C-R) association between children's respiratory clinic visits and PM2.5 concentrations. This analysis was separately performed on three respiratory disease categories that were selected from the Taiwanese National Health Insurance database, which includes 41 districts in the Taipei area of Taiwan from 2005 to 2007. The findings reveal a non-linear C-R pattern of PM2.5, particularly in acute respiratory infections. However, a PM2.5 increase at relatively lower levels can elevate the same-day respiratory health risks of both preschool children (respiratory risks, except in instances where PM2.5 levels are extremely high, and these occurrences do exhibit a significant positive influence on respiratory health that is especially notable in schoolchildren. A significant high relative rate of respiratory clinic visits are concentrated in highly populated areas. We highlight the non-linearity of the respiratory health effects of PM2.5 on children to investigate this population-based association. The C-R relationship in this study can provide a highly valuable alternative for assessing the effects of ambient air pollution on human health.

  20. An Efficient and High Performance Linear Recursive Variable Expansion Implementation of the Smith-Waterman Algorithm

    NARCIS (Netherlands)

    Hasan, L.; Al-Ars, Z.

    2009-01-01

    In this paper, we present an efficient and high performance linear recursive variable expansion (RVE) implementation of the Smith-Waterman (S-W) algorithm and compare it with a traditional linear systolic array implementation. The results demonstrate that the linear RVE implementation performs up to

  1. Novel cyclen-based linear polymer as a high-affinity binding material for DNA condensation

    Institute of Scientific and Technical Information of China (English)

    XIANG YongZhe; WANG Na; ZHANG Ji; LI Kun; ZHANG ZhongWei; LIN HongHui; YU XiaoQi

    2009-01-01

    A novel cyclen-based linear polyamine (POGEC) was designed and synthesized from the reaction be-tween 1,3-propanediol diglycidyl ether and 1,7-bis(diethoxyphosphory)-1,4,7,10-tetraazacyclod- odecane.High-affinity binding between POGEC and DNA was demonstrated by agarose gel electrophoresis and scanning electron microscopy (SEM). Moreover, the formed POGEC/DNA complex (termed polyplex) could be disassociated to release the free DNA through addition of the physiological concentration of NaCl solution. Fluorescence spectrum was used to measure the high-affinity binding and DNA con-densation capability of POGEC. Circular dichroism (CD) spectrum indicates that the DNA conformation did not change after binding to POEGC.

  2. Novel cyclen-based linear polymer as a high-affinity binding material for DNA condensation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A novel cyclen-based linear polyamine (POGEC) was designed and synthesized from the reaction between 1,3-propanediol diglycidyl ether and 1,7-bis(diethoxyphosphory)-1,4,7,10-tetraazacyclod-odecane. High-affinity binding between POGEC and DNA was demonstrated by agarose gel electrophoresis and scanning electron microscopy (SEM). Moreover,the formed POGEC/DNA complex (termed polyplex) could be disassociated to release the free DNA through addition of the physiological concentration of NaCl solution. Fluorescence spectrum was used to measure the high-affinity binding and DNA condensation capability of POGEC. Circular dichroism (CD) spectrum indicates that the DNA conformation did not change after binding to POEGC.

  3. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam Y

    2009-01-01

    Designed for a one-semester course on fiber-optics systems and communication links, this book provides a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers.

  4. New linear piezomotors for high-force precise positioning applications

    Science.gov (United States)

    Le Letty, Ronan; Claeyssen, Frank; Barillot, Francois; Six, Marc F.; Bouchilloux, Philippe

    1998-07-01

    Piezomotors are an increasingly competitive alternative to electromagnetic stepper motors, especially in applications where large bandwidths and/or precise positioning control are desired. Piezomotors use a combination of electromechanical and frictional forces and, compared to conventional electromagnetic motors, have the advantages that no power supply is required to maintain the motor in position and no lubrication is necessary in the device. The operating principle of these motors relies on the use of an ultrasonic vibration, which is created via the piezoelectric effect (at resonance in most cases), in order to generate vibration forces at the `stator/rotor' contact interface. A mechanical preload is also applied at this contact interface and is responsible for the motor's holding force at rest. To meet the specifications of an aerospace application, we developed a new design of Linear PiezoMotors (LPMs). The first prototype we built shows very promising results, and makes the LPM a serious candidate to replace conventional stepper motors. The LPM features the following characteristics: a standing force of 100 N, a blocked force of 37 N, a maximum actuation speed of 23 mm/s, a maximum run of 10 mm, a mass of 500 g, an electrical power of 2.2 W, and a position accuracy superior to 1 micrometers . To our knowledge, the driving force delivered by the LPM has never before been achieved in resonant devices. This paper describes the physical operating principles of the LPM, as well as the modeling tools and experimental techniques we used for its development. Several implementation schemes are also presented and show the wide range of possible applications offered by the linear piezomotor.

  5. Intercomparison of passive microwave sea ice concentration retrievals over the high-concentration Arctic sea ice

    DEFF Research Database (Denmark)

    andersen, susanne; Tonboe, R.; Kaleschke, L.

    2007-01-01

    [1] Measurements of sea ice concentration from the Special Sensor Microwave Imager (SSM/I) using seven different algorithms are compared to ship observations, sea ice divergence estimates from the Radarsat Geophysical Processor System, and ice and water surface type classification of 59 wide......-swath synthetic aperture radar (SAR) scenes. The analysis is confined to the high-concentration Arctic sea ice, where the ice cover is near 100%. During winter the results indicate that the variability of the SSM/I concentration estimates is larger than the true variability of ice concentration. Results from...... a trusted subset of the SAR scenes across the central Arctic allow the separation of the ice concentration uncertainty due to emissivity variations and sensor noise from other error sources during the winter of 2003-2004. Depending on the algorithm, error standard deviations from 2.5 to 5.0% are found...

  6. High Stokes shift perylene dyes for luminescent solar concentrators.

    Science.gov (United States)

    Sanguineti, Alessandro; Sassi, Mauro; Turrisi, Riccardo; Ruffo, Riccardo; Vaccaro, Gianfranco; Meinardi, Francesco; Beverina, Luca

    2013-02-25

    Highly efficient plastic based single layer Luminescent Solar Concentrators (LSCs) require the design of luminophores having complete spectral separation between absorption and emission spectra (large Stokes shift). We describe the design, synthesis and characterization of a new perylene dye possessing Stokes shift as high as 300 meV, fluorescent quantum yield in the LSC slab of 70% and high chemical and photochemical stability.

  7. Augmented switching linear dynamical system model for gas concentration estimation with MOX sensors in an open sampling system.

    Science.gov (United States)

    Di Lello, Enrico; Trincavelli, Marco; Bruyninckx, Herman; De Laet, Tinne

    2014-07-11

    In this paper, we introduce a Bayesian time series model approach for gas concentration estimation using Metal Oxide (MOX) sensors in Open Sampling System (OSS). Our approach focuses on the compensation of the slow response of MOX sensors, while concurrently solving the problem of estimating the gas concentration in OSS. The proposed Augmented Switching Linear System model allows to include all the sources of uncertainty arising at each step of the problem in a single coherent probabilistic formulation. In particular, the problem of detecting on-line the current sensor dynamical regime and estimating the underlying gas concentration under environmental disturbances and noisy measurements is formulated and solved as a statistical inference problem. Our model improves, with respect to the state of the art, where system modeling approaches have been already introduced, but only provided an indirect relative measures proportional to the gas concentration and the problem of modeling uncertainty was ignored. Our approach is validated experimentally and the performances in terms of speed of and quality of the gas concentration estimation are compared with the ones obtained using a photo-ionization detector.

  8. Augmented Switching Linear Dynamical System Model for Gas Concentration Estimation with MOX Sensors in an Open Sampling System

    Directory of Open Access Journals (Sweden)

    Enrico Di Lello

    2014-07-01

    Full Text Available In this paper, we introduce a Bayesian time series model approach for gas concentration estimation using Metal Oxide (MOX sensors in Open Sampling System (OSS. Our approach focuses on the compensation of the slow response of MOX sensors, while concurrently solving the problem of estimating the gas concentration in OSS. The proposed Augmented Switching Linear System model allows to include all the sources of uncertainty arising at each step of the problem in a single coherent probabilistic formulation. In particular, the problem of detecting on-line the current sensor dynamical regime and estimating the underlying gas concentration under environmental disturbances and noisy measurements is formulated and solved as a statistical inference problem. Our model improves, with respect to the state of the art, where system modeling approaches have been already introduced, but only provided an indirect relative measures proportional to the gas concentration and the problem of modeling uncertainty was ignored. Our approach is validated experimentally and the performances in terms of speed of and quality of the gas concentration estimation are compared with the ones obtained using a photo-ionization detector.

  9. TSS concentration in sewers estimated from turbidity measurements by means of linear regression accounting for uncertainties in both variables.

    Science.gov (United States)

    Bertrand-Krajewski, J L

    2004-01-01

    In order to replace traditional sampling and analysis techniques, turbidimeters can be used to estimate TSS concentration in sewers, by means of sensor and site specific empirical equations established by linear regression of on-site turbidity Tvalues with TSS concentrations C measured in corresponding samples. As the ordinary least-squares method is not able to account for measurement uncertainties in both T and C variables, an appropriate regression method is used to solve this difficulty and to evaluate correctly the uncertainty in TSS concentrations estimated from measured turbidity. The regression method is described, including detailed calculations of variances and covariance in the regression parameters. An example of application is given for a calibrated turbidimeter used in a combined sewer system, with data collected during three dry weather days. In order to show how the established regression could be used, an independent 24 hours long dry weather turbidity data series recorded at 2 min time interval is used, transformed into estimated TSS concentrations, and compared to TSS concentrations measured in samples. The comparison appears as satisfactory and suggests that turbidity measurements could replace traditional samples. Further developments, including wet weather periods and other types of sensors, are suggested.

  10. Influence of silicon concentration on linear contraction process of Al-Si binary alloy

    Directory of Open Access Journals (Sweden)

    J. Mutwil

    2008-12-01

    Full Text Available Investigations of shrinkage phenomena during solidification and cooling of aluminium and aluminium-silicon alloys (AlSi5, AlSi7, AlSi9, AlSi11, AlSi12.5, AlSi18, AlSi21 have been conducted. A vertical shrinkage rod casting with circular cross-section (constant or fixed: tapered has been used as a test sample. By constant cross-section a test channel mould was parted and allowed a constrained contraction to examine. No parted test channel mould was tapered and allowed an unconstrained contraction to investigate. In the experiments the dimensions changes of solidifying test bar and the test mould have been registered, what has allowed to explain a mechanism of pre-shrinkage extension of solidifying metals and alloys. Registered time dependence of the test bar and the test mould dimension changes have shown, that so-called pre-shrinkage extension has been by mould thermal extension caused. The investigation results have also shown that time- and temperature dependences of shrinkage of Al-Si alloys have been on silicon concentration depended.

  11. Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations.

    OpenAIRE

    Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H

    2003-01-01

    Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hai...

  12. Applications of nonimaging optics for very high solar concentrations

    Energy Technology Data Exchange (ETDEWEB)

    O`Gallagher, J.; Winston, R.

    1997-12-31

    Using the principles and techniques of nonimaging optics, solar concentrations that approach the theoretical maximum can be achieved. This has applications in solar energy collection wherever concentration is desired. In this paper, we survey recent progress in attaining and using high and ultrahigh solar fluxes. We review a number of potential applications for highly concentrated solar energy and the current status of the associated technology. By making possible new and unique applications for intense solar flux, these techniques have opened a whole new frontier for research and development of potentially economic uses of solar energy.

  13. Evaluation Of Electrical And Thermal Performance Of A Linear Hybrid CPV-T Micro-Concentrator System

    Science.gov (United States)

    Everett, Vernie; Harvey, Judy; Surve, Sachin; Thomsen, Elizabeth; Walter, Daniel; Vivar, Marta; Blakers, Andrew; Tanner, Andrew; Greaves, Mikal; Le Leivre, Peter

    2011-12-01

    Chromasun Inc. and The Australian National University have developed a low-concentration, linear, hybrid micro-concentrator (MCT) system suitable for urban rooftop installation. The system produces both electrical and thermal power, integrating the functionality of separate flat plate photovoltaic and solar hot water systems. The MCT system utilises industry-standard components, including modified mono-crystalline silicon one-sun solar cells, commonly used in flat panel applications. The MCT manufacturing processes are designed around low-cost methods, and tap directly into existing economies of scale. Initial test results without any system optimisation has demonstrated an electrical output of more than 300 W, and a thermal output of more than 1500 W at 950 W/m2 DNI.

  14. Sparse linear discriminant analysis by thresholding for high dimensional data

    CERN Document Server

    Shao, Jun; Deng, Xinwei; Wang, Sijian; 10.1214/10-AOS870

    2011-01-01

    In many social, economical, biological and medical studies, one objective is to classify a subject into one of several classes based on a set of variables observed from the subject. Because the probability distribution of the variables is usually unknown, the rule of classification is constructed using a training sample. The well-known linear discriminant analysis (LDA) works well for the situation where the number of variables used for classification is much smaller than the training sample size. Because of the advance in technologies, modern statistical studies often face classification problems with the number of variables much larger than the sample size, and the LDA may perform poorly. We explore when and why the LDA has poor performance and propose a sparse LDA that is asymptotically optimal under some sparsity conditions on the unknown parameters. For illustration of application, we discuss an example of classifying human cancer into two classes of leukemia based on a set of 7,129 genes and a training ...

  15. Electron beam treatment of exhaust gas with high NOx concentration

    Science.gov (United States)

    Licki, Janusz; Chmielewski, Andrzej G.; Pawelec, Andrzej; Zimek, Zbigniew; Witman, Sylwia

    2014-05-01

    Simulated exhaust gases with a high NOx concentration, ranging from 200 to 1700 ppmv, were irradiated by an electron beam from an accelerator. In the first part of this study, only exhaust gases were treated. Low NOx removal efficiencies were obtained for high NOx concentrations, even with high irradiation doses applied. In the second part of study, gaseous ammonia or/and vapor ethanol were added to the exhaust gas before its inlet to the plasma reactor. These additions significantly enhanced the NOx removal efficiency. The synergistic effect of high SO2 concentration on NOx removal was observed. The combination of electron beam treatment with the introduction of the above additions and with the performance of irradiation under optimal parameters ensured high NOx removal efficiency without the application of a solid-state catalyst.

  16. [Reasons of high concentration ammonium in Yellow River, China].

    Science.gov (United States)

    Zhang, Xue-qing; Xia, Xing-hui; Yang, Zhi-feng

    2007-07-01

    Ammonium nitrogen contamination is one of the major problems of the Yellow River in China. The speciation, concentration and sources of nitrogen compounds as well as the water environment conditions of the Yellow River had been analyzed to study the reasons for the fact that the ammonium nitrogen concentration was above the water quality standard. In addition, laboratory experiments had been carried out to investigate the effects of suspended sediment (SS) on nitrification rate. The results indicated that the presence of SS could accelerate the nitrification process, therefore, the effects of SS on nitrification rate was not the reason for the high level of ammonium nitrogen in the river. The excessive and continuous input of nitrogen contaminants to the river was the fundamental reason for the high concentration of ammonium nitrogen. Organic and ammonium nitrogen with high concentration inhibitted the nitrification processes. When the initial NH4+ -N concentrations were 10.1, 18.4 and 28.2 mg/L, nitrification efficiencies were 17.4%, 13.0% and 2.5%, respectively. When the initial organic nitrogen concentrations were 5.5 and 8.6 mg/L, the maximum concentrations of ammonium nitrogen produced by the oxidation of organic nitrogen would reach 0.47 and 1.69 mg/L and they would last for 2 days and 6 days, respectively. The oxygen-consuming organics and toxic substance existing in the river water could inhibit the activity of nitrifying bacteria, and thus lead to the accumulation of ammonium nitrogen. In addition, the high pH value of river water resulted in the high concentration of nonionic ammonium nitrogen which would reduce the activity of nitrifying bacteria and decrease the nitrification rates. Besides, low river runoff, low SS content and low activity of nitrifying bacteria resulted in the high level of ammonium nitrogen of the river in the low water season.

  17. Subharmonic, non-linear fundamental and ultraharmonic imaging of microbubble contrast at high frequencies.

    Science.gov (United States)

    Daeichin, Verya; Bosch, Johan G; Needles, Andrew; Foster, F Stuart; van der Steen, Antonius; de Jong, Nico

    2015-02-01

    There is increasing use of ultrasound contrast agent in high-frequency ultrasound imaging. However, conventional contrast detection methods perform poorly at high frequencies. We performed systematic in vitro comparisons of subharmonic, non-linear fundamental and ultraharmonic imaging for different depths and ultrasound contrast agent concentrations (Vevo 2100 system with MS250 probe and MicroMarker ultrasound contrast agent, VisualSonics, Toronto, ON, Canada). We investigated 4-, 6- and 10-cycle bursts at three power levels with the following pulse sequences: B-mode, amplitude modulation, pulse inversion and combined pulse inversion/amplitude modulation. The contrast-to-tissue (CTR) and contrast-to-artifact (CAR) ratios were calculated. At a depth of 8 mm, subharmonic pulse-inversion imaging performed the best (CTR = 26 dB, CAR = 18 dB) and at 16 mm, non-linear amplitude modulation imaging was the best contrast imaging method (CTR = 10 dB). Ultraharmonic imaging did not result in acceptable CTRs and CARs. The best candidates from the in vitro study were tested in vivo in chicken embryo and mouse models, and the results were in a good agreement with the in vitro findings.

  18. Approximate Stream Function wavemaker theory for highly non-linear waves in wave flumes

    DEFF Research Database (Denmark)

    Zhang, H.W.; Schäffer, Hemming Andreas

    2007-01-01

    An approximate Stream Function wavemaker theory for highly non-linear regular waves in flumes is presented. This theory is based on an ad hoe unified wave-generation method that combines linear fully dispersive wavemaker theory and wave generation for non-linear shallow water waves. This is done...... by applying a dispersion correction to the paddle position obtained for non-linear long waves. The method is validated by a number of wave flume experiments while comparing with results of linear wavemaker theory, second-order wavemaker theory and Cnoidal wavemaker theory within its range of application....

  19. Differences in Swallowing between High and Low Concentration Taste Stimuli

    Directory of Open Access Journals (Sweden)

    Ahmed Nagy

    2014-01-01

    Full Text Available Taste is a property that is thought to potentially modulate swallowing behavior. Whether such effects depend on taste, intensity remains unclear. This study explored differences in the amplitudes of tongue-palate pressures in swallowing as a function of taste stimulus concentration. Tongue-palate pressures were collected in 80 healthy women, in two age groups (under 40, over 60, stratified by genetic taste status (nontasters, supertasters. Liquids with different taste qualities (sweet, sour, salty, and bitter were presented in high and low concentrations. General labeled magnitude scale ratings captured perceived taste intensity and liking/disliking of the test liquids. Path analysis explored whether factors of taste, concentration, age group, and/or genetic taste status impacted: (1 perceived intensity; (2 palatability; and (3 swallowing pressures. Higher ratings of perceived intensity were found in supertasters and with higher concentrations, which were more liked/disliked than lower concentrations. Sweet stimuli were more palatable than sour, salty, or bitter stimuli. Higher concentrations elicited stronger tongue-palate pressures independently and in association with intensity ratings. The perceived intensity of a taste stimulus varies as a function of stimulus concentration, taste quality, participant age, and genetic taste status and influences swallowing pressure amplitudes. High-concentration salty and sour stimuli elicit the greatest tongue-palate pressures.

  20. The Non-Linear Child: Ontogeny, Isoniazid Concentration, and NAT2 Genotype Modulate Enzyme Reaction Kinetics and Metabolism

    Directory of Open Access Journals (Sweden)

    Zoe Rogers

    2016-09-01

    Full Text Available N-acetyltransferase 2 (NAT2 catalyzes the acetylation of isoniazid to N-acetylisoniazid. NAT2 polymorphism explains 88% of isoniazid clearance variability in adults. We examined the effects of clinical and genetic factors on Michaelis-Menten reaction kinetic constants of maximum velocity (Vmax and affinity (Km in children 0–10 years old. We measured the rates of isoniazid elimination and N-acetylisoniazid production in the blood of 30 children. Since maturation effects could be non-linear, we utilized a pharmacometric approach and the artificial intelligence method, multivariate adaptive regression splines (MARS, to identify factors predicting NAT2 Vmax and Km by examining clinical, genetic, and laboratory factors in toto. Isoniazid concentration predicted both Vmax and Km and superseded the contribution of NAT2 genotype. Age non-linearly modified the NAT2 genotype contribution until maturation at ≥5.3 years. Thus, enzyme efficiency was constrained by substrate concentration, genes, and age. Since MARS output is in the form of basis functions and equations, it allows multiscale systems modeling from the level of cellular chemical reactions to whole body physiological parameters, by automatic selection of significant predictors by the algorithm.

  1. High Black Carbon (BC) Concentrations along Indian National Highways

    Science.gov (United States)

    Kumar, S.; Singh, A. K.; Singh, R. P.

    2015-12-01

    Abstract:Black carbon (BC), the optically absorbing component of carbonaceous aerosol, has direct influence on radiation budget and global warming. Vehicular pollution is one of the main sources for poor air quality and also atmospheric pollution. The number of diesel vehicles has increased on the Indian National Highways during day and night; these vehicles are used for the transport of goods from one city to another city and also used for public transport. A smoke plume from the vehicles is a common feature on the highways. We have made measurements of BC mass concentrations along the Indian National Highways using a potable Aethalometer installed in a moving car. We have carried out measurements along Varanasi to Kanpur (NH-2), Varanasi to Durgapur (NH-2), Varanasi to Singrauli (SH-5A) and Varanasi to Ghazipur (NH-29). We have found high concentration of BC along highways, the average BC mass concentrations vary in the range 20 - 40 µg/m3 and found high BC mass concentrations up to 600 μg/m3. Along the highways high BC concentrations were characteristics of the presence of industrial area, power plants, brick kilns and slow or standing vehicles. The effect of increasing BC concentrations along the National Highways and its impact on the vegetation and human health will be presented. Key Words: Black Carbon; Aethalometer; mass concentration; Indian National Highways.

  2. Non-linear Flight Dynamics at High Angles of Attack

    DEFF Research Database (Denmark)

    Granasy, P.; Sørensen, C.B.; Mosekilde, Erik

    1998-01-01

    The methods of nonlinear dynamics are applied to the longitudinal motion of a vectored thrust aircraft, in particular the behavior at high angles of attack. Our model contains analytic nonlinear aerodynamical coefficients based on NASA windtunnel experiments on the F-18 high-alpha research vehicle...... (HARV). When the aircraft is forced with small thrust deflections whilst in poststall equilibrium, chaotic motion is observed at certain frequencies. At other frequencies, several limiting states coexist....

  3. Laser-engraved carbon nanotube paper for instilling high sensitivity, high stretchability, and high linearity in strain sensors

    KAUST Repository

    Xin, Yangyang

    2017-06-29

    There is an increasing demand for strain sensors with high sensitivity and high stretchability for new applications such as robotics or wearable electronics. However, for the available technologies, the sensitivity of the sensors varies widely. These sensors are also highly nonlinear, making reliable measurement challenging. Here we introduce a new family of sensors composed of a laser-engraved carbon nanotube paper embedded in an elastomer. A roll-to-roll pressing of these sensors activates a pre-defined fragmentation process, which results in a well-controlled, fragmented microstructure. Such sensors are reproducible and durable and can attain ultrahigh sensitivity and high stretchability (with a gauge factor of over 4.2 × 10(4) at 150% strain). Moreover, they can attain high linearity from 0% to 15% and from 22% to 150% strain. They are good candidates for stretchable electronic applications that require high sensitivity and linearity at large strains.

  4. Triaxial fluxgate gradiometer of high stability and linearity

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz

    2005-01-01

    . The transducers are of the ringcore type with very low noise and high thermal stability. They use amorphous metal magnetic core (Vitrovac 6025). The cores have been annealed in two different processes with different temperatures and stress. With this instrument, three components of the gradient tensor can...

  5. Triaxial fluxgate gradiometer of high stability and linearity

    DEFF Research Database (Denmark)

    Merayo, José M.G.; Brauer, Peter; Primdahl, Fritz

    2005-01-01

    . The transducers are of the ringcore type with very low noise and high thermal stability. They use amorphous metal magnetic core (Vitrovac 6025). The cores have been annealed in two different processes with different temperatures and stress. With this instrument, three components of the gradient tensor can...

  6. Consistent group selection in high-dimensional linear regression

    CERN Document Server

    Wei, Fengrong; 10.3150/10-BEJ252

    2010-01-01

    In regression problems where covariates can be naturally grouped, the group Lasso is an attractive method for variable selection since it respects the grouping structure in the data. We study the selection and estimation properties of the group Lasso in high-dimensional settings when the number of groups exceeds the sample size. We provide sufficient conditions under which the group Lasso selects a model whose dimension is comparable with the underlying model with high probability and is estimation consistent. However, the group Lasso is, in general, not selection consistent and also tends to select groups that are not important in the model. To improve the selection results, we propose an adaptive group Lasso method which is a generalization of the adaptive Lasso and requires an initial estimator. We show that the adaptive group Lasso is consistent in group selection under certain conditions if the group Lasso is used as the initial estimator.

  7. Acoustic trapping with a high frequency linear phased array

    OpenAIRE

    Zheng, Fan; Ying LI; Hsu, Hsiu-Sheng; Liu, Changgeng; Tat Chiu, Chi; Lee, Changyang; Ham Kim, Hyung; Shung, K. Kirk

    2012-01-01

    A high frequency ultrasonic phased array is shown to be capable of trapping and translating microparticles precisely and efficiently, made possible due to the fact that the acoustic beam produced by a phased array can be both focused and steered. Acoustic manipulation of microparticles by a phased array is advantageous over a single element transducer since there is no mechanical movement required for the array. Experimental results show that 45 μm diameter polystyrene microspheres can be eas...

  8. N2O production by ammonia oxidizing bacteria in an enriched nitrifying sludge linearly depends on inorganic carbon concentration.

    Science.gov (United States)

    Peng, Lai; Ni, Bing-Jie; Ye, Liu; Yuan, Zhiguo

    2015-05-01

    The effect of inorganic carbon (IC) on nitrous oxide (N2O) production by ammonia oxidizing bacteria (AOB) was investigated over a concentration range of 0-12 mmol C/L, encompassing typical IC levels in a wastewater treatment reactors. The AOB culture was enriched along with nitrite-oxidizing bacteria (NOB) in a sequencing batch reactor (SBR) to perform complete nitrification. Batch experiments were conducted with continuous carbon dioxide (CO2) stripping or at controlled IC concentrations. The results revealed a linear relationship between N2O production rate (N2OR) and IC concentration (R(2) = 0.97) within the IC range studied, suggesting a substantial effect of IC on N2O production by AOB. Similar results were also obtained with an AOB culture treating anaerobic sludge digestion liquor. The fundamental mechanism responsible for this dependency is unclear; however, in agreement with previous studies, it was observed that the ammonia oxidation rate (AOR) was also influenced by the IC concentration, which could be well described by the Monod kinetics. These resulted in an exponential relationship between N2OR and AOR, as previously observed in experiments where AOR was altered by varying dissolved oxygen and ammonia concentrations. It is therefore possible that IC indirectly affected N2OR by causing a change in AOR. The observation in this study indicates that alkalinity (mostly contributed by IC) could be a significant factor influencing N2O production and should be taken into consideration in estimating and mitigating N2O emissions in wastewater treatment systems.

  9. Acoustic trapping with a high frequency linear phased array.

    Science.gov (United States)

    Zheng, Fan; Li, Ying; Hsu, Hsiu-Sheng; Liu, Changgeng; Tat Chiu, Chi; Lee, Changyang; Ham Kim, Hyung; Shung, K Kirk

    2012-11-19

    A high frequency ultrasonic phased array is shown to be capable of trapping and translating microparticles precisely and efficiently, made possible due to the fact that the acoustic beam produced by a phased array can be both focused and steered. Acoustic manipulation of microparticles by a phased array is advantageous over a single element transducer since there is no mechanical movement required for the array. Experimental results show that 45 μm diameter polystyrene microspheres can be easily and accurately trapped and moved to desired positions by a 64-element 26 MHz phased array.

  10. Numerical simulation of a Linear Fresnel Reflector Concentrator used as direct generator in a Solar-GAX cycle

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez, N.; Sauceda, D.; Beltran, R. [Instituto de Ingenieria, Universidad Autonoma de Baja California, Blvd. Benito Juarez y Calle de la Normal s/n, Mexicali, Baja California 21280 (Mexico); Garcia-Valladares, O. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Privada Xochicalco s/n, Temixco, Morelos 62580 (Mexico)

    2010-03-15

    In this work a methodological analysis to design and evaluate the technical feasibility of use a Linear Fresnel Reflector Concentrator (LFRC) as generator in an advanced absorption refrigeration system (Solar-GAX cycle) has been carried out. For this purpose, a detailed one-dimensional numerical simulation of the thermal and fluid-dynamic behavior of a LFRC that solves, in a segregated manner, four subroutines: (a) fluid flow inside the receptor tube, (b) heat transfer in the receptor tube wall, (c) heat transfer in cover tube wall, and (d) solar thermal analysis in the solar concentrator has been developed. The LFRC numerical model has been validated with experimental data obtained from the technical literature; after that, a parametric study for different configurations of design has been carried out in order to obtain the highest solar concentration with the lowest thermal losses, keeping in mind both specific weather conditions and construction restrictions. The numerical result obtained demonstrates that using a LFRC as a direct generator in a Solar-GAX cycle satisfy not only the quantity and quality of the energy demanded by the advanced cooling system, it also allows to obtain higher global efficiencies of the system due to it can be operated in conditions where the maximum performance of the Solar-GAX cycle is obtained without affecting in any significant way the solar collector efficiency. (author)

  11. High current, 0.5-MA, fast, 100-ns, linear transformer driver experiments

    Directory of Open Access Journals (Sweden)

    Michael G. Mazarakis

    2009-05-01

    Full Text Available The linear transformer driver (LTD is a new method for constructing high current, high-voltage pulsed accelerators. The salient feature of the approach is switching and inductively adding the pulses at low voltage straight out of the capacitors through low inductance transfer and soft iron core isolation. Sandia National Laboratories are actively pursuing the development of a new class of accelerator based on the LTD technology. Presently, the high current LTD experimental research is concentrated on two aspects: first, to study the repetition rate capabilities, reliability, reproducibility of the output pulses, switch prefires, jitter, electrical power and energy efficiency, and lifetime measurements of the cavity active components; second, to study how a multicavity linear array performs in a voltage adder configuration relative to current transmission, energy and power addition, and wall plug to output pulse electrical efficiency. Here we report the repetition rate and lifetime studies performed in the Sandia High Current LTD Laboratory. We first utilized the prototype ∼0.4-MA, LTD I cavity which could be reliably operated up to ±90-kV capacitor charging. Later we obtained an improved 0.5-MA, LTD II version that can be operated at ±100  kV maximum charging voltage. The experimental results presented here were obtained with both cavities and pertain to evaluating the maximum achievable repetition rate and LTD cavity performance. The voltage adder experiments with a series of double sized cavities (1 MA, ±100  kV will be reported in future publications.

  12. Sterile Filtration of Highly Concentrated Protein Formulations: Impact of Protein Concentration, Formulation Composition, and Filter Material.

    Science.gov (United States)

    Allmendinger, Andrea; Mueller, Robert; Huwyler, Joerg; Mahler, Hanns-Christian; Fischer, Stefan

    2015-10-01

    Differences in filtration behavior of concentrated protein formulations were observed during aseptic drug product manufacturing of biologics dependent on formulation composition. The present study investigates filtration forces of monoclonal antibody formulations in a small-scale set-up using polyvinylidene difluoride (PVDF) or polyethersulfone (PES) filters. Different factors like formulation composition and protein concentration related to differences in viscosity, as well as different filtration rates were evaluated. The present study showed that filtration behavior was influenced by the presence or absence of a surfactant in the formulation, which defines the interaction between filter membrane and surface active formulation components. This can lead to a change in filter resistance (PES filter) independent on the buffer system used. Filtration behavior was additionally defined by rheological non-Newtonian flow behavior. The data showed that high shear rates resulting from small pore sizes and filtration pressure up to 1.0 bar led to shear-thinning behavior for highly concentrated protein formulations. Differences in non-Newtonian behavior were attributed to ionic strength related to differences in repulsive and attractive interactions. The present study showed that the interplay of formulation composition, filter material, and filtration rate can explain differences in filtration behavior/filtration flux observed for highly concentrated protein formulations thus guiding filter selection.

  13. Design of a high linearity and high gain accuracy analog baseband circuit for DAB receiver

    Science.gov (United States)

    Li, Ma; Zhigong, Wang; Jian, Xu; Yiqiang, Wu; Junliang, Wang; Mi, Tian; Jianping, Chen

    2015-02-01

    An analog baseband circuit of high linearity and high gain accuracy for a digital audio broadcasting receiver is implemented in a 0.18-μm RFCMOS process. The circuit comprises a 3rd-order active-RC complex filter (CF) and a programmable gain amplifier (PGA). An automatic tuning circuit is also designed to tune the CF's pass band. Instead of the class-A fully differential operational amplifier (FDOPA) adopted in the conventional CF and PGA design, a class-AB FDOPA is specially employed in this circuit to achieve a higher linearity and gain accuracy for its large current swing capability with lower static current consumption. In the PGA circuit, a novel DC offset cancellation technique based on the MOS resistor is introduced to reduce the settling time significantly. A reformative switching network is proposed, which can eliminate the switch resistor's influence on the gain accuracy of the PGA. The measurement result shows the gain range of the circuit is 10-50 dB with a 1-dB step size, and the gain accuracy is less than ±0.3 dB. The OIP3 is 23.3 dBm at the gain of 10 dB. Simulation results show that the settling time is reduced from 100 to 1 ms. The image band rejection is about 40 dB. It only draws 4.5 mA current from a 1.8 V supply voltage.

  14. Denitrification of fertilizer wastewater at high chloride concentration

    DEFF Research Database (Denmark)

    Ucisik, Ahmed Süheyl; Henze, Mogens

    g/l. The results of the experiments showed that biological denitrification was feasible at the extreme environmental conditions prevailing in fertilizer wastewater. Stable continuous biological denitrfication of the synthetic high chloride wastewater was performed up to 77.4 g Cl/l at 37 degree C......Wastewater from fertilizer industry is characterized by high contents of chloride concentration, which normally vary between 60 and 76 g/l. Experiments with bilogical denitrification were performed in lab-scale "fill and draw" reactors with synthetic wastewater with chloride concentrations up to 77.4...

  15. High estrogen concentrations in receiving river discharge from a concentrated livestock feedlot.

    Science.gov (United States)

    Chen, Te-San; Chen, Ting-Chien; Yeh, Kuei-Jyum C; Chao, How-Ran; Liaw, Ean-Tun; Hsieh, Chi-Ying; Chen, Kuan-Chung; Hsieh, Lien-Te; Yeh, Yi-Lung

    2010-07-15

    Environmental estrogenic chemicals interrupt endocrine systems and generate reproductive abnormalities in wildlife, especially natural and synthetic estrogenic steroid hormones such as 17beta-estradiol (E2), estrone (E1), estriol (E3), 17alpha-ethynylestradiol (EE2), and diethylstilbestrol (DES). Concentrated animal feedlot operations (CAFOs) are of particular concern since large amounts of naturally excreted estrogens are discharged into aquatic environments. This study investigated E2, E1, E3, EE2, and DES with high performance liquid chromatography/tandem mass (HPLC-MS/MS) analyses along Wulo Creek in southern Taiwan, near a concentrated livestock feedlot containing 1,030,000 broiler chickens, 934,000 laying hens, 85,000 pigs, and 1500 cattle. Sampling was performed from December 2008 to May 2009, in which 54 samples were collected. Experimental results indicate that concentrations of EE2 were lower than the limit of detection (LOD), and concentrations of DES were only detected twice. Concentrations ranged from 7.4 to 1267 ng/L for E1, from not detected (ND) to 313.6 ng/L for E2, and from ND to 210 ng/L for E3. E1 had the highest average mass fraction (72.2 + or - 3.6%), which was significantly higher than E3 (16.2 + or - 1.7%) and E2 (11.5 + or - 2.6%). Additionally, the mean E2 equivalent quotient (EEQ) ranged from 17.3 to 137.9 ng-E2/L. Despite having a markedly lower concentration than E1, E2 more significantly contributed (52.4 + or - 6.0%) EEQ than E1 (19.7 + or - 3.5%). Moreover, the concentrations of E2, E1, and E3 upstream were significantly higher than concentrations downstream, suggesting a high attenuation effect and fast degradation in the study water. Most concentrations in winter season were higher than those of spring season due to the low dilution effect and low microbial activity in the winter season. Based on the results of this study, we recommend further treatment of the wastewater discharge from the feedlot.

  16. Biodegradation dynamics of high catechol concentrations by Aspergillus awamori.

    Science.gov (United States)

    Stanchev, Veselin; Stoilova, Ivanka; Krastanov, Albert

    2008-06-15

    The biodegradation process of high catechol concentrations by Aspergillus awamori was investigated. The values of the kinetic constants for a model of specific growth rate at different initial conditions were determined. At 1.0 g/L catechol concentration, the biodegradation process proceeded in the conditions of substrate limitation. At higher catechol concentrations (2.0 and 3.0 g/L) a presence of substrate inhibition was established. The dynamics of the specific catechol degradation rate was studied and the values of catechol and biomass concentrations, maximizing the specific catechol degradation rate, were estimated analytically. The specified ratio catechol/biomass could serve as a starting base for determination of the initial conditions for a batch process, for specifying the moment of feeding for a fed-batch process, and for monitoring and control of a continuous process by the aim of time-optimal control.

  17. A high-speed linear algebra library with automatic parallelism

    Science.gov (United States)

    Boucher, Michael L.

    1994-01-01

    Parallel or distributed processing is key to getting highest performance workstations. However, designing and implementing efficient parallel algorithms is difficult and error-prone. It is even more difficult to write code that is both portable to and efficient on many different computers. Finally, it is harder still to satisfy the above requirements and include the reliability and ease of use required of commercial software intended for use in a production environment. As a result, the application of parallel processing technology to commercial software has been extremely small even though there are numerous computationally demanding programs that would significantly benefit from application of parallel processing. This paper describes DSSLIB, which is a library of subroutines that perform many of the time-consuming computations in engineering and scientific software. DSSLIB combines the high efficiency and speed of parallel computation with a serial programming model that eliminates many undesirable side-effects of typical parallel code. The result is a simple way to incorporate the power of parallel processing into commercial software without compromising maintainability, reliability, or ease of use. This gives significant advantages over less powerful non-parallel entries in the market.

  18. High shear treatment of concentrates and drying conditions influence the solubility of milk protein concentrate powders.

    Science.gov (United States)

    Augustin, Mary Ann; Sanguansri, Peerasak; Williams, Roderick; Andrews, Helen

    2012-11-01

    The solubility of milk protein concentrate (MPC) powders was influenced by the method used for preparing the concentrate, drying conditions, and the type of dryer used. Increasing total solids of the ultrafiltered concentrates (23% total solids, TS) by diafiltration to 25% TS or evaporation to 31% TS decreased the solubility of MPC powders (80-83% protein, w/w dry basis), with ultrafiltration followed by evaporation to higher total solids having the greater detrimental effect on solubility. High shear treatment (homogenisation at 350/100 bar, microfluidisation at 800 bar or ultrasonication at 24 kHz, 600 watts) of ultrafiltered and diafiltered milk protein concentrates prior to spray drying increased the nitrogen solubility of MPC powders (82% protein, w/w dry basis). Of the treatments applied, microfluidisation was the most effective for increasing nitrogen solubility of MPC powders after manufacture and during storage. Manufacture of MPC powders (91% protein, w/w dry basis) prepared on two different pilot-scale dryers (single stage or two stage) from milk protein concentrates (20% TS) resulted in powders with different nitrogen solubility and an altered response to the effects of microfluidisation. Microfluidisation (400, 800 and 1200 bar) of the concentrate prior to drying resulted in increased long term solubility of MPC powders that were prepared on a single stage dryer but not those produced on a two stage spray dryer. This work demonstrates that microfluidisation can be used as a physical intervention for improving MPC powder solubility. Interactions between the method of preparation and treatment of concentrate prior to drying, the drying conditions and dryer type all influence MPC solubility characteristics.

  19. High-concentration planar microtracking photovoltaic system exceeding 30% efficiency

    Science.gov (United States)

    Price, Jared S.; Grede, Alex J.; Wang, Baomin; Lipski, Michael V.; Fisher, Brent; Lee, Kyu-Tae; He, Junwen; Brulo, Gregory S.; Ma, Xiaokun; Burroughs, Scott; Rahn, Christopher D.; Nuzzo, Ralph G.; Rogers, John A.; Giebink, Noel C.

    2017-08-01

    Prospects for concentrating photovoltaic (CPV) power are growing as the market increasingly values high power conversion efficiency to leverage now-dominant balance of system and soft costs. This trend is particularly acute for rooftop photovoltaic power, where delivering the high efficiency of traditional CPV in the form factor of a standard rooftop photovoltaic panel could be transformative. Here, we demonstrate a fully automated planar microtracking CPV system solar cell at >660× concentration ratio over a 140∘ full field of view. In outdoor testing over the course of two sunny days, the system operates automatically from sunrise to sunset, outperforming a 17%-efficient commercial silicon solar cell by generating >50% more energy per unit area per day in a direct head-to-head competition. These results support the technical feasibility of planar microtracking CPV to deliver a step change in the efficiency of rooftop solar panels at a commercially relevant concentration ratio.

  20. Concentration measurement of yeast suspensions using high frequency ultrasound backscattering.

    Science.gov (United States)

    Elvira, Luis; Vera, Pedro; Cañadas, Francisco Jesús; Shukla, Shiva Kant; Montero, Francisco

    2016-01-01

    This work proposes the use of an ultrasound based technique to measure the concentration of yeasts in liquid suspension. This measurement was achieved by the detection and quantification of ultrasonic echoes backscattered by the cells. More specifically, the technique was applied to the detection and quantification of Saccharomyces cerevisiae. A theoretical approach was proposed to get the average density and sound speed of the yeasts, which were found to be 1116 kg/m(3) and 1679 m/s, respectively. These parameters were needed to model the waves backscattered by each single cell. A pulse-echo arrangement working around 50 MHz, being able to detect echoes from single yeasts was used to characterize experimentally yeast solutions from 10(2) to 10(7)cells/ml. The Non-negative Matrix Factorization denoising technique was applied for data analysis. This technique required a previous learning of the spectral patterns of the echoes reflected from yeasts in solution and the base noise from the liquid medium. Comparison between pulse correlation (without denoising) and theoretical and experimental pattern learning was made to select the best signal processing. A linear relation between ultrasound output and concentration was obtained with correlation coefficient R(2)=0.996 for the experimental learning. Concentrations from 10(4) to 10(7)cells/ml were detected above the base noise. These results show the viability of using the ultrasound backscattering technique to detect yeasts and measure their concentration in liquid cultures, improving the sensitivity obtained using spectrophotometric methods by one order of magnitude.

  1. Intermodulation Linearity in High-k/Metal Gate 28 nm RF CMOS Transistors

    Directory of Open Access Journals (Sweden)

    Zhen Li

    2015-09-01

    Full Text Available This paper presents experimental characterization, simulation, and Volterra series based analysis of intermodulation linearity on a high-k/metal gate 28 nm RF CMOS technology. A figure-of-merit is proposed to account for both VGS and VDS nonlinearity, and extracted from frequency dependence of measured IIP3. Implications to biasing current and voltage optimization for linearity are discussed.

  2. Beryllium-10 concentrations in water samples of high northern latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Strobl, C.; Eisenhauer, A.; Schulz, V.; Baumann, S.; Mangini, A. [Heidelberger Akademie der Wissenschaften, Heildelberg (Germany); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    {sup 10}Be concentrations in the water column of high northern latitudes were not available so far. We present different {sup 10}Be profiles from the Norwegian-Greenland Sea, the Arctic Ocean, and the Laptev Sea. (author) 3 fig., 3 refs.

  3. Optimization of Scatterer Concentration in High-Gain Scattering Media

    Institute of Scientific and Technical Information of China (English)

    ZHU Jiu-Gao; ZHU He-Yuan; SUN Die-Chi; DU Ge-Guo; LI Fu-Ming

    2001-01-01

    We report the scatterer concentration-dependent behaviour of laser action in high-gain scattering media. Amodified model of a random laser is proposed to explain the experimental results in good agreement. We mayuse this modified model to design and optimize the random laser system. A further detailed model is needed toquantitatively analyse the far-field distribution of random laser action.

  4. [Toxic effects of high concentrations of ammonia on Euglena gracilis].

    Science.gov (United States)

    Liu, Yan; Shi, Xiao-Rong; Cui, Yi-Bin; Li, Mei

    2013-11-01

    Ammonia is among the common contaminants in aquatic environments. The present study aimed at evaluation of the toxicity of ammonia at high concentration by detecting its effects on the growth, pigment contents, antioxidant enzyme activities, and DNA damage (comet assay) of a unicellular microalga, Euglena gracilis. Ammonia restrained the growth of E. gracilis, while at higher concentrations, ammonia showed notable inhibition effect, the growth at 2 000 mg x L(-1) was restrained to 55.7% compared with that of the control; The contents of photosynthetic pigments and protein went up with increasing ammonia dosage and decreased when the ammonia concentration was above 1000 mg x L(-1); In addition, there was an obvious increase in SOD and POD activities, at higher concentration (2 000 mg x L(-1)), activities of SOD and POD increased by 30.7% and 49.4% compared with those of the control, indicating that ammonia could promote activities of antioxidant enzymes in E. gracilis; The degree of DNA damage observed in the comet assay increased with increasing ammonia concentration, which suggested that high dose of ammonia may have potential mutagenicity on E. gracilis.

  5. Quantitation of low concentrations of polysorbates in high protein concentration formulations by solid phase extraction and cobalt-thiocyanate derivatization.

    Science.gov (United States)

    Kim, Justin; Qiu, Jinshu

    2014-01-02

    A spectrophotometric method was developed to quantify low polysorbate (PS) levels in biopharmaceutical formulations containing high protein concentrations. In the method, Oasis HLB solid phase extraction (SPE) cartridge was used to extract PS from high protein concentration formulations. After loading a sample, the cartridge was washed with 4M guanidine HCl and 10% (v/v) methanol, and the retained PS was eluted by acetonitrile. Following the evaporation of acetonitrile, aqueous cobalt-thiocyanate reagent was added to react with the polyoxyethylene oxide chain of polysorbates to form a blue colored PS-cobaltothiocyante complex. This colored complex was then extracted into methylene chloride and measured spectrophotometrically at 620 nm. The method performance was evaluated on three products containing 30-40 mg L(-1) PS-20 and PS-80 in ≤70 g L(-1) protein formulations. The method was specific (no matrix interference identified in three types of protein formulations), sensitive (quantitation limit of 10 mg L(-1) PS) and robust with good precision (relative standard deviation ≤6.4%) and accuracy (spike recoveries from 95% to 101%). The linear range of the method for both PS-20 and PS-80 was 10 to 80 mg L(-1) PS. By diluting samples with 6M guanidine HCl and/or using different methylene chloride volumes to extract the colored complexes of standards and samples, the method could accurately and precisely quantify 40 mg L(-1) PS in up to 300 g L(-1) protein formulations.

  6. Investigation of linear optical absorption coefficients in core-shell quantum dot (QD) luminescent solar concentrators (LSCs)

    Science.gov (United States)

    Ebrahimipour, Bahareh Alsadat; Askari, Hassan Ranjbar; Ramezani, Ali Behjat

    2016-09-01

    The interlevel absorption coefficient of CdSe/ZnS and ZnS/CdSe core-shell Quantum Dot (QD) in luminescent solar concentrators (LSCs) is reported. By considering the quantum confinement effects, the wave functions and eigenenergies of electrons in the nonperturebative system consists of a core-shell QD have been numerically calculated under the frame work of effective-mass approximation by solving a three-dimensional Schrӧdinger equation. And then the absorption coefficient is obtained under density matrix approximation considering in the polymer sheets of the concentrator including the core-shell QDs. The effect of the hetero-structure geometry upon the energy spectrum and absorption coefficient associated to interlevel transitions was also considered. The results show that the core-shell QDs can absorb the photons with higher energy in solar spectrum as compared to the inverted core-shell. And with a small shell layer diameter, the core-shell QDs produce larger linear absorption coefficients and consequently higher efficiency values, however it is inversed for inverted core-shell QDs. The work described here gives a detailed insight into the promise of QD-based LSCs and the optoelectronic devices applications.

  7. Sorption-desorption kinetics and toxic cell concentration in marine phytoplankton microalgae exposed to Linear Alkylbenzene Sulfonate.

    Science.gov (United States)

    Renaud, Florent; Oberhänsli, François; Teyssié, Jean-Louis; Miramand, Pierre; Temara, Ali; Warnau, Michel

    2011-05-01

    Linear Alkylbenzene Sulfonates (LAS) are ubiquitous surfactants. Traces can be found in coastal environments. Sorption and toxicity of C(12)-LAS congeners were studied in controlled conditions (2-3500 μg C(12)LAS/L) in five marine phytoplanktonic species, using standardized methods. IC(50) values ranged from 0.5 to 2 mg LAS/L. Sorption of (14)C(12)-6 LAS isomer was measured at environmentally relevant trace levels (4μg/L) using liquid scintillation counting. Steady-state sorption on algae was reached within 5h in the order dinoflagellate>diatoms>green algae. The sorption data, fitted a L-type Freundlich isotherm, indicating saturation. Desorption was rapid but a low LAS fraction was still sorbed after 24h. Toxic cell concentration was 0.38±0.09 mg/g for the studied species. LAS toxicity results from sorption on biological membranes leading to non-specific disturbance of algal growth. Results indicate that LAS concentrations in coastal environments do not represent a risk for these organisms.

  8. High-efficiency organic solar concentrators for photovoltaics.

    Science.gov (United States)

    Currie, Michael J; Mapel, Jonathan K; Heidel, Timothy D; Goffri, Shalom; Baldo, Marc A

    2008-07-11

    The cost of photovoltaic power can be reduced with organic solar concentrators. These are planar waveguides with a thin-film organic coating on the face and inorganic solar cells attached to the edges. Light is absorbed by the coating and reemitted into waveguide modes for collection by the solar cells. We report single- and tandem-waveguide organic solar concentrators with quantum efficiencies exceeding 50% and projected power conversion efficiencies as high as 6.8%. The exploitation of near-field energy transfer, solid-state solvation, and phosphorescence enables 10-fold increases in the power obtained from photovoltaic cells, without the need for solar tracking.

  9. Bioleaching of marmatite in high concentration of iron

    Institute of Scientific and Technical Information of China (English)

    邱冠周; 吴伯增; 覃文庆; 蓝卓越

    2002-01-01

    Bioleaching of marmatite with a culture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans in high concentration of iron was studied, the results show that the zinc leaching rate of the mixed culture is faster than that of the sole Thiobacillus ferrooxidans, the increasing iron concentration in leaching solution enhances the zinc leaching rate. The SEM analysis indicates that the chemical leaching residues is covered with porous solid layer of elemental sulfur, while elemental sulfur is not found in the bacterial leaching residues. The primary role of bacteria in bioleaching of sphalerite is to oxidize the chemical leaching products of ferrous ion and elemental sulfur, thus the indirect mechanism prevails in the bioleaching of marmatite.

  10. High concentration of calcium ions in Golgi apparatus

    Institute of Scientific and Technical Information of China (English)

    XUESHAOBAI; M.ROBERTNICOUD; 等

    1994-01-01

    The interphase NIH3T3 cells were vitally fluorescentstained with calcium indicator fluo-3 and Glogi probe C6-NBD-ceramide,and then the single cells were examined by laser scanning confocal microscopy(LSCFM) for subcellular distributions of Ca2+ and the location of Golgi apparatus.In these cells,the intracellular Ca2+ were found to be highly concentrated in the Golgi apparatus.The changes of distribution of cytosolic high Ca2+ region and the Golgi apparatus coincided with the cell cycle phase.In calcium free medium,when the plasma membrane of the cells which had been loaded with fluo-3/AM were permeated by digitonin,the fluorescence of the Golgi region decreased far less than that of the cytosol.Our results indicated that the Glogi lumen retained significantly high concentration of free calcium.

  11. Review of silicon solar cells for high concentrations

    Science.gov (United States)

    Schwartz, R. J.

    1982-06-01

    The factors that limit the performance of high concentration silicon solar cells are reviewed. The design of a conventional high concentration cell is discussed, together with the present state of the art. Unconventional cell designs that have been proposed to overcome the limitations of the conventional design are reviewed and compared. The current status of unconventional cells is reviewed. Among the unconventional cells discussed are the interdigitated back-contact cell, the double-sided cell, the polka dot cell, and the V-groove cell. It is noted that all the designs for unconventional cells require long diffusion lengths for high efficiency operation, even though the demands in this respect are less for those cells with the optical path longer than the diffusion path.

  12. High-order harmonic generation driven by chirped laser pulses induced by linear and non linear phenomena

    CERN Document Server

    Neyra, E; Pérez-Hernández, J A; Ciappina, M F; Roso, L; Torchia, G A

    2016-01-01

    We present a theoretical study of high-order harmonic generation (HHG) driven by ultrashort optical pulses with different kind of chirps. The goal of the present work is perform a detailed study to clarify the relevant parameters in the chirped pulses to achieve a noticeable cut-off extensions in HHG. These chirped pulses are generated using both linear and nonlinear dispersive media.The description of the origin of the physical mechanisms responsible of this extension is, however, not usually reported with enough detail in the literature. The study of the behaviour of the harmonic cut-off with these kind of pulses is carried out in the classical context, by the integration of the Newton-Lorentz equation complemented with the quantum approach, based on the integration of the time dependent Schr\\"odinger equation in full dimensions (TDSE-3D), we are able to understand the underlying physics.

  13. Water-to-air transfer of branched and linear PFOA: Influence of pH, concentration and water type

    Directory of Open Access Journals (Sweden)

    Jana H. Johansson

    2017-03-01

    Full Text Available The volatilisation of perfluorooctanoic acid (PFOA was measured experimentally at a range of pH values using a previously published laboratory method. Water-to-air transfer was studied for five structural isomers, namely: the linear isomer (n-PFOA and the four most commonly occurring branched isomers (3-, 4-, 5- and 6-PFOA. The influence of water concentration and water type on the pH-dependent water-to-air transfer was also investigated for n-PFOA. The water-to-air transfer was studied over the course of 48 h at pH values ranging from 0.2 to 5.5. Under all experimental conditions tested, the volatilisation of PFOA was negligible at pH > 2.5. In experiments performed with MilliQ water, volatilisation increased with decreasing water pH. In experiments performed with tap water and lake water, maximum volatilisation was observed at pH 1. The concentration of PFOA in water had no influence on the pH value at which water-to-air transfer was observed (i.e. at pH < 2.5 for the concentration range tested (0.1–50 μg/L PFOA in deionised water. Although the percentage of PFOA volatilised was significantly different for the four branched isomers at low pH, volatilisation was not observed above pH 2.5 for any branched isomer suggesting that all PFOA isomers have a low pKa. Overall, these laboratory results demonstrate that volatilisation of any structural isomer of PFOA from water is negligible at environmentally-relevant conditions. It is unlikely that PFOA isomers will be fractionated in the environment as a result of volatilisation because it is a process of negligible environmental relevance.

  14. Design of a linear detector array unit for high energy x-ray helical computed tomography and linear scanner

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Tae; Park, Jong Hwan; Kim, Gi Yoon [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of); Kim, Dong Geun [Medical Imaging Department, ASTEL Inc., Seongnam (Korea, Republic of); Park, Shin Woong; Yi, Yun [Dept. of Electronics and Information Eng, Korea University, Seoul (Korea, Republic of); Kim, Hyun Duk [Research Center, Luvantix ADM Co., Ltd., Daejeon (Korea, Republic of)

    2016-11-15

    A linear detector array unit (LdAu) was proposed and designed for the high energy X-ray 2-d and 3-d imaging systems for industrial non-destructive test. Specially for 3-d imaging, a helical CT with a 15 MeV linear accelerator and a curved detector is proposed. the arc-shape detector can be formed by many LdAus all of which are arranged to face the focal spot when the source-to-detector distance is fixed depending on the application. An LdAu is composed of 10 modules and each module has 48 channels of CdWO{sub 4} (CWO) blocks and Si PIn photodiodes with 0.4 mm pitch. this modular design was made for easy manufacturing and maintenance. through the Monte carlo simulation, the CWO detector thickness of 17 mm was optimally determined. the silicon PIn photodiodes were designed as 48 channel arrays and fabricated with NTD (neutron transmutation doping) wafers of high resistivity and showed excellent leakage current properties below 1 nA at 10 V reverse bias. to minimize the low-voltage breakdown, the edges of the active layer and the guard ring were designed as a curved shape. the data acquisition system was also designed and fabricated as three independent functional boards; a sensor board, a capture board and a communication board to a Pc. this paper describes the design of the detectors (CWO blocks and Si PIn photodiodes) and the 3-board data acquisition system with their simulation results.

  15. Multiwavelength fiber lasers based on spatial mode beating for high resolution linear and angular displacement sensing

    Science.gov (United States)

    Chen, Nan-Kuang; Chang, Yung-Hsiang; Cheng, Wood-Hi; Guo, Tuan; Guan, Bai-Ou

    2014-05-01

    We demonstrate multiwavelength fiber lasers by incorporating the micro Michelson interferometer with spatial mode beating phenomenon, which comes from the interferences among cladding modes, into ring cavity for high resolution linear and angular displacement sensing.

  16. Decomposition of high concentration SF6 using an electron beam

    Science.gov (United States)

    Son, Youn-Suk; Lee, Sung-Joo; Choi, Chang Yong; Park, Jun-Hyeong; Kim, Tak-Hyun; Jung, In-Ha

    2016-07-01

    In this study, high concentration SF6 (2-10%) was decomposed using an electron beam irradiation. Various influential factors were investigated to improve the destruction and removal efficiency (DRE) of SF6. The initial concentrations of SF6, absorbed doses, SF6/H2 ratios and retention times were the main factors of concern. As a result, the DRE increased as the adsorbed dose and retention time increased. The DRE of SF6 also increased up to 20% approximately when H2 was added to the reaction mixture. On the other hand, the DRE of SF6 decreased as initial concentrations of SF6 increased. Finally, the main by-product formed from SF6 decomposition by the electron beam was HF.

  17. Life at high salt concentrations, intracellular KCl concentrations, and acidic proteomes

    Directory of Open Access Journals (Sweden)

    Aharon eOren

    2013-11-01

    Full Text Available Extremely halophilic microorganisms that accumulate KCl for osmotic balance (the Halobacteriaceae, Salinibacter have a large excess of acidic amino acids in their proteins. This minireview explores the occurrence of acidic proteomes in halophiles of different physiology and phylogenetic affiliation. For fermentative bacteria of the order Halanaerobiales, known to accumulate KCl, an acidic proteome was predicted. However, this is not confirmed by genome analysis. The reported excess of acidic amino acids is due to a high content of Gln and Asn, which yield Glu and Asp upon acid hydrolysis. The closely related Halorhodospira halophila and Halorhodospira halochloris use different strategies to cope with high salt. The first has an acidic proteome and accumulates high KCl concentrations at high salt concentrations; the second does not accumulate KCl and lacks an acidic proteome. Acidic proteomes can be predicted from the genomes of some moderately halophilic aerobes that accumulate organic osmotic solutes (Halomonas elongata, Chromohalobacter salexigens and some marine bacteria. Based on the information on cultured species it is possible to understand the pI profiles predicted from metagenomic data from hypersaline environments.

  18. High Voltage Solar Concentrator Experiment with Implications for Future Space Missions - S6a-35

    Science.gov (United States)

    George, I. S. Mehdi P. J.; O'Neill, M.; Matson, R.; Borckschmidt, A.

    2004-12-01

    This paper describes the design, development, fabrication, and test of a high performance, high voltage solar concentrator array. This assembly is believed to be the first ever terrestrial triple-junction-cell solar array rated at over 1 kW. The concentrator provides over 200 W/square meter power output at a nominal 600 Vdc while operating under terrestrial sunlight. Space-quality materials and fabrication techniques were used for the array, and the 3005-meter elevation installation below the Tropic of Cancer allowed testing as close as possible to space deployment without an actual launch. The array includes two concentrator modules, each with a 3 square meter aperture area. Each concentrator module uses a linear Fresnel lens to focus sunlight onto a photovoltaic receiver that uses 240 series-connected triple-junction solar cells. Operation of the two receivers in series can provide 1200 Vdc which would be adequate for the "direct drive" of some ion engines or microwave transmitters in space. Lens aperture width is 84 cm and the cell active width is 3.2 cm, corresponding to a geometric concentration ratio of 26X. The evaluation includes the concentrator modules, the solar cells, and the materials and techniques used to attach the solar cells to the receiver heat sink. For terrestrial applications, a finned aluminum extrusion was used for the heat sink for the solar cells, maintaining a low cell temperature so that solar cell efficiency remains high.

  19. Biodegradation studies of oil sludge containing high hydrocarbons concentration

    Energy Technology Data Exchange (ETDEWEB)

    Olguin-Lora, P.; Munoz-Colunga, A.; Castorena-Cortes, G.; Roldan-Carrillo, T.; Quej Ake, L.; Reyes-Avila, J.; Zapata-Penasco, I.; Marin-Cruz, J.

    2009-07-01

    Oil industry has a significant impact on environment due to the emission of, dust, gases, waste water and solids generated during oil production all the way to basic petrochemical product manufacturing stages. the aim of this work was to evaluate the biodegradation of sludge containing high hydrocarbon concentration originated by a petroleum facility. A sludge sampling was done at the oil residuals pool (ORP) on a gas processing center. (Author)

  20. Particle sedimentation monitoring in high-concentration slurries

    Science.gov (United States)

    Nagasawa, Yoshihiro; Kato, Zenji; Tanaka, Satoshi

    2016-11-01

    In this study, the sedimentation states of particles in high-concentration slurries were elucidated by monitoring their internal states. We prepared transparent high-concentration silica slurries by adjusting the refractive index of the aqueous glycerol liquid in which the particles were dispersed to match that of the silica particles. In addition, a fluorescent dye was dissolved in the liquid. Then, we directly observed the individual and flocculated particles in the slurries during sedimentation by confocal laser scanning fluorescent microscopy. The particles were found to sediment very slowly while exhibiting fluctuating motion. The particle sedimentation rate in the high-concentration slurry with the aqueous glycerol solution (η =0.068 Pa. s ) and a particle volume fraction on the order of 0.3 was determined to be 1.58 ± 0.66 μ m. min-1 on the basis of the obtained image sequences for 24.9 h. In-situ observation provides a large amount of information about the sedimentation behavior of particles in condensed matter.

  1. Improved Dispersion of Carbon Nanotubes in Polymers at High Concentrations

    Science.gov (United States)

    Liu, Chao-Xuan; Choi, Jin-Woo

    2012-01-01

    The polymer nanocomposite used in this work comprises elastomer poly(dimethylsiloxane) (PDMS) as a polymer matrix and multi-walled carbon nanotubes (MWCNTs) as a conductive nanofiller. To achieve uniform distribution of carbon nanotubes within the polymer, an optimized dispersion process was developed, featuring a strong organic solvent—chloroform, which dissolved PDMS base polymer easily and allowed high quality dispersion of MWCNTs. At concentrations as high as 9 wt.%, MWCNTs were dispersed uniformly through the polymer matrix, which presented a major improvement over prior techniques. The dispersion procedure was optimized via extended experimentation, which is discussed in detail. PMID:28348312

  2. Feasibility Study on High Concentrating Photovoltaic Power Towers

    Science.gov (United States)

    Frohberger, Dirk; Jaus, Joachim; Wiesenfarth, Maike; Schramek, Philipp; Bett, Andreas W.

    2010-10-01

    This paper presents an analysis on the concept of high concentrating PV power towers. A feasibility study is conducted in order to evaluate the future potential of this technology. Objective of the analysis is to provide an improved basis for establishing research and development priorities for the PV power tower concept. Performance assessments and cost calculations for a 1 MW prototype PV tower power are derived. Based on the assumption of a highly homogeneously illuminated receiver, levelized costs of electricity of 0.29 €/kWh have been calculated for a prototype PV tower power.

  3. Effects of high nitrogen concentrations on the growth of submersed macrophytes at moderate phosphorus concentrations.

    Science.gov (United States)

    Yu, Qing; Wang, Hong-Zhu; Li, Yan; Shao, Jian-Chun; Liang, Xiao-Min; Jeppesen, Erik; Wang, Hai-Jun

    2015-10-15

    Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth.

  4. Vitamin E Concentrations in Adults with HIV/AIDS on Highly Active Antiretroviral Therapy

    Directory of Open Access Journals (Sweden)

    Daniella J. Itinoseki Kaio

    2014-09-01

    Full Text Available HIV/AIDS patients are probably more predisposed to vitamin E deficiency, considering that they are more exposed to oxidative stress. Additionally, there are an extensive number of drugs in the highly active antiretroviral therapy (HAART regimens that may interfere with vitamin E concentrations. The objective of this study was to compare serum concentrations of alpha-tocopherol in 182 HIV/AIDS patients receiving different HAART regimens. The patients were divided into three groups according to regimen: nucleoside analog reverse-transcriptase inhibitors (NRTIs + non-nucleoside analog reverse-transcriptase inhibitors (NNRTIs; NRTIs + protease inhibitors + ritonavir; NRTIs + other classes. Alpha-tocopherol was assessed by high-performance liquid chromatography. Multiple linear regression analysis was used to evaluate the effects of HAART regimen, time of use, and compliance with the regimen on alpha-tocopherol concentrations. Alpha-tocopherol concentrations were on average 4.12 μmol/L lower for the NRTIs + other classes regimen when compared to the NRTIs + NNRTIs regimen (p = 0.037. A positive association (p < 0.001 was observed between alpha-tocopherol and cholesterol concentrations, a finding due, in part, to the relationship between liposoluble vitamins and lipid profile. This study demonstrated differences in alpha-tocopherol concentrations between patients using different HAART regimens, especially regimens involving the use of new drugs. Long-term prospective cohort studies are needed to monitor vitamin E status in HIV/AIDS patients since the beginning of treatment.

  5. Wet oxidation of real coke wastewater containing high thiocyanate concentration.

    Science.gov (United States)

    Oulego, Paula; Collado, Sergio; Garrido, Laura; Laca, Adriana; Rendueles, Manuel; Díaz, Mario

    2014-01-01

    Coke wastewaters, in particular those with high thiocyanate concentrations, represent an important environmental problem because of their very low biodegradability. In this work, the treatment by wet oxidation of real coke wastewaters containing concentrations of thiocyanate above 17 mM has been studied in a 1-L semi-batch reactor at temperatures between 453 and 493 K, with total oxygen pressures in the range of 2.0-8.0 MPa. A positive effect of the matrix of real coke wastewater was observed, resulting in faster thiocyanate degradation than was obtained with synthetic wastewaters. Besides, the effect of oxygen concentration and temperature on thiocyanate wet oxidation was more noticeable in real effluents than in synthetic wastewaters containing only thiocyanate. It was also observed that the degree of mineralization of the matrix organic compounds was higher when the initial thiocyanate concentration increased. Taking into account the experimental data, kinetic models were obtained, and a mechanism implying free radicals was proposed for thiocyanate oxidation in the matrix considered. In all cases, sulphate, carbonates and ammonium were identified as the main reaction products of thiocyanate wet oxidation.

  6. High harmonic generation with fully tunable polarization by train of linearly polarized pulses

    Science.gov (United States)

    Neufeld, Ofer; Bordo, Eliyahu; Fleischer, Avner; Cohen, Oren

    2017-02-01

    We propose and demonstrate, analytically and numerically, a scheme for generation of high-order harmonics with fully tunable polarization, from circular through elliptic to linear, while barely changing the other properties of the high harmonic radiation and where the ellipticity values of all the harmonic orders essentially coincide. The high harmonics are driven by a train of quasi-monochromatic linearly polarized pulses that are identical except for their polarization angles, which is the tuning knob. This system gives rise to full control over the polarization of the harmonics while largely preserving the single-cycle, single-atom and macroscopic physics of ‘ordinary’ high harmonic generation, where both the driver and high harmonics are linearly polarized.

  7. Strategies for the production of high concentrations of bioethanol from seaweeds: production of high concentrations of bioethanol from seaweeds.

    Science.gov (United States)

    Yanagisawa, Mitsunori; Kawai, Shigeyuki; Murata, Kousaku

    2013-01-01

    Bioethanol has attracted attention as an alternative to petroleum-derived fuel. Seaweeds have been proposed as some of the most promising raw materials for bioethanol production because they have several advantages over lignocellulosic biomass. However, because seaweeds contain low contents of glucans, i.e., polysaccharides composed of glucose, the conversion of only the glucans from seaweed is not sufficient to produce high concentrations of ethanol. Therefore, it is also necessary to produce ethanol from other specific carbohydrate components of seaweeds, including sulfated polysaccharides, mannitol, alginate, agar and carrageenan. This review summarizes the current state of research on the production of ethanol from seaweed carbohydrates for which the conversion of carbohydrates to sugars is a key step and makes comparisons with the production of ethanol from lignocellulosic biomass. This review provides valuable information necessary for the production of high concentrations of ethanol from seaweeds.

  8. Preconditioning Schur Complement Systems of Highly-Indefinite Linear Systems for a Parallel Hybrid Solve

    Institute of Scientific and Technical Information of China (English)

    I.Yamazaki; X.S.Li; E.G.Ng

    2010-01-01

    A parallel hybrid linear solver based on the Schur complement method has the potential to balance the robustness of direct solvers with the efficiency of precon-ditioned iterative solvers. However, when solving large-scale highly-indefinite linear systems, this hybrid solver often suffers from either slow convergence or large memory requirements to solve the Schur complement systems. To overcome this challenge, we in this paper discuss techniques to preprocess the Schur complement systems in paral-lel. Numerical results of solving large-scale highly-indefinite linear systems from various applications demonstrate that these techniques improve the reliability and performance of the hybrid solver and enable efficient solutions of these linear systems on hundreds of processors, which was previously infeasible using existing state-of-the-art solvers.

  9. Chronic Diarrhea Associated with High Teriflunomide Blood Concentration

    OpenAIRE

    Duquette, André; Frenette, Anne Julie; Doré, Maxime

    2016-01-01

    Objective To report the case of a patient treated with leflunomide that presented with chronic diarrhea associated with high teriflunomide blood concentration. Case Summary An 84-year-old woman taking leflunomide 20 mg once daily for the past 2 years to treat rheumatoid arthritis (RA) was investigated for severe chronic diarrhea that had been worsening for the past 5 months. The patient’s general condition progressively deteriorated and included electrolyte imbalances and a transient loss of ...

  10. Effect of high soil copper concentration on mycorrhizal grapevines

    Science.gov (United States)

    Nogales, Amaia; Santos, Erika S.; Viegas, Wanda; Aran, Diego; Pereira, Sofia H.; Vidigal, Patricia; Lopes, Carlos M.; Abreu, M. Manuela

    2017-04-01

    Repeated application of Copper (Cu) based fungicides in vineyards since the end of the 19th century has led to a significant increase in the concentration of this chemical element in many viticultural soils. Although Cu is an essential micronutrient for most organisms, it can be toxic for the development and survival of plants and soil (micro)organisms at high concentrations and eventually lead to yield loses in viticulture, as it negatively affects key physiological and biogeochemical processes. However, some soil microorganisms, including arbuscular mycorrhizal fungi (AMF), have developed adaptive mechanisms for persistence in environments with supra-optimal levels of essential elements or in the presence of harmful ones, as well as for increasing plant tolerance to such abiotic stress conditions. The objective of this work was to evaluate the effect of a high total soil concentration of Cu on microbial soil activity as well as on the development of mycorrhizal and non-mycorrhizal grapevines. A microcosm assay was set up under greenhouse and controlled conditions. Touriga Nacional grapevine variety plants grafted onto 1103P rootstocks were inoculated either with the AMF Rhizophagus irregularis or Funneliformis mosseae, or were left as non-inoculated controls. After three months, they were transplanted to containers filled with 4 kg of a sandy soil (pH: 7.0; electrical conductivity: 0.08 mS/cm; [organic C]: 5.6 g/kg; [N-NO3]: 1.1 mg/kg; [N-NH4]: 2.5 mg/kg; [extractable K]: 45.1 mg/kg; [extractable P]: 52.3 mg/kg), collected near to a vineyard in Pegões (Portugal). Two treatments were carried out: with and without Cu application. The soil with high Cu concentration was prepared by adding 300 mg Cu/kg (in the form of an aqueous solution of CuSO4·5H2O) followed by an incubation during four weeks in plastic bags at room temperature in dark. Physico-chemical soil characteristics (pH, electrical conductivity and nutrients concentration in available fraction), soil

  11. Stabilization of sandwich non-linear systems with low-and-high gain feedback design

    NARCIS (Netherlands)

    Stoorvogel, Anton A.; Wang, Xu; Saberi, Ali; Sannuti, Peddapullaiah

    2010-01-01

    In this paper, we consider the problems of semi- global and global internal stabilization of a class of sandwich systems consisting of two linear systems with a saturation element in between. We develop here low-and-high gain and scheduled low-and-high gain state feedback design methodolo- gies to s

  12. Characterization of Radiation Hardened Bipolar Linear Devices for High Total Dose Missions

    Science.gov (United States)

    McClure, Steven S.; Harris, Richard D.; Rax, Bernard G.; Thorbourn, Dennis O.

    2012-01-01

    Radiation hardened linear devices are characterized for performance in combined total dose and displacement damage environments for a mission scenario with a high radiation level. Performance at low and high dose rate for both biased and unbiased conditions is compared and the impact to hardness assurance methodology is discussed.

  13. Particulate Matter Concentrations in East Oakland's High Street Corridor

    Science.gov (United States)

    Lei, P.; Jackson, J.; Lewis, R.; Marigny, A.; Mitchell, J. D.; Nguyen, R.; Philips, B.; Randle, D.; Romero, D.; Spears, D.; Telles, C.; Weissman, D.

    2012-12-01

    Particulate matter (PM) is a complex mixture of small solid pieces and/or liquid droplets in the air. High concentrations of PM can pose a serious health hazard because inhalation can result in breathing problems and/or aggravate asthma. Long term exposure can increase the likelihood of respiratory problems like asthma and emphysema as well as cancer. The smaller the particles, the deeper they can get into the respiratory system. For this reason, the smallest particles, those smaller than 2.5 micrometers in diameter (PM2.5), are the most dangerous. PM2.5 is largely emitted from motor vehicles burning fuels that don't break down fully. Our research team investigated the levels of PM2.5 as well as particles smaller than 10 micrometers (PM10) and total suspended particulate (TSP) along the northeast-southwest trending High Street Corridor, near Fremont High School in East Oakland, California. Using the Aerocet 531 mass particle counter, team members walked through neighborhoods and along major roads within a 1 mile radius of Fremont High School. The Aerocet 531 recorded two minute average measurements of all the relevant PM sizes, which are reported in mg/m3. Measurements were consistently taken in the morning, between 8:30 and 11:30 am. Preliminary results indicate maximum readings of all PM sizes at sites that are in close proximity to a major freeway (Interstate-880). These results support our initial hypothesis that proximity to major roads and freeways, especially those with high diesel-fuel burning truck traffic, would be the primary factor affecting PM concentration levels. Preliminary median and maximum readings all suggest particulate matter levels below what the EPA would consider unhealthy or risky.

  14. LAPACK++: A design overview of object-oriented extensions for high performance linear algebra

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J.J. [Oak Ridge National Lab., TN (United States). Mathematical Sciences Section]|[Univ. of Tennessee, Knoxville, TN (United States). Computer Science Dept.; Pozo, R. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Computer Science; Walker, D.W. [Oak Ridge National Lab., TN (United States). Mathematical Sciences Section

    1993-12-31

    LAPACK++ is an object-oriented C++ extension of the LAPACK (Linear Algebra PACKage) library for solving the common problems of numerical linear algebra: linear systems, linear least squares, and eigenvalue problems on high-performance computer architectures. The advantages of an object-oriented approach include the ability to encapsule various matrix representations, hide their implementation details, reduce the number of subroutines, simplify their calling sequences, and provide an extendible software framework that can incorporate future extensions of LAPACK such as ScaLAPACK++ for distributed memory architectures. The authors present an overview of the object-oriented design of the matrix and decomposition classes in C++ and discuss its impact on elegance, generality, and performance.

  15. LAPACK++: A design overview of object-oriented extensions for high performance linear algebra

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J.J. [Oak Ridge National Lab., TN (United States). Mathematical Sciences Section]|[Univ. of Tennessee, Knoxville (United States). Dept. of Computer Science; Pozo, R. [Univ. of Tennessee, Knoxville (United States). Dept. of Computer Science; Walker, D.W. [Oak Ridge National Lab., TN (United States). Mathematical Sciences Section

    1993-12-31

    LAPACK++ is an object-oriented C++ extension of the LAPACK (Linear Algebra PACKage) library for solving the common problems of numerical linear algebra: linear systems, linear least squares, and eigenvalue problems on high-performance computer architectures. The advantages of an object-oriented approach include the ability to encapsulate various matrix representations, hide their implementation details, reduce the number of subroutines, simplify their calling sequences, and provide an extendible software framework that can incorporate future extensions of LAPACK, such as ScaLAPACK++ for distributed memory architectures. The authors present an overview of the object-oriented design of the matrix and decomposition classes in C++ and discuss its impact on elegance, generality, and performance.

  16. High manganese concentrations in rocks at Gale crater, Mars

    Science.gov (United States)

    Lanza, Nina L.; Fischer, Woodward W.; Wiens, Roger C.; Grotzinger, John; Ollila, Ann M.; Anderson, Ryan B.; Clark, Benton C.; Gellert, Ralf; Mangold, Nicolas; Maurice, Sylvestre; Le Mouélic, Stéphane; Nachon, Marion; Schmidt, Mariek E.; Berger, Jeffrey; Clegg, Samuel M.; Forni, Olivier; Hardgrove, Craig; Melikechi, Noureddine; Newsom, Horton E.; Sautter, Violaine

    2014-01-01

    The surface of Mars has long been considered a relatively oxidizing environment, an idea supported by the abundance of ferric iron phases observed there. However, compared to iron, manganese is sensitive only to high redox potential oxidants, and when concentrated in rocks, it provides a more specific redox indicator of aqueous environments. Observations from the ChemCam instrument on the Curiosity rover indicate abundances of manganese in and on some rock targets that are 1–2 orders of magnitude higher than previously observed on Mars, suggesting the presence of an as-yet unidentified manganese-rich phase. These results show that the Martian surface has at some point in time hosted much more highly oxidizing conditions than has previously been recognized.

  17. Shock initiation studies on high concentration hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Sheffield, Stephen A [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Stahl, David B [Los Alamos National Laboratory; Gibson, L. Lee [Los Alamos National Laboratory; Bartram, Brian D. [Los Alamos National Laboratory

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  18. Shock initiation studies on high concentration hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Sheffield, Stephen A [Los Alamos National Laboratory; Dattelbaum, Dana M [Los Alamos National Laboratory; Stahl, David B [Los Alamos National Laboratory; Gibson, L. Lee [Los Alamos National Laboratory; Bartram, Brian D. [Los Alamos National Laboratory

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  19. Performance Testing of a High Temperature Linear Alternator for Stirling Convertors

    Science.gov (United States)

    Metscher, Jonathan F.; Geng, Steven M.

    2016-01-01

    The NASA Glenn Research Center has conducted performance testing of a high temperature linear alternator (HTLA) in support of Stirling power convertor development for potential future Radioisotope Power Systems (RPS). The high temperature linear alternator is a modified version of that used in Sunpower's Advanced Stirling Convertor (ASC), and is capable of operation at temperatures up to 200 deg. Increasing the temperature capability of the linear alternator could expand the mission set of future Stirling RPS designs. High temperature Neodymium-Iron-Boron (Nd-Fe-B) magnets were selected for the HTLA application, and were fully characterized and tested prior to use. Higher temperature epoxy for alternator assembly was also selected and tested for thermal stability and strength. A characterization test was performed on the HTLA to measure its performance at various amplitudes, loads, and temperatures. HTLA endurance testing at 200 deg is currently underway.

  20. High nitrogen supply and carbohydrate content reduce fungal endophyte and alkaloid concentration in Lolium perenne.

    Science.gov (United States)

    Rasmussen, Susanne; Parsons, Anthony J; Bassett, Shalome; Christensen, Michael J; Hume, David E; Johnson, Linda J; Johnson, Richard D; Simpson, Wayne R; Stacke, Christina; Voisey, Christine R; Xue, Hong; Newman, Jonathan A

    2007-01-01

    The relationship between cool-season grasses and fungal endophytes is widely regarded as mutualistic, but there is growing uncertainty about whether changes in resource supply and environment benefit both organisms to a similar extent. Here, we infected two perennial ryegrass (Lolium perenne) cultivars (AberDove, Fennema) that differ in carbohydrate content with three strains of Neotyphodium lolii (AR1, AR37, common strain) that differ intrinsically in alkaloid profile. We grew endophyte-free and infected plants under high and low nitrogen (N) supply and used quantitative PCR (qPCR) to estimate endophyte concentrations in harvested leaf tissues. Endophyte concentration was reduced by 40% under high N supply, and by 50% in the higher sugar cultivar. These two effects were additive (together resulting in 75% reduction). Alkaloid production was also reduced under both increased N supply and high sugar cultivar, and for three of the four alkaloids quantified, concentrations were linearly related to endophyte concentration. The results stress the need for wider quantification of fungal endophytes in the grassland-foliar endophyte context, and have implications for how introducing new cultivars, novel endophytes or increasing N inputs affect the role of endophytes in grassland ecosystems.

  1. Source identification of high glyme concentrations in the Oder River.

    Science.gov (United States)

    Stepien, D K; Püttmann, W

    2014-05-01

    The objective of the following study was to identify the source of high concentrations of glycol diethers (diglyme, triglyme, and tetraglyme) in the Oder River. Altogether four sampling campaigns were conducted and over 50 surface samples collected. During the first two samplings of the Oder River in the Oderbruch region (km 626-690), glymes were detected at concentrations reaching 0.065 μg L(-1) (diglyme), 0.54 μg L(-1) (triglyme) and 1.7 μg L(-1) (tetraglyme). The subsequent sampling of the Oder River, from the area close to the source to the Poland-Germany border (about 500 km) helped to identify the possible area of the dominating glyme entry into the river between km 310 and km 331. During that sampling, the maximum concentration of triglyme was 0.46 μg L(-1) and tetraglyme 2.2 μg L(-1); diglyme was not detected. The final sampling focused on the previously identified area of glyme entry, as well as on tributaries of the Oder River. Samples from Czarna Woda stream and Kaczawa River contained even higher concentrations of diglyme, triglyme, and tetraglyme, reaching 5.2 μg L(-1), 13 μg L(-1) and 81 μg L(-1), respectively. Finally, three water samples were analyzed from a wastewater treatment plant receiving influents from a Copper Smelter and Refinery; diglyme, triglyme, and tetraglyme were present at a maximum concentration of 1700 μg L(-1), 13,000 μg L(-1), and 190,000 μg L(-1), respectively. Further research helped to identify the source of glymes in the wastewater. The gas desulfurization process Solinox uses a mixture of glymes (Genosorb(®)1900) as a physical absorption medium to remove sulfur dioxide from off-gases from the power plant. The wastewater generated from the process and from the maintenance of the equipment is initially directed to the wastewater treatment plant where it undergoes mechanical and chemical treatment processes before being discharged to the tributaries of the Oder River. Although monoglyme was

  2. Liquid chromatography-electrospray linear ion trap mass spectrometry analysis of targeted neuropeptides in Tac1(-/-) mouse spinal cords reveals significant lower concentration of opioid peptides.

    Science.gov (United States)

    Saidi, Mouna; Beaudry, Francis

    2015-08-01

    Tachykinin and opioid peptides play a central role in pain transmission, modulation and inhibition. The treatment of pain is very important in medicine and many studies using NK1 receptor antagonists failed to show significant analgesic effects in humans. Recent investigations suggest that both pronociceptive tachykinins and the analgesic opioid systems are important for normal pain sensation. The analysis of opioid peptides in Tac1(-/-) spinal cord tissues offers a great opportunity to verify the influence of the tachykinin system on specific opioid peptides. The objectives of this study were to develop an HPLC-MS/MRM assay to quantify targeted peptides in spinal cord tissues. Secondly, we wanted to verify if the Tac1(-/-) mouse endogenous opioid system is hampered and therefore affects significantly the pain modulatory pathways. Targeted neuropeptides were analyzed by high performance liquid chromatography linear ion trap mass spectrometry. Our results reveal that EM-2, Leu-Enk and Dyn A were down-regulated in Tac1(-/-) spinal cord tissues. Interestingly, Dyn A was almost 3 fold down-regulated (p<0.0001). No significant concentration differences were observed in mouse Tac1(-/-) spinal cords for Met-Enk and CGRP. The analysis of Tac1(-/-) mouse spinal cords revealed noteworthy decreases of EM-2, Leu-Enk and Dyn A concentrations which strongly suggest a significant impact on the endogenous pain-relieving mechanisms. These observations may have insightful impact on future analgesic drug developments and therapeutic strategies.

  3. Effects of high concentrations of dietary crude glycerin on dairy cow productivity and milk quality.

    Science.gov (United States)

    Ezequiel, J M B; Sancanari, J B D; Machado Neto, O R; da Silva, Z F; Almeida, M T C; Silva, D A V; van Cleef, F O S; van Cleef, E H C B

    2015-11-01

    An increasing worldwide interest in alternative fuel sources and in a more diversified energy matrix has provided incentives for the biodiesel industry, generating large amounts of the by-product crude glycerin, a potential alternative feed for dairy cows. A replicated 3×3 Latin square study was conducted to evaluate the effects of high concentrations of crude glycerin on dry matter intake, milk yield and composition, milk fatty acid profile, and blood metabolites of medium-yield cows. Ruminally cannulated Holstein cows (n=6; 587 ± 39 kg of body weight; 114 ± 29 d in milk; and 20 ± 1.5 kg/d milk yield) were used in the study. The experimental period included 2 wk for adaptation and 1 wk for data collection. Cows were fed diets containing 0 (control), 15, or 30% crude glycerin (83% glycerol). Cows were milked, milk weights were recorded twice daily, and milk samples were collected for milk quality analyses at d 18 and 19 in each experimental period. Feeding cows with crude glycerin linearly decreased dry-matter intake, the 3.5% fat-corrected milk, and the solid-corrected milk yield. Hepatic enzymes were not affected by dietary treatments, except gamma-glutamyl transferase, which was decreased with the 15% crude glycerin diet. Serum glucose and albumin showed quadratic effect with increasing inclusion of crude glycerin. Plasma cholesterol as well as total protein linearly decreased with increasing inclusion of crude glycerin. Milk fat concentration and yield showed a quadratic effect of treatments. Solid yield decreased linearly with increasing inclusion of crude glycerin. Odd-chain fatty acids and conjugated linoleic acid in milk fat linearly increased with addition of crude glycerin in the diets. Together, these results suggest that crude glycerin has potential to replace corn; however, feeding diets in which corn is replaced with crude glycerin at 30% of dietary DM greatly reduces animal performance.

  4. Investigating cold gelation properties of recombined highly concentrated micellar casein concentrate and cream for use in cheese making.

    Science.gov (United States)

    Lu, Y; McMahon, D J; Vollmer, A H

    2016-07-01

    Highly concentrated micellar casein concentrate (HC-MCC), a potential ingredient for cheese making, contains ~20% casein with ~70% of serum proteins removed by microfiltration and diafiltration of skim milk, followed by vacuum evaporation. Our objective was to investigate cold gelation properties of recombined concentrated milk (RCM) by mixing thawed frozen HC-MCC and cream under different casein levels, pH, and protein-to-fat ratios, and with addition of sodium citrate or calcium. The HC-MCC was recombined with cream using low shear at 50°C for 30 min, and rheological measurements were conducted. Cold-gelling temperature [the temperature at which storage modulus (G')=loss modulus (G″)] was linearly correlated with casein levels from 8.6 to 11.5% (R(2)=0.71), pH from 6.6 to 7.0 (R(2)=0.96), and addition of sodium citrate from 0 to 0.36mmol/g of casein (R(2)=0.80). At pH 7.0, gelation occurred at 12, 26, and 38°C with 9, 10, and 11% casein, respectively. At pH 6.6, 6.8, and 7.0, RCM with 12% casein gelled at a mean temperature of 12, 26, and 37°C, respectively. Adding calcium chloride at 0.17mmol/g of casein significantly increased cold-gelling temperature from 18 to ≥50°C, whereas no significant change was observed at levels up to 0.12mmol/g of casein. Different protein to fat ratios ranging from 0.8 to 1.2 did not significantly influence gelling temperature. In transmission electron micrographs of RCM with 12% casein, casein micelles were nonspherical and partially dissociated into small protein strands. Upon addition of calcium chloride at 0.21mmol/g of casein, casein micelles were more spherical and retained colloidal structure with the presence of aggregated casein micelles. These gelation processes of RCM with or without addition of trisodium citrate were both reversible. We propose that cold gelation of RCM occurs when protein strands that have been partially released from the casein micelles entangle, restrict their mobility, and form a fine

  5. On high-continuity transfinite element formulations for linear-nonlinear transient thermal problems

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    This paper describes recent developments in the applicability of a hybrid transfinite element methodology with emphasis on high-continuity formulations for linear/nonlinear transient thermal problems. The proposed concepts furnish accurate temperature distributions and temperature gradients making use of a relatively smaller number of degrees of freedom; and the methodology is applicable to linear/nonlinear thermal problems. Characteristic features of the formulations are described in technical detail as the proposed hybrid approach combines the major advantages and modeling features of high-continuity thermal finite elements in conjunction with transform methods and classical Galerkin schemes. Several numerical test problems are evaluated and the results obtained validate the proposed concepts for linear/nonlinear thermal problems.

  6. Rotatable high-resolution ARPES system for tunable linear-polarization geometry

    Science.gov (United States)

    Iwasawa, H.; Schwier, E. F.; Zheng, M.; Kojima, Y.; Hayashi, H.; Jiang, J.; Higashiguchi, M.; Aiura, Y.; Namatame, H.; Taniguchi, M.

    2017-01-01

    A rotatable high-resolution angle-resolved photoemission spectroscopy (ARPES) system has been developed to utilize tunable linear-polarization geometries on the linear undulator beamline (BL-1) at Hiroshima Synchrotron Radiation Center. By rotating the whole ARPES measurement system, the photoelectron detection plane can be continuously changed from parallel to normal against the electric field vector of linearly polarized undulator radiation. This polarization tunability enables us to identify the symmetry of the initial electronic states with respect to the mirror planes, and to selectively observe the electronic states based on the dipole selection rule in the photoemission process. Specifications of the rotatable high-resolution ARPES system are described, as well as its capabilities with some representative experimental results. PMID:28664891

  7. Catalytic wet air oxidation of high concentration pharmaceutical wastewater.

    Science.gov (United States)

    Zhan, Wei; Wang, Xiaocong; Li, Daosheng; Ren, Yongzheng; Liu, Dongqi; Kang, Jianxiong

    2013-01-01

    In this study, we investigated the pretreatment of a high concentration pharmaceutical wastewater by catalytic wet air oxidation (CWAO) process. Different experiments were conducted to investigate the effects of the catalyst type, operating temperature, initial system pH, and oxygen partial pressure on the oxidation of the wastewater. Results show that the catalysts prepared by the co-precipitation method have better catalytic activity compared to others. Chemical oxygen demand (COD) conversion increased with the increase in temperature from 160 to 220 °C and decreased with the increase in pH. Moreover, the effect of the oxygen partial pressure on the COD conversion was significant only during the first 20 min of the reaction. Furthermore, the biodegradability of the wastewater improved greatly after CWAO, the ratio of BOD5/COD increased less than 0.1-0.75 when treated at 220 °C (BOD: biochemical oxygen demand).

  8. Acquisition and Analysis of Data from High Concentration Solutions

    KAUST Repository

    Besong, Tabot M.D.

    2016-05-13

    The problems associated with ultracentrifugal analysis of macromolecular solutions at high (>10 mg/ml) are reviewed. Especially for the case of solutes which are non-monodisperse, meaningful results are not readily achievable using sedimentation velocity approaches. It is shown however by both simulation and analysis of practical data that using a modified form of an algorithm (INVEQ) published in other contexts, sedimentation equilibrium (SE) profiles can be analysed successfully, enabling topics such as oligomer presence or formation to be defined.To achieve this, it is necessary to employ an approach in which the solution density, which in an SE profile is radius-dependent, is taken into consideration. Simulation suggests that any reasonable level of solute concentration can be analysed.

  9. Plasma endotoxin core antibody concentration and linear growth are unrelated in rural Malawian children aged 2-5 years

    Science.gov (United States)

    Environmental enteropathy is subclinical inflammation of the upper gastrointestinal tract associated with reduced linear growth in developing countries. Usually investigators have used biopsy or a dual sugar absorption test to assess environmental enteropathy. Such tests are time and resource intens...

  10. Rheological properties of highly concentrated protein-stabilized emulsions.

    Science.gov (United States)

    Dimitrova, Tatiana D; Leal-Calderon, Fernando

    2004-05-20

    We prepared concentrated quasi monodisperse hexadecane-in-water emulsions stabilized by various proteins and investigated their rheological properties. Some protein-stabilized emulsions possess remarkably high elasticity and at the same time they are considerably fragile--they exhibit coalescence at yield strain and practically do not flow. The elastic storage modulus G' and the loss modulus G" of the emulsions were determined for different oil volume fractions above the random close packing. Surprisingly, the dimensionless elastic moduli G'/(sigma/a), sigma being the interfacial tension, and a being the mean drop radius, obtained for emulsions stabilized by different proteins do not collapse on a single master curve. They are almost always substantially higher than the corresponding values obtained for equivalent Sodium Dodecyl Sulfate (SDS)-stabilized emulsions. The unusually high elasticity cannot be attributed to a specificity of the continuous phase, because the osmotic equation of state of our emulsions is found identical to the one obtained for samples stabilized by classical surfactants. In parallel, we mimicked the thin films that separate the droplets in the concentrated emulsion and found that the protein adsorption layers contain a substantial number of sticky surface aggregates. These severely obstruct local rearrangements of individual drops in respect to their neighbors which leads to coalescence at yield strain. Furthermore, we found that G'/(sigma/a) is correlated (for a given oil volume fraction) to the dilatational elastic modulus, of the protein layer adsorbed on the droplets. The intrinsic elasticity of the protein layers, together with the blocked local rearrangements are considered as the main factors determining the unusual bulk elasticity of the studied emulsions.

  11. Do high concentrations of microcystin prevent Daphnia control of phytoplankton?

    Science.gov (United States)

    Chislock, Michael F; Sarnelle, Orlando; Jernigan, Lauren M; Wilson, Alan E

    2013-04-15

    Toxin-producing cyanobacteria have frequently been hypothesized to limit the ability of herbivorous zooplankton (such as Daphnia) to control phytoplankton biomass by inhibiting feeding, and in extreme cases, causing zooplankton mortality. Using limnocorral experiments in hyper-eutrophic ponds located in Alabama and Michigan (U.S.A.), we tested the hypothesis that high levels of cyanobacteria and microcystin, a class of hepatotoxins produced by several cyanobacterial genera, prevent Daphnia from strongly reducing phytoplankton abundance. At the start of the first experiment (Michigan), phytoplankton communities were dominated by toxic Microcystis and Anabaena (∼96% of total phytoplankton biomass), and concentrations of microcystin were ∼3 μg L⁻¹. Two weeks after adding Daphnia pulicaria from a nearby eutrophic lake, microcystin levels increased to ∼6.5 μg L⁻¹, yet Daphnia populations increased exponentially (r = 0.24 day⁻¹). By the third week, Daphnia had suppressed phytoplankton biomass by ∼74% relative to the no Daphnia controls and maintained reduced phytoplankton biomass until the conclusion of the five-week experiment. In the second experiment (Alabama), microcystin concentrations were greater than 100 μg L⁻¹, yet a mixture of three D. pulicaria clones from eutrophic lakes in southern MI increased and again reduced phytoplankton biomass, in this case by over 80%. The ability of Daphnia to increase in abundance and suppress phytoplankton biomass, despite high initial levels of cyanobacteria and microcystin, indicates that the latter does not prevent strong control of phytoplankton biomass by Daphnia genotypes that are adapted to environments with abundant cyanobacteria and associated cyanotoxins.

  12. Highly Concentrated Acetic Acid Poisoning: 400 Cases Reviewed

    Directory of Open Access Journals (Sweden)

    Konstantin Brusin

    2012-12-01

    Full Text Available Background: Caustic substance ingestion is known for causing a wide array of gastrointestinal and systemic complications. In Russia, ingestion of acetic acid is a major problem which annually affects 11.2 per 100,000 individuals. The objective of this study was to report and analyze main complications and outcomes of patients with 70% concentrated acetic acid poisoning. Methods: This was a retrospective study of patients with acetic acid ingestion who were treated at Sverdlovsk Regional Poisoning Treatment Center during 2006 to 2012. GI mucosal injury of each patient was assessed with endoscopy according to Zargar’s scale. Data analysis was performed to analyze the predictors of stricture formation and mortality. Results: A total of 400 patients with median age of 47 yr were included. GI injury grade I was found in 66 cases (16.5%, IIa in 117 (29.3%, IIb in 120 (30%, IIIa in 27 (16.7% and IIIb in 70 (17.5%. 11% of patients developed strictures and overall mortality rate was 21%. Main complications were hemolysis (55%, renal injury (35%, pneumonia (27% and bleeding during the first 3 days (27%. Predictors of mortality were age 60 to 79 years, grade IIIa and IIIb of GI injury, pneumonia, stages “I”, “F” and “L” of kidney damage according to the RIFLE scale and administration of prednisolone. Predictors of stricture formation were ingestion of over 100 mL of acetic acid and grade IIb and IIIa of GI injury. Conclusion: Highly concentrated acetic acid is still frequently ingested in Russia with a high mortality rate. Patients with higher grades of GI injury, pneumonia, renal injury and higher amount of acid ingested should be more carefully monitored as they are more susceptible to develop fatal consequences.          

  13. Highly linear and transparent 3-18 GHz optical microwave link

    DEFF Research Database (Denmark)

    Nielsen, Torben Nørskov; Gliese, Ulrik Bo; Christensen, T.;

    1994-01-01

    A highly linear optical microwave link transmitter based on heterodyne phase-locked DFB lasers is presented. The transmitter is transparent for FM and PM input signals with carrier frequencies ranging from 3-18 GHz. Distortion-free transmission of a 7.6 GHz FM PAL video signal over 25 km of optical...

  14. High Order Finite Difference Methods, Multidimensional Linear Problems and Curvilinear Coordinates

    Science.gov (United States)

    Nordstrom, Jan; Carpenter, Mark H.

    1999-01-01

    Boundary and interface conditions are derived for high order finite difference methods applied to multidimensional linear problems in curvilinear coordinates. The boundary and interface conditions lead to conservative schemes and strict and strong stability provided that certain metric conditions are met.

  15. Optical Sampling at 80 Gbit/s Using a Highly Non-Linear Photonic Crystal Fiber

    Institute of Scientific and Technical Information of China (English)

    Andrea Tersigni; Vanessa Calle; Anders Clausen; Palle Jeppesen; Kim P. Hansen; Jacob R. Folkenberg

    2003-01-01

    Optical sampling using four-wave mixing in 50m of newly developed highly non-linear photo niccrystal fiber has been achieved at 80 Gbit/s with an Extinction Ratio of 12 dB. A basic characterization is also included.

  16. Modeling and experiments on differential pumping in linear plasma generators operating at high gas flows

    NARCIS (Netherlands)

    van Eck, H. J. N.; Koppers, W. R.; van Rooij, G. J.; W. J. Goedheer,; Engeln, R.; D.C. Schram,; Cardozo, N. J. L.; Kleyn, A. W.

    2009-01-01

    The direct simulation Monte Carlo (DSMC) method was used to investigate the efficiency of differential pumping in linear plasma generators operating at high gas flows. Skimmers are used to separate the neutrals from the plasma beam, which is guided from the source to the target by a strong axial mag

  17. Production of high transient heat and particle fluxes in a linear plasma device

    NARCIS (Netherlands)

    De Temmerman, G.; Zielinski, J. J.; van der Meiden, H.; Melissen, W.; Rapp, J.

    2010-01-01

    We report on the generation of high transient heat and particle fluxes in a linear plasma device by pulsed operation of the plasma source. A capacitor bank is discharged into the source to transiently increase the discharge current up to 1.7 kA, allowing peak densities and temperature of 70x10(20) m

  18. Split Stirling linear cryogenic cooler for a new generation of high temperature infrared imagers

    Science.gov (United States)

    Veprik, A.; Zechtzer, S.; Pundak, N.

    2010-04-01

    Split linear cryocoolers find use in a variety of infrared equipment installed in airborne, heliborne, marine and vehicular platforms along with hand held and ground fixed applications. An upcoming generation of portable, high-definition night vision imagers will rely on the high-temperature infrared detectors, operating at elevated temperatures, ranging from 95K to 200K, while being able to show the performance indices comparable with these of their traditional 77K competitors. Recent technological advances in industrial development of such high-temperature detectors initialized attempts for developing compact split Stirling linear cryogenic coolers. Their known advantages, as compared to the rotary integral coolers, are superior flexibility in the system packaging, constant and relatively high driving frequency, lower wideband vibration export, unsurpassed reliability and aural stealth. Unfortunately, such off-the-shelf available linear cryogenic coolers still cannot compete with rotary integral rivals in terms of size, weight and power consumption. Ricor developed the smallest in the range, 1W@95K, linear split Stirling cryogenic cooler for demanding infrared applications, where power consumption, compactness, vibration, aural noise and ownership costs are of concern.

  19. High Bandwidth Rotary Fast Tool Servos and a Hybrid Rotary/Linear Electromagnetic Actuator

    Energy Technology Data Exchange (ETDEWEB)

    Montesanti, Richard Clement [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2005-09-01

    This thesis describes the development of two high bandwidth short-stroke rotary fast tool servos and the hybrid rotary/linear electromagnetic actuator developed for one of them. Design insights, trade-o® methodologies, and analytical tools are developed for precision mechanical systems, power and signal electronic systems, control systems, normal-stress electromagnetic actuators, and the dynamics of the combined systems.

  20. A linear concentrating Fresnel collector driving a NH{sub 3}-H{sub 2}O absorption chiller

    Energy Technology Data Exchange (ETDEWEB)

    Haeberle, A.; Luginsland, F.; Zahler, C.; Berger, M. [PSE GmbH, Freiburg (Germany); Rommel, M.; Henning, H.M. [Fraunhofer ISE, Freiburg (Germany); Guerra, M.; Paoli, F. De [Robur S.p.A., Verdellino/Zingonia (Italy); Motta, M.; Aprile, M. [Politecnico di Milano (Italy)

    2007-07-01

    With linear Fresnel collectors it is possible to provide process heat up to 200 C using a pressurized water circuit for heat transfer and therefore they are perfectly suited to power efficient absorption chillers. The tests and measurements at the solar cooling system in Bergamo show that this prototype of the PSE Fresnel collector can provide temperatures of 180 C with an efficiency of approx. 40% with respect to DNI. The system is working stable since one year. Enhancement potential has been identified at the receiver and the thermal capacities of the system. This year in October PSE will install a Fresnel collector with a primary mirror area of 352m{sup 3} and a length of 64 m on the roof of the faculty of engineering at the University of Seville, Spain. This collector with a thermal peak power of approx. 176 kW will drive a double effect H{sub 2}O/LiBr absorption chiller with a maximum cooling power of 174 kW which will be used for air-conditioning of this building. At this site the wet-cooling tower for heat rejection, which is usually necessary for H{sub 2}O/LiBr absorption chillers, will be substituted by a water heat exchanger fed by water out of the nearby river Guadalquivir. The double effect absorption chiller offers a high COP which makes this system a further attractive application of solar process heat for solar thermal cooling. PSE plans to offer its FRESNEL process heat collector in 2008 commercially for solar process heat applications. The development of the PSE Fresnel process heat collector war partially funded by Deutsche Bundesstiftung Umwelt. (orig.)

  1. Design philosophy and construction of a high concentration compound parabolic concentrator

    CSIR Research Space (South Africa)

    Roos, TH

    2010-09-01

    Full Text Available A compound parabolic concentrator (CPC) with a concentration ratio of 16:1 is under development at CSIR for volumetric receiver and solar fuels development. The ideal shape has been approximated by 6 and 12 facets in the longitudinal...

  2. Formulation and validation of high-order linearized models of helicopter flight mechanics

    Science.gov (United States)

    Kim, Frederick D.; Celi, Roberto; Tischler, Mark B.

    1990-01-01

    A high-order linearized model of helicopter flight dynamics is extracted from a nonlinear time domain simulation. The model has 29 states that describe the fuselage rigid body degrees of freedom, the flap and lag dynamics in a nonrotating coordinate system, the inflow dynamics, the delayed entry of the horizontal tail into the main rotor wake, and, approximately, the blade torsion dynamics. The nonlinear simulation is obtained by extensively modifying the GENHEL computer program. The results indicate that the agreement between the linearized and the nonlinear model is good for small perturbations, and deteriorates for large amplitude maneuvers.

  3. Analysis of electric field control methods for foil coils in high-voltage linear actuators

    Directory of Open Access Journals (Sweden)

    Beek T.A. van

    2015-12-01

    Full Text Available This paper describes multiple electric field control methods for foil coils in high-voltage coreless linear actuators and their sensitivity to misalignment. The investigated field control methods consist of resistive, refractive, capacitive and geometrical solutions for mitigating electric stress at edges and corners of foil coils. These field control methods are evaluated using 2-D boundary element and finite element methods. A comparison is presented between the field control methods and their ability to mitigate electric stress in coreless linear actuators. Furthermore, the sensitivity to misalignment of the field control methods is investigated.

  4. Excitation Forces on Point Absorbers Exposed to High Order Non-linear Waves

    DEFF Research Database (Denmark)

    Viuff, Thomas Hansen; Andersen, Morten Thøtt; Kramer, Morten

    2013-01-01

    of proper methods to calculate design pressure distributions has led to structural failures such as buckling in the shells in wave energy prototypes. As a step towards understanding the complex loading from high order non-linear waves, this paper presents a practical approach to estimate wave excitation...... forces accounting for both non-linearity and diffraction effects. The method is validated by laboratory experiments using a hemispherical point absorber with a 6-axis force transducer, but the technique is believed to be applicable for most types of submerged or semi-submerged floating devices...

  5. Lucas Polynomial Approach for System of High-Order Linear Differential Equations and Residual Error Estimation

    Directory of Open Access Journals (Sweden)

    Muhammed Çetin

    2015-01-01

    Full Text Available An approximation method based on Lucas polynomials is presented for the solution of the system of high-order linear differential equations with variable coefficients under the mixed conditions. This method transforms the system of ordinary differential equations (ODEs to the linear algebraic equations system by expanding the approximate solutions in terms of the Lucas polynomials with unknown coefficients and by using the matrix operations and collocation points. In addition, the error analysis based on residual function is developed for present method. To demonstrate the efficiency and accuracy of the method, numerical examples are given with the help of computer programmes written in Maple and Matlab.

  6. High-performance deployable structures for the support of high-concentration ratio solar array modules

    Science.gov (United States)

    Mobrem, M.

    1985-01-01

    A study conducted on high-performance deployable structures for the support of high-concentration ratio solar array modules is discussed. Serious consideration is being given to the use of high-concentration ratio solar array modules or applications such as space stations. These concentrator solar array designs offer the potential of reduced cost, reduced electrical complexity, higher power per unit area, and improved survivability. Arrays of concentrators, such as the miniaturized Cassegrainian concentrator modules, present a serious challenge to the structural design because their mass per unit area (5.7 kg/square meters) is higher than that of flexible solar array blankets, and the requirement for accurate orientation towards the Sun (plus or minus 0.5 degree) requires structures with improved accuracy potentials. In addition, use on a space station requires relatively high structural natural frequencies to avoid deleterious interactions with control systems and other large structural components. The objective here is to identify and evaluate conceptual designs of structures suitable for deploying and accurately supporting high-concentration ratio solar array modules.

  7. Ultra-High Speed Switching Functionalities using none-linear fibres

    DEFF Research Database (Denmark)

    Galili, Michael

    2007-01-01

    This thesis deals with optical signal processing of high-speed optical data signals at 160-640 Gbit/s. By exploiting non-linear effects in optical fibres several signal processing functionalities are implemented. This includes wavelength conversion of intensity modulated and phase modulated data...... signals, conversion between intensity and phase modulation, clock recovery for synchronising a receiver to an incoming data signal and finally reduction of timing sensitivity in such high-speed systems....

  8. Lepton flavour violation at high energies: the LHC and a Linear Collider

    CERN Document Server

    Teixeira, A M; Figueiredo, A J R; Romao, J C

    2014-01-01

    We discuss several manifestations of charged lepton flavour violation at high energies. Focusing on a supersymmetric type I seesaw, considering constrained and semi-constrained supersymmetry breaking scenarios, we analyse different observables, both at the LHC and at a future Linear Collider. We further discuss how the synergy between low- and high-energy observables can shed some light on the underlying mechanism of lepton flavour violation.

  9. The R&D Works on the High Intensity Proton Linear Accelerator for Nuclear Waste Transmutation

    CERN Document Server

    Ito, N; Ino, H; Kawai, M; Kusano, J; Mizumoto, M; Murata, H; Oguri, H; Okumura, Y; Touchi, Y

    1996-01-01

    The R&D works of the 10MeV/10mA proton linear accelerator have been carried out for last four years. A high brightness hydrogen ion source, an RFQ and an RF power source have been developed and examined to achieve 2MeV proton beam. A DTL hot test model was also fabricated and a high power test has been carried out. The present status of the R&D works are described in this paper.

  10. Highly Excited Mesons, Linear Regge Trajectories and the Pattern of the Chiral Symmetry Realization

    CERN Document Server

    Shifman, M

    2007-01-01

    The chiral symmetry of QCD shows up in the linear Weyl--Wigner mode at short Euclidean distances or at high temperatures. On the other hand, low-lying hadronic states exhibit the nonlinear Nambu--Goldstone mode. An interesting question was raised as to whether the linear realization of the chiral symmetry is asymptotically restored for highly excited states. We address it in a number of ways. On the phenomenological side we argue that to the extent the meson Regge trajectories are observed to be linear and equidistant, the Weyl--Wigner mode is not realized. This picture is supported by quasiclassical arguments implying that the quark spin interactions in high excitations are weak, the trajectories are linear, and there is no chiral symmetry restoration. Then we use the string/gauge duality. In the top-down Sakai--Sugimoto construction the nonlinear realization of the chiral symmetry is built in. In the bottom-up AdS/QCD construction by Erlich et al., and Karch et al. the situation is more ambiguous. However, ...

  11. Genome mining expands the chemical diversity of the cyanobactin family to include highly modified linear peptides.

    Science.gov (United States)

    Leikoski, Niina; Liu, Liwei; Jokela, Jouni; Wahlsten, Matti; Gugger, Muriel; Calteau, Alexandra; Permi, Perttu; Kerfeld, Cheryl A; Sivonen, Kaarina; Fewer, David P

    2013-08-22

    Ribosomal peptides are produced through the posttranslational modification of short precursor peptides. Cyanobactins are a growing family of cyclic ribosomal peptides produced by cyanobacteria. However, a broad systematic survey of the genetic capacity to produce cyanobactins is lacking. Here we report the identification of 31 cyanobactin gene clusters from 126 genomes of cyanobacteria. Genome mining suggested a complex evolutionary history defined by horizontal gene transfer and rapid diversification of precursor genes. Extensive chemical analyses demonstrated that some cyanobacteria produce short linear cyanobactins with a chain length ranging from three to five amino acids. The linear peptides were N-prenylated and O-methylated on the N and C termini, respectively, and named aeruginosamide and viridisamide. These findings broaden the structural diversity of the cyanobactin family to include highly modified linear peptides with rare posttranslational modifications.

  12. Design and development of a high-concentration and high-efficiency photovoltaic concentrator using a curved Fresnel lens

    Energy Technology Data Exchange (ETDEWEB)

    Scharlack, R.S.; Moffat, A.

    1983-08-01

    Thermo Electron has designed a high concentration photovoltaic module that uses a domed, point-focus Fresnel lens. Their design, design optimization process, and results from lens and receiver tests are described in this report. A complete module has not been fabricated and probably will not be fabricated in the future; however, Thermo Electron's optical design, analysis, and testing of both secondary optical units and domed Fresnel lenses have made a significant contribution to our project. Tooling errors prevented the lens from reaching its potential efficiency by the end of the contract, and resolution of these tooling problems is currently being attempted with a follow-on contract, No. 68-9463.

  13. Analysis of junior high school students' attempt to solve a linear inequality problem

    Science.gov (United States)

    Taqiyuddin, Muhammad; Sumiaty, Encum; Jupri, Al

    2017-08-01

    Linear inequality is one of fundamental subjects within junior high school mathematics curricula. Several studies have been conducted to asses students' perform on linear inequality. However, it can hardly be found that linear inequality problems are in the form of "ax + b interviews. The other sources of the data are from teachers' interview and mathematics books used by students. After that, the constant comparative method was used to analyse the data. The result shows that the majority approached the question by doing algebraic operations. Interestingly, most of them did it incorrectly. In contrast, algebraic operations were correctly used by some of them. Moreover, the others performed expected-numbers solution, rewriting the question, translating the inequality into words, and blank answer. Furthermore, we found that there is no one who was conscious of the existence of all-numbers solution. It was found that this condition is reasonably due to how little the learning components concern about why a procedure of solving a linear inequality works and possibilities of linear inequality solution.

  14. Prospectus for the development of a linear algebra library for high-performance computers

    Energy Technology Data Exchange (ETDEWEB)

    Demmell, J.; Dongarra, J.J.; Du Croz, J.; Greenbaum, A.; Hammarling, S.; Sorensen, D.

    1987-09-01

    We propose to design and implement a transportable linear algebra library in Fortran 77 for efficient use on high-performance computers. The library is intended to provide a uniform set of subroutines to solve the most common linear algebra problems and to run efficiently on a wide range of architectures. This library, which will be freely accessible via computer network, not only will ease code development, make codes more portable among machines of different architectures, and increase efficiency, but also will provide tools for evaluating computer performance. The library will be based on the well-known and widely used LINPACK and EISPACK packages for linear equation solving, eigenvalue problems, and linear least squares. LINPACK and EISPACK have provided an important infrastructure for scientific computing on serial machines, but they were not designed to exploit the profusion of parallel and vector architectures not becoming available. We propose to restructure the algorithms in terms of calls to a small number of extended Basic Linear algebra Subroutines each of which implements a basic operation such as matrix multiplication, rank-k matrix updates, and the solution of triangular systems. These operations can be optimized for each architecture, but the underlying numerical algorithms will be the same for all machines. 11 refs.

  15. High-temperature piezoelectric materials for elements of linear piezo motors

    Science.gov (United States)

    Khramtsov, A. M.; Spitsin, A. I.; Segalla, A. G.; Ponomarev, S. V.; Rikkonen, S. V.

    2016-11-01

    This paper discusses technological and construction ways to achieve a high working temperature with a high displacement in linear piezo motors. The first part reviews the results of the piezoelectric material development, its temperature stability testing and basic parameters for piezo motors. The second part focuses on the multilayer structure of piezoelectric elements, which are based on high-temperature piezoelectric materials (HTPM). Also analyzed are working temperatures of multilayer piezoelectric elements (MPE) and their hysteresis. Finally, the third part shows a comparison of three recent prototypes of high-temperature MPEs that were in our lab using different materials.

  16. Non-Linear High Amplitude Oscillations in Wave-shaped Resonators

    Science.gov (United States)

    Antao, Dion; Farouk, Bakhtier

    2011-11-01

    A numerical and experimental study of non-linear, high amplitude standing waves in ``wave-shaped'' resonators is reported here. These waves are shock-less and can generate peak acoustic overpressures that can exceed the ambient pressure by three/four times its nominal value. A high fidelity compressible axisymmetric computational fluid dynamic model is used to simulate the phenomena in cylindrical and arbitrarily shaped axisymmetric resonators. Working fluids (Helium, Nitrogen and R-134a) at various operating pressures are studied. The experiments are performed in a constant cross-section cylindrical resonator in atmospheric pressure nitrogen and helium to provide model validation. The high amplitude non-linear oscillations demonstrated can be used as a prime mover in a variety of applications including thermoacoustic cryocooling. The work reported is supported by the US National Science Foundation under grant CBET-0853959.

  17. A project for developing a linear algebra library for high-performance computers

    Energy Technology Data Exchange (ETDEWEB)

    Demmel, J.; Dongarra, J.; DuCroz, J.; Greenbaum, A.; Hammarling, S.; Sorensen, D.

    1988-01-01

    Argonne National Laboratory, the Courant Institute for Mathematical Sciences, and the Numerical Algorithms Group, Ltd., are developing a transportable linear algebra library in Fortran 77. The library is intended to provide a uniform set of subroutines to solve the most common linear algebra problems and to run efficiently on a wide range of high-performance computers. To be effective, the new library must satisfy several criteria. First, it must be highly efficient, or at least ''tunable'' to high efficiency, on each machine. Second, the user interface must be uniform across machines. Otherwise much of the convenience of portability will be lost. Third, the program must be widely available. NETLIB has demonstrated how useful and important it is for these codes to be available easily, and preferably on line. We intend to distribute the new library in a similar way, for no cost or a nominal cost only. In addition, the programs must be well documented.

  18. A Monolithic CMOS Magnetic Hall Sensor with High Sensitivity and Linearity Characteristics.

    Science.gov (United States)

    Huang, Haiyun; Wang, Dejun; Xu, Yue

    2015-10-27

    This paper presents a fully integrated linear Hall sensor by means of 0.8 μm high voltage complementary metal-oxide semiconductor (CMOS) technology. This monolithic Hall sensor chip features a highly sensitive horizontal switched Hall plate and an efficient signal conditioner using dynamic offset cancellation technique. An improved cross-like Hall plate achieves high magnetic sensitivity and low offset. A new spinning current modulator stabilizes the quiescent output voltage and improves the reliability of the signal conditioner. The tested results show that at the 5 V supply voltage, the maximum Hall output voltage of the monolithic Hall sensor microsystem, is up to ±2.1 V and the linearity of Hall output voltage is higher than 99% in the magnetic flux density range from ±5 mT to ±175 mT. The output equivalent residual offset is 0.48 mT and the static power consumption is 20 mW.

  19. Influence of a high vacuum on the precise positioning using an ultrasonic linear motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Wan-Soo; Lee, Dong-Jin; Lee, Sun-Kyu [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2011-01-15

    This paper presents an investigation of the ultrasonic linear motor stage for use in a high vacuum environment. The slider table is driven by the hybrid bolt-clamped Langevin-type ultrasonic linear motor, which is excited with its different modes of natural frequencies in both lateral and longitudinal directions. In general, the friction behavior in a vacuum environment becomes different from that in an environment of atmospheric pressure and this difference significantly affects the performance of the ultrasonic linear motor. In this paper, to consistently provide stable and high power of output in a high vacuum, frequency matching was conducted. Moreover, to achieve the fine control performance in the vacuum environment, a modified nominal characteristic trajectory following control method was adopted. Finally, the stage was operated under high vacuum condition, and the operating performances were investigated compared with that of a conventional PI compensator. As a result, robustness of positioning was accomplished in a high vacuum condition with nanometer-level accuracy.

  20. Carbon Nanofibers Modified Graphite Felt for High Performance Anode in High Substrate Concentration Microbial Fuel Cells

    Directory of Open Access Journals (Sweden)

    Youliang Shen

    2014-01-01

    Full Text Available Carbon nanofibers modified graphite fibers (CNFs/GF composite electrode was prepared for anode in high substrate concentration microbial fuel cells. Electrochemical tests showed that the CNFs/GF anode generated a peak current density of 2.42 mA cm−2 at a low acetate concentration of 20 mM, which was 54% higher than that from bare GF. Increase of the acetate concentration to 80 mM, in which the peak current density of the CNFs/GF anode greatly increased and was up to 3.57 mA cm−2, was seven times as that of GF anode. Morphology characterization revealed that the biofilms in the CNFs/GF anode were much denser than those in the bare GF. This result revealed that the nanostructure in the anode not only enhanced current generation but also could tolerate high substrate concentration.

  1. Enhanced Efficiencies for High-Concentration, Multijunction PV Systems by Optimizing Grid Spacing under Nonuniform Illumination

    Directory of Open Access Journals (Sweden)

    Pratibha Sharma

    2014-01-01

    Full Text Available The design of a triple junction solar cell’s front contact grid can significantly affect cell conversion efficiency under high concentration. We consider one aspect of grid design, choosing a linear grid within a distributed resistance cell model to optimize finger spacings at concentrations between 500 and 2500 suns under uniform and nonuniform illumination. Optimization for maximum efficiency under Gaussian irradiance profiles is done by SPICE analysis. Relative to the optimized uniform illumination designs, we find enhancements of 0.5% to 2% in absolute efficiencies for uniform spacing. Efficiency enhancement with nonuniform spacing under nonuniform illumination is also evaluated. Our model suggests that, at lower concentrations (<1000 suns, the penalty for using uniformly spaced fingers instead of nonuniformly spaced fingers is <0.1%. However, at a concentration of 2500 suns the penalty increases to 0.3%. Thus, relative to a uniform irradiance optimization, an absolute efficiency increase of 2.3% can be attained for an optimized nonuniform spacing given the Gaussian irradiance profile under consideration.

  2. An Automatic High Efficient Method for Dish Concentrator Alignment

    OpenAIRE

    Yong Wang; Song Li; Jinshan Xu; Yijiang Wang; Xu Cheng; Changgui Gu; Shengyong Chen; Bin Wan

    2014-01-01

    Alignment of dish concentrator is a key factor to the performance of solar energy system. We propose a new method for the alignment of faceted solar dish concentrator. The isosceles triangle configuration of facet’s footholds determines a fixed relation between light spot displacements and foothold movements, which allows an automatic determination of the amount of adjustments. Tests on a 25 kW Stirling Energy System dish concentrator verify the feasibility, accuracy, and efficiency of our...

  3. Supercharging with m-nitrobenzyl alcohol and propylene carbonate: forming highly charged ions with extended, near-linear conformations.

    Science.gov (United States)

    Going, Catherine C; Williams, Evan R

    2015-04-07

    The effectiveness of the supercharging reagents m-nitrobenzyl alcohol (m-NBA) and propylene carbonate at producing highly charged protein ions in electrospray ionization is compared. Addition of 5% m-NBA or 15% propylene carbonate increases the average charge of three proteins by ∼21% or ∼23%, respectively, when these ions are formed from denaturing solutions (water/methanol/acetic acid). These results indicate that both reagents are nearly equally effective at supercharging when used at their optimum concentrations. A narrowing of the charge state distribution occurs with both reagents, although this effect is greater for propylene carbonate. Focusing the ion signal into fewer charge states has the advantage of improving sensitivity. The maximum charge state of ubiquitin formed with propylene carbonate is 21+, four charges higher than previously reported. Up to nearly 30% of all residues in a protein can be charged, and the collisional cross sections of the most highly charged ions of both ubiquitin and cytochrome c formed with these supercharging reagents were measured for the first time and found to be similar to those calculated for theoretical highly extended, linear or near-linear conformations. Under native supercharging conditions, m-NBA is significantly more effective at producing high charge states than propylene carbonate.

  4. Selection of common bean lines with high grain yield and high grain calcium and iron concentrations

    Directory of Open Access Journals (Sweden)

    Nerinéia Dalfollo Ribeiro

    2014-02-01

    Full Text Available Genetic improvement of common bean nutritional quality has advantages in marketing and can contribute to society as a food source. The objective of this study was to evaluate the genetic variability for grain yield, calcium and iron concentrations in grains of inbred common bean lines obtained by different breeding methods. For this, 136 F7 inbred lines were obtained using the Pedigree method and 136 F7 inbred lines were obtained using the Single-Seed Descent (SSD method. The lines showed genetic variability for grain yield, and concentrations of calcium and iron independently of the method of advancing segregating populations. The Pedigree method allows obtaining a greater number of lines with high grain yield. Selection using the SSD method allows the identification of a larger number of lines with high concentrations of calcium and iron in grains. Weak negative correlations were found between grain yield and calcium concentration (r = -0.0994 and grain yield and iron concentration (r = -0.3926. Several lines show genetic superiority for grain yield and concentrations of calcium and iron in grains and their selection can result in new common bean cultivars with high nutritional quality.

  5. Using high-frequency vibrations and non-linear inclusions to create metamaterials with adjustable effective properties

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Thomsen, Jon Juel

    2009-01-01

    We investigate how high-frequency (HF) excitation combined with strongly non-linear elasticity may influence the effective properties for low-frequency wave propagation. The HF effects are demonstrated for linear spring-mass chains with embedded non-linear parts. The investigated mechanical syste...

  6. Linear and nonlinear optical absorption coefficients in GaAs/Ga{sub 1-x}Al{sub x}As concentric double quantum rings: Effects of hydrostatic pressure and aluminum concentration

    Energy Technology Data Exchange (ETDEWEB)

    Baghramyan, H.M. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Barseghyan, M.G., E-mail: mbarsegh@ysu.am [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Kirakosyan, A.A. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Restrepo, R.L. [Escuela de Ingenieria de Antioquia, AA 7516 Medellin (Colombia); Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226 Medellin (Colombia)

    2013-02-15

    The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga{sub 1-x}Al{sub x}As two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and aluminum concentration the energies of the ground (n=1,l=0) and the first excited state (n=2,l=1) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and aluminum concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, aluminum concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the aluminum concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum. - Highlights: Black-Right-Pointing-Pointer Linear and nonlinear intra-band absorption in quantum rings. Black-Right-Pointing-Pointer Threshold energy strongly depends on the hydrostatic pressure. Black-Right-Pointing-Pointer Threshold energy strongly depends on the stoichiometry and sizes of structure. Black-Right-Pointing-Pointer Optical absorption is affected by the incident optical intensity.

  7. Speed up linear scan in high-dimensions by sorting one-dimensional projections

    Directory of Open Access Journals (Sweden)

    Jiangtao Cui

    2011-06-01

    Full Text Available High-dimensional indexing is a pervasive challenge faced in multimedia retrieval. Existing indexing methods applying linear scan strategy, such as VA-file and its variations, are still efficient when the dimensionality is high. In this paper, we propose a new access idea implemented on linear scan based methods to speed up the nearest-neighbor queries. The idea is to map high-dimensional points into two kinds of one-dimensional values using projection and distance computation. The projection values on the line determined by the first Principal Component are sorted and indexed using a B+-tree, and the distances of each point to a reference point are also embedded into leaf node of the B+-tree. When performing nearest neighbor search, the Partial Distortion Searching and triangular inequality are employed to prune search space. In the new search algorithm, only a small portion of data points need to be linearly accessed by computing the bounded distance on the one-dimensional line, which can reduce the I/O and processor time dramatically. Experiment results on large image databases show that the new access method provides a faster search speed than existing high-dimensional index methods.

  8. A latent factor linear mixed model for high-dimensional longitudinal data analysis.

    Science.gov (United States)

    An, Xinming; Yang, Qing; Bentler, Peter M

    2013-10-30

    High-dimensional longitudinal data involving latent variables such as depression and anxiety that cannot be quantified directly are often encountered in biomedical and social sciences. Multiple responses are used to characterize these latent quantities, and repeated measures are collected to capture their trends over time. Furthermore, substantive research questions may concern issues such as interrelated trends among latent variables that can only be addressed by modeling them jointly. Although statistical analysis of univariate longitudinal data has been well developed, methods for modeling multivariate high-dimensional longitudinal data are still under development. In this paper, we propose a latent factor linear mixed model (LFLMM) for analyzing this type of data. This model is a combination of the factor analysis and multivariate linear mixed models. Under this modeling framework, we reduced the high-dimensional responses to low-dimensional latent factors by the factor analysis model, and then we used the multivariate linear mixed model to study the longitudinal trends of these latent factors. We developed an expectation-maximization algorithm to estimate the model. We used simulation studies to investigate the computational properties of the expectation-maximization algorithm and compare the LFLMM model with other approaches for high-dimensional longitudinal data analysis. We used a real data example to illustrate the practical usefulness of the model. Copyright © 2013 John Wiley & Sons, Ltd.

  9. An Automatic High Efficient Method for Dish Concentrator Alignment

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2014-01-01

    for the alignment of faceted solar dish concentrator. The isosceles triangle configuration of facet’s footholds determines a fixed relation between light spot displacements and foothold movements, which allows an automatic determination of the amount of adjustments. Tests on a 25 kW Stirling Energy System dish concentrator verify the feasibility, accuracy, and efficiency of our method.

  10. Prediction of Nociceptive Responses during Sedation by Linear and Non-Linear Measures of EEG Signals in High Frequencies.

    Directory of Open Access Journals (Sweden)

    Umberto Melia

    Full Text Available The level of sedation in patients undergoing medical procedures evolves continuously, affected by the interaction between the effect of the anesthetic and analgesic agents and the pain stimuli. The monitors of depth of anesthesia, based on the analysis of the electroencephalogram (EEG, have been progressively introduced into the daily practice to provide additional information about the state of the patient. However, the quantification of analgesia still remains an open problem. The purpose of this work is to improve the prediction of nociceptive responses with linear and non-linear measures calculated from EEG signal filtered in frequency bands higher than the traditional bands. Power spectral density and auto-mutual information function was applied in order to predict the presence or absence of the nociceptive responses to different stimuli during sedation in endoscopy procedure. The proposed measures exhibit better performances than the bispectral index (BIS. Values of prediction probability of Pk above 0.75 and percentages of sensitivity and specificity above 70% were achieved combining EEG measures from the traditional frequency bands and higher frequency bands.

  11. Starch source in high concentrate rations does not affect rumen pH, histamine and lipopolysaccharide concentrations in dairy cows

    NARCIS (Netherlands)

    Pilachai, R.; Schonewille, J.T.; Thamrongyoswittayakul, C.; Aiumlamai, S.; Wachirapakom, C.; Everts, H.; Hendriks, W.H.

    2012-01-01

    The replacement of ground corn by cassava meal on rumen pH, lipopolysaccharide (LPS) and histamine concentrations under typical Thai feeding conditions (high concentrate diets and rice straw as the sole source of roughage) was investigated. Four rumen-fistulated crossbred Holstein, non-pregnant, dry

  12. High-frequency linear transducer improves detection of an intrauterine pregnancy in first-trimester ultrasonography.

    Science.gov (United States)

    Tabbut, Matthew; Harper, Devin; Gramer, Diane; Jones, Robert

    2016-02-01

    The objective was to determine if the need for transvaginal ultrasonographic examination can be decreased by the addition of the transabdominal high-frequency, 12-4-MHz linear transducer after a failed examination with the 6-2-mHz curvilinear transducer when evaluating for an intrauterine pregnancy (IUP). This is a prospective pilot study of women in their first trimester of pregnancy presenting to the emergency department with abdominal pain and/or vaginal bleeding. If no IUP was identified using the curvilinear transducer via the transabdominal approach, they were subsequently scanned using the linear transducer. Patients without evidence of an IUP transabdominally were scanned via the transvaginal approach. Eighty-one patients were evaluated; no IUP was visualized in 27 using the standard curvilinear transducer approach, and these then had an ultrasonography performed with the linear transducer. Of these, 9 patients (33.3%; 0.95 confidence interval [CO], 15.5%-51.1%) were found to have an IUP with the linear transducer. For the 18 patients who received a transvaginal scan, 15 patients (83.3%; 0.95 CI, 66.1%-100%) had no IUP identified with the transvaginal transducer, and 3 (16.7%; 0.95 CI, 0%-33.9%) had an IUP identified. The transabdominal use of a high-frequency linear transducer in the evaluation of patients in the first trimester after failed curvilinear transducer results in a clinically significant reduction in the need for transvaginal ultrasonography to confirm the presence of an IUP. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Linear Polarization Measurements for High-Spin States in 146Gd

    CERN Document Server

    Krishichayan,; Basu, S K; Bhowmik, R K; Chakraborty, A; Chaturvedi, L; Dhal, A; Garg, U; Ghugre, S S; Goswami, R; Jhingan, A; Madhvan, N; Rao, P V Madhusudhana; Mukhopadhyay, S; Muralithar, S; Nath, S; Pattabiraman, N S; Ray, S; Saha, S; Sarkar, M Saha; Sarkar, S; Singh, R; Singh, R P; Sinha, A K; Sinha, R K; Sugathan, P; Yogi, B K

    2013-01-01

    A {\\gamma}-ray linear polarization measurement has been performed to directly determine the parities for the levels in 146Gd nucleus. High-spin states in this nucleus were populated in a reaction 115In + 34S at 140 MeV incident energy. Linearly polarized {\\gamma} - rays emitted from oriented states were measured using a Compton polarimeter consisting of an array of 8 Compton-suppressed Clover detectors. Unambiguous assignments of the spin and parity have been made for most of the observed levels and changes made in the previously reported spin-parity assignments for a few levels. Shell model calculations performed with judicious truncation over the {\\pi}(gdsh) valence space interpret the structure of only the low-lying levels up to J{\\pi} = 19+ and 9-. N = 82 neutron-core breaking is found to be essential for high spin states with excitation energies Ex > 7 MeV.

  14. High-resolution mapping of linear antibody epitopes using ultrahigh-density peptide microarrays

    DEFF Research Database (Denmark)

    Buus, Søren; Rockberg, Johan; Forsström, Björn

    2012-01-01

    -resolution mapping of linear antibody epitopes, we have used ultrahigh-density peptide microarrays generating several hundred thousand different peptides per array. Using exhaustive length and substitution analysis, we have successfully examined the specificity of a panel of polyclonal antibodies raised against......Antibodies empower numerous important scientific, clinical, diagnostic, and industrial applications. Ideally, the epitope(s) targeted by an antibody should be identified and characterized, thereby establishing antibody reactivity, highlighting possible cross-reactivities, and perhaps even warning...... against unwanted (e.g. autoimmune) reactivities. Antibodies target proteins as either conformational or linear epitopes. The latter are typically probed with peptides, but the cost of peptide screening programs tends to prohibit comprehensive specificity analysis. To perform high-throughput, high...

  15. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    Energy Technology Data Exchange (ETDEWEB)

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  16. LPWCO method for the treatment of high concentrated organic wastewater

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Based on wet air oxidation (WAO) and Fenton reagent, thispaper raises a new low pressure wet catalytic oxidation(LPWCO)which requires low pressure for the treatment of highlyconcentrated and refractory organic wastewater. Compared withgeneral wet air oxidation, the pressure of the treatment(0.1-0.6MPa) is only one of tens to percentage of latter(3.5-10MPa). Inaddition, its temperature is no more than 180℃.Compared withFenton reagent, while H2O2/COD(weight ratio) less than 1.2, theremoval of COD in the treatment is over twenty percents more thanFenton's even the value of COD is more than 14000mg/L. In thispaper, we study the effect factor of COD removal and the mechanismof this treatment. The existence of synergistic effect (catalytic oxidation and carbonization) for COD removal in H2SO4-Fenton reagent system under the condition of applied pressure and heating (0.1-0.6MPa, 104-165℃) was verified. The best condition of this disposal are as follows:H2O2/COD(weight ratio)=0.2-1.0, Fe2+ 0.6×10-3 mol, H2SO4 0.5mol, COD>1×104mg/L, the operating pressure is 0.1-0.6MPa and temperature is 104-165℃. This method suit to dispose the high-concentrated refractory wastewater, especially to the wastewater containing H2SO produced in the manufacture of pesticide, dyestuff and petrochemical works.

  17. High order explicit symplectic integrators for the Discrete Non Linear Schr\\"odinger equation

    CERN Document Server

    Boreux, Jehan; Hubaux, Charles

    2010-01-01

    We propose a family of reliable symplectic integrators adapted to the Discrete Non-Linear Schr\\"odinger equation; based on an idea of Yoshida (H. Yoshida, Construction of higher order symplectic integrators, Physics Letters A, 150, 5,6,7, (1990), pp. 262.) we can construct high order numerical schemes, that result to be explicit methods and thus very fast. The performances of the integrators are discussed, studied as functions of the integration time step and compared with some non symplectic methods.

  18. Parametric macromodelling of linear high-frequency systems using multiple frequency scaling and sequential sampling

    OpenAIRE

    Chemmangat Manakkal Cheriya, Krishnan; Ferranti, Francesco; Dhaene, Tom; Knockaert, Luc

    2014-01-01

    An enhanced parametric macromodelling scheme is presented for linear high-frequency systems based on the use of multiple frequency scaling coefficients and a sequential sampling algorithm to fully automate the entire modelling process. The proposed method is applied on a ring resonator bandpass filter example and compared with another state-of-the-art macromodelling method to show its improved modelling capability and reduced setup time.

  19. Development of 2D Bi-SQUID Arrays with High Linearity

    CERN Document Server

    Berggren, S; Longhini, P; Palacios, A; Mukhanov, O A; de Escobar, A Leese; Taylor, B J; de Andrade, M C; Nisenoff, M; Fagaly, R L; Wong, T; Cho, E; Wong, E; In, V

    2013-01-01

    We develop a two-dimensional (2D) Superconducting Quantum Interference Filter (SQIF) array based on recently introduced high-linearity tri-junction bi-SQUIDs. Our bi-SQUID SQIF array design is based on a tight integration of individual bi- SQUID cells sharing inductances with adjacent cells. We provide extensive computer simulations, analysis and experimental measurements, in which we explore the phase dynamics and linearity of the array voltage response. The non-uniformity in inductances of the bi-SQUIDs produces a pronounced zero-field single antipeak in the voltage response. The anti-peak linearity and size can be optimized by varying the critical current of the additional junction of each bi-SQUID. The layout implementation of the tight 2D array integration leads to a distinct geometrical diamond shape formed by the merged dual bi-SQUID cells. Different size 2D arrays are fabricated using standard HYPRES niobium 4.5 kA/cm2 fabrication process. The measured linearity, power gain, and noise properties will ...

  20. High Oxygen Concentrations Adversely Affect the Performance of Pulmonary Surfactant.

    Science.gov (United States)

    Smallwood, Craig D; Boloori-Zadeh, Parnian; Silva, Maricris R; Gouldstone, Andrew

    2017-08-01

    Although effective in the neonatal population, exogenous pulmonary surfactant has not demonstrated a benefit in pediatric and adult subjects with hypoxic lung injury despite a sound physiologic rationale. Importantly, neonatal surfactant replacement therapy is administered in conjunction with low fractional FIO2 while pediatric/adult therapy is administered with high FIO2 . We suspected a connection between FIO2 and surfactant performance. Therefore, we sought to assess a possible mechanism by which the activity of pulmonary surfactant is adversely affected by direct oxygen exposure in in vitro experiments. The mechanical performance of pulmonary surfactant was evaluated using 2 methods. First, Langmuir-Wilhelmy balance was utilized to study the reduction in surface area (δA) of surfactant to achieve a low bound value of surface tension after repeated compression and expansion cycles. Second, dynamic light scattering was utilized to measure the size of pulmonary surfactant particles in aqueous suspension. For both experiments, comparisons were made between surfactant exposed to 21% and 100% oxygen. The δA of surfactant was 21.1 ± 2.0% and 35.8 ± 2.0% during exposure to 21% and 100% oxygen, respectively (P = .02). Furthermore, dynamic light-scattering experiments revealed a micelle diameter of 336.0 ± 12.5 μm and 280.2 ± 11.0 μm in 21% and 100% oxygen, respectively (P < .001), corresponding to a ∼16% decrease in micelle diameter following exposure to 100% oxygen. The characteristics of pulmonary surfactant were adversely affected by short-term exposure to oxygen. Specifically, surface tension studies revealed that short-term exposure of surfactant film to high concentrations of oxygen expedited the frangibility of pulmonary surfactant, as shown with the δA. This suggests that reductions in pulmonary compliance and associated adverse effects could begin to take effect in a very short period of time. If these findings can be demonstrated in vivo, a role for

  1. A review on non-linear aeroelasticity of high aspect-ratio wings

    Science.gov (United States)

    Afonso, Frederico; Vale, José; Oliveira, Éder; Lau, Fernando; Suleman, Afzal

    2017-02-01

    Current economic constraints and environmental regulations call for design of more efficient aircraft configurations. An observed trend in aircraft design to reduce the lift induced drag and improve fuel consumption and emissions is to increase the wing aspect-ratio. However, a slender wing is more flexible and subject to higher deflections under the same operating conditions. This effect may lead to changes in dynamic behaviour and in aeroelastic response, potentially resulting in instabilities. Therefore, it is important to take into account geometric non-linearities in the design of high aspect-ratio wings, as well as having accurate computational codes that couple the aerodynamic and structural models in the presence of non-linearities. Here, a review on the state-of-the-art on non-linear aeroelasticity of high aspect-ratio wings is presented. The methodologies employed to analyse high aspect-ratio wings are presented and their applications discussed. Important observations from the state-of-the-art studies are drawn and the current challenges in the field are identified.

  2. Highly Linear, Broadband Optical Modulator Based on Electro-optic Polymer

    CERN Document Server

    Zhang, Xingyu; Lin, Che-yun; Wang, Alan X; Hosseini, Amir; Chen, Ray T

    2014-01-01

    In this paper, we present the design, fabrication and characterization of a traveling wave directional coupler modulator based on electro-optic polymer, which is able to provide both high linearity and broad bandwidth. The high linearity is realized by introducing domain-inversion technique in the two-domain directional coupler. A travelling wave electrode is designed to function with bandwidth-length product of 302GHz cm, by achieving low microwave loss, excellent impedance matching and velocity matching, as well as smooth electric field profile transformation. The 3-dB bandwidth of the device is measured to be 10GHz. The spurious free dynamic range of about 110dB Hz^(2/3) is measured over the modulation frequency range 2-8GHz. To the best of our knowledge, such high linearity is first measured at the frequency up to 8GHz. In addition, a 1-to-2 multi-mode interference 3dB-splitter, a photobleached refractive index taper and a quasi-vertical taper are used to reduce the optical insertion loss of the device.

  3. High-Efficiency Organic Solar Concentrators for Photovoltaics

    National Research Council Canada - National Science Library

    Michael J. Currie; Jonathan K. Mapel; Timothy D. Heidel; Shalom Goffri; Marc A. Baldo

    2008-01-01

    The cost of photovoltaic power can be reduced with organic solar concentrators. These are planar waveguides with a thin-film organic coating on the face and inorganic solar cells attached to the edges...

  4. A comparative study between the use of artificial neural networks and multiple linear regression for caustic concentration prediction in a stage of alumina production

    Directory of Open Access Journals (Sweden)

    Giovanni Leopoldo Rozza

    2015-09-01

    Full Text Available With world becoming each day a global village, enterprises continuously seek to optimize their internal processes to hold or improve their competitiveness and make better use of natural resources. In this context, decision support tools are an underlying requirement. Such tools are helpful on predicting operational issues, avoiding cost risings, loss of productivity, work-related accident leaves or environmental disasters. This paper has its focus on the prediction of spent liquor caustic concentration of Bayer process for alumina production. Caustic concentration measuring is essential to keep it at expected levels, otherwise quality issues might arise. The organization requests caustic concentration by chemical analysis laboratory once a day, such information is not enough to issue preventive actions to handle process inefficiencies that will be known only after new measurement on the next day. Thereby, this paper proposes using Multiple Linear Regression and Artificial Neural Networks techniques a mathematical model to predict the spent liquor´s caustic concentration. Hence preventive actions will occur in real time. Such models were built using software tool for numerical computation (MATLAB and a statistical analysis software package (SPSS. The models output (predicted caustic concentration were compared with the real lab data. We found evidence suggesting superior results with use of Artificial Neural Networks over Multiple Linear Regression model. The results demonstrate that replacing laboratorial analysis by the forecasting model to support technical staff on decision making could be feasible.

  5. Study on a high thrust force bi-double-sided permanent magnet linear synchronous motor

    Directory of Open Access Journals (Sweden)

    Liang Tong

    2016-03-01

    Full Text Available A high thrust force bi-double-sided permanent magnet linear synchronous motor used in gantry-type five-axis machining center is designed and its performance was tested in this article. This motor is the subproject of Chinese National Science and Technology Major Project named as “development of domestic large thrust linear motor used in high-speed gantry-type five-axis machining center project” jointly participated by enterprises and universities. According to the requirement of the application environment and motor performance parameters, the linear motor’s basic dimensions, form of windings, and magnet arrangement are preliminarily specified through theoretical analysis and calculation. To verify the correctness of the result of the calculation, the finite element model of the motor is established. The static and dynamic characteristics of the motor are studied and analyzed through the finite element method, and the initial scheme is revised. The prototype of the motor is manufactured based on the final revised structure parameters, and the performance of the motor is fully tested using the evaluation platform for direct-drive motor component. Experimental test results meet the design requirements and show the effectiveness of design method and process.

  6. Control of Switching Characteristics of Silicon-based Semiconductor Diode Using High Energy Linear Accelerator

    Directory of Open Access Journals (Sweden)

    N. Harihara Krishnan

    2013-05-01

    Full Text Available This paper reports control of switching characteristics of silicon-based semiconductor diode using electron beam produced using linear accelerator. Conventionally, p-n junction chips of diode are exposed to gamma rays from a radioactive source or electron beam from a microtron, depending upon the required level of correction. High energy linear accelerators featuring simultaneous exposure of multiple chips are recent advancements in radiation technology. The paper presents the results of the radiation process using a 10 MeV linear accelerator as applied in industrial manufacturing of a high voltage diode (2600 V. The achieved values of reverse recovery time were found to be within the design limits. The suitability of the new process was verified by constructing the trade-off curve between the switching and conduction parameters of the diode for the complete range using large number of experimental samples. The paper summarizes the advantages of the new process over the conventional methods specifically with reference to industrial requirements. The developed process has been successfully implemented in semiconductor manufacturing.

  7. Optical and Near-infrared Polarimetry for a Highly Dormant Comet 209P/LINEAR

    Science.gov (United States)

    Kuroda, Daisuke; Ishiguro, Masateru; Watanabe, Makoto; Akitaya, Hiroshi; Takahashi, Jun; Hasegawa, Sunao; Ui, Takahiro; Kanda, Yuka; Takaki, Katsutoshi; Itoh, Ryosuke; Moritani, Yuki; Imai, Masataka; Goda, Shuhei; Takagi, Yuhei; Morihana, Kumiko; Honda, Satoshi; Arai, Akira; Hanayama, Hidekazu; Nagayama, Takahiro; Nogami, Daisaku; Sarugaku, Yuki; Murata, Katsuhiro; Morokuma, Tomoki; Saito, Yoshihiko; Oasa, Yumiko; Sekiguchi, Kazuhiro; Watanabe, Jun-ichi

    2015-12-01

    We conducted an optical and near-infrared polarimetric observation of the highly dormant Jupiter-Family Comet, 209P/LINEAR. Because of its low activity, we were able to determine the linear polarization degrees of the coma dust particles and nucleus independently, that is Pn = {30.3}-0.9+1.3% at α = 92.°2 and Pn = {31.0}-0.7+1.0% at α = 99.°5 for the nucleus, and Pc = {28.8}-0.4+0.4% at α = 92.°2 and {29.6}-0.3+0.3% at α = 99.°5 for the coma. We detected no significant variation in P at the phase angle coverage of 92.°2-99.°5, which may imply that the obtained polarization degrees are nearly at maximum in the phase-polarization curves. By fitting with an empirical function, we obtained the maximum values of linear polarization degrees Pmax = 30.8% for the nucleus and Pmax = 29.6% for the dust coma. The Pmax of the dust coma is consistent with those of dust-rich comets. The low geometric albedo of Pv = 0.05 was derived from the slope-albedo relationship and was associated with high {P}{max}. We examined Pmax-albedo relations between asteroids and 209P, and found that the so-called Umov law seems to be applicable on this cometary surface.

  8. Increasing sodium bicarbonate level in high-concentrate diets for heifers. II. Effects on chewing and feeding behaviors.

    Science.gov (United States)

    González, L A; Ferret, A; Manteca, X; Calsamiglia, S

    2008-05-01

    Four Holstein heifers (264 ± 12 kg initial BW) were used in a 4 × 4 Latin square design with 21-day experimental periods to determine the effect of increasing levels of sodium bicarbonate (BICARB) (0%, 1.25%, 2.5% and 5%, of concentrate dry matter (DM) basis) on chewing and feed intake behavior when fed high-concentrate diets. Concentrate (13.41% CP, 13.35% NDF) and barley straw were fed once a day at 0830 h ad libitum. Feed bunks placed on scales and video recording were used to measure 24-h feed intake and chewing behavior, respectively. The patterns of feeding behavior (feed intake, meal size and length) and chewing behavior (eating, ruminating and total chewing) were studied by dividing the day into 12 intervals of 2-h each, beginning at feeding (interval 1 through 12). Number of meals per day and eating rate decreased linearly with increasing buffer level, but meal length increased linearly. No treatment effects were observed in sum of daily meal lengths or average meal size. The treatment × interval interaction was significant on meal size, length and feed intake. The size and length of those meals occurring during the 4 h post-feeding increased linearly. However, meal size tended to decrease in the evening between 8 and 12 h, whereas feed intake decreased linearly from 6 to 10 h and from 12 to 14 h post-feeding. Buffer concentration did not affect the percentage of time spent ruminating, eating or drinking per day but the buffer level × interval interaction was significant. Time spent eating expressed as min per kg of DM or organic matter (OM) intake increased linearly with buffer levels. Proportion of time spent eating increased linearly during the intervals between 0 and 4 h post-feeding. Time spent ruminating decreased linearly during the 2 h post-feeding, and also in the evening from 12 to 14 h, and at night from 18 to 22 h post-feeding, but the effect was quadratic between 8 and 10 h when intermediate buffer levels showed the greatest ruminating

  9. Large area polycrystalline diamond films as high current photocathodes for linear induction accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Shurter, R.P.; Moir, D.C.; Devlin, D.J.; Springer, R.W.

    1997-08-01

    Investigations are underway at Los Alamos to develop a new generation of high current, low source temperature photo cathodes able to operate in vacuum environments with pressures above 10e-6 torr without poisoning or degradation of emission properties. Polycrystalline diamond films are emerging as the ideal material for these photocathodes. Robustness, high quantum efficiency and high thermal conductivity are fundamental necessary attributes that are found in diamond. The high electron/hole mobility in the boron doped diamond lattice and the ability to create a negative electron affinity surface through downward band bending allow for high current density emission with quantum efficiencies of 0.5% when illuminated by a ArF laser. We report the results to date toward the development of a four kiloampere photocathode with a source temperature below 5eV for the DARHT linear induction Accelerator

  10. Highly stable linear carbonate-containing electrolytes with fluoroethylene carbonate for high-performance cathodes in sodium-ion batteries

    Science.gov (United States)

    Lee, Yongwon; Lee, Jaegi; Kim, Hyungsub; Kang, Kisuk; Choi, Nam-Soon

    2016-07-01

    Employing linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) as electrolyte solvents provides an opportunity to design appropriate electrolyte systems for high-performance sodium-ion batteries (SIBs). However, in practice, the use of linear carbonate-containing electrolytes is quite challenging because linear carbonates readily decompose at Na metal electrodes or sodiated anodes. One of the promising approaches is using an electrolyte additive to resolve the critical problems related to linear carbonates. Our investigation reveals that remarkable enhancement in electrochemical performance of Na4Fe3(PO4)2(P2O7) cathodes with linear carbonate-containing electrolytes is achieved by using a fluoroethylene carbonate (FEC) additive. Importantly, the initial Coulombic efficiency of the Na deposition/stripping on a stainless steel (SS) electrode is drastically improved from 16% to 90% by introducing the FEC additive into ethylene carbonate (EC)/propylene carbonate (PC)/DEC (5/3/2, v/v/v)/0.5 M NaClO4. The underlying mechanism of FEC at the electrode-electrolyte interface is clearly demonstrated by 13C nuclear magnetic resonance (NMR). In addition, the Na4Fe3(PO4)2(P2O7) cathode in EC/PC/DEC (5/3/2, v/v/v)/0.5 M sodium perchlorate (NaClO4) with FEC delivers a discharge capacity of 90.5 mAh g-1 at a current rate of C/2 and exhibits excellent capacity retention of 97.5% with high Coulombic efficiency of 99.6% after 300 cycles at 30 °C.

  11. High-performance small-scale solvers for linear Model Predictive Control

    DEFF Research Database (Denmark)

    Frison, Gianluca; Sørensen, Hans Henrik Brandenborg; Dammann, Bernd

    2014-01-01

    In Model Predictive Control (MPC), an optimization problem needs to be solved at each sampling time, and this has traditionally limited use of MPC to systems with slow dynamic. In recent years, there has been an increasing interest in the area of fast small-scale solvers for linear MPC......, with the two main research areas of explicit MPC and tailored on-line MPC. State-of-the-art solvers in this second class can outperform optimized linear-algebra libraries (BLAS) only for very small problems, and do not explicitly exploit the hardware capabilities, relying on compilers for that. This approach...... problems 2 to 8 times faster than the current state-of-the-art solver for this class of problems, and the high-performance is maintained for MPC problems with up to a few hundred states....

  12. AN EFFICIENT APPROACH FOR EXTRACTION OF LINEAR FEATURES FROM HIGH RESOLUTION INDIAN SATELLITE IMAGERIES

    Directory of Open Access Journals (Sweden)

    DK Bhattacharyya

    2010-07-01

    Full Text Available This paper presents an Object oriented feature extraction approach in order to classify the linear features like drainage, roads etc. from high resolution Indian satellite imageries. It starts with the multiresolution segmentations of image objects for optimal separation and representation of image regions or objects. Fuzzy membership functions were defined for a selected set of image object parameters such as mean, ratio, shape index, area etc. for representation of required image objects. Experiment was carried out for both panchromatic (CARTOSAT-I and multispectral (IRSP6 LISS IV Indiansatellite imageries. Experimental results show that the extractionof linear features can be achieved in a satisfactory level throughproper segmentation and appropriate definition & representationof key parameters of image objects.

  13. Development of manufacturing capability for high-concentration, high-efficiency silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, R.A.; Verlinden, P.J.; Crane, R.A.; Swanson, R.N. [SunPower Corp., Sunnyvale, CA (United States)

    1996-10-01

    This report presents a summary of the major results from a program to develop a manufacturable, high-efficiency silicon concentrator solar cell and a cost-effective manufacturing facility. The program was jointly funded by the Electric Power Research Institute, Sandia National Laboratories through the Concentrator Initiative, and SunPower Corporation. The key achievements of the program include the demonstration of 26%-efficient silicon concentrator solar cells with design-point (20 W/cm{sup 2}) efficiencies over 25%. High-performance front-surface passivations; that were developed to achieve this result were verified to be absolutely stable against degradation by 475 days of field exposure at twice the design concentration. SunPower demonstrated pilot production of more than 1500 of these cells. This cell technology was also applied to pilot production to supply 7000 17.7-cm{sup 2} one-sun cells (3500 yielded wafers) that demonstrated exceptional quality control. The average efficiency of 21.3% for these cells approaches the peak efficiency ever demonstrated for a single small laboratory cell within 2% (absolute). Extensive cost models were developed through this program and calibrated by the pilot-production project. The production levels achieved indicate that SunPower could produce 7-10 MW of concentrator cells per year in the current facility based upon the cell performance demonstrated during the program.

  14. Highly Sensitive Cadmium Concentration Sensor Using Long Period Grating

    Directory of Open Access Journals (Sweden)

    A. S. Lalasangi

    2011-08-01

    Full Text Available In this paper we have proposed a simple and effective Long Period Grating chemical sensor for detecting the traces of Cadmium (Cd++ in drinking water at ppm level. Long Period gratings (LPG were fabricated by point-by-point technique with CO2 laser. We have characterized the LPG concentration sensor sensitivity for different solutions of Cd concentrations varying from 0.01 ppm to 0.04 ppm by injecting white Light source and observed transmitted spectra using Optical Spectrum Analyzer (OSA. Proper reagents have been used in the solutions for detection of the Cd species. The overall shift in wavelength is 10 nm when surrounding medium gradually changed from water to 0.04 ppm of cadmium concentrations. A comparative study has been done using sophisticated spectroscopic atomic absorption spectrometer (AAS and Inductively Coupled Plasma (ICP instruments. The spectral sensitivity enhancement was done by modifying grating surface with gold nanoparticles.

  15. Methods and devices for high-throughput dielectrophoretic concentration

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Blake A. (San Francisco, CA); Cummings, Eric B. (Livermore, CA); Fiechtner, Gregory J. (Germantown, MD); Fintschenko, Yolanda (Livermore, CA); McGraw, Gregory J. (Ann Arbor, MI); Salmi, Allen (Escalon, CA)

    2010-02-23

    Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

  16. Methods and devices for high-throughput dielectrophoretic concentration

    Science.gov (United States)

    Simmons, Blake A.; Cummings, Eric B.; Fiechtner, Gregory J.; Fintschenko, Yolanda; McGraw, Gregory J.; Salmi, Allen

    2010-02-23

    Disclosed herein are methods and devices for assaying and concentrating analytes in a fluid sample using dielectrophoresis. As disclosed, the methods and devices utilize substrates having a plurality of pores through which analytes can be selectively prevented from passing, or inhibited, on application of an appropriate electric field waveform. The pores of the substrate produce nonuniform electric field having local extrema located near the pores. These nonuniform fields drive dielectrophoresis, which produces the inhibition. Arrangements of electrodes and porous substrates support continuous, bulk, multi-dimensional, and staged selective concentration.

  17. High Quantum Efficiency and High Concentration Erbium-Doped Silica Glasses Fabricated by Sintering Nanoporous Glasses

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method was used to prepare erbium-doped high silica (SiO2%>96%) glasses by sintering nanoporous glasses. The concentration of erbium ions in high silica glasses can be considerably more than that in silica glasses prepared by using conventional methods. The fluorescence of 1532 nm has an FWHM (Full Wave at Half Maximum) of 50 nm, wider than 35 nm of EDSFA (erbium-doped silica fiber amplifer), and hence the glass possesses potential application in broadband fiber amplifiers. The Judd-Ofelt theoretical analysis reflects that the quantum efficiency of this erbium-doped glass is about 0.78, although the erbium concentration in this glass (6×103) is about twenty times higher than that in silica glass. These excellent characteristics of Er-doped high silica glass will be conducive to its usage in optical amplifiers and microchip lasers.

  18. Approximating high-dimensional dynamics by barycentric coordinates with linear programming

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Yoshito, E-mail: yoshito@sat.t.u-tokyo.ac.jp; Aihara, Kazuyuki; Suzuki, Hideyuki [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Department of Mathematical Informatics, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan); CREST, JST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Shiro, Masanori [Department of Mathematical Informatics, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan); Mathematical Neuroinformatics Group, Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan); Takahashi, Nozomu; Mas, Paloma [Center for Research in Agricultural Genomics (CRAG), Consorci CSIC-IRTA-UAB-UB, Barcelona 08193 (Spain)

    2015-01-15

    The increasing development of novel methods and techniques facilitates the measurement of high-dimensional time series but challenges our ability for accurate modeling and predictions. The use of a general mathematical model requires the inclusion of many parameters, which are difficult to be fitted for relatively short high-dimensional time series observed. Here, we propose a novel method to accurately model a high-dimensional time series. Our method extends the barycentric coordinates to high-dimensional phase space by employing linear programming, and allowing the approximation errors explicitly. The extension helps to produce free-running time-series predictions that preserve typical topological, dynamical, and/or geometric characteristics of the underlying attractors more accurately than the radial basis function model that is widely used. The method can be broadly applied, from helping to improve weather forecasting, to creating electronic instruments that sound more natural, and to comprehensively understanding complex biological data.

  19. High heat flux capabilities of the Magnum-PSI linear plasma device

    Energy Technology Data Exchange (ETDEWEB)

    De Temmerman, G., E-mail: g.c.detemmerman@differ.nl; Berg, M.A. van den; Scholten, J.; Lof, A.; Meiden, H.J. van der; Eck, H.J.N. van; Morgan, T.W.; Kruijf, T.M. de; Zeijlmans van Emmichoven, P.A.; Zielinski, J.J.

    2013-10-15

    Magnum-PSI is an advanced linear plasma device uniquely capable of producing plasma conditions similar to those expected in the divertor of ITER both steady-state and transients. The machine is designed both for fundamental studies of plasma–surface interactions under high heat and particle fluxes, and as a high-heat flux facility for the tests of plasma-facing components under realistic plasma conditions. To study the effects of transient heat loads on a plasma-facing surface, a novel pulsed plasma source system as well as a high power laser is available. In this article, we will describe the capabilities of Magnum-PSI for high-heat flux tests of plasma-facing materials.

  20. Approximating high-dimensional dynamics by barycentric coordinates with linear programming.

    Science.gov (United States)

    Hirata, Yoshito; Shiro, Masanori; Takahashi, Nozomu; Aihara, Kazuyuki; Suzuki, Hideyuki; Mas, Paloma

    2015-01-01

    The increasing development of novel methods and techniques facilitates the measurement of high-dimensional time series but challenges our ability for accurate modeling and predictions. The use of a general mathematical model requires the inclusion of many parameters, which are difficult to be fitted for relatively short high-dimensional time series observed. Here, we propose a novel method to accurately model a high-dimensional time series. Our method extends the barycentric coordinates to high-dimensional phase space by employing linear programming, and allowing the approximation errors explicitly. The extension helps to produce free-running time-series predictions that preserve typical topological, dynamical, and/or geometric characteristics of the underlying attractors more accurately than the radial basis function model that is widely used. The method can be broadly applied, from helping to improve weather forecasting, to creating electronic instruments that sound more natural, and to comprehensively understanding complex biological data.

  1. 77 GHz MEMS antennas on high-resistivity silicon for linear and circular polarization

    KAUST Repository

    Sallam, M. O.

    2011-07-01

    Two new MEMS antennas operating at 77 GHz are presented in this paper. The first antenna is linearly polarized. It possesses a vertical silicon wall that carries a dipole on top of it. The wall is located on top of silicon substrate covered with a ground plane. The other side of the substrate carries a microstrip feeding network in the form of U-turn that causes 180 phase shift. This phase-shifter feeds the arms of the dipole antenna via two vertical Through-Silicon Vias (TSVs) that go through the entire wafer. The second antenna is circularly polarized and formed using two linearly polarized antennas spatially rotated with respect to each other by 90 and excited with 90 phase shift. Both antennas are fabricated using novel process flow on a single high-resistivity silicon wafer via bulk micromachining. Only three processing steps are required to fabricate these antennas. The proposed antennas have appealing characteristics, such as high polarization purity, high gain, and high radiation efficiency. © 2011 IEEE.

  2. Generation of High Purity Photon-Pair in a Short Highly Non-Linear Fiber

    Science.gov (United States)

    2013-01-01

    of entangled photon pairs in optical fiber attracted enormous interest due to its better spatial mode definition and inherent compatibility with...existing fiber optics technologies for long distance transmission, storage and processing. Entangled photon pair generation in optical fiber is...nonlinear microstructure fiber (HNMSF) [7]. In contrast, entangled photon pair generation at telecom wavelengths via SFWM using highly nonlinear fiber

  3. Evaluation for Long Term PM10 Concentration Forecasting using Multi Linear Regression (MLR and Principal Component Regression (PCR Models

    Directory of Open Access Journals (Sweden)

    Samsuri Abdullah

    2016-07-01

    Full Text Available Air pollution in Peninsular Malaysia is dominated by particulate matter which is demonstrated by having the highest Air Pollution Index (API value compared to the other pollutants at most part of the country. Particulate Matter (PM10 forecasting models development is crucial because it allows the authority and citizens of a community to take necessary actions to limit their exposure to harmful levels of particulates pollution and implement protection measures to significantly improve air quality on designated locations. This study aims in improving the ability of MLR using PCs inputs for PM10 concentrations forecasting. Daily observations for PM10 in Kuala Terengganu, Malaysia from January 2003 till December 2011 were utilized to forecast PM10 concentration levels. MLR and PCR (using PCs input models were developed and the performance was evaluated using RMSE, NAE and IA. Results revealed that PCR performed better than MLR due to the implementation of PCA which reduce intricacy and eliminate data multi-collinearity.

  4. Optical and Near-Infrared Polarimetry for a Highly Dormant Comet 209P/LINEAR

    CERN Document Server

    Kuroda, Daisuke; Watanabe, Makoto; Akitaya, Hiroshi; Takahashi, Jun; Hasegawa, Sunao; Ui, Takahiro; Kanda, Yuka; Takaki, Katsutoshi; Itoh, Ryosuke; Moritani, Yuki; Imai, Masataka; Goda, Shuhei; Takagi, Yuhei; Morihana, Kumiko; Honda, Satoshi; Arai, Akira; Hanayama, Hidekazu; Nagayama, Takahiro; Nogami, Daisaku; Sarugaku, Yuki; Murata, Katsuhiro; Morokuma, Tomoki; Saito, Yoshihiko; Oasa, Yumiko; Sekiguchi, Kazuhiro; Watanabe, Jun-ichi

    2015-01-01

    We conducted an optical and near-infrared polarimetric observation of the highly dormant Jupiter-Family Comet, 209P/LINEAR. Because of its low activity, we were able to determine the linear polarization degrees of the coma dust particles and nucleus independently, that is $P_n$=30.3$^{+1.3}_{-0.9}$% at $\\alpha$=92.2$^\\circ$ and $P_n$=31.0$^{+1.0}_{-0.7}$% at $\\alpha$=99.5$^\\circ$ for the nucleus, and $P_c$=28.8$^{+0.4}_{-0.4}$% at $\\alpha$=92.2$^\\circ$ and 29.6$^{+0.3}_{-0.3}$% at $\\alpha$=99.5$^\\circ$ for the coma. We detected no significant variation in $P$ at the phase angle coverage of 92.2$^\\circ$-99.5$^\\circ$, which may imply that the obtained polarization degrees are nearly at maximum in the phase-polarization curves. By fitting with an empirical function, we obtained the maximum values of linear polarization degrees $P_\\mathrm{max}$=30.8% for the nucleus and $P_\\mathrm{max}$=29.6% for the dust coma. The $P_\\mathrm{max}$ of the dust coma is consistent with those of dust-rich comets. The low geometric a...

  5. Linear drag law for high-Reynolds-number flow past an oscillating body

    Science.gov (United States)

    Agre, Natalie; Childress, Stephen; Zhang, Jun; Ristroph, Leif

    2016-07-01

    An object immersed in a fast flow typically experiences fluid forces that increase with the square of speed. Here we explore how this high-Reynolds-number force-speed relationship is affected by unsteady motions of a body. Experiments on disks that are driven to oscillate while progressing through air reveal two distinct regimes: a conventional quadratic relationship for slow oscillations and an anomalous scaling for fast flapping in which the time-averaged drag increases linearly with flow speed. In the linear regime, flow visualization shows that a pair of counterrotating vortices is shed with each oscillation and a model that views a train of such dipoles as a momentum jet reproduces the linearity. We also show that appropriate scaling variables collapse the experimental data from both regimes and for different oscillatory motions into a single drag-speed relationship. These results could provide insight into the aerodynamic resistance incurred by oscillating wings in flight and they suggest that vibrations can be an effective means to actively control the drag on an object.

  6. High-harmonic generation in benzene with linearly- and circularly-polarised laser pulses

    CERN Document Server

    Wardlow, Abigail

    2015-01-01

    High harmonic generation in benzene is studied using a mixed quantum-classical approach in which the electrons are described using time-dependent density functional theory while the ions move classically. The interaction with both circularly- and linearly-polarised infra-red ($\\lambda = 800$ nm) laser pulses of duration 10 cycles (26.7 fs) is considered. The effect of allowing the ions to move is investigated as is the effect of including self-interaction corrections to the exchange-correlation functional. Our results for circularly-polarised pulses are compared with previous calculations in which the ions were kept fixed and self-interaction corrections were not included while our results for linearly-polarised pulses are compared with both previous calculations and experiment. We find that even for the short duration pulses considered here, the ionic motion greatly influences the harmonic spectra. While ionization and ionic displacements are greatest when linearly-polarised pulses are used, the response to ...

  7. Hierarchical Shrinkage Priors and Model Fitting for High-dimensional Generalized Linear Models

    Science.gov (United States)

    Yi, Nengjun; Ma, Shuangge

    2013-01-01

    Genetic and other scientific studies routinely generate very many predictor variables, which can be naturally grouped, with predictors in the same groups being highly correlated. It is desirable to incorporate the hierarchical structure of the predictor variables into generalized linear models for simultaneous variable selection and coefficient estimation. We propose two prior distributions: hierarchical Cauchy and double-exponential distributions, on coefficients in generalized linear models. The hierarchical priors include both variable-specific and group-specific tuning parameters, thereby not only adopting different shrinkage for different coefficients and different groups but also providing a way to pool the information within groups. We fit generalized linear models with the proposed hierarchical priors by incorporating flexible expectation-maximization (EM) algorithms into the standard iteratively weighted least squares as implemented in the general statistical package R. The methods are illustrated with data from an experiment to identify genetic polymorphisms for survival of mice following infection with Listeria monocytogenes. The performance of the proposed procedures is further assessed via simulation studies. The methods are implemented in a freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). PMID:23192052

  8. Rail temperature rise characteristics caused by linear eddy current brake of high-speed train

    Directory of Open Access Journals (Sweden)

    Xiaoshan Lu

    2014-12-01

    Full Text Available The rail temperature rises when the linear eddy current brake of high-speed train is working, which may lead to a change of rail physical characteristics or an effect on train operations. Therefore, a study concerning the characteristics of rail temperature rise caused by eddy current has its practical necessity. In the research, the working principle of a linear eddy current brake is introduced and its FEA model is established. According to the generation mechanism of eddy current, the theoretical formula of the internal energy which is produced by the eddy current is deduced and the thermal load on the rail is obtained. ANSYS is used to simulate the rail temperature changes under different conditions of thermal loads. The research result shows the main factors which contribute to the rising of rail temperature are the train speed, brake gap and exciting current. The rail temperature rises non-linearly with the increase of train speed. The rail temperature rise curve is more sensitive to the exciting current than the air gap. Moreover, the difference stimulated by temperature rising between rails of 60 kg/m and 75 kg/m is presented as well.

  9. Speed optimized linear-mode high-voltage CMOS avalanche photodiodes with high responsivity.

    Science.gov (United States)

    Enne, R; Steindl, B; Zimmermann, H

    2015-10-01

    Two different speed optimized avalanche photodiodes (APDs) fabricated in a 0.35 μm standard high-voltage (HV) complementary metal-oxide-semiconductor (CMOS) process with a high unamplified responsivity (avalanche gain M=1) of 0.41 A/W at 670 nm are presented. These APDs differ regarding the effective doping of the deep p well (90% and 75%), using lateral well modulation doping. Compared to the -3  dB bandwidth of the unmodulated APD with 100% doping (850 MHz), this optimization leads to an improved bandwidth of 1.02 and 1.25 GHz for the 75% APD and 90% APD, respectively, both at a gain of M=50.

  10. Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Monomucleotides

    Science.gov (United States)

    Kanavarioti, Anastassia

    1997-08-01

    Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2-methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2+ in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MeImpU and 2-MeImpC produce about 65% of oligomers including 4% of the 3',5'-linked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of internucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MeImpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

  11. High concentrations of pepsin in bronchoalveolar lavage fluid from children with cystic fibrosis are associated with high interleukin-8 concentrations.

    LENUS (Irish Health Repository)

    McNally, P

    2012-02-01

    BACKGROUND: Gastro-oesophageal reflux is common in children with cystic fibrosis (CF) and is thought to be associated with pulmonary aspiration of gastric contents. The measurement of pepsin in bronchoalveolar lavage (BAL) fluid has recently been suggested to be a reliable indicator of aspiration. The prevalence of pulmonary aspiration in a group of children with CF was assessed and its association with lung inflammation investigated. METHODS: This was a cross-sectional case-control study. BAL fluid was collected from individuals with CF (n=31) and healthy controls (n=7). Interleukin-8 (IL-8), pepsin, neutrophil numbers and neutrophil elastase activity levels were measured in all samples. Clinical, microbiological and lung function data were collected from medical notes. RESULTS: The pepsin concentration in BAL fluid was higher in the CF group than in controls (mean (SD) 24.4 (27.4) ng\\/ml vs 4.3 (4.0) ng\\/ml, p=0.03). Those with CF who had raised pepsin concentrations had higher levels of IL-8 in the BAL fluid than those with a concentration comparable to controls (3.7 (2.7) ng\\/ml vs 1.4 (0.9) ng\\/ml, p=0.004). Within the CF group there was a moderate positive correlation between pepsin concentration and IL-8 in BAL fluid (r=0.48, p=0.04). There was no association between BAL fluid pepsin concentrations and age, sex, body mass index z score, forced expiratory volume in 1 s or Pseudomonas aeruginosa colonisation status. CONCLUSIONS: Many children with CF have increased levels of pepsin in the BAL fluid compared with normal controls. Increased pepsin levels were associated with higher IL-8 concentrations in BAL fluid. These data suggest that aspiration of gastric contents occurs in a subset of patients with CF and is associated with more pronounced lung inflammation.

  12. The Gent University 15 MeV high-current linear electron accelerator facility

    Science.gov (United States)

    Mondelaers, W.; Van Laere, K.; Goedefroot, A.; Van den Bossche, K.

    1996-01-01

    The Gent University 15 MeV 20kW linear electron accelerator facility was initially designed for fundamental nuclear physics research. During the last years a large effort has been devoted to the expansion of the range of machine applications in view of a new extensive experimental programme in the fields of atomic and solid-state physics, biomaterials research, polymer chemistry, space research, food technology, high-dose dosimetry and radiation therapy. The accelerator facility in its present configuration, the peripheral equipment and the experimental programme are described with emphasis on the original features.

  13. A Family of High-Performance Solvers for Linear Model Predictive Control

    DEFF Research Database (Denmark)

    Frison, Gianluca; Sokoler, Leo Emil; Jørgensen, John Bagterp

    2014-01-01

    In Model Predictive Control (MPC), an optimization problem has to be solved at each sampling time, and this has traditionally limited the use of MPC to systems with slow dynamic. In this paper, we propose an e_cient solution strategy for the unconstrained sub-problems that give the search......, and techniques such as inexact search direction and mixed precision computation. Finally, we test our HPMPC toolbox, a family of high-performance solvers tailored for MPC and implemented using these techniques, that is shown to be several times faster than current state-of-the-art solvers for linear MPC....

  14. Tunable Microwave Photonic Notch Filter Based on a high-birefringence linearly chirped fiber Bragg grating

    Energy Technology Data Exchange (ETDEWEB)

    Jin Yongxing; Dong Xinyong; Wang Jianfeng [Institute of Optoelectronic Technology, China Jiliang University, Hangzhou (China); Zhou Junqiang, E-mail: phyjyxin@gmail.com [Network Technology Research Centre, Nanyang Technological University (Singapore)

    2011-02-01

    In this paper, a continuously tunable microwave photonic notch filter is proposed and experimentally demonstrated. This filter is based on the differential group delay generated by a high-birefringence linearly chirped fiber Bragg grating. This microwave photonic filter belongs to the orthogonal polarization approach, polarization maintaining structure ensures the filter free from the random optical interference problem. Its response is induced by the differential group delay (DGD) of the Hi-Bi LCFBG and it can be varied by tuning the grating through adding gradient strength to the grating. Free spectral range tuning by 9.27 GHz with more than 35 dB notch rejection is achieved.

  15. Characterization and modeling of performance of Polymer Composites Reinforced with Highly Non-Linear Cellulosic Fibers

    Science.gov (United States)

    Rozite, L.; Joffe, R.; Varna, J.; Nyström, B.

    2012-02-01

    The behaviour of highly non-linear cellulosic fibers and their composite is characterized. Micro-mechanisms occurring in these materials are identified. Mechanical properties of regenerated cellulose fibers and composites are obtained using simple tensile test. Material visco-plastic and visco-elastic properties are analyzed using creep tests. Two bio-based resins are used in this study - Tribest and EpoBioX. The glass and flax fiber composites are used as reference materials to compare with Cordenka fiber laminates.

  16. Fast and high-quality reconstruction in electron tomography based on an enhanced linear forward model

    Science.gov (United States)

    Kohr, H.; Louis, A. K.

    2011-04-01

    We study single-axis electron tomography and present an improved version of the linear forward model given by Fanelli and Öktem (2008 Inverse Problems 24 013001) which accounts for inelastic scattering and image distortions caused by imperfect optics. Based on the concept of approximate inverse, we derive an algorithm of filtered backprojection type which is much faster than the frequently used iterative methods. Numerical tests with simulated and measured transmission electron microscope data and comparisons with other FBP-type methods reveal that our algorithm provides reconstructions with high contrast and resolution, while the noise level is significantly reduced.

  17. Dynamical Lie algebra method for highly excited vibrational state of asymmetric linear tetratomic molecules

    Institute of Scientific and Technical Information of China (English)

    冯东太; 丁世良; 王美山

    2003-01-01

    The highly excited vibrational states of asymmetric linear tetratomic molecules are studied in the framework of Lie algebra. By using symmetric group U1(4) U2(4) U3(4), we construct the Hamiltonian that includes not only Casimir operators but also Majorana operators M12,M13 and M23, which are useful for getting potential energy surface and force constants in Lie algebra method. By Lie algebra treatment, we obtain the eigenvalues of the Hamiltonian, and make the concrete calculation for molecule C2HF.

  18. 线聚光太阳能集热器发展综述%A Review of Linear Concentrated Solar Collectors’ Development

    Institute of Scientific and Technical Information of China (English)

    黄建新; 唐梓彭; 魏超

    2016-01-01

    线聚光太阳能集热器在太阳能光热发电、工业用热以及民用太阳能供热与制冷等领域有着广泛的应用前景。本文综述了两类典型线聚光太阳能集热器:抛物面槽式集热器(PTC)与线性菲涅尔反射器(LFR)的发展与现阶段应用状况,并对线聚光集热器在我国未来的应用前景进行了讨论。%Linear concentrated solar collectors have a wide prospect of applications in aspects like solar thermal power generation, industrial heat supply or domestic solar heating and cooling. This paper focused on two kinds of linear concen-trated solar collectors which are Parabolic Trough Collector, PTC and Linear Fresnel Reflector,LFR. Their developments and applications were reviewed and their future application prospect in China was discussed.

  19. A high efficiency and power factor, segmented linear constant current LED driver

    Science.gov (United States)

    Yongyuan, Li; Wei, Guo; Zhangming, Zhu

    2015-04-01

    A high efficiency, high power factor, and linear constant current LED driver based on adaptive segmented linear architecture is presented. When the input voltage varied, the proposed LED driver automatically switched over LED strings according to the segmented LED voltage drop, which increased the LED lighting time. The efficiency and power factor are improved, while the system design is simplified by this control scheme. Without the usage of electrolytic capacitor and magnetic components, the proposed driver possesses advantages of smaller size, longer lifetime and lower cost over others. The proposed driver is implemented in 0.8 μm 5 V/40 V HVCMOS process, which occupies an active area of 820 × 920 μm2. The measured results show that the average value of the internal reference voltage is 500 ± 7 mV, with a standard deviation of only 4.629 mV, thus LED current can be set accurately. Under 220 V root mean square 50 Hz utility voltage and the number ratio of the three LED strings being 47 : 17 : 16, the system can realize a high power factor of 0.974 and power conversion efficiency of 93.4%. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033).

  20. A Monolithic CMOS Magnetic Hall Sensor with High Sensitivity and Linearity Characteristics

    Directory of Open Access Journals (Sweden)

    Haiyun Huang

    2015-10-01

    Full Text Available This paper presents a fully integrated linear Hall sensor by means of 0.8 μm high voltage complementary metal-oxide semiconductor (CMOS technology. This monolithic Hall sensor chip features a highly sensitive horizontal switched Hall plate and an efficient signal conditioner using dynamic offset cancellation technique. An improved cross-like Hall plate achieves high magnetic sensitivity and low offset. A new spinning current modulator stabilizes the quiescent output voltage and improves the reliability of the signal conditioner. The tested results show that at the 5 V supply voltage, the maximum Hall output voltage of the monolithic Hall sensor microsystem, is up to ±2.1 V and the linearity of Hall output voltage is higher than 99% in the magnetic flux density range from ±5 mT to ±175 mT. The output equivalent residual offset is 0.48 mT and the static power consumption is 20 mW.

  1. A Monolithic CMOS Magnetic Hall Sensor with High Sensitivity and Linearity Characteristics

    Science.gov (United States)

    Huang, Haiyun; Wang, Dejun; Xu, Yue

    2015-01-01

    This paper presents a fully integrated linear Hall sensor by means of 0.8 μm high voltage complementary metal-oxide semiconductor (CMOS) technology. This monolithic Hall sensor chip features a highly sensitive horizontal switched Hall plate and an efficient signal conditioner using dynamic offset cancellation technique. An improved cross-like Hall plate achieves high magnetic sensitivity and low offset. A new spinning current modulator stabilizes the quiescent output voltage and improves the reliability of the signal conditioner. The tested results show that at the 5 V supply voltage, the maximum Hall output voltage of the monolithic Hall sensor microsystem, is up to ±2.1 V and the linearity of Hall output voltage is higher than 99% in the magnetic flux density range from ±5 mT to ±175 mT. The output equivalent residual offset is 0.48 mT and the static power consumption is 20 mW. PMID:26516864

  2. Development and characterization of a high speed linear- moving-stage for multispectral measurements

    Science.gov (United States)

    Rosenberger, M.; Preissler, M.; Fütterer, R.; Zhang, C.; Celestre, R.; Notni, G.

    2016-11-01

    Multispectral imaging is one of the key topics in the upcoming years, a lot of measurement tasks can be solved using the additional spectral information. For the separation of these additional information bands plenty technologies were developed in the last decades. All of them have characteristic advantages and disadvantages. One working principle is the use of a filter wheel containing different filters between the image sensor and the lens. The additional element inside the light propagation path as well as the lens imperfections lead to chromatic aberrations. To compensate the resulting focus error some investigation were made. One option is the movement of the image sensor stage to a better focus position. Therefore high precision moving stage with high movement speed are characteristic parameters which have to be considered during the construction. In this paper a linear motor stage paired with two high precision linear bearings were connected together to achieve the demanded requirements. For the evaluation of this new approach, several measurements determining the dynamic as well as the static specifications were made to proof the achieved characteristics and will be shown in the paper. With this approach, a miniaturised precision system inside the multispectral imager a precision repeatability of less than four microns can be achieved.

  3. High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

    Energy Technology Data Exchange (ETDEWEB)

    Tantawi, S.G.; Nantista, C.D.; Dolgashev, V.A.; Pearson, C.; Nelson, J.; Jobe, K.; Chan, J.; Fant, K.; Frisch, J.; /SLAC; Atkinson, D.; /LLNL, Livermore

    2005-08-10

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  4. Terahertz radiation source using a high-power industrial electron linear accelerator

    Indian Academy of Sciences (India)

    YASHVIR KALKAL; VINIT KUMAR

    2017-04-01

    High-power $(\\sim 100 kW)$ industrial electron linear accelerators (linacs) are used for irradiations, e.g., for pasteurization of food products, disinfection of medical waste, etc.We propose that high-power electron beam from such an industrial linac can first pass through an undulator to generate useful terahertz (THz) radiation, and the spent electron beam coming out of the undulator can still be used for the intended industrial applications. This will enhance the utilization of a high-power industrial linac. We have performed calculation of spontaneous emission in the undulator to show that for typical parameters, continuous terahertz radiation having power of the order of $\\mu$W can be produced, which may be useful for many scientific applications such as multispectral imaging of biological samples, chemical samples etc.

  5. Terahertz radiation source using a high-power industrial electron linear accelerator

    Science.gov (United States)

    Kalkal, Yashvir; Kumar, Vinit

    2017-04-01

    High-power (˜ 100 kW) industrial electron linear accelerators (linacs) are used for irradiations, e.g., for pasteurization of food products, disinfection of medical waste, etc. We propose that high-power electron beam from such an industrial linac can first pass through an undulator to generate useful terahertz (THz) radiation, and the spent electron beam coming out of the undulator can still be used for the intended industrial applications. This will enhance the utilization of a high-power industrial linac. We have performed calculation of spontaneous emission in the undulator to show that for typical parameters, continuous terahertz radiation having power of the order of μW can be produced, which may be useful for many scientific applications such as multispectral imaging of biological samples, chemical samples etc.

  6. High pressure inertial focusing for separating and concentrating bacteria at high throughput

    Science.gov (United States)

    Cruz, J.; Hooshmand Zadeh, S.; Graells, T.; Andersson, M.; Malmström, J.; Wu, Z. G.; Hjort, K.

    2017-08-01

    Inertial focusing is a promising microfluidic technology for concentration and separation of particles by size. However, there is a strong correlation of increased pressure with decreased particle size. Theory and experimental results for larger particles were used to scale down the phenomenon and find the conditions that focus 1 µm particles. High pressure experiments in robust glass chips were used to demonstrate the alignment. We show how the technique works for 1 µm spherical polystyrene particles and for Escherichia coli, not being harmful for the bacteria at 50 µl min-1. The potential to focus bacteria, simplicity of use and high throughput make this technology interesting for healthcare applications, where concentration and purification of a sample may be required as an initial step.

  7. Simultaneous determination of multiple marker constituents in concentrated Gegen Tang granule by high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Yip Yuekeung

    2007-06-01

    Full Text Available Abstract Background Concentrated Gegen Tang (GT granule is a widely available traditional Chinese medicinal product for the treatment of cold and flu. There was no reliable analytical method available for the quality assessment of GT granules. Methods An HPLC method with an Agilent Zorbax SB-Phenyl Stablebond column (250 × 4.6 mm, 5 μm was developed and validated. The mobile phase gradient was a mixture of 0.1% trifluoroacetic acid (TFA in acetonitrile (ACN and 0.1% TFA in water. The detection with a diode-array detector was set at 207, 230, 250 and 275 nm. Seven components, namely puerarin, daidzein, paeoniflorin, cinnamic acid, glycyrrhizin, ephedrine and pseudoephedrine were selected as marker compounds for the evaluation. Results The regression equations revealed good linear relationships (correlation coefficients: 0.9994–0.9998 between the peak areas and concentrations. The recovery was between 98.8% and 101.7% with good precision and accuracy. The quality of GT granule from four different manufacturers was evaluated with this newly developed method. Samples from four manufacturers showed similar profiles but contents of the detected markers varied significantly among manufacturers and batches. Conclusion A new method using high performance liquid chromatography (HPLC has been developed for simple and reliable quality control of commercial concentrated GT granules. Sensitivity was increased by multi-wavelength detection. The contents of selected marker components in GT granules varied significantly among manufacturers and batches, making it necessary to evaluate the quality of concentrated GT granules in the market.

  8. Effects of exposure to high concentrations of waterborne Tl on K and Tl concentrations in Chironomus riparius larvae.

    Science.gov (United States)

    Belowitz, Ryan; Leonard, Erin M; O'Donnell, Michael J

    2014-11-01

    Thallium (Tl) is a non-essential metal which is released into the environment primarily as the result of anthropogenic activities such as fossil fuel burning and smelting of ores. The ionic radius of monovalent Tl⁺ is similar to that of K⁺ and Tl⁺ may thus interfere with K⁺-dependent processes. We determined that the acute (48 h) lethal concentration where 50% of the organisms do not survive (LC₅₀) of Tl for 4th instar Chironomus riparius larvae was 723 μmol L⁻¹. Accumulation of Tl by the whole animal was saturable, with a maximum accumulation (Jmax) of 4637 μmol kg⁻¹ wet mass, and K(D) of 670 μmol Tl l⁻¹. Tl accumulation by the gut appeared saturable at the lowest four Tl concentrations, with a Jmax of 2560 μmol kg⁻¹ wet mass and a K(D) of 54.5 μmol Tl l⁻¹. The saturable accumulation at the gut may be indicative of a limited capacity for intracellular detoxification, such as storage in lysosomes or complexation with metal-binding proteins. Tl accumulation by the hemolymph was found to be linear and Tl concentrations in the hemolymph were ~75% of the exposure concentration at Tl exposures >26.9 μmol L⁻¹. There was not a significant decrease in whole animal, gut or hemolymph K during exposure to waterborne Tl at any of the concentrations tested (up to 1500 μmol L⁻¹). The avoidance of hypokalemia by C. riparius larvae may contribute to survival during acute waterborne exposures to Tl. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Area under the curve predictions of dalbavancin, a new lipoglycopeptide agent, using the end of intravenous infusion concentration data point by regression analyses such as linear, log-linear and power models.

    Science.gov (United States)

    Bhamidipati, Ravi Kanth; Syed, Muzeeb; Mullangi, Ramesh; Srinivas, Nuggehally

    2017-03-14

    1. Dalbavancin, a lipoglycopeptide, is approved for treating gram-positive bacterial infections. Area under plasma concentration versus time curve (AUCinf) of dalbavancin is a key parameter and AUCinf/MIC ratio is a critical pharmacodynamic marker. 2. Using end of intravenous infusion concentration (i.e. Cmax) Cmax versus AUCinf relationship for dalbavancin was established by regression analyses (i.e. linear, log-log, log-linear and power models) using 21 pairs of subject data. 3. The predictions of the AUCinf were performed using published Cmax data by application of regression equations. The quotient of observed/predicted values rendered fold difference. The mean absolute error (MAE)/root mean square error (RMSE) and correlation coefficient (r) were used in the assessment. 4. MAE and RMSE values for the various models were comparable. The Cmax versus AUCinf exhibited excellent correlation (r > 0.9488). The internal data evaluation showed narrow confinement (0.84-1.14-fold difference) with a RMSE regression models, a single time point strategy of using Cmax (i.e. end of 30-min infusion) is amenable as a prospective tool for predicting AUCinf of dalbavancin in patients.

  10. New PSA high concentration solar furnace SF40

    Science.gov (United States)

    Rodriguez, Jose; Cañadas, Inmaculada; Zarza, Eduardo

    2016-05-01

    A new solar furnace has been designed and built at Plataforma Solar de Almería. In this work, its main components such as heliostat, concentrator, attenuator and test table, and the method used to align them are described. Other equipment like the auxiliary systems necessary for the solar operation, vacuum chamber and gas system are outlined too. Finally, the thermal characteristics of the focus were measured during a test campaign, where different planes along the optical axis were scanned with a radiometer, and the peak flux was obtained and is presented in the last section of this report.

  11. High-performance flat-panel solar thermoelectric generators with high thermal concentration.

    Science.gov (United States)

    Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

    2011-05-01

    The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m(-2)) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity.

  12. Investigations of non-linear polymers as high performance lubricant additives

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Joshua W.; Bhattacharya, Priyanka; Qu, Jun; Bays, J. Timothy; Cosimbescu, Lelia

    2015-03-22

    Off-the-shelf available engine oils contain an assortment of additives that increase the performance of base oils and maximize the overall efficiency of the machine. With ever increasing requirements for fuel efficiency, the demand for novel materials that outperform older generations is also on the rise. One approach towards increasing overall efficiency is to reduce internal friction and wear in an engine. From an additive approach, this is typically achieved by altering the bulk oil’s viscosity at high temperatures via polymers. In general, the hydrodynamic volume of polymers increase (expand) at elevated temperatures and decrease (contract/deflate) with declining temperatures and this effect is enhanced be carefully designing specific structures and architectures. The natural thinning tendency of base oil with increasing temperatures is in part mitigated by the expansion of the macromolecules added, and the overall effect is decreasing the viscosity losses at high temperatures. Traditional polymer architectures vary from linear to dendritic, where linear polymers of the same chemical composition and molecular weight to its dendritic counterpart will undergo a more significant free volume change in solution with regards to temperature changes. This advantage has been exploited in the literature towards the production of viscosity modifiers. However, one major disadvantage of linear polymers is degradation due to mechanical shear forces and high temperatures causing a shorter additive lifetime. Dendrimers on the other hand are known to demonstrate superior robustness to shear degradation when compared to their respective linear counterparts. An additional advantage of the dendritic architecture is the ability to tailor the peripheral end-groups towards influencing polymer-solvent and/or polymer-surface interactions. Comb-burst hyperbranched polymers are a hybrid of the aforementioned architectures and provide several compromises between the traditional

  13. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    Energy Technology Data Exchange (ETDEWEB)

    Womac, A.R. [University of Tennessee; Igathinathane, C. [Mississippi State University (MSU); Sokhansanj, Shahabaddine [ORNL; Narayan, S. [First American Scientific Co.

    2009-04-01

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.

  14. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    Energy Technology Data Exchange (ETDEWEB)

    Igathinathane, C. [Agricultural and Biological Engineering Department, 130 Creelman Street, Mississippi State University, Mississippi State, Mississippi 39762 (United States); Womac, A.R. [Department of Biosystems Engineering and Soil Science, 2506 E. J. Chapman Drive, The University of Tennessee, Knoxville, Tennessee 37996 (United States); Sokhansanj, S. [Oak Ridge National Laboratory, Environmental Sciences Division, Oak Ridge, P. O. Box 2008, Tennessee 37831 (United States); Narayan, S. [First American Scientific Company, 100 Park Royal South West Vancouver, British Columbia, V7T 1A2 (Canada)

    2009-04-15

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force-displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4-5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths {>=} 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks. (author)

  15. Lygus hesperus (Heteroptera: Miridae) tolerates high concentrations of dietary nickel

    Institute of Scientific and Technical Information of China (English)

    ROBERT S. BOYD

    2007-01-01

    Nickel hyperaccumulator plants contain unusually elevated levels of Ni (> 1 000 μg Ni/g). Some insect herbivores, including Lygus hesperus (Western tarnished plant bug), have been observed feeding on the California Ni hyperaccumulator Streptanthus polygaloides. This bug may be able to utilize S. polygaloides as a host either through its feeding behavior or by physiological tolerance of Ni. This experiment determined the Ni tolerance of L. hesperus by offering insects artificial diet amended with 0,0.4, 1, 2, 4.5,10, 20 and 40 mmol Ni/L and recording survival. Survival varied due to Ni concentration, with diets containing 10 mmol Ni/L and greater resulting in significantly lower survival compared to the control (0 mmol Ni/L) treatment. Insects tolerated diet containing as much as 4.5 mmol Ni/L, a relatively elevated Ni concentration. I conclude that L. hesperus can feed on S. polygaloides because it is Ni-tolerant, probably due to physiological mechanisms that provide it with resistance to plant chemical defenses including elemental defenses such as hyperaccumulated Ni.

  16. A high-linearity SiGe RF power amplifier for 3G and 4G small basestations

    OpenAIRE

    Johansson, Ted; Solati, Noora; Fritzin, Jonas

    2012-01-01

    This article presents the design and evaluation of a linear 3.3V SiGe power amplifier for 3G and 4G femtocells with 18dBm modulated output power at 2140 MHz. Different biasing schemes to achieve high linearity with low standby current were studied. The adjacent channel power ratio linearity performance with wide-band code division multiple access (3G) and long term evolution (4G) downlink signals were compared and differences analysed and explained.

  17. The challenges of transitioning from linear to high-order overlay control in advanced lithography

    Science.gov (United States)

    Adel, M.; Izikson, P.; Tien, D.; Huang, C. K.; Robinson, J. C.; Eichelberger, B.

    2008-03-01

    In the lithography section of the ITRS 2006 update, at the top of the list of difficult challenges appears the text "overlay of multiple exposures including mask image placement". This is a reflection of the fact that today overlay is becoming a major yield risk factor in semiconductor manufacturing. Historically, lithographers have achieved sufficient alignment accuracy and hence layer to layer overlay control by relying on models which define overlay as a linear function of the field and wafer coordinates. These linear terms were easily translated to correctibles in the available exposure tool degrees of freedom on the wafer and reticle stages. However, as the 45 nm half pitch node reaches production, exposure tool vendors have begun to make available, and lithographers have begun to utilize so called high order wafer and field control, in which either look up table or high order polynomial models are modified on a product by product basis. In this paper, the major challenges of this transition will be described. It will include characterization of the sources of variation which need to be controlled by these new models and the overlay and alignment sampling optimization problem which needs to be addressed, while maintaining the ever tightening demands on productivity and cost of ownership.

  18. Uncovering signal transduction networks from high-throughput data by integer linear programming.

    Science.gov (United States)

    Zhao, Xing-Ming; Wang, Rui-Sheng; Chen, Luonan; Aihara, Kazuyuki

    2008-05-01

    Signal transduction is an important process that transmits signals from the outside of a cell to the inside to mediate sophisticated biological responses. Effective computational models to unravel such a process by taking advantage of high-throughput genomic and proteomic data are needed to understand the essential mechanisms underlying the signaling pathways. In this article, we propose a novel method for uncovering signal transduction networks (STNs) by integrating protein interaction with gene expression data. Specifically, we formulate STN identification problem as an integer linear programming (ILP) model, which can be actually solved by a relaxed linear programming algorithm and is flexible for handling various prior information without any restriction on the network structures. The numerical results on yeast MAPK signaling pathways demonstrate that the proposed ILP model is able to uncover STNs or pathways in an efficient and accurate manner. In particular, the prediction results are found to be in high agreement with current biological knowledge and available information in literature. In addition, the proposed model is simple to be interpreted and easy to be implemented even for a large-scale system.

  19. Entropy Generation in Flow of Highly Concentrated Non-Newtonian Emulsions in Smooth Tubes

    Directory of Open Access Journals (Sweden)

    Rajinder Pal

    2014-10-01

    Full Text Available Entropy generation in adiabatic flow of highly concentrated non-Newtonian emulsions in smooth tubes of five different diameters (7.15–26.54 mm was investigated experimentally. The emulsions were of oil-in-water type with dispersed-phase concentration (Φ ranging from 59.61–72.21% vol. The emulsions exhibited shear-thinning behavior in that the viscosity decreased with the increase in shear rate. The shear-stress (τ versus shear rate (˙γ data of emulsions could be described well by the power-law model: τ=K˙γn. The flow behavior index n was less than 1 and it decreased sharply with the increase in Φ whereas the consistency index K increased rapidly with the increase in Φ . For a given emulsion and tube diameter, the entropy generation rate per unit tube length increased linearly with the increase in the generalized Reynolds number ( Re_n on a log-log scale. For emulsions with Φ ≤65.15 % vol., the entropy generation rate decreased with the increase in tube diameter. A reverse trend in diameter-dependence was observed for the emulsion with Φ of 72.21% vol. New models are developed for the prediction of entropy generation rate in flow of power-law emulsions in smooth tubes. The experimental data shows good agreement with the proposed models.

  20. High Energy Density Lithium Air Batteries for Oxygen Concentrators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For NASA's Exploration Medical Capabilities mission, extremely high specific energy power sources, with specific energy over 2000 Wh/kg, are urgently sought after....

  1. Celecoxib concentration predicts decrease in prostaglandin E2 concentrations in nipple aspirate fluid from high risk women

    Directory of Open Access Journals (Sweden)

    Flynn John T

    2008-02-01

    Full Text Available Abstract Background Epidemiologic studies suggest that long term low dose celecoxib use significantly lowers breast cancer risk. We previously demonstrated that 400 mg celecoxib taken twice daily for 2 weeks lowered circulating plasma and breast nipple aspirate fluid (NAF prostaglandin (PGE2 concentrations in post- but not premenopausal high risk women. We hypothesized that circulating concentrations of celecoxib influenced PGE2 response, and that plasma levels of the drug are influenced by menopausal status. To address these hypotheses, the aims of the study were to determine: 1 if circulating plasma concentrations of celecoxib correlated with the change in plasma or NAF PGE2 concentrations from baseline to end of treatment, and 2 whether menopausal status influenced circulating levels of celecoxib. Methods Matched NAF and plasma were collected from 46 high risk women who were administered celecoxib twice daily for two weeks, 20 subjects receiving 200 mg and 26 subjects 400 mg of the agent. NAF and plasma samples were collected before and 2 weeks after taking celecoxib. Results In women taking 400 mg bid celecoxib, plasma concentrations of the agent correlated inversely with the change in NAF PGE2 levels from pre- to posttreatment. Nonsignificant trends toward higher celecoxib levels were observed in post- compared to premenopausal women. There was a significant decrease in NAF but not plasma PGE2 concentrations in postmenopausal women who took 400 mg celecoxib (p = 0.03. Conclusion In high risk women taking 400 mg celecoxib twice daily, plasma concentrations of celecoxib correlated with downregulation of PGE2 production by breast tissue. Strategies synergistic with celecoxib to downregulate PGE2 are of interest, in order to minimize the celecoxib dose required to have an effect.

  2. A High-Frequency High Frame Rate Duplex Ultrasound Linear Array Imaging System for Small Animal Imaging

    Science.gov (United States)

    Zhang, Lequan; Xu, Xiaochen; Hu, Changhong; Sun, Lei; Yen, Jesse T.; Cannata, Jonathan M.; Shung, K. Kirk

    2010-01-01

    High-frequency (HF) ultrasound imaging has been shown to be useful for non-invasively imaging anatomical structures of the eye and small animals in biological and pharmaceutical research, achieving superior spatial resolution. Cardiovascular research utilizing mice requires not only real-time B-scan imaging, but also ultrasound Doppler to evaluate both anatomy and blood flow of the mouse heart. This paper reports the development of a high frequency ultrasound duplex imaging system capable of both B-mode imaging and Doppler flow measurements, using a 64-element linear array. The system included a HF pulsed-wave Doppler module, a 32-channel HF B-mode imaging module, a PC with a 200 MS/s 14-bit A/D card, and real-time LabView software. A 50dB signal-to-noise ratio (SNR) and a depth of penetration of larger than 12 mm were achieved using a 35 MHz linear array with 50 μm pitch. The two-way beam widths were determined to be 165 μm to 260 μm and the clutter energy to total energy ratio (CTR) were 9.1 dB to 12 dB, when the array was electronically focused at different focal points at depths from 4.8 mm to 9.6 mm. The system is capable of acquiring real-time B-mode images at a rate greater than 400 frames per second (fps) for a 4.8 × 13 mm field of view, using a 30 MHz 64-element linear array with 100 μm pitch. Sample in vivo cardiac high frame rate images and duplex images of mouse hearts are shown to assess its current imaging capability and performance for small animals. PMID:20639149

  3. Design of a Linear Variable Differential Transformer With High Rejection to External Interfering Magnetic Field

    CERN Document Server

    Martino, M; Losito, R; Masi, A; Danisi, A

    2010-01-01

    The sensitivity of linear variable differential transformer (LVDT) position sensors to external slowly varying magnetic fields represents a critical issue when these sensors are installed close to high-current cables or electrical motors with significant fringe fields. The resulting position error can reach several hundreds of micrometers against a specified uncertainty normally below a few micrometers. In this paper, the design of a LVDT position sensor with high rejection to external constant or slowly varying magnetic fields is addressed by exploiting the finite element method (FEM) simulator FLUX. A shield, isolated from the sensor's magnetic circuit, has been considered to reduce the effect of magnetic fields on the secondary voltages of the LVDT. In addition, a dc current is used in order to polarize the magnetic circuit to reduce the sensitivity of the sensor to external interferences.

  4. Modeling and comparison of superconducting linear actuators for highly dynamic motion

    Directory of Open Access Journals (Sweden)

    Bruyn B.J.H. de

    2015-12-01

    Full Text Available This paper presents a numerical modeling method for AC losses in highly dynamic linear actuators with high temperature superconducting (HTS tapes. The AC losses and generated force of two actuators, with different placement of the cryostats, are compared. In these actuators, the main loss component in the superconducting tapes are hysteresis losses, which result from both the non-sinusoidal phase currents and movement of the permanent magnets. The modeling method, based on the H-formulation of the magnetic fields, takes into account permanent magnetization and movement of permanent magnets. Calculated losses as function of the peak phase current of both superconducting actuators are compared to those of an equivalent non-cryogenic actuator.

  5. High energy X-ray photon counting imaging using linear accelerator and silicon strip detectors

    Science.gov (United States)

    Tian, Y.; Shimazoe, K.; Yan, X.; Ueda, O.; Ishikura, T.; Fujiwara, T.; Uesaka, M.; Ohno, M.; Tomita, H.; Yoshihara, Y.; Takahashi, H.

    2016-09-01

    A photon counting imaging detector system for high energy X-rays is developed for on-site non-destructive testing of thick objects. One-dimensional silicon strip (1 mm pitch) detectors are stacked to form a two-dimensional edge-on module. Each detector is connected to a 48-channel application specific integrated circuit (ASIC). The threshold-triggered events are recorded by a field programmable gate array based counter in each channel. The detector prototype is tested using 950 kV linear accelerator X-rays. The fast CR shaper (300 ns pulse width) of the ASIC makes it possible to deal with the high instant count rate during the 2 μs beam pulse. The preliminary imaging results of several metal and concrete samples are demonstrated.

  6. High energy X-ray photon counting imaging using linear accelerator and silicon strip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Y., E-mail: cycjty@sophie.q.t.u-tokyo.ac.jp [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Shimazoe, K.; Yan, X. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ueda, O.; Ishikura, T. [Fuji Electric Co., Ltd., Fuji, Hino, Tokyo 191-8502 (Japan); Fujiwara, T. [National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Uesaka, M.; Ohno, M. [Nuclear Professional School, the University of Tokyo, 2-22 Shirakata-shirane, Tokai, Ibaraki 319-1188 (Japan); Tomita, H. [Department of Quantum Engineering, Nagoya University, Furo, Chikusa, Nagoya 464-8603 (Japan); Yoshihara, Y. [Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Takahashi, H. [Department of Bioengineering, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Nuclear Engineering and Management, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2016-09-11

    A photon counting imaging detector system for high energy X-rays is developed for on-site non-destructive testing of thick objects. One-dimensional silicon strip (1 mm pitch) detectors are stacked to form a two-dimensional edge-on module. Each detector is connected to a 48-channel application specific integrated circuit (ASIC). The threshold-triggered events are recorded by a field programmable gate array based counter in each channel. The detector prototype is tested using 950 kV linear accelerator X-rays. The fast CR shaper (300 ns pulse width) of the ASIC makes it possible to deal with the high instant count rate during the 2 μs beam pulse. The preliminary imaging results of several metal and concrete samples are demonstrated.

  7. Linearity Analysis on a Series-Split Capacitor Array for High-Speed SAR ADCs

    Directory of Open Access Journals (Sweden)

    Yan Zhu

    2010-01-01

    Full Text Available A novel Capacitor array structure for Successive Approximation Register (SAR ADC is proposed. This circuit efficiently utilizes charge recycling to achieve high-speed of operation and it can be applied to high-speed and low-to-medium-resolution SAR ADC. The parasitic effects and the static linearity performance, namely, the INL and DNL, of the proposed structure are theoretically analyzed and behavioral simulations are performed to demonstrate its effectiveness under those nonidealities. Simulation results show that to achieve the same conversion performance the proposed capacitor array structure can reduce the average power consumed from the reference ladder by 90% when compared to the binary-weighted splitting capacitor array structure.

  8. Non-linear interaction between high energy ions and MHD-modes

    Energy Technology Data Exchange (ETDEWEB)

    Bergkvist, Tommy

    2001-12-01

    When heating a fusion plasma with ICRE or NBI a non-Maxwellian distribution function with high energy ions is created. Ions which are in resonance with a MHD mode will interact with the electric field from the mode and in some circumstances energy will flow from the particles to the mode or opposite. A quasi-linear model for the interaction between high energy ions and a MHD mode has been developed. To solve the time evolution of the MHD mode a module has been implemented into the Monte Carlo code FIDO, which is used for calculating a 3-dimensional distribution function. The model has been tested for an internal kink mode during fishbone oscillations.

  9. The linear-quadratic model is inappropriate to model high dose per fraction effects in radiosurgery.

    Science.gov (United States)

    Kirkpatrick, John P; Meyer, Jeffrey J; Marks, Lawrence B

    2008-10-01

    The linear-quadratic (LQ) model is widely used to model the effect of total dose and dose per fraction in conventionally fractionated radiotherapy. Much of the data used to generate the model are obtained in vitro at doses well below those used in radiosurgery. Clinically, the LQ model often underestimates tumor control observed at radiosurgical doses. The underlying mechanisms implied by the LQ model do not reflect the vascular and stromal damage produced at the high doses per fraction encountered in radiosurgery and ignore the impact of radioresistant subpopulations of cells. The appropriate modeling of both tumor control and normal tissue toxicity in radiosurgery requires the application of emerging understanding of molecular-, cellular-, and tissue-level effects of high-dose/fraction-ionizing radiation and the role of cancer stem cells.

  10. Determination of water quality variables, endotoxin concentration, and enterobacteriaceae concentration and identification in Southern High Plains dairy lagoons

    Science.gov (United States)

    The objectives of this study were to determine the concentration of endotoxin, determine 20 water quality variables, and identify and enumerate fungal and bacterial pathogens from United States southern High Plains dairy lagoons and control lakes during summer and winter. Water samples were collecte...

  11. Linear concentrating collector as an air heater in the heating system of building in Polish climatic conditions

    Directory of Open Access Journals (Sweden)

    Nemś Magdalena

    2016-01-01

    Full Text Available The article presents the analysis of the performance of a concentrating collector in the heating system of a residential building. Air was used as the working fluid. The heating requirements of the building were determined for each day of the year. The amount of direct irradiation reaching the absorber’s surface on all the days of the year was determined with the use of hourly meteorological data for Wroclaw, shared by the Ministry of Infrastructure and Growth. It was assumed that the collector is equipped with a tracking system working in one axis. Calculations and comparisons were made for the amount of solar irradiation for three values of the receiver’s inclination angle: β1=60°, β2=90° and β3=30°. Statistical method was used in order to determine the optimum inclination of the mirror and the amount of flowing air. This method involves creating a plan of experiment with three levels of changeability for two input factors. In the last stage, the amount of heat obtained from the installation during all the days of the year was analysed. The gains were juxtaposed on the diagram with the building’s heat demand. The analysis has shown that the heat requirements can be met only partially.

  12. The pulsed linear induction motor concept for high-speed trains

    Energy Technology Data Exchange (ETDEWEB)

    Turman, B.N.; Marder, B.M.; Rohwein, G.J.; Aeschliman, D.P.; Kelley, J.B.; Cowan, M.; Zimmerman, R.M.

    1995-06-01

    The SERAPBIM (SEgmented RAil PHased Induction Motor) concept is a linear induction motor concept which uses rapidly-pulsed magnetic fields and a segmented reaction rail, as opposed to low-frequency fields and continuous reaction rails found in conventional linear induction motors. These improvements give a high-traction, compact, and efficient linear motor that has potential for advanced high speed rail propulsion. In the SERAPBIM concept, coils on the vehicle push against a segmented aluminum rail, which is mounted on the road bed. Current is pulsed as the coils cross an edge of the segmented rail, inducing surface currents which repel the coil. The coils must be pulsed in synchronization with the movement by reaction rail segments. This is provided by a sense-and-fire circuit that controls the pulsing of the power modulators. Experiments were conducted to demonstrate the feasibility of the pulsed induction motor and to collect data that could be used for scaling calculations. A 14.4 kg aluminum plate was accelerated down a 4 m track to speeds of over 15 m/sec with peak thrust up to 18 kN per coilset. For a trainset capable of 200 mph speed, the SERAPHIM concept design is based on coils which are each capable of producing up to 3.5 kN thrust, and 30 coil pairs are mounted on each power car. Two power cars, one at each end of the train, provide 6 MW from two gas turbine prime power units. The thrust is about 210.000 N and is essentially constant up to 200 km/hr since wheel slippage does not limit thrust as with conventional wheeled propulsion. A key component of the SERAPHIM concept is the use of passive wheel-on-rah support for the high speed vehicle. Standard steel wheels are capable of handling over 200 mph. The SERAPHIM cost is comparable to that for steel-wheel high-speed rail, and about 10% to 25% of the projected costs for a comparable Maglev system.

  13. High-Performance Near-Infrared Luminescent Solar Concentrators.

    Science.gov (United States)

    Rondão, Raquel; Frias, Ana R; Correia, Sandra F H; Fu, Lianshe; de Zea Bermudez, Verónica; André, Paulo S; Ferreira, Rute A S; Carlos, Luís D

    2017-04-12

    Luminescent solar concentrators (LSCs) appear as candidates to enhance the performance of photovoltaic (PV) cells and contribute to reduce the size of PV systems, decreasing, therefore, the amount of material needed and thus the cost associated with energy conversion. One way to maximize the device performance is to explore near-infrared (NIR)-emitting centers, resonant with the maximum optical response of the most common Si-based PV cells. Nevertheless, very few examples in the literature demonstrate the feasibility of fabricating LSCs emitting in the NIR region. In this work, NIR-emitting LSCs are reported using silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) (SiNc or NIR775) immobilized in an organic-inorganic tri-ureasil matrix (t-U(5000)). The photophysical properties of the SiNc dye incorporated into the tri-ureasil host closely resembled those of SiNc in tetrahydrofuran solution (an absolute emission quantum yield of ∼0.17 and a fluorescence lifetime of ∼3.6 ns). The LSC coupled to a Si-based PV device revealed an optical conversion efficiency of ∼1.5%, which is among the largest values known in the literature for NIR-emitting LSCs. The LSCs were posteriorly coupled to a Si-based commercial PV cell, and the synergy between the t-U(5000) and SiNc molecules enabled an effective increase in the external quantum efficiency of PV cells, exceeding 20% in the SiNc absorption region.

  14. An astigmatic corrected target-aligned heliostat for high concentration

    Energy Technology Data Exchange (ETDEWEB)

    Zaibel, R.; Dagan, E.; Karni, J. [Solar Research Facility, The Weizmann Institute of Science, Rehovot (Israel); Ries, Harald [Ludwig-Maximilians-Universitaet, Sektion Physik, Munich (Germany)

    1995-05-28

    Conventional heliostats suffer from astigmatism for non-normal incidence. For tangential rays the focal length is shortened while for sagittal rays it is longer than the nominal focal length. Due to this astigmatism it is impossible to produce a sharp image of the sun, and the rays will be spread over a larger area. In order to correct this the heliostat should have different curvature radii along the sagittal and tangential direction in the heliostat plane just like a non axial part of a paraboloid. In conventional heliostats, where the first axis, fixed with respect to the ground, is vertical while the second, fixed with respect to the reflector surface, is horizontal, such an astigmatism correction is not practical because the sagittal and tangential directions rotate with respect to the reflector. We suggest an alternative mount where the first axis is oriented towards the target. The second axis, perpendicular to the first and tangent to the reflector, coincides with the tangential direction. With this mounting sagittal and tangential direction are fixed with respect to the reflector during operation. Therefore a partial astigmatism compensation is possible. We calculate the optimum correction and show the performance of the heliostat. We also show predicted yearly average concentrations

  15. The high current, fast, 100ns, Linear Transformer Driver (LTD) developmental project at Sandia National Laboratories.

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Kevin S.; Long, Finis W.; Sinebryukhov, Vadim A. (High Current Electronic Institute (HCEI), Tomsk, Russia); Kim, Alexandre A. (High Current Electronic Institute (HCEI), Tomsk, RUSSIA); Wakeland, Peter Eric (Ktech Corporation, Albuquerque, NM); McKee, G. Randall; Woodworth, Joseph Ray; McDaniel, Dillon Heirman; Fowler, William E.; Mazarakis, Michael Gerrassimos; Porter, John Larry, Jr.; Struve, Kenneth William; Stygar, William A.; LeChien, Keith R.; Matzen, Maurice Keith

    2010-04-01

    Sandia National Laboratories, Albuquerque, N.M., USA, in collaboration with the High Current Electronic Institute (HCEI), Tomsk, Russia, is developing a new paradigm in pulsed power technology: the Linear Transformer Driver (LTD) technology. This technological approach can provide very compact devices that can deliver very fast high current and high voltage pulses straight out of the cavity with out any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The load may be a vacuum electron diode, a z-pinch wire array, a gas puff, a liner, an isentropic compression load (ICE) to study material behavior under very high magnetic fields, or a fusion energy (IFE) target. This is because the output pulse rise time and width can be easily tailored to the specific application needs. In this paper we briefly summarize the developmental work done in Sandia and HCEI during the last few years, and describe our new MYKONOS Sandia High Current LTD Laboratory.

  16. Flexible, phase-matched, linear receive arrays for high-field MRI in monkeys.

    Science.gov (United States)

    Goense, Jozien; Logothetis, Nikos K; Merkle, Hellmut

    2010-10-01

    High signal-to-noise ratios (SNR) are essential for high-resolution anatomical and functional MRI. Phased arrays are advantageous for this but have the drawback that they often have inflexible and bulky configurations. Particularly in experiments where functional MRI is combined with simultaneous electrophysiology, space constraints can be prohibitive. To this end we developed a highly flexible multiple receive element phased array for use on anesthetized monkeys. The elements are interchangeable and different sizes and combinations of coil elements can be used, for instance, combinations of single and overlapped elements. The preamplifiers including control electronics are detachable and can serve a variety of prefabricated and phase matched arrays of different configurations, allowing the elements to always be placed in close proximity to the area of interest. Optimizing performance of the individual elements ensured high SNR at the cortical surface as well as in deeper laying structures. Performance of a variety of arrangements of gapped linear arrays was evaluated at 4.7 and 7T in high-resolution anatomical and functional MRI.

  17. EFFICIENCY OF LINEAR PULSE ELECTROMECHANICAL CONVERTERS DESIGNED TO CREATE IMPACT LOADS AND HIGH SPEEDS

    Directory of Open Access Journals (Sweden)

    V.F. Bolyukh

    2015-06-01

    Full Text Available Considered linear impulse electromechanical converters (LIEC are used to create a significant impact and high-acceleration actuators on a short active site. The most effective types of LIEC are induction-dynamic (IDC, electro-dynamic (EDC and electro-magnetic (EMC converters. In all these types of short-term excitement LIEC carried briefly of the inductor from a pulsed source. This occurs when the magnetic field of the inductor causes the electro-dynamic or electromagnetic forces, leading to a linear movement of the armature. However, the issue at evaluating the effects of IDC, EDC and EMC, for creating a shock simultaneously with high speed to the specified criteria in the presence of ferromagnetic core virtually unexplored. The paper presents the simulated computer-WIDE 2D model of LIEC of coaxial configuration with ferromagnetic core by using software package COMSOL Multiphysics 4.4, taking into account the related electro-magnetic, thermal, and magnetic fields. In addition a synthesis of high-performance IDC, EDC and EMC to ensure maximum impact and speed of the operating element, whereby the comparative analysis of the effectiveness of the IDC, EDC and EMC via an integral index, taking into account the maximum value and momentum of electro-dynamic or electromagnetic force acting on the armature, maximum and average speed armature, efficiency, mass and dimensions performance transducer stray field, the maximum current density in the inductor is carried out. On the basis of the eight selection policies set the most efficient types of power and speed LIEC. It is shown that any one of the strategies IDC selection is not the best. To ensure maximum impact force is the most effective EMC and to ensure the greatest speed – EDC.

  18. High-power multimode X-band rf pulse compression system for future linear colliders

    Directory of Open Access Journals (Sweden)

    Sami G. Tantawi

    2005-04-01

    Full Text Available We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC. The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  19. Emulsifier development for high-concentrated reverse emulsions

    OpenAIRE

    Kovalenko, I. L.; V.P. Kuprin

    2016-01-01

    The reverse emulsions have found broad application in ore mining industry as matrixes of emulsion explosive substances and boring washing waters. The defining characteristic of reverse emulsions of industrial explosive substances is the high stability and immunity to crystallization. Aim: The aim of this work is to assess the mechanism of emulsifiers effect like SMO and some PIBSA-derivatives, that are most abundantly used in world practice, and also to develop an effective domestic emulsifie...

  20. High urinary phthalate concentration associated with delayed pubarche in girls

    DEFF Research Database (Denmark)

    Frederiksen, H; Sørensen, K; Mouritsen, A;

    2012-01-01

    Phthalates are a group of chemicals present in numerous consumer products. They have anti-androgenic properties in experimental studies and are suspected to be involved in human male reproductive health problems. A few studies have shown associations between phthalate exposure and changes...... and controls. We demonstrated that delayed pubarche, but not thelarche, was associated with high phthalate excretion in urine samples from 725 healthy school girls, which may suggest anti-androgenic actions of phthalates in our study group of girls....

  1. The neutron dose equivalent around high energy medical electron linear accelerators

    Directory of Open Access Journals (Sweden)

    Poje Marina

    2014-01-01

    Full Text Available The measurement of neutron dose equivalent was made in four dual energy linear accelerator rooms. Two of the rooms were reconstructed after decommissioning of 60Co units, so the main limitation was the space. The measurements were performed by a nuclear track etched detectors LR-115 associated with the converter (radiator that consist of 10B and with the active neutron detector Thermo BIOREM FHT 742. The detectors were set at several locations to evaluate the neutron ambient dose equivalent and/or neutron dose rate to which medical personnel could be exposed. Also, the neutron dose dependence on collimator aperture was analyzed. The obtained neutron dose rates outside the accelerator rooms were several times smaller than the neutron dose rates inside the accelerator rooms. Nevertheless, the measured neutron dose equivalent was not negligible from the aspect of the personal dosimetry with almost 2 mSv a year per person in the areas occupied by staff (conservative estimation. In rooms with 15 MV accelerators, the neutron exposure to the personnel was significantly lower than in the rooms having 18 MV accelerators installed. It was even more pronounced in the room reconstructed after the 60Co decommissioning. This study confirms that shielding from the neutron radiation should be considered when building vaults for high energy linear accelerators, especially when the space constraints exist.

  2. High-Precision CMOS Analog Computational Circuits Based on a New Linearly Tunable OTA

    Directory of Open Access Journals (Sweden)

    A. Naderi Saatlo

    2016-06-01

    Full Text Available Implementation of CMOS current-mode analog computational circuits are presented in this paper. A new Linearly Tunable OTA is employed in a modified structure as a basic building block for implementation of the circuits either linear or nonlinear functions. The proposed trans-conductance amplifier provides a constant Gm over a wide range of input voltage which allows the implementation of high precision computational circuits including square rooting, squaring, multiplication and division functions. Layout pattern of the proposed circuit confirms that the circuit can be implemented in 102μm*69μm active area. In order to verify the performance of the circuits, the post layout simulation results are presented through the use of HSPICE and Cadence with TSMC level 49 (BSIM3v3 parameters for 0.18 μm CMOS technology, where under supply voltage of 1.8 V, the maximum relative error of the circuits within 500 µA of input range is about 11 μA (2.2 % error and the THD remains as low as 1.2 % for the worst case. Moreover, the power dissipation of the complete structure is found to be 0.66 mW.

  3. Enabling linear alkyl carbonate electrolytes for high voltage Li-ion cells

    Science.gov (United States)

    Xia, Jian; Petibon, Remi; Xiong, Deijun; Ma, Lin; Dahn, J. R.

    2016-10-01

    Some of the problems of current electrolytes for high voltage Li-ion cells originate from ethylene carbonate (EC) which is thought to be an essential electrolyte component for Li-ion cells. Ethylene carbonate-free electrolytes containing 1 M LiPF6 in ethylmethyl carbonate (EMC) with small loadings of vinylene carbonate, fluoroethylene carbonate, or (4R,5S)-4,5-Difluoro-1,3-dioxolan-2-one acting as ;enablers; were developed. These electrolytes used in Li(Ni0.4Mn0.4Co0.2)O2/graphite pouch type Li-ion cells tested at 4.2 V and 4.5 V yielded excellent charge-discharge cycling and storage properties. The results for cells containing linear alkyl carbonate electrolytes with no EC were compared to those of cells with EC-containing electrolytes incorporating additives proven to enhance cyclability of cells. The combination of EMC with appropriate amounts of these enablers yields cells with better performance than cells with EC-containing electrolytes incorporating additives tested to 4.5 V. Further optimizing these linear alkyl carbonate electrolytes with appropriate co-additives may represent a viable path to the successful commercial utilization of NMC/graphite Li-ion cells operated to 4.5 V and above.

  4. New, Highly Accurate Propagator for the Linear and Nonlinear Schr\\"odinger Equation

    CERN Document Server

    Tal-Ezer, Hillel; Schaefer, Ido; 10.1007/s10915-012-9583-x

    2012-01-01

    A propagation method for the time dependent Schr\\"odinger equation was studied leading to a general scheme of solving ode type equations. Standard space discretization of time-dependent pde's usually results in system of ode's of the form u_t -Gu = s where G is a operator (matrix) and u is a time-dependent solution vector. Highly accurate methods, based on polynomial approximation of a modified exponential evolution operator, had been developed already for this type of problems where G is a linear, time independent matrix and s is a constant vector. In this paper we will describe a new algorithm for the more general case where s is a time-dependent r.h.s vector. An iterative version of the new algorithm can be applied to the general case where G depends on t or u. Numerical results for Schr\\"odinger equation with time-dependent potential and to non-linear Schr\\"odinger equation will be presented.

  5. High Dynamic Range RF Front End with Noise Cancellation and Linearization for WiMAX Receivers

    Directory of Open Access Journals (Sweden)

    J.-M. Wu

    2012-06-01

    Full Text Available This research deals with verification of the high dynamic range for a heterodyne radio frequency (RF front end. A 2.6 GHz RF front end is designed and implemented in a hybrid microwave integrated circuit (HMIC for worldwide interoperability for microwave access (WiMAX receivers. The heterodyne RF front end consists of a low-noise amplifier (LNA with noise cancellation, an RF bandpass filter (BPF, a downconverter with linearization, and an intermediate frequency (IF BPF. A noise canceling technique used in the low-noise amplifier eliminates a thermal noise and then reduces the noise figure (NF of the RF front end by 0.9 dB. Use of a downconverter with diode linearizer also compensates for gain compression, which increases the input-referred third-order intercept point (IIP3 of the RF front end by 4.3 dB. The proposed method substantially increases the spurious-free dynamic range (DRf of the RF front end by 3.5 dB.

  6. Deep Sea Memory of High Atmospheric CO2 Concentration

    Science.gov (United States)

    Mathesius, Sabine; Hofmann, Matthias; Caldeira, Ken; Schellnhuber, Hans Joachim

    2015-04-01

    Carbon dioxide removal (CDR) from the atmosphere has been proposed as a powerful measure to mitigate global warming and ocean acidification. Planetary-scale interventions of that kind are often portrayed as "last-resort strategies", which need to weigh in if humankind keeps on enhancing the climate-system stock of CO2. Yet even if CDR could restore atmospheric CO2 to substantially lower concentrations, would it really qualify to undo the critical impacts of past emissions? In the study presented here, we employed an Earth System Model of Intermediate Complexity (EMIC) to investigate how CDR might erase the emissions legacy in the marine environment, focusing on pH, temperature and dissolved oxygen. Against a background of a world following the RCP8.5 emissions path ("business-as-usual") for centuries, we simulated the effects of two massive CDR interventions with CO2 extraction rates of 5 GtC yr-1 and 25 GtC yr-1, respectively, starting in 2250. We found that the 5 GtC yr-1 scheme would have only minor ameliorative influence on the oceans, even after several centuries of application. By way of contrast, the extreme 25 GtC yr-1 scheme eventually leads to tangible improvements. However, even with such an aggressive measure, past CO2 emissions leave a substantial legacy in the marine environment within the simulated period (i.e., until 2700). In summary, our study demonstrates that anthropogenic alterations of the oceans, caused by continued business-as-usual emissions, may not be reversed on a multi-centennial time scale by the most aspirational geoengineering measures. We also found that a transition from the RCP8.5 state to the state of a strong mitigation scenario (RCP2.6) is not possible, even under the assumption of extreme extraction rates (25 GtC yr-1). This is explicitly demonstrated by simulating additional scenarios, starting CDR already in 2150 and operating until the atmospheric CO2 concentration reaches 280 ppm and 180 ppm, respectively. The simulated

  7. High plasma uric acid concentration: causes and consequences

    Directory of Open Access Journals (Sweden)

    de Oliveira Erick

    2012-04-01

    Full Text Available Abstract High plasma uric acid (UA is a precipitating factor for gout and renal calculi as well as a strong risk factor for Metabolic Syndrome and cardiovascular disease. The main causes for higher plasma UA are either lower excretion, higher synthesis or both. Higher waist circumference and the BMI are associated with higher insulin resistance and leptin production, and both reduce uric acid excretion. The synthesis of fatty acids (tryglicerides in the liver is associated with the de novo synthesis of purine, accelerating UA production. The role played by diet on hyperuricemia has not yet been fully clarified, but high intake of fructose-rich industrialized food and high alcohol intake (particularly beer seem to influence uricemia. It is not known whether UA would be a causal factor or an antioxidant protective response. Most authors do not consider the UA as a risk factor, but presenting antioxidant function. UA contributes to > 50% of the antioxidant capacity of the blood. There is still no consensus if UA is a protective or a risk factor, however, it seems that acute elevation is a protective factor, whereas chronic elevation a risk for disease.

  8. Experimental investigations of the neutron contamination in high-energy photon fields at medical linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Brunckhorst, Elin

    2009-02-26

    The scope of this thesis was to develop a device for the detection of the photoneutron dose inside the high-energy photon field. The photoneutron contamination of a Siemens PRIMUS linear accelerator was investigated in detail in its 15 MV photon mode. The experimental examinations were performed with three ionisation chambers (a tissue equivalent chamber, a magnesium chamber and a {sup 10}B-coated magnesium chamber) and two types of thermoluminescence detectors (enriched with {sup 6}Li and {sup 7}Li, respectively). The detectors have different sensitivities to photons and neutrons and their combination allows the dose separation in a mixed neutron/photon field. The application of the ionisation chamber system, as well as the present TLD system for photoneutron detection in high-energy photon beams is a new approach. The TLD neutron sensitivity was found to be too low for a measurement inside the open photon field and the further investigation focused on the ionisation chambers. The three ionisation chambers were calibrated at different photon and neutron sources and a the borated magnesium chamber showed a very high response to thermal neutrons. For a cross check of the calibration, the three chambers were also used for dose separation of a boron neutron capture therapy beam where the exact determination of the thermal neutron dose is essential. Very accurate results were achieved for the thermal neutron dose component. At the linear accelerator the chamber system was reduced to a paired chamber system utilising the two magnesium chambers, since the fast neutron component was to small to be separated. The neutron calibration of the three chambers could not be applied, instead a conversion of measured thermal neutron signal by the borated chamber to Monte Carlo simulated total neutron dose was performed. Measurements for open fields in solid water and liquid water were performed with the paired chamber system. In larger depths the neutron dose could be determined

  9. Design requirements for high-efficiency high concentration ratio space solar cells

    Science.gov (United States)

    Rauschenbach, H.; Patterson, R.

    1980-01-01

    A miniaturized Cassegrainian concentrator system concept was developed for low cost, multikilowatt space solar arrays. The system imposes some requirements on solar cells which are new and different from those imposed for conventional applications. The solar cells require a circular active area of approximately 4 mm in diameter. High reliability contacts are required on both front and back surfaces. The back area must be metallurgically bonded to a heat sink. The cell should be designed to achieve the highest practical efficiency at 100 AMO suns and at 80 C. The cell design must minimize losses due to nonuniform illumination intensity and nonnormal light incidence. The primary radiation concern is the omnidirectional proton environment.

  10. Characterization of blood donors with high haemoglobin concentration

    DEFF Research Database (Denmark)

    Magnussen, K; Hasselbalch, H C; Ullum, H;

    2013-01-01

    Background and Objectives  The literature contains little on the prevalence and causes of high predonation haemoglobin levels among blood donors. This study aimed to characterize and develop an algorithm to manage would-be donors with polycythaemia. Materials and Methods  Between November 2009......, erythropoietin, ferritin, platelet count and leucocyte count, JAK2 V617 and JAK2 exon12 analysis, as well as other routine measurements. Results  Among 46 such donors, 39 had a history of smoking, which contributes to erythrocytosis. Two had PV, five had severe hypertension, one of them because of renal artery...

  11. Waste to Energy Potential - A High Concentration Anaerobic Bioreactor

    Science.gov (United States)

    2012-05-23

    REPORT DATE 23 MAY 2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Waste to Energy Potential - A High...and fermentative bacteria break down organic carbon to VFAs Acetogens break down VFAs to CH3CO2 − and H2 + Acetoclastic methanogens break...s -999999 999999 7 481 su -999999 999999 0 .. -999999 999999 HCA8 pti Flo$&-tdgc Tan.\\ feed su -999999 999999 0 .. -999999 999999 A-l>o -999999

  12. High-gradient breakdown studies of an X -band Compact Linear Collider prototype structure

    Science.gov (United States)

    Wu, Xiaowei; Shi, Jiaru; Chen, Huaibi; Shao, Jiahang; Abe, Tetsuo; Higo, Toshiyasu; Matsumoto, Shuji; Wuensch, Walter

    2017-05-01

    A Compact Linear Collider prototype traveling-wave accelerator structure fabricated at Tsinghua University was recently high-gradient tested at the High Energy Accelerator Research Organization (KEK). This X -band structure showed good high-gradient performance of up to 100 MV /m and obtained a breakdown rate of 1.27 ×10-8 per pulse per meter at a pulse length of 250 ns. This performance was similar to that of previous structures tested at KEK and the test facility at the European Organization for Nuclear Research (CERN), thereby validating the assembly and bonding of the fabricated structure. Phenomena related to vacuum breakdown were investigated and are discussed in the present study. Evaluation of the breakdown timing revealed a special type of breakdown occurring in the immediately succeeding pulse after a usual breakdown. These breakdowns tended to occur at the beginning of the rf pulse, whereas usual breakdowns were uniformly distributed in the rf pulse. The high-gradient test was conducted under the international collaboration research program among Tsinghua University, CERN, and KEK.

  13. High-gradient breakdown studies of an X-band Compact Linear Collider prototype structure

    Directory of Open Access Journals (Sweden)

    Xiaowei Wu

    2017-05-01

    Full Text Available A Compact Linear Collider prototype traveling-wave accelerator structure fabricated at Tsinghua University was recently high-gradient tested at the High Energy Accelerator Research Organization (KEK. This X-band structure showed good high-gradient performance of up to 100  MV/m and obtained a breakdown rate of 1.27×10^{−8} per pulse per meter at a pulse length of 250 ns. This performance was similar to that of previous structures tested at KEK and the test facility at the European Organization for Nuclear Research (CERN, thereby validating the assembly and bonding of the fabricated structure. Phenomena related to vacuum breakdown were investigated and are discussed in the present study. Evaluation of the breakdown timing revealed a special type of breakdown occurring in the immediately succeeding pulse after a usual breakdown. These breakdowns tended to occur at the beginning of the rf pulse, whereas usual breakdowns were uniformly distributed in the rf pulse. The high-gradient test was conducted under the international collaboration research program among Tsinghua University, CERN, and KEK.

  14. REVIEW: Internal high linear energy transfer (LET) targeted radiotherapy for cancer

    Science.gov (United States)

    Allen, Barry J.

    2006-07-01

    High linear energy transfer (LET) radiation for internal targeted therapy has been a long time coming on to the medical therapy scene. While fundamental principles were established many decades ago, the clinical implementation has been slow. Localized neutron capture therapy, and more recently systemic targeted alpha therapy, are at the clinical trial stage. What are the attributes of these therapies that have led a band of scientists and clinicians to dedicate so much of their careers? High LET means high energy density, causing double strand breaks in DNA, and short-range radiation, sparing adjacent normal tissues. This targeted approach complements conventional radiotherapy and chemotherapy. Such therapies fail on several fronts. Foremost is the complete lack of progress for the control of primary GBM, the holy grail for cancer therapies. Next is the inability to regress metastatic cancer on a systemic basis. This has been the task of chemotherapy, but palliation is the major application. Finally, there is the inability to inhibit the development of lethal metastatic cancer after successful treatment of the primary cancer. This review charts, from an Australian perspective, the developing role of local and systemic high LET, internal radiation therapy.

  15. Synchronization of High-order Discrete-time Linear Complex Networks with Time-varying Delays

    Institute of Scientific and Technical Information of China (English)

    HaiLong Li; JianXiang Xi; YaoQing Cao; DuoSheng Wu

    2014-01-01

    Synchronization of high-order discrete-time complex networks with undirected topologies is studied and the impacts of time delays are investigated. Firstly, by the state decomposition, synchronization problems are transformed into asymptotic stability ones of multiple lower dimensional time-delayed subsystems. Then, linear matrix inequality ( LMI) criteria for synchronization are given, which can guarantee the scalability of complex networks since they only include three LMI constraints independent of the number of agents. Moreover, an explicit expression of the synchronization function is presented, which can describe the synchronization behavior of all agents in complex networks. Finally, a numerical example is given to demonstrate the theoretical results, where it is shown that if the gain matrices of synchronization protocols satisfy LMI criteria for synchronization, synchronization can be achieved.

  16. A Linear Algebra Framework for Static High Performance Fortran Code Distribution

    Directory of Open Access Journals (Sweden)

    Corinne Ancourt

    1997-01-01

    Full Text Available High Performance Fortran (HPF was developed to support data parallel programming for single-instruction multiple-data (SIMD and multiple-instruction multiple-data (MIMD machines with distributed memory. The programmer is provided a familiar uniform logical address space and specifies the data distribution by directives. The compiler then exploits these directives to allocate arrays in the local memories, to assign computations to elementary processors, and to migrate data between processors when required. We show here that linear algebra is a powerful framework to encode HPF directives and to synthesize distributed code with space-efficient array allocation, tight loop bounds, and vectorized communications for INDEPENDENT loops. The generated code includes traditional optimizations such as guard elimination, message vectorization and aggregation, and overlap analysis. The systematic use of an affine framework makes it possible to prove the compilation scheme correct.

  17. Ultra-high-frequency piecewise-linear chaos using delayed feedback loops

    Science.gov (United States)

    Cohen, Seth D.; Rontani, Damien; Gauthier, Daniel J.

    2012-12-01

    We report on an ultra-high-frequency (>1 GHz), piecewise-linear chaotic system designed from low-cost, commercially available electronic components. The system is composed of two electronic time-delayed feedback loops: A primary analog loop with a variable gain that produces multi-mode oscillations centered around 2 GHz and a secondary loop that switches the variable gain between two different values by means of a digital-like signal. We demonstrate experimentally and numerically that such an approach allows for the simultaneous generation of analog and digital chaos, where the digital chaos can be used to partition the system's attractor, forming the foundation for a symbolic dynamics with potential applications in noise-resilient communications and radar.

  18. Assessing Risk in Costing High-energy Accelerators: from Existing Projects to the Future Linear Collider

    CERN Document Server

    Lebrun, Philippe

    2010-01-01

    High-energy accelerators are large projects funded by public money, developed over the years and constructed via major industrial contracts both in advanced technology and in more conventional domains such as civil engineering and infrastructure, for which they often constitute one-of markets. Assessing their cost, as well as the risk and uncertainty associated with this assessment is therefore an essential part of project preparation and a justified requirement by the funding agencies. Stemming from the experience with large circular colliders at CERN, LEP and LHC, as well as with the Main Injector, the Tevatron Collider Experiments and Accelerator Upgrades, and the NOvA Experiment at Fermilab, we discuss sources of cost variance and derive cost risk assessment methods applicable to the future linear collider, through its two technical approaches for ILC and CLIC. We also address disparities in cost risk assessment imposed by regional differences in regulations, procedures and practices.

  19. High-order sliding mode observer for fractional commensurate linear systems with unknown input

    KAUST Repository

    Belkhatir, Zehor

    2017-05-20

    In this paper, a high-order sliding mode observer (HOSMO) is proposed for the joint estimation of the pseudo-state and the unknown input of fractional commensurate linear systems with single unknown input and a single output. The convergence of the proposed observer is proved using a Lyapunov-based approach. In addition, an enhanced variant of the proposed fractional-HOSMO is introduced to avoid the peaking phenomenon and thus to improve the estimation results in the transient phase. Simulation results are provided to illustrate the performance of the proposed fractional observer in both noise-free and noisy cases. The effect of the observer’s gains on the estimated pseudo-state and unknown input is also discussed.

  20. Highly non-linear solid core photonic crystal fiber with one nano hole

    Science.gov (United States)

    Gangwar, Rahul Kumar; Bhardwaj, Vanita; Singh, Vinod Kumar

    2015-08-01

    The numerical study of newly designed solid core photonic crystal fiber (SCPCF) having three hexagonal air hole rings in cladding region and one small nano hole at the center are presented. By using full vectorial finite element method (FV-FEM), we analyses the optical properties like effective area, nonlinearity and confinement loss of the proposed PCF. Results show that the change in core diameter controls the effective area, nonlinearity and confinement loss. A low effective area (3.34 µm2), high nonlinearity (36.34 W-1km-1) and low confinement loss (0.00106 dB/km) are achieved at the communication wavelength 1.55 µm for the SCPCF having core air hole diameter 0.10 µm, cladding air holes diameter 1.00 µm and pitch 2.50 µm. This type of PCF is very useful in non-linear applications such as supercontinuum generation, four wave mixing, second harmonic generation etc.

  1. High-Speed Linear Raman Spectroscopy for Instability Analysis of a Bluff Body Flame

    Science.gov (United States)

    Kojima, Jun; Fischer, David

    2013-01-01

    We report a high-speed laser diagnostics technique based on point-wise linear Raman spectroscopy for measuring the frequency content of a CH4-air premixed flame stabilized behind a circular bluff body. The technique, which primarily employs a Nd:YLF pulsed laser and a fast image-intensified CCD camera, successfully measures the time evolution of scalar parameters (N2, O2, CH4, and H2O) in the vortex-induced flame instability at a data rate of 1 kHz. Oscillation of the V-shaped flame front is quantified through frequency analysis of the combustion species data and their correlations. This technique promises to be a useful diagnostics tool for combustion instability studies.

  2. Profiling high performance dense linear algebra algorithms on multicore architectures for power and energy efficiency

    KAUST Repository

    Ltaief, Hatem

    2011-08-31

    This paper presents the power profile of two high performance dense linear algebra libraries i.e., LAPACK and PLASMA. The former is based on block algorithms that use the fork-join paradigm to achieve parallel performance. The latter uses fine-grained task parallelism that recasts the computation to operate on submatrices called tiles. In this way tile algorithms are formed. We show results from the power profiling of the most common routines, which permits us to clearly identify the different phases of the computations. This allows us to isolate the bottlenecks in terms of energy efficiency. Our results show that PLASMA surpasses LAPACK not only in terms of performance but also in terms of energy efficiency. © 2011 Springer-Verlag.

  3. CMOS high linearity PA driver with an on-chip transformer for W-CDMA application

    Energy Technology Data Exchange (ETDEWEB)

    Fu Jian; Mei Niansong; Huang Yumei; Hong Zhiliang, E-mail: yumeihuang@fudan.edu.cn [ASIC and System State Key Laboratory, Fudan University, Shanghai 201203 (China)

    2011-09-15

    A fully integrated high linearity differential power amplifier driver with an on-chip transformer in a standard 0.13-{mu}m CMOS process for W-CDMA application is presented. The transformer not only accomplishes output impedance matching, but also acts as a balun for converting differential signals to single-ended ones. Under a supply voltage of 3.3 V, the measured maximum power is larger than 17 dBm with a peak power efficiency of 21%. The output power at the 1-dB compression point and the power gain are 12.7 dBm and 13.2 dB, respectively. The die size is 0.91 x 1.12 mm{sup 2}. (semiconductor integrated circuits)

  4. High performance waveguide-coupled Ge-on-Si linear mode avalanche photodiodes.

    Science.gov (United States)

    Martinez, Nicholas J D; Derose, Christopher T; Brock, Reinhard W; Starbuck, Andrew L; Pomerene, Andrew T; Lentine, Anthony L; Trotter, Douglas C; Davids, Paul S

    2016-08-22

    We present experimental results for a selective epitaxially grown Ge-on-Si separate absorption and charge multiplication (SACM) integrated waveguide coupled avalanche photodiode (APD) compatible with our silicon photonics platform. Epitaxially grown Ge-on-Si waveguide-coupled linear mode avalanche photodiodes with varying lateral multiplication regions and different charge implant dimensions are fabricated and their illuminated device characteristics and high-speed performance is measured. We report a record gain-bandwidth product of 432 GHz for our highest performing waveguide-coupled avalanche photodiode operating at 1510nm. Bit error rate measurements show operation with BER-12, in the range from -18.3 dBm to -12 dBm received optical power into a 50 Ω load and open eye diagrams with 13 Gbps pseudo-random data at 1550 nm.

  5. ANALYSIS OF HIGH FIELD NON-LINEAR LOSSES ON SRF SURFACES DUE TO SPECIFIC TOPOGRAPHIC ROUGHNESS

    Energy Technology Data Exchange (ETDEWEB)

    Chen Xu,Charles Reece,Michael Kelley

    2012-07-01

    The high-field performance of SRF cavities will eventually be limited by the realization of fundamental material limits, whether it is Hc1 or Hsh, or some derivative thereof, at which the superconductivity is lost. Before reaching this fundamental field limit at the macro level, it must be encountered at localized, perhaps microscopic, sites of field enhancement due to local topography. If such sites are small enough, they may produce thermally stabilized normal-conducting regions which contribute non-linear losses when viewed from the macro resonant field perspective, and thus produce degradation in Q0. We have undertaken a calculation of local surface magnetic field enhancement from specific fine topographic structure by conformal mapping method and numerically. A solution of the resulting normal conducting volume has been derived and the corresponding RF Ohmic loss simulated.

  6. Robust Hessian Locally Linear Embedding Techniques for High-Dimensional Data

    Directory of Open Access Journals (Sweden)

    Xianglei Xing

    2016-05-01

    Full Text Available Recently manifold learning has received extensive interest in the community of pattern recognition. Despite their appealing properties, most manifold learning algorithms are not robust in practical applications. In this paper, we address this problem in the context of the Hessian locally linear embedding (HLLE algorithm and propose a more robust method, called RHLLE, which aims to be robust against both outliers and noise in the data. Specifically, we first propose a fast outlier detection method for high-dimensional datasets. Then, we employ a local smoothing method to reduce noise. Furthermore, we reformulate the original HLLE algorithm by using the truncation function from differentiable manifolds. In the reformulated framework, we explicitly introduce a weighted global functional to further reduce the undesirable effect of outliers and noise on the embedding result. Experiments on synthetic as well as real datasets demonstrate the effectiveness of our proposed algorithm.

  7. CMOS high linearity PA driver with an on-chip transformer for W-CDMA application

    Institute of Scientific and Technical Information of China (English)

    Fu Jian; Mei Niansong; Huang Yumei; Hong Zhiliang

    2011-01-01

    A fully integrated high linearity differential power amplifier driver with an on-chip transformer in a standard 0.13-μm CMOS process for W-CDMA application is presented.The transformer not only accomplishes output impedance matching,but also acts as a balun for converting differential signals to single-ended ones.Under a supply voltage of 3.3 V,the measured maximum power is larger than 17 dBm with a peak power efficiency of 21%.The output power at the 1-dB compression point and the power gain are 12.7 dBm and 13.2 dB,respectively.The die size is 0.91 × 1.12 mm2.

  8. High-contrast linear optical pulse compression using a temporal hologram.

    Science.gov (United States)

    Li, Bo; Fernández-Ruiz, Maria R; Lou, Shuqin; Azaña, José

    2015-03-01

    Temporal holograms can be realized by temporal amplitude-only modulation devices and used for generation and processing of complex (amplitude and phase) time-domain signals. Based on the temporal hologram concept, we numerically and experimentally demonstrate a novel design for linear optical pulse compression using temporal modulation of continuous-wave light combined with dispersion. The newly introduced scheme overcomes the undesired background problem that is intrinsic to designs based on temporal zone plates, while also offering an energy efficiency of ~25%. This pulse compression scheme can ideally provide an arbitrarily high time-bandwidth product using a low peak-power modulation driving signal, though in practice it is limited by the achievable modulation bandwidth and dispersion amount.

  9. Design of a High Linearity Four-Quadrant Analog Multiplier in Wideband Frequency Range

    Directory of Open Access Journals (Sweden)

    Abdul kareem Mokif Obais

    2017-05-01

    Full Text Available In this paper, a voltage mode four quadrant analog multiplier in the wideband frequency rangeis designed using a wideband operational amplifier (OPAMP and squaring circuits. The wideband OPAMP is designed using 10 identical NMOS transistorsand operated with supply voltages of ±12V. Two NMOS transistors and two wideband OPAMP are utilized in the design of the proposed squaring circuit. All the NMOS transistors are based on 0.35µm NMOStechnology. The multiplier has input and output voltage ranges of ±10 V, high range of linearity from -10 V to +10 V, and cutoff frequency of about 5 GHz. The proposed multiplier is designed on PSpice in Orcad 16.6

  10. A high sensitive 66 dB linear dynamic range receiver for 3-D laser radar

    Science.gov (United States)

    Ma, Rui; Zheng, Hao; Zhu, Zhangming

    2017-08-01

    This study presents a CMOS receiver chip realized in 0.18 μm standard CMOS technology and intended for high precision 3-D laser radar. The chip includes an adjustable gain transimpedance pre-amplifier, a post-amplifier and two timing comparators. An additional feedback is employed in the regulated cascode transimpedance amplifier to decrease the input impedance, and a variable gain transimpedance amplifier controlled by digital switches and analog multiplexer is utilized to realize four gain modes, extending the input dynamic range. The measurement shows that the highest transimpedance of the channel is 50 k {{Ω }}, the uncompensated walk error is 1.44 ns in a wide linear dynamic range of 66 dB (1:2000), and the input referred noise current is 2.3 pA/\\sqrt{{Hz}} (rms), resulting in a very low detectable input current of 1 μA with SNR = 5.

  11. S-phase cells are more sensitive to high-linear energy transfer radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Naidu, M.; Liu, S.; Zhang, P.; Zhang, S.; Wang, H.; Wang, Y.

    2009-07-15

    S-phase cells are more resistant to low-linear energy transfer (LET) ionizing radiation (IR) than nonsynchronized and G{sub 1}-phase cells, because both nonhomologous end-joining (NHEJ) and homologous recombination repair can repair DNA double-strand breaks (DSBs) in the S phase. Although it was reported 3 decades ago that S-phase cells did not show more resistance to high-LET IR than cells in other phases, the mechanism remains unclear. We therefore attempted to study the phenotypes and elucidate the mechanism involved. Wild-type and NHEJ-deficient cell lines were synchronized using the double-thymidine approach. A clonogenic assay was used to detect the sensitivity of nonsynchronized, synchronized S-phase, and G{sub 2}-phase cells to high- and low-LET IR. The amounts of Ku bound to DSBs in the high- and low-LET-irradiated cells were also examined. S-phase wild-type cells (but not NHEJ-deficient cells) were more sensitive to high-LET IR than nonsynchronized and G{sub 2}-phase cells. In addition, S-phase wild-type cells showed less efficient Ku protein binding to DSBs than nonsynchronized and G{sub 2}-phase cells in response to high-LET IR, although all cells at all phases showed similarly efficient levels of Ku protein binding to DSBs in response to low-LET IR. S-phase cells are more sensitive to high-LET IR than nonsynchronized and G{sub 2}-phase cells, because of the following mechanism: it is more difficult for Ku protein to bind to high-LET IR-induced DNA DSBs in S-phase cells than in cells at other phases, which results in less efficient NHEJ.

  12. Recent testing of secondary concentrators at NREL`s high-flux solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, D.; Winston, R.; O`Gallagher, J. [Univ. of Chicago, IL (United States); Bingham, C.; Lewandowski, A.; Pitts, R.; Scholl, K. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    Several tests have been completed on new secondary concentrators at the High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL). The first test measured the power from the exit of a High-Index secondary that achieves an average concentration of 50,000 suns. The second concentrator tested pumped an Nd:YAG laser crystal. The concentrator designs are presented, along with data from on-sun testing at the HFSF.

  13. Development of a 64 channel ultrasonic high frequency linear array imaging system

    Science.gov (United States)

    Hu, ChangHong; Zhang, Lequan; Cannata, Jonathan M.; Yen, Jesse; Shung, K. Kirk

    2011-01-01

    In order to improve the lateral resolution and extend the field of view of a previously reported 48 element 30 MHz ultrasound linear array and 16-channel digital imaging system, the development of a 256 element 30 MHz linear array and an ultrasound imaging system with increased channel count has been undertaken. This paper reports the design and testing of a 64 channel digital imaging system which consists of an analog front-end pulser/receiver, 64 channels of Time-Gain Compensation (TGC), 64 channels of high-speed digitizer as well as a beamformer. A Personal Computer (PC) is used as the user interface to display real-time images. This system is designed as a platform for the purpose of testing the performance of high frequency linear arrays that have been developed in house. Therefore conventional approaches were taken it its implementation. Flexibility and ease of use are of primary concern whereas consideration of cost-effectiveness and novelty in design are only secondary. Even so, there are many issues at higher frequencies but do not exist at lower frequencies need to be solved. The system provides 64 channels of excitation pulsers while receiving simultaneously at a 20 MHz–120 MHz sampling rate to 12-bits. The digitized data from all channels are first fed through Field Programmable Gate Arrays (FPGAs), and then stored in memories. These raw data are accessed by the beamforming processor to re-build the image or to be downloaded to the PC for further processing. The beamformer that applies delays to the echoes of each channel is implemented with the strategy that combines coarse (8.3ns) and fine delays (2 ns). The coarse delays are integer multiples of the sampling clock rate and are achieved by controlling the write enable pin of the First-In-First-Out (FIFO) memory to obtain valid beamforming data. The fine delays are accomplished with interpolation filters. This system is capable of achieving a maximum frame rate of 50 frames per second. Wire phantom

  14. Development of a 64 channel ultrasonic high frequency linear array imaging system.

    Science.gov (United States)

    Hu, ChangHong; Zhang, Lequan; Cannata, Jonathan M; Yen, Jesse; Shung, K Kirk

    2011-12-01

    In order to improve the lateral resolution and extend the field of view of a previously reported 48 element 30 MHz ultrasound linear array and 16-channel digital imaging system, the development of a 256 element 30 MHz linear array and an ultrasound imaging system with increased channel count has been undertaken. This paper reports the design and testing of a 64 channel digital imaging system which consists of an analog front-end pulser/receiver, 64 channels of Time-Gain Compensation (TGC), 64 channels of high-speed digitizer as well as a beamformer. A Personal Computer (PC) is used as the user interface to display real-time images. This system is designed as a platform for the purpose of testing the performance of high frequency linear arrays that have been developed in house. Therefore conventional approaches were taken it its implementation. Flexibility and ease of use are of primary concern whereas consideration of cost-effectiveness and novelty in design are only secondary. Even so, there are many issues at higher frequencies but do not exist at lower frequencies need to be solved. The system provides 64 channels of excitation pulsers while receiving simultaneously at a 20-120 MHz sampling rate to 12-bits. The digitized data from all channels are first fed through Field Programmable Gate Arrays (FPGAs), and then stored in memories. These raw data are accessed by the beamforming processor to re-build the image or to be downloaded to the PC for further processing. The beamformer that applies delays to the echoes of each channel is implemented with the strategy that combines coarse (8.3 ns) and fine delays (2 ns). The coarse delays are integer multiples of the sampling clock rate and are achieved by controlling the write enable pin of the First-In-First-Out (FIFO) memory to obtain valid beamforming data. The fine delays are accomplished with interpolation filters. This system is capable of achieving a maximum frame rate of 50 frames per second. Wire phantom images

  15. Linear molecular beacons for highly sensitive bioanalysis based on cyclic Exo III enzymatic amplification.

    Science.gov (United States)

    Yang, Chaoyong James; Cui, Liang; Huang, Jiahao; Yan, Ling; Lin, Xiaoyan; Wang, Chunming; Zhang, Wei Yun; Kang, Huaizhi

    2011-09-15

    Sensitive analysis or monitoring of biomolecules and small molecules is very important for many biological researches, clinical diagnosis and forensic investigations. As a sequence-independent exonuclease, Exonuclease III (Exo III) has been widely used for amplified detection of proteins and nucleic acids where displacing probes or molecular beacons are used as the signaling probes. However, displacing probes suffer slow hybridization rate and high background signal and molecular beacons are difficult to design and prone to undesired nonspecific interactions. Herein, we report a new type of probes called linear molecular beacons (LMBs) for use in Exo III amplification assays to improve hybridization kinetics and reduce background noises. LMBs are linear oligonucleotide probes with a fluorophore and quencher attached to 3' terminal and penultimate nucleotides, respectively. Compared to conventional molecular beacons and displacing probes, LMBs are easy to design and synthesize. More importantly, LMBs have a much lower background noise and allow faster reaction rates. Using LMBs in cyclic Exo III amplification assay, ultrasensitive nucleic acid detection methods were developed with a detection limit of less than 120fM, which is 2 orders of magnitude lower than that of conventional molecular beacons or displacing probes-based Exo III amplification assays. Furthermore, LMBs can be extended as universal probes for detection of non-nucleic acid molecules such as cocaine with high sensitivity. These results demonstrate that the combination of Exo III amplification and LMB signaling provides a general method for ultrasensitive and selective detection of a wide range of targets. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Multivariate linear regression of high-dimensional fMRI data with multiple target variables.

    Science.gov (United States)

    Valente, Giancarlo; Castellanos, Agustin Lage; Vanacore, Gianluca; Formisano, Elia

    2014-05-01

    Multivariate regression is increasingly used to study the relation between fMRI spatial activation patterns and experimental stimuli or behavioral ratings. With linear models, informative brain locations are identified by mapping the model coefficients. This is a central aspect in neuroimaging, as it provides the sought-after link between the activity of neuronal populations and subject's perception, cognition or behavior. Here, we show that mapping of informative brain locations using multivariate linear regression (MLR) may lead to incorrect conclusions and interpretations. MLR algorithms for high dimensional data are designed to deal with targets (stimuli or behavioral ratings, in fMRI) separately, and the predictive map of a model integrates information deriving from both neural activity patterns and experimental design. Not accounting explicitly for the presence of other targets whose associated activity spatially overlaps with the one of interest may lead to predictive maps of troublesome interpretation. We propose a new model that can correctly identify the spatial patterns associated with a target while achieving good generalization. For each target, the training is based on an augmented dataset, which includes all remaining targets. The estimation on such datasets produces both maps and interaction coefficients, which are then used to generalize. The proposed formulation is independent of the regression algorithm employed. We validate this model on simulated fMRI data and on a publicly available dataset. Results indicate that our method achieves high spatial sensitivity and good generalization and that it helps disentangle specific neural effects from interaction with predictive maps associated with other targets.

  17. High-order optical nonlinearities in nanocomposite films dispersed with semiconductor quantum dots at high concentrations

    Science.gov (United States)

    Tomita, Yasuo; Matsushima, Shun-suke; Yamagami, Ryu-ichi; Jinzenji, Taka-aki; Sakuma, Shohei; Liu, Xiangming; Izuishi, Takuya; Shen, Qing

    2017-06-01

    We describe the nonlinear optical properties of inorganic-organic nanocomposite films in which semiconductor CdSe quantum dots as high as 6.8 vol.% are dispersed. Open/closed Z-scan measurements, degenerate multi-wave mixing and femtosecond pump-probe/transient grating measurements are conducted. It is shown that the observed fifth-order optical nonlinearity has the cascaded third-order contribution that becomes prominent at high concentrations of CdSe QDs. It is also shown that there are picosecond-scale intensity-dependent and nanosecond-scale intensity-independent decay components in absorptive and refractive nonlinearities. The former is caused by the Auger process, while the latter comes from the electron-hole recombination process.

  18. On the non-linear high-order theory of unidirectional sandwich panels with a transversely flexible core

    Energy Technology Data Exchange (ETDEWEB)

    Frostig, Yeoshua; Sheinman, Izhak [Technion-Israel Inst. of Technology, Faculty of Civil and Environmental Engineering, Haifa (Israel); Thomsen, Ole Thybo [Aalborg Univ., Inst. of Mechanical Engineering, Aalborg (Denmark)

    2005-03-01

    The paper presents a general geometrically non-linear high-order theory of sandwich panels that takes into account the high-order geometrical non-linearities in the core as well as in the face sheets and is based on a variational approach. The formulation, which yields a set of rather complicated governing equations, has been simplified in two different approaches and has been compared with FEA results for verification. The first formulation uses the kinematic relations of large displacements with moderate rotations for the face sheets, non-linear kinematic relations for the core and it assumes that the distribution of the vertical normal stresses through the depth of the core are linear. The second approach uses the general formulation to the non-linear high-order theory of sandwich panels (HSAPT) that considers geometrical non-linearities in the face sheets and only linear high-order effects in the core. The numerical results of the two formulations are presented for a three point bending loading scheme, which is associated with a limit point behavior. The results of the two formulations are compared in terms of displacements, bending moments and shear stresses and transverse (vertical) normal stresses at the face-core interfaces on one hand, and load versus these structural quantities on the other hand. The results have compared well with FEA results obtained using the commercial codes ADINA and ANSYS. (Author)

  19. Donor impurity-related linear and nonlinear optical absorption coefficients in GaAs/Ga{sub 1−x}Al{sub x}As concentric double quantum rings: Effects of geometry, hydrostatic pressure, and aluminum concentration

    Energy Technology Data Exchange (ETDEWEB)

    Baghramyan, H.M.; Barseghyan, M.G.; Kirakosyan, A.A. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Restrepo, R.L. [Física Teórica y Aplicada, Escuela de Ingeniería de Antioquia, AA 7516, Medellín (Colombia); Grupo de Materia Condensada-UdeA, Instituto de Física, Facultadde Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21,Medellín (Colombia); Mora-Ramos, M.E. [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultadde Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21,Medellín (Colombia); Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico); Duque, C.A., E-mail: cduque@fisica.udea.edu.co [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultadde Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21,Medellín (Colombia)

    2014-01-15

    The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs/Ga{sub 1−x}Al{sub x}As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the aluminum concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, aluminum concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements. -- Highlights: • Intra-band optical absorption associated to impurity states in double quantum rings. • Combined effects of hydrostatic pressure and aluminum concentration are studied. • The influences mentioned above lead to shifts of resonant peaks. • It is discussed an unusual property exhibited by the third-order nonlinear absorption.

  20. EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF HIGH CONCENTRATION JET FLOW IN NEAR REGION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The diffusion characteristics of the high concentration jet flowissued from a round nozzle above the free surface into moving waterbody were experimentally investigated. By means of flow visualization technique, the diffusion behavior of the high concentration jet was observed and analysed, Concentration distribution in the near region was obtained by sampling and quantitative measurements. Experimental results indicate that the diffusion mechanics of the high concentration jet flow are greatly influenced by initial momentum, buoyancy, turbulent structure, ambient current and boundary conditions, showing complicated flow patterns and concentration distribution characteristics that are different from previous results for submerged jets.

  1. Rayleigh-wave mode separation by high-resolution linear radon transform

    Science.gov (United States)

    Luo, Y.; Xia, J.; Miller, R.D.; Xu, Y.; Liu, J.; Liu, Q.

    2009-01-01

    Multichannel analysis of surface waves (MASW) method is an effective tool for obtaining vertical shear wave profiles from a single non-invasive measurement. One key step of the MASW method is generation of a dispersion image and extraction of a reliable dispersion curve from raw multichannel shot records. Because different Rayleigh-wave modes normally interfere with each other in the time and space domain, it is necessary to perform mode separation and reconstruction to increase the accuracy of phase velocities determined from a dispersion image. In this paper, we demonstrate the effectiveness of high-resolution linear Radon transform (LRT) as a means of separating and reconstructing multimode, dispersive Rayleigh-wave energy. We first introduce high-resolution LRT methods and Rayleigh-wave mode separation using high-resolution LRT. Next, we use synthetic data and a real-world example to demonstrate the effectiveness of Rayleigh-wave mode separation using high-resolution LRT. Our synthetic and real-world results demonstrate that (1) high-resolution LRT successfully separates and reconstructs multimode dispersive Rayleigh-wave energy with high resolution allowing the multimode energy to be more accurately determined. The horizontal resolution of the Rayleigh-wave method can be increased by extraction of dispersion curves from a pair of traces in the mode-separated shot gather and (2) multimode separation and reconstruction expand the usable frequency range of higher mode dispersive energy, which increases the depth of investigation and provides a means for accurately determining cut-off frequencies. ?? 2009 The Authors Journal compilation ?? 2009 RAS.

  2. Induction of apoptosis by high linear energy transfer radiation: role of p53

    Energy Technology Data Exchange (ETDEWEB)

    Coelho, D.; Fischer, B.; Holl, V.; Dufour, P. [Lab. de Cancerologie Experimentale et de Radiobiologie, LCER, Inst. de Recherche contre les Cancers de l' Appareil Digestif, IRCAD, Hopital Civil, Strasbourg CEDEX (France); Denis, J.M.; Gueulette, J. [Lab. de Radiobiologie et de Radioprotection, Faculte de Medecine, Univ. Catholique de Louvain, Bruxelles (Belgium); Bergerat, J.P.; Bischoff, P. [Lab. de Cancerologie Experimentale et de Radiobiologie, LCER, Inst. de Recherche contre les Cancers de l' Appareil Digestif, IRCAD, Hopital Civil, Strasbourg CEDEX (France)

    2002-07-01

    The involvement of the tumor suppressor p53 gene in the sensitivity of many cell types towards low linear energy transfer (LET) radiation is now well established. However, little information is available on the relationship between p53 status of tumor cells and their ability to undergo apoptosis following exposure to high-LET radiation. Here we present the results of experiments carried out with the human lymphoblastoid cell line TK6 and its p53 knock-out counterpart NH32. Cells were irradiated at doses ranging from 0.25 to 8 Gy with fast neutrons (65 MeV), carbon ions (95 MeV/nucleon), and X rays (15 MV). For both cell lines, the occurrence of apoptosis, determined by the quantification of hypodiploid particles as well as the activation of several caspases, was compared with their sensitivity towards high-LET radiation. Results indicate that p53 is involved in the response of TK6 cells to fast neutrons and carbon ions, as measured by cell proliferation and occurrence of apoptosis. However, p53-deficient cells are still able to undergo apoptosis following irradiation. This suggests that heavy ions and fast neutrons induce cellular damage that is not under the control of p53. The involvement of executioner caspases in high-LET radiation induced apoptosis was also evaluated by use of specific inhibitors. (author)

  3. TERA high gradient test program of RF cavities for medical linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Degiovanni, A., E-mail: alberto.degiovanni@cern.ch [TERA Foundation-via G. Puccini 11, 28100 Novara (Italy); Ecole Polytechnique Federale Lausanne EPFL-1015 Lausanne (Switzerland); Amaldi, U. [TERA Foundation-via G. Puccini 11, 28100 Novara (Italy); Universita Milano Bicocca-Piazza della Scienza 1, 20126 Milan (Italy); Bonomi, R. [TERA Foundation-via G. Puccini 11, 28100 Novara (Italy); Politecnico di Torino-Corso Duca degli Abruzzi 24, 10129 Turin (Italy); Garlasche, M. [TERA Foundation-via G. Puccini 11, 28100 Novara (Italy); Garonna, A. [TERA Foundation-via G. Puccini 11, 28100 Novara (Italy); Ecole Polytechnique Federale Lausanne EPFL-1015 Lausanne (Switzerland); Verdu-Andres, S. [TERA Foundation-via G. Puccini 11, 28100 Novara (Italy); Instituto de Fisica Corpuscular IFIC (CSIC-UVEG)-Paterna, 46071 Valencia (Spain); Wegner, R. [CERN- 1211 Geneva (Switzerland)

    2011-11-21

    The scientific community and the medical industries are putting a considerable effort into the design of compact, reliable and cheap accelerators for hadrontherapy. Up to now only circular accelerators are used to deliver beams with energies suitable for the treatment of deep seated tumors. The TERA Foundation has proposed and designed a hadrontherapy facility based on the cyclinac concept: a high gradient linear accelerator placed downstream of a cyclotron used as an injector. The overall length of the linac, and therefore its final cost, is almost inversely proportional to the average accelerating gradient achieved in the linac. TERA, in collaboration with the CLIC RF group, has started a high gradient test program. The main goal is to study the high gradient behavior of prototype cavities and to determine the appropriate linac operating frequency considering important issues such as machine reliability and availability of distributed power sources. A preliminary test of a 3 GHz cavity has been carried out at the beginning of 2010, giving encouraging results. Further investigations are planned before the end of 2011. A set of 5.7 GHz cavities is under production and will be tested in a near future. The construction and test of a multi-cell structure is also foreseen.

  4. TERA high gradient test program of RF cavities for medical linear accelerators

    Science.gov (United States)

    Degiovanni, A.; Amaldi, U.; Bonomi, R.; Garlasché, M.; Garonna, A.; Verdú-Andrés, S.; Wegner, R.

    2011-11-01

    The scientific community and the medical industries are putting a considerable effort into the design of compact, reliable and cheap accelerators for hadrontherapy. Up to now only circular accelerators are used to deliver beams with energies suitable for the treatment of deep seated tumors. The TERA Foundation has proposed and designed a hadrontherapy facility based on the cyclinac concept: a high gradient linear accelerator placed downstream of a cyclotron used as an injector. The overall length of the linac, and therefore its final cost, is almost inversely proportional to the average accelerating gradient achieved in the linac. TERA, in collaboration with the CLIC RF group, has started a high gradient test program. The main goal is to study the high gradient behavior of prototype cavities and to determine the appropriate linac operating frequency considering important issues such as machine reliability and availability of distributed power sources. A preliminary test of a 3 GHz cavity has been carried out at the beginning of 2010, giving encouraging results. Further investigations are planned before the end of 2011. A set of 5.7 GHz cavities is under production and will be tested in a near future. The construction and test of a multi-cell structure is also foreseen.

  5. Emulsifier development for high-concentrated reverse emulsions

    Directory of Open Access Journals (Sweden)

    I.L. Kovalenko

    2016-05-01

    Full Text Available The reverse emulsions have found broad application in ore mining industry as matrixes of emulsion explosive substances and boring washing waters. The defining characteristic of reverse emulsions of industrial explosive substances is the high stability and immunity to crystallization. Aim: The aim of this work is to assess the mechanism of emulsifiers effect like SMO and some PIBSA-derivatives, that are most abundantly used in world practice, and also to develop an effective domestic emulsifier of reverse emulsions. Materials and methods: Using the semi-dynamic method with use of the reverse stalagmometer it was determined the decreasing in interfacial tension on “water / diesel fuel” border in the presence of 0.5 wt % sorbitan monooleate of various producers. Emulsions with use of the chosen emulsifiers using the dynamic mixer on the basis of monosolution of ammonium nitrate and diesel fuel have been produced. The emulsions have the following composition, wt %: ammonium nitrate – 76.8; water – 15.6; diesel fuel – 6.0; emulsifier – 1.6. Results: By the researches results of the interfacial tension “surfactant water / solution in diesel fuel”, the stability of emulsions using monosolution of ammonium nitrate and the IR spectrums of SMO of various producers it is established that presence in product of impurity of oleic acid, di- and trioleates leads to decreasing in interphase activity, increasing of emulsifier oil solubility and decreasing the resistance of emulsions to crystallization. On the basis of the spectral data analysis it is suggested about possibility of specific interaction on the mechanism of “spectral resonance” between emulsifiers of the PIBSA-MEA, LZX type and crystals nucleus of NH4NO3 ammonium nitrate in dispersed phase of emulsion. Amidation of vegetable oils by monoethanol amine is implemented at the reduced temperatures (90…100 °C. It was proved the availability mainly of fatty acids amides in product

  6. Development of High-Thrust and Double-Sided Linear Synchronous Motor Module For Liquid Crystal Display Equipment

    Institute of Scientific and Technical Information of China (English)

    Myung-jin; CHUNG; Sang-yeon; HWANG

    2010-01-01

    <正>Recently,there is an increasing requirement for controlling linear motion up to a few hundred of millimeter strokes in the area of the liquid crystal display(LCD) production equipment.The requirements of the motion system for LCD production equipment are high acceleration and high velocity with positioning accuracy.To satisfy these requirements,it has to be designed with the high-thrust force and low velocity ripple.In this work, high-thrust and double-sided linear synchronous motor (LSM)module is proposed and the developed high-thrust and double-sided LSM module is verified by performance test.

  7. Experimental Study of Sorbitol Production by Zymomonas mobilis in High Sucrose Concentration

    OpenAIRE

    Rui Sérgio dos Santos Ferreira da Silva; João Batista Buzato; Maria Antonia Pedrine Colabone Celligoi; Marcos Roberto de Oliveira

    2004-01-01

    The sorbitol presents several industrial applications and its conventional production is of high cost and low yield. Sorbitol production by Zymomonas mobilis production has attracted attention as both production cost and environmental impact are low. The sorbitol plays an osmo-protective rule so that its production is promoted by high sugar concentrations. This work has evaluated the effect of high sucrose concentration in the sorbitol production. The raise of sucrose concentration from 100 t...

  8. Ground-roll noise extraction and suppression using high-resolution linear Radon transform

    Science.gov (United States)

    Hu, Yue; Wang, Limin; Cheng, Feng; Luo, Yinhe; Shen, Chao; Mi, Binbin

    2016-05-01

    Ground-roll is a main type of strong noises in petroleum seismic exploration. Suppression of this kind of noise is essential to improve the signal-to-noise ratio of seismic data. In the time-offset (t-x) domain, the ground-roll noise and the effective waves (e.g., direct waves, reflections) overlap with each other in terms of time and frequency, which make it difficult to suppress ground roll noise in exploration seismic data. However, significant different features shown in the frequency-velocity (f-v) domain make it possible to separate ground roll noise and effective waves effectively. We propose a novel method to separate them using high-resolution linear Radon transform (LRT). Amplitude and phase information is preserved during the proposed quasi-reversible transformation. The reversibility and linearity of LRT provide a foundation for ground-roll noise suppression in the f-v domain. We extract the energy of ground-roll noise in the f-v domain, and transform the extracted part back to the t-x domain to obtain the ground-roll noise shot gather. Finally, the extracted ground-roll noise is subtracted from the original data arithmetically. Theoretical tests and a real world example have been implemented to illustrate that the ground-roll noise suppression can be achieved with negligible distortion of the effective signals. When compared with the adaptive ground-roll attenuation method and the K-L transform method, the real world example shows the superiority of our method in suppressing the ground-roll noise and preserving the amplitude and phase information of effective waves.

  9. Static and Dynamic Characteristic Simulation of Feed System Driven by Linear Motor in High Speed Computer Numerical Control Lathe

    Directory of Open Access Journals (Sweden)

    Yang Zeqing

    2013-07-01

    Full Text Available In order to design the feed system of high speed Computer Numerical Control (CNC lathe, the static and dynamic characteristics of feed system driven by linear motor in high speed CNC lathe were analyzed. The slide board was taking as the main moving part of the feed system, and the guide rail was the main support component of the linear motor feed system. The mechanical structure static stiffness of feed system is researched through the slide board statics analysis. The simulation results show that the maximum deformation of the slide board occurs in the middle of the slide board where the linear motor is placed. The linear motor feed system control model was established based on analysis of high-speed linear feed system control principle, and the linear motor feed system transfer function was established, and servo dynamic stiffness factors were analyzed. The control parameters of the servo system and actuating mechanism parameters of feed system on the effect of the linear motor servo dynamic stiffness were analyzed using MATLAB software. The simulation results show that the position loop proportional gain, speed loop proportional gain and speed loop integral response time are the biggest influence factors on servo dynamic stiffness. The displacement response is reduced under the cutting interference force step inputting, the servo dynamic stiffness is increased, the number of system oscillation is also reduced, and the system tends to be stable.  

  10. Seasonal variation of benzo(a)pyrene in the Spanish airborne PM10. Multivariate linear regression model applied to estimate BaP concentrations.

    Science.gov (United States)

    Callén, M S; López, J M; Mastral, A M

    2010-08-15

    The estimation of benzo(a)pyrene (BaP) concentrations in ambient air is very important from an environmental point of view especially with the introduction of the Directive 2004/107/EC and due to the carcinogenic character of this pollutant. A sampling campaign of particulate matter less or equal than 10 microns (PM10) carried out during 2008-2009 in four locations of Spain was collected to determine experimentally BaP concentrations by gas chromatography mass-spectrometry mass-spectrometry (GC-MS-MS). Multivariate linear regression models (MLRM) were used to predict BaP air concentrations in two sampling places, taking PM10 and meteorological variables as possible predictors. The model obtained with data from two sampling sites (all sites model) (R(2)=0.817, PRESS/SSY=0.183) included the significant variables like PM10, temperature, solar radiation and wind speed and was internally and externally validated. The first validation was performed by cross validation and the last one by BaP concentrations from previous campaigns carried out in Zaragoza from 2001-2004. The proposed model constitutes a first approximation to estimate BaP concentrations in urban atmospheres with very good internal prediction (Q(CV)(2)=0.813, PRESS/SSY=0.187) and with the maximal external prediction for the 2001-2002 campaign (Q(ext)(2)=0.679 and PRESS/SSY=0.321) versus the 2001-2004 campaign (Q(ext)(2)=0.551, PRESS/SSY=0.449).

  11. Optimal explicit strong stability preserving Runge–Kutta methods with high linear order and optimal nonlinear order

    KAUST Repository

    Gottlieb, Sigal

    2015-04-10

    High order spatial discretizations with monotonicity properties are often desirable for the solution of hyperbolic PDEs. These methods can advantageously be coupled with high order strong stability preserving time discretizations. The search for high order strong stability time-stepping methods with large allowable strong stability coefficient has been an active area of research over the last two decades. This research has shown that explicit SSP Runge-Kutta methods exist only up to fourth order. However, if we restrict ourselves to solving only linear autonomous problems, the order conditions simplify and this order barrier is lifted: explicit SSP Runge-Kutta methods of any linear order exist. These methods reduce to second order when applied to nonlinear problems. In the current work we aim to find explicit SSP Runge-Kutta methods with large allowable time-step, that feature high linear order and simultaneously have the optimal fourth order nonlinear order. These methods have strong stability coefficients that approach those of the linear methods as the number of stages and the linear order is increased. This work shows that when a high linear order method is desired, it may still be worthwhile to use methods with higher nonlinear order.

  12. Nafion/SiO2 Nanocomposites: High Potential Catalysts for Alkylation of Benzene with Linear C9-C13 Alkenes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    High surface area Nafion/SiO2 nanocomposites with nano-sized Nafion resin particles entrapped and dispersed within the highly porous silica matrix exhibited significantly enhanced activity, high selectivity and long-term stability for the alkylation of benzene with linear C9-C13 alkenes owing to the increased accessibility of Nafion resin-based acid sites to reactants.

  13. A high dynamic range linear RF power detector with a preceding LNA

    Science.gov (United States)

    Yingbo, Dai; Kefeng, Han; Na, Yan; Xi, Tan

    2012-01-01

    A design of high dynamic range linear radio frequency power detector (PD), aimed for transmitter carrier leakage suppression is presented in this paper. Based on the logarithmic amplifier principle, this detector utilizes the successive detection method to achieve a high dynamic range in the radio frequency band. In order to increase sensitivity, a low noise amplifier (LNA) is placed in the front of this detector. DC coupling is adopted in this architecture to reduce parasitics and save area, but this will unavoidably cause DC offsets in the circuit which are detrimental to the dynamic range. So a DC offset cancelling (DCOC) technique is proposed to solve the problem. Finally, this detector was fabricated in the SMIC 0.13 μm CMOS process. The measured results show that it achieves a wide dynamic range of 50 dB/40 dB with log errors in ±1 dB at 900 MHz/2 GHz, while draws 16 mA from a 1.5 V power supply. The active chip area is 0.27 × 0.67 mm2.

  14. High Productivity Programming of Dense Linear Algebra on Heterogeneous NUMA Architectures

    KAUST Repository

    Alomairy, Rabab M.

    2013-07-01

    High-end multicore systems with GPU-based accelerators are now ubiquitous in the hardware landscape. Besides dealing with the nontrivial heterogeneous environ- ment, end users should often take into consideration the underlying memory architec- ture to decrease the overhead of data motion, especially when running on non-uniform memory access (NUMA) platforms. We propose the OmpSs parallel programming model approach using its Nanos++ dynamic runtime system to solve the two challeng- ing problems aforementioned, through 1) an innovative NUMA node-aware scheduling policy to reduce data movement between NUMA nodes and 2) a nested parallelism feature to concurrently exploit the resources available from the GPU devices as well as the CPU host, without compromising the overall performance. Our approach fea- tures separation of concerns by abstracting the complexity of the hardware from the end users so that high productivity can be achieved. The Cholesky factorization is used as a benchmark representative of dense numerical linear algebra algorithms. Superior performance is also demonstrated on the symmetric matrix inversion based on Cholesky factorization, commonly used in co-variance computations in statistics. Performance on a NUMA system with Kepler-based GPUs exceeds that of existing implementations, while the OmpSs-enabled code remains very similar to its original sequential version.

  15. Ghosts in high dimensional non-linear dynamical systems: The example of the hypercycle

    Energy Technology Data Exchange (ETDEWEB)

    Sardanyes, Josep [Complex Systems Laboratory (ICREA-UPF), Barcelona Biomedical Research Park (PRBB-GRIB), Dr. Aiguader 88, 08003 Barcelona (Spain)], E-mail: josep.sardanes@upf.edu

    2009-01-15

    Ghost-induced delayed transitions are analyzed in high dimensional non-linear dynamical systems by means of the hypercycle model. The hypercycle is a network of catalytically-coupled self-replicating RNA-like macromolecules, and has been suggested to be involved in the transition from non-living to living matter in the context of earlier prebiotic evolution. It is demonstrated that, in the vicinity of the saddle-node bifurcation for symmetric hypercycles, the persistence time before extinction, T{sub {epsilon}}, tends to infinity as n{yields}{infinity} (being n the number of units of the hypercycle), thus suggesting that the increase in the number of hypercycle units involves a longer resilient time before extinction because of the ghost. Furthermore, by means of numerical analysis the dynamics of three large hypercycle networks is also studied, focusing in their extinction dynamics associated to the ghosts. Such networks allow to explore the properties of the ghosts living in high dimensional phase space with n = 5, n = 10 and n = 15 dimensions. These hypercyclic networks, in agreement with other works, are shown to exhibit self-maintained oscillations governed by stable limit cycles. The bifurcation scenarios for these hypercycles are analyzed, as well as the effect of the phase space dimensionality in the delayed transition phenomena and in the scaling properties of the ghosts near bifurcation threshold.

  16. Does the cerebral cortex exploit high dimensional, non-linear dynamics for information processing?

    Directory of Open Access Journals (Sweden)

    Wolf Singer

    2016-09-01

    Full Text Available The discovery of stimulus induced synchronisation in the visual cortex suggested the possibility that the relations among low-level stimulus features are encoded by the temporal relationship between neuronal discharges. In this framework, temporal coherence is considered a signature of perceptual grouping. This insight triggered a large number of experimental studies which sought to investigate the relationship between temporal coordination and cognitive functions. While some core predictions derived from the initial hypothesis were confirmed, these studies, also revealed a rich dynamical landscape beyond simple coherence whose role in signal processing is still poorly understood. In this paper a framework is presented which establishes links between the various manifestations of cortical dynamics by assigning specific coding functions to low dimensional dynamic features such as synchronized oscillations and phase shifts on the one hand and high dimensional non-linear, non-stationary dynamics on the other. The data serving as basis for this synthetic approach have been obtained with chronic multisite recordings from the visual cortex of anesthetized cats and from monkeys trained to solve cognitive tasks. It is proposed that the low dimensional dynamics characterized by synchronized oscillations and large-scale correlations are sub-states that represent the results of computations performed in the high dimensional state space provided by recurrently coupled networks.

  17. High frequency analysis of a plate carrying a concentrated nonlinear spring-mass system

    Science.gov (United States)

    Culver, Dean; Dowell, Earl

    2016-09-01

    Examining the behavior of dynamical systems with many degrees of freedom undergoing random excitation at high frequency often requires substantial computation. These requirements are even more stringent for nonlinear systems. One approach for describing linear systems, Asymptotic Modal Analysis (AMA), has been extended to nonlinear systems in this paper. A prototypical system, namely a thin plate carrying a concentrated hardening cubic spring-mass, is explored. The study focuses on the response of three principal variables to random, frequency-bounded excitation: the displacement of the mounting location of the discrete spring-mass, the relative displacement of the discrete mass to this mounting location, and the absolute displacement of the discrete mass. The results indicate that extending AMA to nonlinear systems for input frequency bands containing a large number of modes is feasible. Several advantageous properties of nonlinear AMA are found, and an additional reduced frequency-domain modal method, Dominance-Reduced Classical Modal Analysis (DRCMA), is proposed that is intermediate in accuracy and the cost of computation between AMA and Classical Modal Analysis (CMA).

  18. Determination of plasma lactic acid concentration and specific activity using high-performance liquid chromatography.

    Science.gov (United States)

    Bleiberg, B; Steinberg, J J; Katz, S D; Wexler, J; LeJemtel, T

    1991-08-23

    Assessment of lactate metabolism is of particular interest during exercise and in disease states such as diabetes, shock, and absorptive abnormalities of short-chain fatty acids by the colon. We describe an analytical method that introduces radio-active tracers and high-performance liquid chromatography (HPLC) to simultaneously analyze concentrations and specific activities (SAs) of plasma lactate. The HPLC conditions included separation on a reversed-phase column (octadecylsilane) and an isocratic buffer (30% acetonitrile in water). [3H]Acetate served as an internal standard. Lactate and acetate were extracted from plasma samples with diethyl ether following a pH adjustment to less than 1.0 and back-extracted into a hydrophilic phase with sodium carbonate (2 mM, pH greater than 10.0). Lactate is detected in the ultraviolet range (242 and 320 nm) by derivatization with alpha-bromoacetophenone. Control plasma samples were studied after an overnight fast for precision and analytical recovery. Calibration curves were linear in the range 0.18-6.0 mM (r = 0.92). The precision was 3% and the analytical recovery was 87%. The detection limit of the method was 36 pmol. Determination of lactate metabolism was performed in a patient with chronic congestive heart failure who was administered primed-continuous L-[U-14C]lactate (10 microCi bolus and 0.3 microCi/min continuously) during a 60-min rest period. Mean arterial lactate concentration and SA were 1.69 +/- 0.2 mM and 253.8 +/- 22 dpm/mumol, respectively. Systemic lactate turnover was 25.65 mumol/kg per min. Lactic acid systemic turnover, organ uptake and release rates can be accurately determined by isocratic HPLC.

  19. High catechin concentrations detected in Withania somnifera (ashwagandha by high performance liquid chromatography analysis

    Directory of Open Access Journals (Sweden)

    Sulaiman Siti

    2011-08-01

    Full Text Available Abstract Background Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt. Methods WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods. Results High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%. Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g. Conclusion The results indicating that W. somnifera is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of W. somnifera such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties.

  20. Metasurface integrated high energy efficient and high linearly polarized InGaN/GaN light emitting diode.

    Science.gov (United States)

    Wang, Miao; Xu, Fuyang; Lin, Yu; Cao, Bing; Chen, Linghua; Wang, Chinhua; Wang, Jianfeng; Xu, Ke

    2017-07-06

    We proposed and demonstrated an integrated high energy efficient and high linearly polarized InGaN/GaN green LED grown on (0001) oriented sapphire with combined metasurface polarizing converter and polarizer system. It is different from those conventional polarized light emissions generated with plasmonic metallic grating in which at least 50% high energy loss occurs inherently due to high reflection of the transverse electric (TE) component of an electric field. A reflecting metasurface, with a two dimensional elliptic metal cylinder array (EMCA) that functions as a half-wave plate, was integrated at the bottom of a LED such that the back-reflected TE component, that is otherwise lost by a dielectric/metal bi-layered wire grids (DMBiWG) polarizer on the top emitting surface of the LED, can be converted to desired transverse magnetic (TM) polarized emission after reflecting from the metasurface. This significantly enhances the polarized light emission efficiency. Experimental results show that extraction efficiency of the polarized emission can be increased by 40% on average in a wide angle of ±60° compared to that with the naked bottom of sapphire substrate, or 20% compared to reflecting Al film on the bottom of a sapphire substrate. An extinction ratio (ER) of average value 20 dB within an angle of ±60° can be simultaneously obtained directly from an InGaN/GaN LED. Our results show the possibility of simultaneously achieving a high degree of polarization and high polarization extraction efficiency at the integrated device level. This advances the field of GaN LED toward energy efficiency, multi-functional applications in illumination, display, medicine, and light manipulation.

  1. Changes in brain iron concentration after exposure to high-altitude hypoxia measured by quantitative susceptibility mapping.

    Science.gov (United States)

    Chen, Lin; Cai, Congbo; Yang, Tianhe; Lin, Jianzhong; Cai, Shuhui; Zhang, Jiaxing; Chen, Zhong

    2017-02-15

    Hypoxia can induce physiological changes. This study aims to explore effects of high-altitude (HA) hypoxia on cerebral iron concentration. Twenty-nine healthy sea-level participants were tested shortly before and after approximately 4-week adaptation to the HA environment at fQinghai-Tibet Plateau (4200m), and were re-investigated after re-adaptation to the sea-level environment one year later. Iron concentration was quantified with quantitative susceptibility mapping (QSM), and the results were compared with transverse relaxation rate (R(*)2) measurements. The variations of magnetic susceptibility indicate that the iron concentration in gray matter regions, especially in basal ganglia, including caudate nucleus, putamen, globus pallidus and substantia nigra, increases significantly after HA exposure. This increase appears consistent with the conclusion from R(*)2 value variations. However, unlike QSM, the R(*)2 value fails to demonstrate the statistical difference of iron content in red nucleus. The re-investigation results show that most variations are recovered after sea-level re-adaptation for one year. Additionally, hemisphere- and gender-related differences in iron concentration changes were analyzed among cerebral regions. The results show greater possibilities in the right hemisphere and females. Further studies based on diffusion tensor imaging (DTI) suggest that the fractional anisotropy increases and the mean diffusivity decreases after HA exposure in six deep gray matter nuclei, with linear dependence on iron concentration only in putamen. In conclusion, the magnetic susceptibility value can serve as a quantitative marker of brain iron, and variations of regional susceptibility reported herein indicate that HA hypoxia can result in significant iron deposition in most deep gray matter regions. Additionally, the linear dependence of DTI metrics on iron concentration in putamen indicates a potential relationship between ferritin and water diffusion.

  2. High-frequency effects in 1D spring-mass systems with strongly non-linear inclusions

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Snaeland, S.O.; Thomsen, Jon Juel

    2010-01-01

    -like systems with embedded non-linear parts, where the masses interact with a limited set of neighbour masses. The presented analytical and numerical results show that the effective properties for LF wave propagation can be altered by establishing HF standing waves in the non-linear regions of the chain......This work generalises the possibilities to change the effective material or structural properties for low frequency (LF) wave propagation, by using high-frequency (HF) external excitation combined with strong non-linear and non-local material behaviour. The effects are demonstrated on 1D chain....... The changes affect the effective stiffness and damping of the system....

  3. Solid-state fluoroscopic imager for high-resolution angiography: parallel-cascaded linear systems analysis.

    Science.gov (United States)

    Vedantham, Srinivasan; Karellas, Andrew; Suryanarayanan, Sankararaman

    2004-05-01

    Cascaded linear systems based modeling techniques have been used in the past to predict important system parameters that have a direct impact on image quality. Such models are also useful in optimizing system parameters to improve image quality. In this work, detailed analysis of a solid-state fluoroscopic imaging system intended for high-resolution angiography is presented with the use of such a model. The imaging system analyzed through this model uses four 8 x 8 cm three-side buttable interlined charge-coupled devices (CCDs) specifically designed for high-resolution angiography and tiled in a seamless fashion to achieve a field of view (FOV) of 16 x 16 cm. Larger FOVs can be achieved by tiling more CCDs in a similar manner. The system employs a CsI:Tl scintillator coupled to the CCDs by straight (nontapering) fiberoptics and can potentially be operated in 78, 156, or 234 microm pixel pitch modes. The system parameters analyzed through this model include presampling modulation transfer function, noise power spectrum, and detective quantum efficiency (DQE). The results of the simulations performed indicate that DQE(0) in excess of 0.6 is achievable, with the imager operating at 156 microm pixel pitch, 30 frames/s, and employing a 450-microm-thick CsI:Tl scintillator, even at a low fluoroscopic exposure rate of 1 microR/frame. Further, at a nominal fluoroscopic exposure rate of 2.5 microR/frame there was no noticeable degradation of the DQE even at the 78 microm pixel pitch mode suggesting that it is feasible to perform high-resolution angiography hitherto unattainable in clinical practice.

  4. High-Efficiency Solar Thermal Vacuum Demonstration Completed for Refractive Secondary Concentrator

    Science.gov (United States)

    Wong, Wayne A.

    2001-01-01

    Common to many of the space applications that utilize solar thermal energy--such as electric power conversion, thermal propulsion, and furnaces--is a need for highly efficient, solar concentration systems. An effort is underway at the NASA Glenn Research Center to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced lightweight primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (>2000 K). The innovative refractive secondary concentrator offers significant advantages over all other types of secondary concentrators. The refractive secondary offers the highest throughput efficiency, provides for flux tailoring, requires no active cooling, relaxes the pointing and tracking requirements of the primary concentrator, and enables very high system concentration ratios. This technology has broad applicability to any system that requires the conversion of solar energy to heat. Glenn initiated the development of the refractive secondary concentrator in support of Shooting Star, a solar thermal propulsion flight experiment, and continued the development in support of Space Solar Power.

  5. Generation of arbitrary monotonic concentration profiles by a serial dilution microfluidic network composed of microchannels with a high fluidic-resistance ratio.

    Science.gov (United States)

    Hattori, Koji; Sugiura, Shinji; Kanamori, Toshiyuki

    2009-06-21

    This paper reports a serial dilution microfluidic network composed of microchannels with a high fluidic-resistance ratio for generating linear concentration profiles as well as logarithmic concentration profiles spanning 3 and 6 orders of magnitude. The microfluidic networks were composed of thin fluidic-resistance microchannels with 160 to 730 microm(2) cross-sectional areas and thick diffusion-mixing microchannels with 3,600 to 17,000 microm(2) cross-sectional areas, and were fabricated from polydimethylsiloxane by multilayer photolithography and replica molding. We proposed a design algorithm of the microfluidic network for an arbitrary monotonic concentration profile by means of a hydrodynamic calculation. Because of the high fluidic-resistance ratio of the fluidic-resistance microchannels to the diffusion-mixing microchannels, appropriate geometry and dimensions of the fluidic-resistance microchannels allowed us to obtain desired concentration profiles. The fabricated microfluidic network was compact, occupying a 8 x 18 to 21.0 x 13.5 mm(2) area on the microchip. Both the linear and the logarithmic concentration profiles were successfully generated with the error less than 15% for the linear concentration profile, 22% and 35% for the logarithmic concentration profiles of 3 and 6 orders of magnitude, respectively. The generated linear concentration profiles of the small molecule, calcein, were independent of the flow rate within the range of 0.009 to 0.23 microL/min. The concentration profiles of the large molecules, dextrans, depended on the flow rate and molecular weight. The required residence time of large molecules in the diffusion-mixing microchannel was correlated with dimensionless diffusion time, Fick number, and was discussed based on the scaling law. These compact, stable serial dilution microfluidic networks are expected to be applied to various integrated on-chip analyses.

  6. High-sensitivity in situ QCLAS-based ammonia concentration sensor for high-temperature applications

    Science.gov (United States)

    Peng, W. Y.; Sur, R.; Strand, C. L.; Spearrin, R. M.; Jeffries, J. B.; Hanson, R. K.

    2016-07-01

    A novel quantum cascade laser (QCL) absorption sensor is presented for high-sensitivity in situ measurements of ammonia (hbox {NH}_3) in high-temperature environments, using scanned wavelength modulation spectroscopy (WMS) with first-harmonic-normalized second-harmonic detection (scanned WMS-2 f/1 f) to neutralize the effect of non-absorption losses in the harsh environment. The sensor utilized the sQ(9,9) transition of the fundamental symmetric stretch band of hbox {NH}_3 at 10.39 {\\upmu }hbox {m} and was sinusoidally modulated at 10 kHz and scanned across the peak of the absorption feature at 50 Hz, leading to a detection bandwidth of 100 Hz. A novel technique was used to select an optimal WMS modulation depth parameter that reduced the sensor's sensitivity to spectral interference from hbox {H}_2hbox {O} and hbox {CO}_2 without significantly sacrificing signal-to-noise ratio. The sensor performance was validated by measuring known concentrations of hbox {NH}_3 in a flowing gas cell. The sensor was then demonstrated in a laboratory-scale methane-air burner seeded with hbox {NH}_3, achieving a demonstrated detection limit of 2.8 ± 0.26 ppm hbox {NH}_3 by mole at a path length of 179 cm, equivalence ratio of 0.6, pressure of 1 atm, and temperatures of up to 600 K.

  7. Changing climate and nutrient transfers: Evidence from high temporal resolution concentration-flow dynamics in headwater catchments.

    Science.gov (United States)

    Ockenden, M C; Deasy, C E; Benskin, C McW H; Beven, K J; Burke, S; Collins, A L; Evans, R; Falloon, P D; Forber, K J; Hiscock, K M; Hollaway, M J; Kahana, R; Macleod, C J A; Reaney, S M; Snell, M A; Villamizar, M L; Wearing, C; Withers, P J A; Zhou, J G; Haygarth, P M

    2016-04-01

    We hypothesise that climate change, together with intensive agricultural systems, will increase the transfer of pollutants from land to water and impact on stream health. This study builds, for the first time, an integrated assessment of nutrient transfers, bringing together a) high-frequency data from the outlets of two surface water-dominated, headwater (~10km(2)) agricultural catchments, b) event-by-event analysis of nutrient transfers, c) concentration duration curves for comparison with EU Water Framework Directive water quality targets, d) event analysis of location-specific, sub-daily rainfall projections (UKCP, 2009), and e) a linear model relating storm rainfall to phosphorus load. These components, in combination, bring innovation and new insight into the estimation of future phosphorus transfers, which was not available from individual components. The data demonstrated two features of particular concern for climate change impacts. Firstly, the bulk of the suspended sediment and total phosphorus (TP) load (greater than 90% and 80% respectively) was transferred during the highest discharge events. The linear model of rainfall-driven TP transfers estimated that, with the projected increase in winter rainfall (+8% to +17% in the catchments by 2050s), annual event loads might increase by around 9% on average, if agricultural practices remain unchanged. Secondly, events following dry periods of several weeks, particularly in summer, were responsible for high concentrations of phosphorus, but relatively low loads. The high concentrations, associated with low flow, could become more frequent or last longer in the future, with a corresponding increase in the length of time that threshold concentrations (e.g. for water quality status) are exceeded. The results suggest that in order to build resilience in stream health and help mitigate potential increases in diffuse agricultural water pollution due to climate change, land management practices should target

  8. A High Order Theory for Linear Thermoelastic Shells: Comparison with Classical Theories

    Directory of Open Access Journals (Sweden)

    V. V. Zozulya

    2013-01-01

    Full Text Available A high order theory for linear thermoelasticity and heat conductivity of shells has been developed. The proposed theory is based on expansion of the 3-D equations of theory of thermoelasticity and heat conductivity into Fourier series in terms of Legendre polynomials. The first physical quantities that describe thermodynamic state have been expanded into Fourier series in terms of Legendre polynomials with respect to a thickness coordinate. Thereby all equations of elasticity and heat conductivity including generalized Hooke's and Fourier's laws have been transformed to the corresponding equations for coefficients of the polynomial expansion. Then in the same way as in the 3D theories system of differential equations in terms of displacements and boundary conditions for Fourier coefficients has been obtained. First approximation theory is considered in more detail. The obtained equations for the first approximation theory are compared with the corresponding equations for Timoshenko's and Kirchhoff-Love's theories. Special case of plates and cylindrical shell is also considered, and corresponding equations in displacements are presented.

  9. Collisional damping of helicon waves in a high density hydrogen linear plasma device

    Science.gov (United States)

    Caneses, Juan F.; Blackwell, Boyd D.

    2016-10-01

    In this paper, we investigate the propagation and damping of helicon waves along the length (50 cm) of a helicon-produced 20 kW hydrogen plasma ({{n}\\text{e}}∼ 1–2 × 1019 m‑3, {{T}\\text{e}}∼ 1–6 eV, H2 8 mTorr) operated in a magnetic mirror configuration (antenna region: 50–200 G and mirror region: 800 G). Experimental results show the presence of traveling helicon waves (4–8 G and {λz}∼ 10–15 cm) propagating away from the antenna region which become collisionally absorbed within 40–50 cm. We describe the use of the WKB method to calculate wave damping and provide an expression to assess its validity based on experimental measurements. Theoretical calculations are consistent with experiment and indicate that for conditions where Coulomb collisions are dominant classical collisionality is sufficient to explain the observed wave damping along the length of the plasma column. Based on these results, we provide an expression for the scaling of helicon wave damping relevant to high density discharges and discuss the location of surfaces for plasma-material interaction studies in helicon based linear plasma devices.

  10. Penalized Ensemble Kalman Filters for High Dimensional Non-linear Systems

    CERN Document Server

    Hou, Elizabeth; Hero, Alfred O

    2016-01-01

    The ensemble Kalman filter (EnKF) is a data assimilation technique that uses an ensemble of models, updated with data, to track the time evolution of a non-linear system. It does so by using an empirical approximation to the well-known Kalman filter. Unfortunately, its performance suffers when the ensemble size is smaller than the state space, as is often the case for computationally burdensome models. This scenario means that the empirical estimate of the state covariance is not full rank and possibly quite noisy. To solve this problem in this high dimensional regime, a computationally fast and easy to implement algorithm called the penalized ensemble Kalman filter (PEnKF) is proposed. Under certain conditions, it can be proved that the PEnKF does not require more ensemble members than state dimensions in order to have good performance. Further, the proposed approach does not require special knowledge of the system such as is used by localization methods. These theoretical results are supported with superior...

  11. Highly non-linear solid core photonic crystal fiber with one nano hole

    Energy Technology Data Exchange (ETDEWEB)

    Gangwar, Rahul Kumar, E-mail: rahul0889@gmail.com; Bhardwaj, Vanita, E-mail: bhardwajphy12@gmail.com; Singh, Vinod Kumar, E-mail: singh.vk.ap@ismdhanbad.co.in [Department of Applied Physics, Indian School of Mines, Dhanbad, Jharkhand (India)

    2015-08-28

    The numerical study of newly designed solid core photonic crystal fiber (SCPCF) having three hexagonal air hole rings in cladding region and one small nano hole at the center are presented. By using full vectorial finite element method (FV-FEM), we analyses the optical properties like effective area, nonlinearity and confinement loss of the proposed PCF. Results show that the change in core diameter controls the effective area, nonlinearity and confinement loss. A low effective area (3.34 µm{sup 2}), high nonlinearity (36.34 W{sup −1}km{sup −1}) and low confinement loss (0.00106 dB/km) are achieved at the communication wavelength 1.55 µm for the SCPCF having core air hole diameter 0.10 µm, cladding air holes diameter 1.00 µm and pitch 2.50 µm. This type of PCF is very useful in non-linear applications such as supercontinuum generation, four wave mixing, second harmonic generation etc.

  12. A high repetition rate experimental setup for quantum non-linear optics with cold Rydberg atoms

    Science.gov (United States)

    Busche, Hannes; Ball, Simon W.; Huillery, Paul

    2016-12-01

    Using electromagnetically induced transparency and photon storage, the strong dipolar interactions between Rydberg atoms and the resulting dipole blockade can be mapped onto light fields to realise optical non-linearities and interactions at the single photon level. We report on the realisation of an experimental apparatus designed to study interactions between single photons stored as Rydberg excitations in optically trapped microscopic ensembles of ultracold 87Rb atoms. A pair of in-vacuum high numerical aperture lenses focus excitation and trapping beams down to 1 μm, well below the Rydberg blockade. Thanks to efficient magneto-optical trap (MOT) loading from an atomic beam generated by a 2D MOT and the ability to recycle the microscopic ensembles more than 20000 times without significant atom loss, we achieve effective repetition rates exceeding 110 kHz to obtain good photon counting statistics on reasonable time scales. To demonstrate the functionality of the setup, we present evidence of strong photon interactions including saturation of photon storage and the retrieval of non-classical light. Using in-vacuum antennae operating at up to 40 GHz, we perform microwave spectroscopy on photons stored as Rydberg excitations and observe an interaction induced change in lineshape depending on the number of stored photons.

  13. Proximity graph analysis for linear networks extraction from high-resolution satellite imagery

    Science.gov (United States)

    Skourikhine, Alexei N.

    2006-05-01

    Reliable and accurate methods for detection and extraction of linear network, such as road networks, in satellite imagery are essential to many applications. We present an approach to the road network extraction from high-resolution satellite imagery that is based on proximity graph analysis. We are jumping off from the classification provided by existing spectral and textural classification tools, which produce a set of candidate road patches. Then, constrained Delaunay triangulation and Chordal Axis transform are used to extract centerline characterization of the delineated candidate road patches. We refine produced center lines to reduce noise influence on patch boundaries, resulting in a smaller set of robust center lines authentically representing their road patches. Refined center lines are triangulated using constrained Delaunay triangulation (CDT) algorithm to generate a sub-optimal mesh of interconnections among them. The generated triangle edges connecting different center lines are used for spatial analysis of the center lines relations. A subset of the Delaunay tessellation grid contains the Euclidian Minimum Spanning Tree (EMST) that provides an approximation of road network. The approach can be generalized to the multi-criteria MST and multi-criteria shortest path algorithms to integrate other factors important for road network extraction, in addition to proximity relations considered by standard EMST.

  14. Choosing processor array configuration by performance modeling for a highly parallel linear algebra algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Littlefield, R.J.; Maschhoff, K.J.

    1991-04-01

    Many linear algebra algorithms utilize an array of processors across which matrices are distributed. Given a particular matrix size and a maximum number of processors, what configuration of processors, i.e., what size and shape array, will execute the fastest The answer to this question depends on tradeoffs between load balancing, communication startup and transfer costs, and computational overhead. In this paper we analyze in detail one algorithm: the blocked factored Jacobi method for solving dense eigensystems. A performance model is developed to predict execution time as a function of the processor array and matrix sizes, plus the basic computation and communication speeds of the underlying computer system. In experiments on a large hypercube (up to 512 processors), this model has been found to be highly accurate (mean error {approximately} 2%) over a wide range of matrix sizes (10 {times} 10 through 200 {times} 200) and processor counts (1 to 512). The model reveals, and direct experiment confirms, that the tradeoffs mentioned above can be surprisingly complex and counterintuitive. We propose decision procedures based directly on the performance model to choose configurations for fastest execution. The model-based decision procedures are compared to a heuristic strategy and shown to be significantly better. 7 refs., 8 figs., 1 tab.

  15. Research on a Linear Piezoelectric Actuator Using T-Shape Transducer to Realize High Mechanical Output

    Directory of Open Access Journals (Sweden)

    Sijia Shao

    2016-04-01

    Full Text Available A modified large thrust ultrasonic linear motor using a T-shape configuration composed of two orthogonal sandwich-type transducers has been proposed in this paper. It is an improved version of a previous T-shape motor. The vertical transducer is used to generate the normal force between the driving foot and slider, while the other push-pull–type horizontal transducer is applied to generate driving force to push the working platform. By superimposing the two longitudinal vibrations, the proposed motor generates an elliptical movement on the driving foot. In order to improve the vibration characteristics and amplify the driving vibration amplitude, the shape of the driving foot and horn have been redesigned and optimized. The finite element method (FEM is used to adjust the structural parameters to degenerate the two working mode frequencies. The prototype has been fabricated and its mechanical output ability has been measured. The output characteristics of the modified motor, compared with the previous T-shape motor, achieve a relatively high level. The typical no-load speed and maximum output thrust of the prototype are 0.83 m/s and 56 N under an exciting voltage of 150 Vrms.

  16. High-Rate Data-Hiding Robust to Linear Filtering for Colored Hosts

    Directory of Open Access Journals (Sweden)

    Pérez-González Fernando

    2009-01-01

    Full Text Available The discrete Fourier transform-rational dither modulation (DFT-RDM has been proposed as a way to provide robustness to linear-time-invariant (LTI filtering for quantization-based watermarking systems. This scheme has been proven to provide high rates for white Gaussian hosts but those rates considerably decrease for nonwhite hosts. In this paper the theoretical analysis of DFT-RDM is generalized to colored Gaussian hosts supplied with an explanation of the performance degradation with respect to white Gaussian hosts. Moreover the characterization of the watermark-to-noise ratio in the frequency domain is shown as an useful tool to give a simple and intuitive measure of performance. Afterwards an extension of DFT-RDM is proposed to improve its performance for colored hosts without assuming any additional knowledge on the attack filter. Our analysis is validated by experiments and the results of several simulations for different attack filters confirm the performance improvement afforded by the whitening operation for both Gaussian colored hosts and audio tracks.

  17. Rotational IMRT delivery using a digital linear accelerator in very high dose rate 'burst mode'

    Science.gov (United States)

    Salter, Bill J.; Sarkar, Vikren; Wang, Brian; Shukla, Himanshu; Szegedi, Martin; Rassiah-Szegedi, Prema

    2011-04-01

    Recently, there has been a resurgence of interest in arc-based IMRT, through the use of 'conventional' multileaf collimator (MLC) systems that can treat large tumor volumes in a single, or very few pass(es) of the gantry. Here we present a novel 'burst mode' modulated arc delivery approach, wherein 2000 monitor units per minute (MU min-1) high dose rate bursts of dose are facilitated by a flattening-filter-free treatment beam on a Siemens Artiste (Oncology Care Systems, Siemens Medical Solutions, Concord, CA, USA) digital linear accelerator in a non-clinical configuration. Burst mode delivery differs from continuous mode delivery, used by Elekta's VMAT (Elekta Ltd, Crawley, UK) and Varian's RapidArc (Varian Medical Systems, Palo Alto, CA, USA) implementations, in that dose is not delivered while MLC leaves are moving. Instead, dose is delivered in bursts over very short arc angles and only after an MLC segment shape has been completely formed and verified by the controller. The new system was confirmed to be capable of delivering a wide array of clinically relevant treatment plans, without machine fault or other delivery anomalies. Dosimetric accuracy of the modulated arc platform, as well as the Prowess (Prowess Inc., Concord, CA, USA) prototype treatment planning version utilized here, was quantified and confirmed, and delivery times were measured as significantly brief, even with large hypofractionated doses. The burst mode modulated arc approach evaluated here appears to represent a capable, accurate and efficient delivery approach.

  18. Accelerating Scientific Applications using High Performance Dense and Sparse Linear Algebra Kernels on GPUs

    KAUST Repository

    Abdelfattah, Ahmad

    2015-01-15

    High performance computing (HPC) platforms are evolving to more heterogeneous configurations to support the workloads of various applications. The current hardware landscape is composed of traditional multicore CPUs equipped with hardware accelerators that can handle high levels of parallelism. Graphical Processing Units (GPUs) are popular high performance hardware accelerators in modern supercomputers. GPU programming has a different model than that for CPUs, which means that many numerical kernels have to be redesigned and optimized specifically for this architecture. GPUs usually outperform multicore CPUs in some compute intensive and massively parallel applications that have regular processing patterns. However, most scientific applications rely on crucial memory-bound kernels and may witness bottlenecks due to the overhead of the memory bus latency. They can still take advantage of the GPU compute power capabilities, provided that an efficient architecture-aware design is achieved. This dissertation presents a uniform design strategy for optimizing critical memory-bound kernels on GPUs. Based on hierarchical register blocking, double buffering and latency hiding techniques, this strategy leverages the performance of a wide range of standard numerical kernels found in dense and sparse linear algebra libraries. The work presented here focuses on matrix-vector multiplication kernels (MVM) as repre- sentative and most important memory-bound operations in this context. Each kernel inherits the benefits of the proposed strategies. By exposing a proper set of tuning parameters, the strategy is flexible enough to suit different types of matrices, ranging from large dense matrices, to sparse matrices with dense block structures, while high performance is maintained. Furthermore, the tuning parameters are used to maintain the relative performance across different GPU architectures. Multi-GPU acceleration is proposed to scale the performance on several devices. The

  19. Evaluation of an analytic linear Boltzmann transport equation solver for high-density inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, S. A. M.; Ansbacher, W. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 3P6 (Canada) and Department of Medical Physics, British Columbia Cancer Agency-Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

    2013-01-15

    Purpose: Acuros external beam (Acuros XB) is a novel dose calculation algorithm implemented through the ECLIPSE treatment planning system. The algorithm finds a deterministic solution to the linear Boltzmann transport equation, the same equation commonly solved stochastically by Monte Carlo methods. This work is an evaluation of Acuros XB, by comparison with Monte Carlo, for dose calculation applications involving high-density materials. Existing non-Monte Carlo clinical dose calculation algorithms, such as the analytic anisotropic algorithm (AAA), do not accurately model dose perturbations due to increased electron scatter within high-density volumes. Methods: Acuros XB, AAA, and EGSnrc based Monte Carlo are used to calculate dose distributions from 18 MV and 6 MV photon beams delivered to a cubic water phantom containing a rectangular high density (4.0-8.0 g/cm{sup 3}) volume at its center. The algorithms are also used to recalculate a clinical prostate treatment plan involving a unilateral hip prosthesis, originally evaluated using AAA. These results are compared graphically and numerically using gamma-index analysis. Radio-chromic film measurements are presented to augment Monte Carlo and Acuros XB dose perturbation data. Results: Using a 2% and 1 mm gamma-analysis, between 91.3% and 96.8% of Acuros XB dose voxels containing greater than 50% the normalized dose were in agreement with Monte Carlo data for virtual phantoms involving 18 MV and 6 MV photons, stainless steel and titanium alloy implants and for on-axis and oblique field delivery. A similar gamma-analysis of AAA against Monte Carlo data showed between 80.8% and 87.3% agreement. Comparing Acuros XB and AAA evaluations of a clinical prostate patient plan involving a unilateral hip prosthesis, Acuros XB showed good overall agreement with Monte Carlo while AAA underestimated dose on the upstream medial surface of the prosthesis due to electron scatter from the high-density material. Film measurements

  20. Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration

    Directory of Open Access Journals (Sweden)

    H. Fuchs

    2012-07-01

    Full Text Available During recent field campaigns, hydroxyl radical (OH concentrations that were measured by laser-induced fluorescence (LIF were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK, methacrolein (MACR and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD, China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS. Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s−1 and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03 × 106 cm−3 and a linear correlation coefficient of R2 = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30–40% (median larger than those by DOAS after MVK (20 ppbv and

  1. Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration

    Science.gov (United States)

    Fuchs, H.; Dorn, H.-P.; Bachner, M.; Bohn, B.; Brauers, T.; Gomm, S.; Hofzumahaus, A.; Holland, F.; Nehr, S.; Rohrer, F.; Tillmann, R.; Wahner, A.

    2012-07-01

    During recent field campaigns, hydroxyl radical (OH) concentrations that were measured by laser-induced fluorescence (LIF) were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK), methacrolein (MACR) and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD), China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS). Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s-1 and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points) yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03) × 106 cm-3 and a linear correlation coefficient of R2 = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30-40% (median) larger than those by DOAS after MVK (20 ppbv) and toluene (90 ppbv) had been added. However, this discrepancy has a

  2. Greedy algorithms for high-dimensional non-symmetric linear problems***

    Directory of Open Access Journals (Sweden)

    Cancès E.

    2013-12-01

    Full Text Available In this article, we present a family of numerical approaches to solve high-dimensional linear non-symmetric problems. The principle of these methods is to approximate a function which depends on a large number of variates by a sum of tensor product functions, each term of which is iteratively computed via a greedy algorithm ? . There exists a good theoretical framework for these methods in the case of (linear and nonlinear symmetric elliptic problems. However, the convergence results are not valid any more as soon as the problems under consideration are not symmetric. We present here a review of the main algorithms proposed in the literature to circumvent this difficulty, together with some new approaches. The theoretical convergence results and the practical implementation of these algorithms are discussed. Their behaviors are illustrated through some numerical examples. Dans cet article, nous présentons une famille de méthodes numériques pour résoudre des problèmes linéaires non symétriques en grande dimension. Le principe de ces approches est de représenter une fonction dépendant d’un grand nombre de variables sous la forme d’une somme de fonctions produit tensoriel, dont chaque terme est calculé itérativement via un algorithme glouton ? . Ces méthodes possèdent de bonnes propriétés théoriques dans le cas de problèmes elliptiques symétriques (linéaires ou non linéaires, mais celles-ci ne sont plus valables dès lors que les problèmes considérés ne sont plus symétriques. Nous présentons une revue des principaux algorithmes proposés dans la littérature pour contourner cette difficulté ainsi que de nouvelles approches que nous proposons. Les résultats de convergence théoriques et la mise en oeuvre pratique de ces algorithmes sont détaillés et leur comportement est illustré au travers d’exemples numériques.

  3. Fully integrated high quality factor GmC bandpass filter stage with highly linear operational transconductance amplifier

    Directory of Open Access Journals (Sweden)

    J. Briem

    2017-09-01

    Full Text Available This paper presents an electrical, fully integrated, high quality (Q factor GmC bandpass filter (BPF stage for a wireless 27 MHz direct conversion receiver for a bendable sensor system-in-foil (Briem et al., 2016. The core of the BPF with a Q factor of more than 200 is an operational transconductance amplifier (OTA with a high linearity at an input range of up to 300 mVpp, diff. The OTA's signal-to-noise-and-distortion-ratio (SNDR of more than 80 dB in the mentioned range is achieved by stabilizing its transconductance Gm with a respective feedback loop and a source degeneration resistors RDG. The filter stage can be tuned and is tolerant to global and local process variations due to offset and common-mode feedback (CMFB control circuits. The results are determined by periodic steady state (PSS simulations at more than 200 global and local process variation parameter and temperature points and corner simulations. It is expected, that the parasitic elements of the layout have no significant influence on the filter behaviour. The current consumption of the whole filter stage is less than 600 µA.

  4. Fully integrated high quality factor GmC bandpass filter stage with highly linear operational transconductance amplifier

    Science.gov (United States)

    Briem, Jochen; Mader, Marco; Reiter, Daniel; Amirpour, Raul; Grözing, Markus; Berroth, Manfred

    2017-09-01

    This paper presents an electrical, fully integrated, high quality (Q) factor GmC bandpass filter (BPF) stage for a wireless 27 MHz direct conversion receiver for a bendable sensor system-in-foil (Briem et al., 2016). The core of the BPF with a Q factor of more than 200 is an operational transconductance amplifier (OTA) with a high linearity at an input range of up to 300 mVpp, diff. The OTA's signal-to-noise-and-distortion-ratio (SNDR) of more than 80 dB in the mentioned range is achieved by stabilizing its transconductance Gm with a respective feedback loop and a source degeneration resistors RDG. The filter stage can be tuned and is tolerant to global and local process variations due to offset and common-mode feedback (CMFB) control circuits. The results are determined by periodic steady state (PSS) simulations at more than 200 global and local process variation parameter and temperature points and corner simulations. It is expected, that the parasitic elements of the layout have no significant influence on the filter behaviour. The current consumption of the whole filter stage is less than 600 µA.

  5. A low noise and high precision linear power supply with thermal foldback protection

    Science.gov (United States)

    Carniti, P.; Cassina, L.; Gotti, C.; Maino, M.; Pessina, G.

    2016-05-01

    A low noise and high precision linear power supply was designed for use in rare event search experiments with macrobolometers. The circuit accepts at the input a "noisy" dual supply voltage up to ±15 V and gives at the output precise, low noise, and stable voltages that can be set between ±3.75 V and ±12.5 V in eight 1.25 V steps. Particular care in circuit design, component selection, and proper filtering results in a noise spectral density of 50 nV / √{ Hz } at 1 Hz and 20 nV / √{ Hz } white when the output is set to ±5 V. This corresponds to 125 nV RMS (0.8 μV peak to peak) between 0.1 Hz and 10 Hz, and 240 nV RMS (1.6 μV peak to peak) between 0.1 Hz and 100 Hz. The power supply rejection ratio (PSRR) of the circuit is 100 dB at low frequency, and larger than 40 dB up to high frequency, thanks to a proper compensation design. Calibration allows to reach a precision in the absolute value of the output voltage of ±70 ppm, or ±350 μV at ±5 V, and to reduce thermal drifts below ±1 ppm/∘C in the expected operating range. The maximum peak output current is about 6 A from each output. An original foldback protection scheme was developed that dynamically limits the maximum output current to keep the temperature of the output transistors within their safe operating range. An add-on card based on an ARM Cortex-M3 microcontroller is devoted to the monitoring and control of all circuit functionalities and provides remote communication via CAN bus.

  6. Vitamin C at high concentrations induces cytotoxicity in malignant melanoma but promotes tumor growth at low concentrations.

    Science.gov (United States)

    Yang, Guang; Yan, Yao; Ma, Younan; Yang, Yixin

    2017-08-01

    Vitamin C has been used in complementary and alternative medicine for cancers regardless of its ineffectiveness in clinical trials and the paradoxical effects antioxidants have on cancer. Vitamin C was found to induce cytotoxicity against cancers. However, the mechanisms of action have not been fully elucidated, and the effects of vitamin C on human malignant melanoma have not been examined. This study revealed that vitamin C at millimolar concentrations significantly reduced the cell viability as well as invasiveness, and induced apoptosis in human malignant melanoma cells. Vitamin C displayed stronger cytotoxicity against the Vemurafenib-resistance cell line A2058 compared with SK-MEL-28. In contrast, vitamin C at micromolar concentrations promoted cell growth, migration and cell cycle progression, and protected against mitochondrial stress. Vemurafenib paradoxically activated the RAS-RAF-MEK-ERK signaling pathway in the Vemurafenib-resistant A2058, however, vitamin C abolished the activations. Vitamin C displayed synergistic cytotoxicity with Vemurafenib against the Vemurafenib-resistant A2058. In vivo assay suggested that lower dosage (equivalent to 0.5 g/70 kg) of vitamin C administered orally increased the melanoma growth. Therefore, vitamin C may exert pro- or anti-melanoma effect depending on concentration. The combination of vitamin C at high dosage and Vemurafenib is promising in overcoming the action of drug resistance. © 2017 Wiley Periodicals, Inc.

  7. Image Enhancement Using Linear Programming Method for High Dynamic Range Image

    Directory of Open Access Journals (Sweden)

    S. Yamini

    2014-01-01

    Full Text Available Now a days in Telecommunication areas the contrast gain is considered as a major constraints. For the enhancement purpose, the technique called Histogram Equalization is involved, but due to over enhancement and not such gain is been obtained. So that for the OCTM is been proposed, where the constraints of HE is been rectified. OCTM gives better efficiency and it is been solved by Linear programming. In this paper the enhancement of HDR Image using linear Programming is done. According to it HDR Image is constructed using the multiple exposures and its contrast is enhanced using the OCTM method using Linear Programming.

  8. Non-linear response of electrode-electrolyte interface at high current density

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, G.A. [Departamento de Bioingenieria, FACET-INSIBIO/UNT-CONICET, CC 327 Correo Central, 4000 Tucuman (Argentina)] e-mail: gruiz@herrera.unt.edu.ar; Felice, C.J. [Departamento de Bioingenieria, FACET-INSIBIO/UNT-CONICET, CC 327 Correo Central, 4000 Tucuman (Argentina); Valentinuzzi, M.E. [Departamento de Bioingenieria, FACET-INSIBIO/UNT-CONICET, CC 327 Correo Central, 4000 Tucuman (Argentina)

    2005-08-01

    A distributed parameter non-linear circuit is presented as fractal model of an electrode-electrolyte interface. It includes the charge transfer resistance and the double layer capacitance at each fractal level. The circuit explains the linear behavior of its series equivalent resistance R {sub eq} with signals of amplitudes <20 mV and constant frequency; however, for amplitudes beyond that limit, non-linearity is manifested in the dc component of the R {sub eq} Fourier spectrum. As a consequence, both the equivalent resistance and reactance drop with voltage, facts reported experimentally by other authors.

  9. High dimensional linear regression models under long memory dependence and measurement error

    Science.gov (United States)

    Kaul, Abhishek

    This dissertation consists of three chapters. The first chapter introduces the models under consideration and motivates problems of interest. A brief literature review is also provided in this chapter. The second chapter investigates the properties of Lasso under long range dependent model errors. Lasso is a computationally efficient approach to model selection and estimation, and its properties are well studied when the regression errors are independent and identically distributed. We study the case, where the regression errors form a long memory moving average process. We establish a finite sample oracle inequality for the Lasso solution. We then show the asymptotic sign consistency in this setup. These results are established in the high dimensional setup (p> n) where p can be increasing exponentially with n. Finally, we show the consistency, n½ --d-consistency of Lasso, along with the oracle property of adaptive Lasso, in the case where p is fixed. Here d is the memory parameter of the stationary error sequence. The performance of Lasso is also analysed in the present setup with a simulation study. The third chapter proposes and investigates the properties of a penalized quantile based estimator for measurement error models. Standard formulations of prediction problems in high dimension regression models assume the availability of fully observed covariates and sub-Gaussian and homogeneous model errors. This makes these methods inapplicable to measurement errors models where covariates are unobservable and observations are possibly non sub-Gaussian and heterogeneous. We propose weighted penalized corrected quantile estimators for the regression parameter vector in linear regression models with additive measurement errors, where unobservable covariates are nonrandom. The proposed estimators forgo the need for the above mentioned model assumptions. We study these estimators in both the fixed dimension and high dimensional sparse setups, in the latter setup, the

  10. Non-Linear Noise Contributions in Highly Dispersive Optical Transmission Systems

    Science.gov (United States)

    Matera, Francesco

    2016-01-01

    This article reports an analytical investigation, confirmed by numerical simulations, about the non-linear noise contribution in single-channel systems adopting generic modulation-detection formats in long links with both managed and unmanaged dispersion compensation and its impact in system performance. This noise contribution is expressed in terms of a pulse non-linear interaction length and permits a simple calculation of the Q-factor. Results point out the dependence of this non-linear noise on the number of amplifiers spans, N, according to the adopted chromatic dispersion compensation scheme, the modulation-detection format, and the signal baud rate. It is also shown how the effects of polarization multiplexing can be taken into account and how this single-channel non-linear noise contribution can be used in a wavelength-division multiplexing (WDM) environment.

  11. Novel Supercomputing Approaches for High Performance Linear Algebra Using FPGAs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop novel FPGA-based algorithmic technology that will enable unprecedented computational power for the solution of large sparse linear equation...

  12. Linear Regression in High Dimension and/or for Correlated Inputs

    Science.gov (United States)

    Jacques, J.; Fraix-Burnet, D.

    2014-12-01

    Ordinary least square is the common way to estimate linear regression models. When inputs are correlated or when they are too numerous, regression methods using derived inputs directions or shrinkage methods can be efficient alternatives. Methods using derived inputs directions build new uncorrelated variables as linear combination of the initial inputs, whereas shrinkage methods introduce regularization and variable selection by penalizing the usual least square criterion. Both kinds of methods are presented and illustrated thanks to the R software on an astronomical dataset.

  13. Diffusion bonding and brazing of high purity copper for linear collider accelerator structures

    Directory of Open Access Journals (Sweden)

    J. W. Elmer

    2001-05-01

    Full Text Available Diffusion bonding and brazing of high purity copper were investigated to develop procedures for joining precision machined copper components for the Next Linear Collider (NLC. Diffusion bonds were made over a range of temperatures from 400 °C to 1000 °C, under two different loading conditions [3.45 kPa (0.5 psi and 3.45 MPa (500 psi], and on two different diamond machined surface finishes. Brazes were made using pure silver, pure gold, and gold-nickel alloys, and different heating rates produced by both radiation and induction heating. Braze materials were applied by both physical vapor deposition (PVD and conventional braze alloy shims. Results of the diffusion bonding experiments showed that bond strengths very near that of the copper base metal could be made at bonding temperatures of 700 °C or higher at 3.45 MPa bonding pressure. At lower temperatures, only partial strength diffusion bonds could be made. At low bonding pressures (3.45 kPa, full strength bonds were made at temperatures of 800 °C and higher, while no bonding (zero strength was observed at temperatures of 700 °C and lower. Observations of the fracture surfaces of the diffusion bonded samples showed the effects of surface finish on the bonding mechanism. These observations clearly indicate that bonding began by point asperity contact, and flatter surfaces resulted in a higher percentage of bonded area under similar bonding conditions. Results of the brazing experiments indicated that pure silver worked very well for brazing under both conventional and high heating rate scenarios. Similarly, pure silver brazed well for both the PVD layers and the braze alloy shims. The gold and gold-containing brazes had problems, mainly due to the high diffusivity of gold in copper. These problems led to the necessity of overdriving the temperature to ensure melting, the presence of porosity in the joint, and very wide braze joints. Based on the overall findings of this study, a two

  14. Design, Fabrication and Test of a High Efficiency Refractive Secondary Concentrator for Solar Applications

    Science.gov (United States)

    Wong, Wayne A.; Geng, Steven M.; Castle, Charles H.; Macosko, Robert P.

    2000-01-01

    Common to many of the space applications that utilize solar thermal energy such as electric power conversion, thermal propulsion, and furnaces, is a need for highly efficient, solar concentration systems. An effort is underway to develop the refractive secondary concentrator, which uses refraction and total internal reflection to efficiently concentrate and direct solar energy. When used in combination with advanced primary concentrators, the refractive secondary concentrator enables very high system concentration ratios (10,000 to 1) and very high temperatures (greater than 2000 K). Presented is an overview of the effort at the NASA Glenn Research Center to evaluate the performance of a prototype single crystal sapphire refractive secondary concentrator and to compare the performance with analytical models. The effort involves the design and fabrication of a secondary concentrator, design and fabrication of a calorimeter and its support hardware, calibration of the calorimeter, testing of the secondary concentrator in NASA Glenn's Tank 6 solar thermal vacuum facility, and comparing the test results with predictions. Test results indicate an average throughput efficiency of 87%. It is anticipated that reduction of a known reflection loss with an anti-reflective coating would result in a secondary concentrator throughput efficiency of approximately 93%.

  15. Advanced Thomson scattering system for high-flux linear plasma generator

    Energy Technology Data Exchange (ETDEWEB)

    Meiden, H. J. van der; Lof, A. R.; Berg, M. A. van den; Brons, S.; Eck, H. J. N. van; Koelman, P. M. J.; Koppers, W. R.; Kruijt, O. G.; Oyevaar, T.; Prins, P. R.; Rapp, J.; Scholten, J.; Smeets, P. H. M.; Star, G. van der; Zeijlmans van Emmichoven, P. A. [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Donne, A. J. H.; Schram, D. C. [FOM Institute DIFFER, Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Eindhoven University of Technology, Eindhoven (Netherlands); Naumenko, N. N. [IPh NASB, Minsk (Belarus); Tugarinov, S. N. [SRC TRINITI, Troitsk, Moscow Reg. (Russian Federation)

    2012-12-15

    An advanced Thomson scattering system has been built for a linear plasma generator for plasma surface interaction studies. The Thomson scattering system is based on a Nd:YAG laser operating at the second harmonic and a detection branch featuring a high etendue (f /3) transmission grating spectrometer equipped with an intensified charged coupled device camera. The system is able to measure electron density (n{sub e}) and temperature (T{sub e}) profiles close to the output of the plasma source and, at a distance of 1.25 m, just in front of a target. The detection system enables to measure 50 spatial channels of about 2 mm each, along a laser chord of 95 mm. By summing a total of 30 laser pulses (0.6 J, 10 Hz), an observational error of 3% in n{sub e} and 6% in T{sub e} (at n{sub e}= 9.4 Multiplication-Sign 10{sup 18} m{sup -3}) can be obtained. Single pulse Thomson scattering measurements can be performed with the same accuracy for n{sub e} > 2.8 Multiplication-Sign 10{sup 20} m{sup -3}. The minimum measurable density and temperature are n{sub e} < 1 Multiplication-Sign 10{sup 17} m{sup -3} and T{sub e} < 0.07 eV, respectively. In addition, using the Rayleigh peak, superimposed on the Thomson scattered spectrum, the neutral density (n{sub 0}) of the plasma can be measured with an accuracy of 25% (at n{sub 0}= 1 Multiplication-Sign 10{sup 20} m{sup -3}). In this report, the performance of the Thomson scattering system will be shown along with unprecedented accurate Thomson-Rayleigh scattering measurements on a low-temperature argon plasma expansion into a low-pressure background.

  16. High-frequency Ultrasound Doppler System for Biomedical Applications with a 30 MHz Linear Array

    Science.gov (United States)

    Xu, Xiaochen; Sun, Lei; Cannata, Jonathan M.; Yen, Jesse T.; Shung, K. Kirk

    2008-01-01

    In this paper, we report the development of the first high-frequency (HF) pulsed-wave Doppler system using a 30 MHz linear array transducer to assess the cardiovascular functions in small animal. This array based pulsed-wave Doppler system included a 16-channel HF analog beamformer, a HF pulsed-wave Doppler module, timing circuits, HF bipolar pulsers, and analog front-ends. The beamformed echoes acquired by the 16 channel analog beamformer, were directly fed to the HF pulsed-wave Doppler module. Then the in-phase and quadrature-phase (IQ) audio Doppler signals were digitized by either a sound card or a Gage digitizer and stored in a PC. The Doppler spectrogram was displayed on a PC in real time. The two-way beam-widths were determined to be 160 μm to 320 μm when the array was electronically focused at different focal points at depths from 5–10 mm. A micro flow phantom, consisting of a polyimide tube with inner diameter of 127 μm, and the wire phantom were used to evaluate and calibrate the system. The results show that the system is capable of detecting motion velocity of the wire phantom as low as 0.1 mm/s, and detecting blood-mimicking flow velocity in the 127 μm tube lower than 7 mm/s. The system was subsequently used to measure the blood flow in vivo in two mouse abdominal superficial vessels with diameters of approximately 200 μm, and a mouse aorta close to the heart. These results demonstrated that this system may become an indispensable part of the current HF array based imaging systems for small animal studies. PMID:17993243

  17. SU-E-T-543: Measurement of Neutron Activation From Different High Energy Varian Linear Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Thatcher, T; Madsen, S; Sudowe, R [University of Nevada, Las Vegas, Las Vegas, NV (United States); Meigooni, A Soleimani [University of Nevada, Las Vegas, Las Vegas, NV (United States); Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States)

    2015-06-15

    Purpose: Linear accelerators producing photons above 10 MeV may induce photonuclear reactions in high Z components of the accelerator. These liberated neutrons can then activate the structural components of the accelerator and other materials in the beam path through neutron capture reactions. The induced activity within the accelerator may contribute to additional dose to both patients and personnel. This project seeks to determine the total activity and activity per activated isotope following irradiation in different Varian accelerators at energies above 10 MeV. Methods: A Varian 21IX accelerator was used to irradiate a 30 cm × 30 cm × 20 cm solid water phantom with 15 MV x-rays. The phantom was placed at an SSD of 100 cm and at the center of a 20 cm × 20 cm field. Activation induced gamma spectra were acquired over a 5 minute interval after 1 and 15 minutes from completion of the irradiation. All measurements were made using a CANBERRA Falcon 5000 Portable HPGe detector. The majority of measurements were made in scattering geometry with the detector situated at 90° to the incident beam, 30 cm from the side of the phantom and approximately 10 cm from the top. A 5 minute background count was acquired and automatically subtracted from all subsequent measurements. Photon spectra were acquired for both open and MLC fields. Results: Based on spectral signatures, nuclides have been identified and their activities calculated for both open and MLC fields. Preliminary analyses suggest that activities from the activation products in the microcurie range. Conclusion: Activation isotopes have been identified and their relative activities determined. These activities are only gross estimates since efficiencies have not been determined for this source-detector geometry. Current efforts are focused on accurate determination of detector efficiencies using Monte Carlo calculations.

  18. Novel DDR Processing of Corn Stover Achieves High Monomeric Sugar Concentrations from Enzymatic Hydrolysis (230 g/L) and High Ethanol Concentration (10% v/v) During Fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaowen; Jennings, Ed; Shekiro, Joe; Kuhn, Erik M.; O' Brien, Marykate; Wang, Wei; Schell, Daniel J.; Himmel, Mike; Elander, Richard T.; Tucker, Melvin P.

    2015-04-03

    Distilling and purifying ethanol, butanol, and other products from second and later generation lignocellulosic biorefineries adds significant capital and operating cost for biofuels production. The energy costs associated with distillation affects plant gate and life cycle analysis costs. Lower titers in fermentation due to lower sugar concentrations from pretreatment increase both energy and production costs. In addition, higher titers decrease the volumes required for enzymatic hydrolysis and fermentation vessels. Therefore, increasing biofuels titers has been a research focus in renewable biofuels production for several decades. In this work, we achieved over 200 g/L of monomeric sugars after high solids enzymatic hydrolysis using the novel deacetylation and disc refining (DDR) process on corn stover. The high sugar concentrations and low chemical inhibitor concentrations from the DDR process allowed ethanol titers as high as 82 g/L in 22 hours, which translates into approximately 10 vol% ethanol. To our knowledge, this is the first time that 10 vol% ethanol in fermentation derived from corn stover without any sugar concentration or purification steps has been reported. Techno-economic analysis shows the higher titer ethanol achieved from the DDR process could significantly reduce the minimum ethanol selling price from cellulosic biomass.

  19. Linear accelerators for high energies. A report on the 1962 conference at Brookhaven

    Energy Technology Data Exchange (ETDEWEB)

    Blewett, John P.

    1963-01-01

    The linear accelerator was invented very early in the history of particle accelerators, but it has been one of the latest accelerators to be exploited. This is principally because of the very large quantities of radio-frequency power required to attain respectable energies in a reasonable distance. Radar developments during World War II resulted in production of the necessary megawatt oscillators or amplifiers, and linear accelerators, both for electrons and positive ions, are now operating in several centers. The electron linear accelerator has been extended to billion-volt energies, and in the Stanford two-mile version it will soon set new energy records between 20 and 40 BeV. The proton linear accelerator has had a less spectacular history. The highest energy yet achieved in a proton linac is about 70 MeV (at the University of Minnesota). Smaller proton linacs are in use as injectors for proton-synchrotrons, but no machine has been built or is under construction for the range above 100 MeV. This is because synchro-cyclotrons for this energy range are much cheaper and have been preferred for this reason, in spite of the fact that the beam from a synchro-cyclotron cannot be nearly as intense or as well collimated as the beam from a linear accelerator.

  20. Thermodynamically consistent description of the hydrodynamics of free surfaces covered by insoluble surfactants of high concentration

    OpenAIRE

    Thiele, Uwe; Archer, Andrew J.; Plapp, Mathis

    2012-01-01

    In this paper we propose several models that describe the dynamics of liquid films which are covered by a high concentration layer of insoluble surfactant. First, we briefly review the 'classical' hydrodynamic form of the coupled evolution equations for the film height and surfactant concentration that are well established for small concentrations. Then we re-formulate the basic model as a gradient dynamics based on an underlying free energy functional that accounts for wettability and capill...

  1. Incomplete Ion Dissociation Underlies the Weakened Attraction between DNA Helices at High Spermidine Concentrations

    OpenAIRE

    Yang,Jie; Rau, Donald C

    2005-01-01

    We have investigated the salt sensitivity of the hexagonal-to-cholesteric phase transition of spermidine-condensed DNA. This transition precedes the resolubilization of precipitated DNA that occurs at high spermidine concentration. The sensitivity of the critical spermidine concentration at the transition point to the anion species and the NaCl concentration indicates that ion pairing of this trivalent ion underlies this unusual transition. Osmotic pressure measurements of spermidine salt sol...

  2. Effect of digestion time on anaerobic digestion with high ammonia concentration

    Science.gov (United States)

    Oktavitri, Nur Indradewi; Purnobasuki, Hery; Kuncoro, Eko Prasetyo; Purnamasari, Indah; Semma Hadinnata, P.

    2016-03-01

    Anaerobic digestion was developed to treat high concentration organic compound efficiently in certain Digestion Time (DT). High ammonia concentration could influenced removal organic compound in digestion. This bench scale study investigated the effect of digestion time on anaerobic batch reactor with high ammonia concentration. Total Ammonia Nitrogen (TAN) concentration was adjusted 4000 and 5000 mg/1, Digestion time was ranged from 0-26 d, operation temperature was ranged from 28-29°C, inoculum was collected from slaughter house sludge. The degradation of Chemical Oxygen Demand (COD) correlated with digestion time. The concentration of TAN from synthetic wastewater contain 5000 mg/1 of TAN more fluctuated than those use 4000 mg/1 of TAN. However, the biogas production from wastewater contained 4000 mg/1 of TAN gradually increased until 24 d of DT. The reactor contain 5000 mg/1 of TAN only growth until 12 d and steady state at over 12 d of digestion time.

  3. Melatonin in Arabidopsis thaliana acts as plant growth regulator at low concentrations and preserves seed viability at high concentrations.

    Science.gov (United States)

    Hernández, Ismaél Gatica; Gomez, Federico José Vicente; Cerutti, Soledad; Arana, María Verónica; Silva, María Fernanda

    2015-09-01

    Since the discovery of melatonin in plants, several roles have been described for different species, organs, and developmental stages. Arabidopsis thaliana, being a model plant species, is adequate to contribute to the elucidation of the role of melatonin in plants. In this work, melatonin was monitored daily by UHPLC-MS/MS in leaves, in order to study its diurnal accumulation as well as the effects of natural and artificial light treatments on its concentration. Furthermore, the effects of exogenous application of melatonin to assess its role in seed viability after heat stress and as a regulator of growth and development of vegetative tissues were evaluated. Our results indicate that melatonin contents in Arabidopsis were higher in plants growing under natural radiation when compared to those growing under artificial conditions, and its levels were not diurnally-regulated. Exogenous melatonin applications prolonged seed viability after heat stress conditions. In addition, melatonin applications retarded leaf senescence. Its effects as growth promoter were dose and tissue-dependent; stimulating root growth at low concentrations and decreasing leaf area at high doses.

  4. Prodigious Effects of Concentration Intensification on Nanoparticle Synthesis: A High-Quality, Scalable Approach.

    Science.gov (United States)

    Williamson, Curtis B; Nevers, Douglas R; Hanrath, Tobias; Robinson, Richard D

    2015-12-23

    Realizing the promise of nanoparticle-based technologies demands more efficient, robust synthesis methods (i.e., process intensification) that consistently produce large quantities of high-quality nanoparticles (NPs). We explored NP synthesis via the heat-up method in a regime of previously unexplored high concentrations near the solubility limit of the precursors. We discovered that in this highly concentrated and viscous regime the NP synthesis parameters are less sensitive to experimental variability and thereby provide a robust, scalable, and size-focusing NP synthesis. Specifically, we synthesize high-quality metal sulfide NPs (200 g) relative to the current field of large-scale (0.1-5 g yields) and laboratory-scale (<0.1 g) efforts. Compared to conventional synthesis methods (hot injection with dilute precursor concentration) characterized by rapid growth and low yield, our highly concentrated NP system supplies remarkably controlled growth rates and a 10-fold increase in NP volumetric production capacity (86 g/L). The controlled growth, high yield, and robust nature of highly concentrated solutions can facilitate large-scale nanomanufacturing of NPs by relaxing the synthesis requirements to achieve monodisperse products. Mechanistically, our investigation of the thermal and rheological properties and growth rates reveals that this high concentration regime has reduced mass diffusion (a 5-fold increase in solution viscosity), is stable to thermal perturbations (∼64% increase in heat capacity), and is resistant to Ostwald ripening.

  5. A High-Quality Preconditioning Technique for Multi-Length-Scale Symmetric Positive Definite Linear Systems

    Institute of Scientific and Technical Information of China (English)

    Ichitaro Yamazaki; Zhaojun Bai; Wenbin Chen; Richard Scalettar

    2009-01-01

    We study preconditioning techniques used in conjunction with the conjugate gradient method for solving multi-length-scale symmetric positive definite linear systems originating from the quantum Monte Carlo simulation of electron interaction of correlated materials. Existing preconditioning techniques are not designed to be adaptive to varying numerical properties of the multi-length-scale systems. In this paper, we propose a hybrid incomplete Cholesky (HIC) preconditioner and demonstrate its adaptivity to the multi-length-scale systems. In addition, we propose an extension of the compressed sparse column with row access (CSCR) sparse matrix storage format to efficiently accommodate the data access pattern to compute the HIC preconditioner. We show that for moderately correlated materials, the HIC preconditioner achieves the optimal linear scaling of the simulation. The development of a linear-scaling preconditioner for strongly correlated materials remains an open topic.

  6. The combined effects of halo and linear doping effects on the high-frequency and switching performance in ballistic CNTFETs

    Institute of Scientific and Technical Information of China (English)

    Wang Wei; Zhang Lu; Wang Xueying; Wang Zhubing; Zhang Ting; Li Na; Yang Xiao

    2014-01-01

    To overcome short-channel effects (SCEs) in high-performance device applications,a novel structure of CNTFET with a combination of halo and linear doping structure (HL-CNTFET) has been proposed.It has been theoretically investigated by a quantum kinetic model,which is based on two-dimensional non-equilibrium Green's functions solved self-consistently with Poisson's equations.We have studied the effect of halo doping and linear doping structure on static and dynamical performances of HL-CNTFET.It is demonstrated that a halo doping structure can decrease the drain leakage current and improve the on/off current ratio,and that linear doping can improve high-frequency and switching performance.

  7. High linear-energy-transfer radiation can overcome radioresistance of glioma stem-like cells to low linear-energy-transfer radiation

    Science.gov (United States)

    Hirota, Yuki; Masunaga, Shin-Ichiro; Kondo, Natsuko; Kawabata, Shinji; Hirakawa, Hirokazu; Yajima, Hirohiko; Fujimori, Akira; Ono, Koji; Kuroiwa, Toshihiko; Miyatake, Shin-Ichi

    2014-01-01

    Ionizing radiation is applied as the standard treatment for glioblastoma multiforme (GBM). However, radiotherapy remains merely palliative, not curative, because of the existence of glioma stem cells (GSCs), which are regarded as highly radioresistant to low linear-energy-transfer (LET) photons. Here we analyzed whether or not high-LET particles can overcome the radioresistance of GSCs. Glioma stem-like cells (GSLCs) were induced from the GBM cell line A172 in stem cell culture medium. The phenotypes of GSLCs and wild-type cells were confirmed using stem cell markers. These cells were irradiated with 60Co gamma rays or reactor neutron beams. Under neutron-beam irradiation, high-LET proton particles can be produced through elastic scattering or nitrogen capture reaction. Radiosensitivity was assessed by a colony-forming assay, and the DNA double-strand breaks (DSBs) were assessed by a histone gamma-H2AX focus detection assay. In stem cell culture medium, GSLCs could form neurosphere-like cells and express neural stem cell markers (Sox2 and Musashi) abundantly in comparison with their parental cells. GSLCs were significantly more radioresistant to gamma rays than their parental cells, but neutron beams overcame this resistance. There were significantly fewer gamma-H2AX foci in the A172 GSLCs 24 h after irradiation with gamma rays than in their parental cultured cells, while there was no apparent difference following neutron-beam irradiation. High-LET radiation can overcome the radioresistance of GSLCs by producing unrepairable DNA DSBs. High-LET radiation therapy might have the potential to overcome GBM's resistance to X-rays in a clinical setting. PMID:23955054

  8. Critical phenomena in ethylbenzene oxidation in acetic acid solution at high cobalt(II) concentrations

    NARCIS (Netherlands)

    Gavrichkov, AA; Zakharov, [No Value

    2005-01-01

    Critical phenomena in ethylbenzene oxidation in an acetic acid solution at high cobalt(ill) concentrations (from 0.01 to 0.2 mol L-1) were studied at 60-90 degrees C by the gasometric (O-2 absorption), spectrophotometric (Co-III accumulation), and chemiluminescence (relative concentration of radical

  9. Whey protein particles modulate mechanical properties of gels at high protein concentrations

    NARCIS (Netherlands)

    Saglam, D.; Venema, P.; Vries, de R.J.; Berg, van den L.; Linden, van der E.

    2014-01-01

    We have studied the influence of dense whey protein particles on the mechanical properties of whey protein isolate (WPI) gels at high protein concentrations (16–22% (w/w)). Incorporation of dense whey protein particles in the gel, while keeping the total protein concentration constant, leads to a co

  10. Rheology of dilute acid hydrolyzed corn stover at high solids concentration

    Science.gov (United States)

    M.R. Ehrhardt; T.O. Monz; T.W. Root; R.K. Connelly; Tim Scott; D.J. Klingenberg

    2010-01-01

    The rheological properties of acid hydrolyzed corn stover at high solids concentration (20–35 wt.%) were investigated using torque rheometry. These materials are yield stress fluids whose rheological properties can be well represented by the Bingham model. Yield stresses increase with increasing solids concentration and decrease with increasing hydrolysis reaction...

  11. Effect of dissolved oxygen concentration on the bioflocculation process in high loaded MBRs

    NARCIS (Netherlands)

    Faust, L.; Temmink, B.G.; Zwijnenburg, A.; Kemperman, A.J.B.; Rijnaarts, H.

    2014-01-01

    High-loaded membrane bioreactors (HL-MBRs), i.e. MBRs which are operated at extremely short sludge and hydraulic retention times, can be applied to flocculate and concentrate sewage organic matter. The concentrated organics can be used for energy recovery, or for the production of more valuable

  12. A High-Efficiency Refractive Secondary Solar Concentrator for High Temperature Solar Thermal Applications

    Science.gov (United States)

    Piszczor, Michael F., Jr.; Macosko, Robert P.

    2000-01-01

    A refractive secondary solar concentrator is a non-imaging optical device that accepts focused solar energy from a primary concentrator and redirects that light, by means of refraction and total internal reflection (TIR) into a cavity where the solar energy is used for power and/or propulsion applications. This concept offers a variety of advantages compared to typical reflective secondary concentrators (or the use of no secondary at all): higher optical efficiency, minimal secondary cooling requirements, a smaller cavity aperture, a reduction of outgassing from the cavity and flux tailoring of the solar energy within the heat receiver. During the past 2 years, NASA Lewis has been aggressively developing this concept in support of the NASA Marshall Shooting Star Flight Experiment. This paper provides a brief overview of the advantages and technical challenges associated with the development of a refractive secondary concentrator and the fabrication of a working unit in support of the flight demonstration program.

  13. Linearity improvement of high-speed avalanche photodiodes using thin depleted absorber operating with higher order modulation format.

    Science.gov (United States)

    Nada, Masahiro; Hoshi, Takuya; Yamazaki, Hiroshi; Hashimoto, Toshikazu; Matsuzaki, Hideaki

    2015-10-19

    We present an avalanche photodiode (APD) with high-speed, high-responsivity and high-linearity operation to cope with higher order modulation format, such as pulse-amplitude modulation (PAM). A hybrid absorber configuration with thin depleted region which we newly employed successfully eliminates the space charge effect in the APD while maintaining high responsivity and operating speed. The fabricated APD shows an improved optical-input-electrical-output linearity for an optical input power over -8 dBm, and an optical receiver with this APD achieves both an error-free operation with a KP4 FEC and a high sensitivity of -17 dBm against a 28-Gbaud PAM4 signal.

  14. Microstructure, thermooxidation and mechanical behavior of a novel highly linear, vitamin E stabilized, UHMWPE

    Energy Technology Data Exchange (ETDEWEB)

    Medel, F.J., E-mail: fjmedel@unizar.es [Department of Mechanical Engineering. Engineering and Architecture School, Universidad de Zaragoza, E-50018, Zaragoza (Spain); Instituto Ciencia de Materiales de Aragon, ICMA, Universidad de Zaragoza-CSIC, E-50018, Zaragoza (Spain); Martinez-Morlanes, M.J. [Department of Materials Science and Technology, Instituto de Investigaciones en Ingenieria de Aragon, I3A, Universidad de Zaragoza, E-50018, Zaragoza (Spain); Alonso, P.J.; Rubin, J. [Instituto Ciencia de Materiales de Aragon, ICMA, Universidad de Zaragoza-CSIC, E-50018, Zaragoza (Spain); Pascual, F.J. [Department of Materials Science and Technology, Instituto de Investigaciones en Ingenieria de Aragon, I3A, Universidad de Zaragoza, E-50018, Zaragoza (Spain); Puertolas, J.A. [Instituto Ciencia de Materiales de Aragon, ICMA, Universidad de Zaragoza-CSIC, E-50018, Zaragoza (Spain); Department of Materials Science and Technology, Instituto de Investigaciones en Ingenieria de Aragon, I3A, Universidad de Zaragoza, E-50018, Zaragoza (Spain)

    2013-01-01

    A novel, vitamin E-stabilized, medical grade ultra-high molecular polyethylene, MG003 (DSM Biomedical; The Netherlands), has been very recently introduced for use in total joint replacements. This homopolymer resin features average molecular weight similar to that of conventional GUR 1050 resin (5.5-6*10{sup 6} g/mol), but a higher degree of linearity. The aim of this study was to characterize the microstructure, thermal and thermooxidation properties as well as the mechanical behavior of this novel MG003 resin before and after gamma irradiation in air to 90 kGy. For this purpose, a combination of experimental techniques were performed including differential scanning calorimetry (DSC), thermogravimetry (TG), transmission electron microscopy (TEM), X-Ray Diffraction, electron paramagnetic resonance (EPR), and uniaxial tensile tests. As-consolidated MG003 materials exhibited higher crystalline contents ({approx} 62%), transition temperatures ({approx} 140 Degree-Sign C), crystal thickness ({approx} 36 nm), yield stress ({approx} 25 MPa) and elastic modulus ({approx} 400 MPa) than GUR 1050 controls (55%, 136 Degree-Sign C, 27 nm, 19 MPa, and 353 MPa, respectively). Irradiation produced similar changes in both MG003 and GUR 1050 materials, specifically increased crystallinity (63% and 60%, respectively), crystal thickness (39 nm and 30 nm), yield stress (27 MPa and 21 MPa), but, above of all, loss of elongation to breakage (down to 442 and 469%, respectively). Thermogravimetric and EPR results suggest comparable susceptibilities to oxidation for both MG003 and GUR 1050 polyethylenes. Based on the present findings, MG003 appears as a promising alternative medical grade polyethylene and it may satisfactorily contribute to the performance of total joint replacements. - Highlights: Black-Right-Pointing-Pointer MG003 UHMWPE materials exhibited higher crystallinity, and melting temperatures than conventional GUR resins. Black-Right-Pointing-Pointer MG003 materials had higher

  15. Potassium double tungstate waveguides with high ytterbium concentration for optical amplification

    NARCIS (Netherlands)

    Yong, Yean-Sheng

    2017-01-01

    In this thesis, the research work concerning high ytterbium concentration potassium double tungstate waveguides catered for optical amplification purpose is presented. The scope of the research work includes the investigation of spectroscopic and optical gain properties in epitaxy layers with

  16. Methods to assess high-resolution subsurface gas concentrations and gas fluxes in wetland ecosystems

    DEFF Research Database (Denmark)

    Elberling, Bo; Kühl, Michael; Glud, Ronnie N.

    2013-01-01

    The need for measurements of soil gas concentrations and surface fluxes of greenhouse gases at high temporal and spatial resolution in wetland ecosystem has lead to the introduction of several new analytical techniques and methods. In addition to the automated flux chamber methodology for high......-resolution estimates of greenhouse gas fluxes across the soil-atmosphere interface, these high-resolution methods include microsensors for quantification of spatiotemporal concentration dynamics in O2 and N2O at micrometer scales, fiber-optic optodes for long-term continuous point measurements of O2 concentrations...... and peat soils are highly heterogeneous, containing a mosaic of dynamic macropore systems created by both macrofauna and flora leading to distinct spatial and temporal variations in gas concentration on a scale of millimeters and minutes. Applications of these new methodologies allow measurements...

  17. Simulation studies for a high resolution time projection chamber at the international linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Muennich, A.

    2007-03-26

    The International Linear Collider (ILC) is planned to be the next large accelerator. The ILC will be able to perform high precision measurements only possible at the clean environment of electron positron collisions. In order to reach this high accuracy, the requirements for the detector performance are challenging. Several detector concepts are currently under study. The understanding of the detector and its performance will be crucial to extract the desired physics results from the data. To optimise the detector design, simulation studies are needed. Simulation packages like GEANT4 allow to model the detector geometry and simulate the energy deposit in the different materials. However, the detector response taking into account the transportation of the produced charge to the readout devices and the effects ofthe readout electronics cannot be described in detail. These processes in the detector will change the measured position of the energy deposit relative to the point of origin. The determination of this detector response is the task of detailed simulation studies, which have to be carried out for each subdetector. A high resolution Time Projection Chamber (TPC) with gas amplification based on micro pattern gas detectors, is one of the options for the main tracking system at the ILC. In the present thesis a detailed simulation tool to study the performance of a TPC was developed. Its goal is to find the optimal settings to reach an excellent momentum and spatial resolution. After an introduction to the present status of particle physics and the ILC project with special focus on the TPC as central tracker, the simulation framework is presented. The basic simulation methods and implemented processes are introduced. Within this stand-alone simulation framework each electron produced by primary ionisation is transferred through the gas volume and amplified using Gas Electron Multipliers (GEMs). The output format of the simulation is identical to the raw data from a

  18. The Linear Stability Properties of Medium- to High- n TAEs in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Gorelenkov, N N; Budny, R V; Kessel, C E; Kramer, G J; McCune, D; Manickam, J; Nazikian, R

    2008-02-14

    This document provides a detailed report on the successful completion of the DOE OFES Theory Milestone for FY2007: Improve the simulation resolution of linear stability properties of Toroidal Alfvén Eigenmodes (TAE) driven by energetic particles and neutral beams in ITER by increasing the numbers of toroidal modes used to 15.

  19. A high-linearity digital-to-time converter technique: constant-slope charging

    NARCIS (Netherlands)

    Ru, Jiayoon Zhiyu; Palattella, Claudia; Geraedts, Paul; Klumperink, Eric; Nauta, Bram

    2015-01-01

    A digital-to-time converter (DTC) controls time delay by a digital code, which is useful, for example, in a sampling oscilloscope, fractional-N PLL, or time-interleaved ADC. This paper proposes constant-slope charging as a method to realize a DTC with intrinsically better integral non-linearity (INL

  20. Multi-Repeated Projection Lithography for High-Precision Linear Scale Based on Average Homogenization Effect

    Directory of Open Access Journals (Sweden)

    Dongxu Ren

    2016-04-01

    Full Text Available A multi-repeated photolithography method for manufacturing an incremental linear scale using projection lithography is presented. The method is based on the average homogenization effect that periodically superposes the light intensity of different locations of pitches in the mask to make a consistent energy distribution at a specific wavelength, from which the accuracy of a linear scale can be improved precisely using the average pitch with different step distances. The method’s theoretical error is within 0.01 µm for a periodic mask with a 2-µm sine-wave error. The intensity error models in the focal plane include the rectangular grating error on the mask, static positioning error, and lithography lens focal plane alignment error, which affect pitch uniformity less than in the common linear scale projection lithography splicing process. It was analyzed and confirmed that increasing the repeat exposure number of a single stripe could improve accuracy, as could adjusting the exposure spacing to achieve a set proportion of black and white stripes. According to the experimental results, the effectiveness of the multi-repeated photolithography method is confirmed to easily realize a pitch accuracy of 43 nm in any 10 locations of 1 m, and the whole length accuracy of the linear scale is less than 1 µm/m.

  1. Multi-Repeated Projection Lithography for High-Precision Linear Scale Based on Average Homogenization Effect.

    Science.gov (United States)

    Ren, Dongxu; Zhao, Huiying; Zhang, Chupeng; Yuan, Daocheng; Xi, Jianpu; Zhu, Xueliang; Ban, Xinxing; Dong, Longchao; Gu, Yawen; Jiang, Chunye

    2016-04-14

    A multi-repeated photolithography method for manufacturing an incremental linear scale using projection lithography is presented. The method is based on the average homogenization effect that periodically superposes the light intensity of different locations of pitches in the mask to make a consistent energy distribution at a specific wavelength, from which the accuracy of a linear scale can be improved precisely using the average pitch with different step distances. The method's theoretical error is within 0.01 µm for a periodic mask with a 2-µm sine-wave error. The intensity error models in the focal plane include the rectangular grating error on the mask, static positioning error, and lithography lens focal plane alignment error, which affect pitch uniformity less than in the common linear scale projection lithography splicing process. It was analyzed and confirmed that increasing the repeat exposure number of a single stripe could improve accuracy, as could adjusting the exposure spacing to achieve a set proportion of black and white stripes. According to the experimental results, the effectiveness of the multi-repeated photolithography method is confirmed to easily realize a pitch accuracy of 43 nm in any 10 locations of 1 m, and the whole length accuracy of the linear scale is less than 1 µm/m.

  2. Concentration influences on recovery in a high gradient magnetic separation axial filter

    Energy Technology Data Exchange (ETDEWEB)

    Murariu, V.; Rezlescu, N.; Rotariu, O.; Badescu, V. [Inst. of Technical Physics, Iasi (Romania)

    1998-05-01

    The buildup differential equations for the case of a single wire in high gradient magnetic filtration (HGMF)-axial configuration taking into account the suspension concentration are solved. A new equation for the deposit contour surface at different moments and for different suspension concentrations are obtained. The existence of a particulate suspension concentration, for which the radial extension velocity of deposit is maximum, is evidenced. The recovery for an ordered ferromagnetic matrix is calculated. The influence of the solid particle concentration from suspension on the filtration efficiency is presented.

  3. Determination of trace concentrations of chlorine in aqueous solutions by high-resolution continuum source graphite furnace molecular absorption spectrometry

    Science.gov (United States)

    Machyňák, Ľubomír; Čacho, František; Němeček, Martin; Beinrohr, Ernest

    2016-11-01

    Trace concentrations of total chlorine were determined by means of molecular absorption of indium mono-chloride (InCl) at 267.217 nm using high-resolution continuum source graphite furnace molecular absorption spectrometry. The effects of chemical modifiers and the amount of In on the sensitivity and accuracy were investigated. The optimum pyrolysis and vaporization temperatures were 600 °C and 1400 °C, respectively. The limit of detection and characteristic mass were found to be 0.10 ng and 0.21 ng, respectively. Potential non-spectral and spectral interferences were tested for various metals and non-metals at concentrations up to 50 mg L- 1 and for phosphoric, sulphuric and nitric acids. No spectral interferences were observed. Significant non-spectral interferences were observed with F, Br, and I at concentrations higher than 1 mg L- 1, 5 mg L- 1 and 25 mg L- 1, respectively, which is probably caused by formation of competitive indium halogen molecules. Higher concentrations of mineral acids depressed the signal owing to the formation of volatile HCl. The calibration curve was linear in the range between 0.3 and 10 ng with a correlation coefficient of R = 0.993. The elaborated method was used for the chlorine determination in various waters and a drug sample.

  4. Subcutaneous absorption kinetics of two highly concentrated preparations of recombinant human growth hormone

    DEFF Research Database (Denmark)

    Laursen, Torben; Jørgensen, Jens Otto Lunde; Susgaard, Søren;

    1993-01-01

    Abstract OBJECTIVE: The relative bioavailability of two highly concentrated (12 IU/ml) formulations of biosynthetic human growth hormone (GH) administered subcutaneously was compared. DESIGN: A randomized, crossover study. Conventional GH therapy was withdrawn 72 hours before each study period. T....... CONCLUSIONS: There is no significant difference between the absorption kinetics and short-term metabolic effects of these two highly concentrated formulations of biosynthetic GH. The two formulations are bioequivalent....

  5. Incomplete ion dissociation underlies the weakened attraction between DNA helices at high spermidine concentrations.

    Science.gov (United States)

    Yang, Jie; Rau, Donald C

    2005-09-01

    We have investigated the salt sensitivity of the hexagonal-to-cholesteric phase transition of spermidine-condensed DNA. This transition precedes the resolubilization of precipitated DNA that occurs at high spermidine concentration. The sensitivity of the critical spermidine concentration at the transition point to the anion species and the NaCl concentration indicates that ion pairing of this trivalent ion underlies this unusual transition. Osmotic pressure measurements of spermidine salt solutions are consistent with this interpretation. Spermidine salts are not fully dissociated at higher concentrations. The competition for DNA binding among the fully charged trivalent ion and the lesser charged complex species at higher concentrations significantly weakens attraction between DNA helices in the condensed state. This is contrary to the suggestion that the binding of spermidine at higher concentrations causes DNA overcharging and consequent electrostatic repulsion.

  6. Transcriptional analysis of adaptation to high glucose concentrations in Zymomonas mobilis.

    Science.gov (United States)

    Zhang, Kun; Shao, Huanhuan; Cao, Qinghua; He, Ming-Xiong; Wu, Bo; Feng, Hong

    2015-02-01

    The ethanologenic bacterium Zymomonas mobilis is usually tolerant to high concentrations of glucose. The addition of sorbitol decreases the lag phase and increases ethanol yield and productivity of the bacteria in high glucose concentrations. The molecular mechanisms of adaptation to high glucose concentrations and the effect of sorbitol are still unclear. In this study, microarray analysis was used to study the global transcriptional adaptation responses of Z. mobilis to high glucose concentrations. A total of 235 genes were differentially expressed when 220 g/L glucose was added with or without 10 mM sorbitol. These genes are involved in diverse aspects of cell metabolism and regulation, including membrane transporters, nitrogen metabolism, and plasmid-encoded genes. However, most differentially expressed genes were downregulated when sorbitol was added. Notably, the transcription of almost all genes involved in the Entner-Doudoroff and ethanol production pathways was not significantly affected. In addition, a prophage and a nitrogen-fixation cluster were significantly induced. These results revealed that Z. mobilis cells responded to high glucose concentrations by regulating the transcriptional levels of genes related to membrane channels and transporters, stress response mechanisms, and metabolic pathways. These data provide insight into the intracellular adaptation responses to high glucose concentrations and reveal strategies to engineer efficient ethanol fermentation in Z. mobilis.

  7. EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF HIGH CONCENTRATION JETS IN ENVIRONMENTAL CURRENTS

    Institute of Scientific and Technical Information of China (English)

    张燕; 王道增; 樊靖郁

    2002-01-01

    By means of flow visualization and quantitative measurement, the diffusionpattern and concentration distribution characteristics of high concentration jets verticallydischarged into shallow moving waterbody were experimentally investigated in waterchannel. The interactions between the high concentration jets and environmental flowconditions were analysed, and the formulae of impinging point coordinate and transversespread angle are gained from data analysis. Experimental results indicate that the jets showcomplicated flow patterns and diffusion characteristics in near region, which are differentfrom common submerged jets, and spread downstream in the manner of density currents.

  8. High efficiency linear compressor driven pulse tube cryocooler operating in liquid nitrogen temperature

    Institute of Scientific and Technical Information of China (English)

    HU JianYing; WANG XiaoTao; DAI Wei; LUO ErCang; HUANG Yu

    2009-01-01

    The inertance tube is one of the key components of a pulse tube cryocooler. It has great influence not only on the efficiency of the pulse tube cryocooler, but also on the efficiency of the linear compressor. Meanwhile, it is very difficult to predict the impedance of an inertance tube because of the turbulent flow. In this paper, using a quasi-turbulent model, the inertance tube is optimized to match a linear compressor driven pulse tube cryocooler. Experimental results show that this model can predict the impedance quite well. With 127 W input electric power, the pulse tube cryocooler obtains 9.4 W cooling power at a temperature of 77 K. The relative Carnot efficiency of the whole system reaches 19.8%.

  9. A highly linear fully integrated CMOS power amplifier with an analog predistortion technique

    Energy Technology Data Exchange (ETDEWEB)

    Jin Boshi; Li Lewei; Wu Qun; Yang Guohui; Zhang Kuang, E-mail: boshijin@rdamicro.com [Department of Electronic and Communications Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-05-15

    A transformer-based CMOS power amplifier (PA) is linearized using an analog predistortion technique for a 2.5-GHz m-WiMAX transmitter. The third harmonic of the power stage and driver stage can be cancelled out in a specific power region. The two-stage PA fabricated in a standard 0.18-{mu}m CMOS process delivers 27.5 dBm with 27% PAE at the 1-dB compression point (P{sub 1dB}) and offers 21 dB gain. The PA achieves 5.5 % EVM and meets the spectrum mask at 20.5 dBm average power. Another conventional PA with a zero-cross-point of g{sub m3} bias is also fabricated and compared to prove its good linearity and efficiency. (semiconductor devices)

  10. Winsorization on linear mixed model (Case study: National exam of senior high school in West Java)

    Science.gov (United States)

    Yuliyani, Leny; Kurnia, Anang; Indahwati

    2017-03-01

    In the case of hierarchical data is typically modeled with linear mixed model (LMM). The LMM requires the assumption of normality which is error and random effects are assumed normal distribution. However in practice, to meet the assumption of normality is difficult especially if the sample is small. Violation of the normality assumption can be caused by outliers. In this paper, we will examine the effect of outliers on the random effects and error and overcome them with the Winsorization technique. The result of application indicated that Winsorization technique with c-tuning constant iterative process produced root mean squared error, AIC, and BIC are smaller than the others. We conclude that Winsorization technique can be used to overcome outliers in linear mixed model fitting.

  11. High Order A-stable Continuous General Linear Methods for Solution of Systems of Initial Value Problems in ODEs

    Directory of Open Access Journals (Sweden)

    Dauda GuliburYAKUBU

    2012-12-01

    Full Text Available Accurate solutions to initial value systems of ordinary differential equations may be approximated efficiently by Runge-Kutta methods or linear multistep methods. Each of these has limitations of one sort or another. In this paper we consider, as a middle ground, the derivation of continuous general linear methods for solution of stiff systems of initial value problems in ordinary differential equations. These methods are designed to combine the advantages of both Runge-Kutta and linear multistep methods. Particularly, methods possessing the property of A-stability are identified as promising methods within this large class of general linear methods. We show that the continuous general linear methods are self-starting and have more ability to solve the stiff systems of ordinary differential equations, than the discrete ones. The initial value systems of ordinary differential equations are solved, for instance, without looking for any other method to start the integration process. This desirable feature of the proposed approach leads to obtaining very high accuracy of the solution of the given problem. Illustrative examples are given to demonstrate the novelty and reliability of the methods.

  12. Gain-scheduled Linear Quadratic Control of Wind Turbines Operating at High Wind Speed

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

    2007-01-01

    This paper addresses state estimation and linear quadratic (LQ) control of variable speed variable pitch wind turbines. On the basis of a nonlinear model of a wind turbine, a set of operating conditions is identified and a LQ controller is designed for each operating point. The controller gains....... Simulation results are given that display good performance of the observers and comparisons with a controller designed by classical methods displays the potential of the method.  ...

  13. Photoneutron production in tungsten, praseodymium, copper and beryllium by using high energy electron linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Jallu, F. E-mail: jalluf@macadam.cea.fr; Lyoussi, A.; Payan, E.; Recroix, H.; Mariani, A.; Nurdin, G.; Buisson, A.; Allano, J

    1999-09-01

    This paper presents comparisons between photoneutron production measurements in tungsten, copper, praseodymium and beryllium, and calculated data resulting from the ELEPHANT (ELEctron, PHoton And Neutron Transport) code. Measurements were made using the DGA/ETCA linear electron accelerator located at Arcueil, France. Bremsstrahlung endpoints varying in the 15-25 MeV energy range were used. Detectors were positioned at different angles with respect to the electron beam axis. Each measured value is compared with the corresponding calculated value.

  14. A High-Accuracy Linear Conservative Difference Scheme for Rosenau-RLW Equation

    Directory of Open Access Journals (Sweden)

    Jinsong Hu

    2013-01-01

    Full Text Available We study the initial-boundary value problem for Rosenau-RLW equation. We propose a three-level linear finite difference scheme, which has the theoretical accuracy of Oτ2+h4. The scheme simulates two conservative properties of original problem well. The existence, uniqueness of difference solution, and a priori estimates in infinite norm are obtained. Furthermore, we analyze the convergence and stability of the scheme by energy method. At last, numerical experiments demonstrate the theoretical results.

  15. [Study of high temperature water vapor concentration measurement method based on absorption spectroscopy].

    Science.gov (United States)

    Chen, Jiu-ying; Liu, Jian-guo; He, Jun-feng; He, Ya-bai; Zhang, Guang-le; Xu, Zhen-yu; Gang, Qiang; Wang, Liao; Yao, Lu; Yuan, Song; Ruan, Jun; Dai, Yun-hai; Kan, Rui-feng

    2014-12-01

    Tunable diode laser absorption spectroscopy (TDLAS) has been developed to realize the real-time and dynamic measurement of the combustion temperature, gas component concentration, velocity and other flow parameters, owing to its high sensitivity, fast time response, non-invasive character and robust nature. In order to obtain accurate water vapor concentration at high temperature, several absorption spectra of water vapor near 1.39 μm from 773 to 1273 K under ordinary pressure were recorded in a high temperature experiment setup using a narrow band diode laser. The absorbance of high temperature absorption spectra was calculated by combined multi-line nonlinear least squares fitting method. Two water vapor absorption lines near 7154.35 and 7157.73 cm(-1) were selected for measurement of water vapor at high temperature. A model method for high temperature water vapor concentration was first proposed. Water vapor concentration from the model method at high temperature is in accordance with theoretical reasoning, concentration measurement standard error is less than 0.2%, and the relative error is less than 6%. The feasibility of this measuring method is verified by experiment.

  16. Design and development of high linearity millimeter wave traveling-wave tube for satellite communications

    Institute of Scientific and Technical Information of China (English)

    何俊; 黄明光; 李现霞; 李海强; 赵磊; 赵建东; 李跃; 赵石雷

    2015-01-01

    The linearity of the traveling-wave tube is a very important characteristic for a modern communication system. To improve the linearity of the traveling-wave tube at no expense of the saturated output power and overall efficiency, a modified pitch profile combined with a small adjustment of operating parameters is proposed. The optimal design of the helix circuit is evaluated theoretically by a large signal analysis, and the experimental test is also carried out to make a comparison of performance between the novel and original designed traveling-wave tubes. The experiments show that the saturated output powers and efficiencies of these two tubes are close to each other, while the linearity of the traveling-wave tube is obviously improved. The total phase shift and AM/PM conversion at saturation of the novel tube, averaged over the operating band, are only 30.6◦/dB and 2.5◦/dB, respectively, which are 20.1◦/dB and 1.6◦/dB lower than those of the original tube, respectively. Moreover, the third-order intermodulation of the novel tube is up to 2.2 dBc lower than that of the original tube.

  17. Additional dose assessment from the activation of high-energy linear accelerators used in radiation therapy

    Directory of Open Access Journals (Sweden)

    Ateia Embarka

    2008-01-01

    Full Text Available It is well known that medical linear accelerators generate activation products when operated above certain electron (photon energies. The aim of the present work is to assess the activation behavior of a medium-energy radiotherapy linear accelerator by applying in situ gamma-ray spectrometry and dose measurements, and to estimate the additional dose to radiotherapy staff on the basis of these results. Spectral analysis was performed parallel to dose rate measurements in the isocenter of the linear accelerator, immediately after the termination of irradiation. The following radioisotopes were detected by spectral analysis: 28Al, 62Cu, 56Mn, 64Cu, 187W, and 57Ni. The short-lived isotopes such as 28Al and 62Cu are the most important factors of the clinical routine, while the contribution to the radiation dose of medium-lived isotopes such as 56Mn, 57Ni, 64Cu, and 187W increases during the working day. Measured dose rates at the isocenter ranged from 2.2 µSv/h to 10 µSv/h in various measuring points of interest for the members of the radiotherapy staff. Within the period of 10 minutes, the dose rate decreased to values of 0.8 µSv/h. According to actual workloads in radiotherapy departments, a realistic exposure scenario was set, resulting in a maximal additional annual whole body dose to the radiotherapy staff of about 3.5 mSv.

  18. A high-accuracy optical linear algebra processor for finite element applications

    Science.gov (United States)

    Casasent, D.; Taylor, B. K.

    1984-01-01

    Optical linear processors are computationally efficient computers for solving matrix-matrix and matrix-vector oriented problems. Optical system errors limit their dynamic range to 30-40 dB, which limits their accuray to 9-12 bits. Large problems, such as the finite element problem in structural mechanics (with tens or hundreds of thousands of variables) which can exploit the speed of optical processors, require the 32 bit accuracy obtainable from digital machines. To obtain this required 32 bit accuracy with an optical processor, the data can be digitally encoded, thereby reducing the dynamic range requirements of the optical system (i.e., decreasing the effect of optical errors on the data) while providing increased accuracy. This report describes a new digitally encoded optical linear algebra processor architecture for solving finite element and banded matrix-vector problems. A linear static plate bending case study is described which quantities the processor requirements. Multiplication by digital convolution is explained, and the digitally encoded optical processor architecture is advanced.

  19. Trace element concentrations and gastrointestinal parasites of Arctic terns breeding in the Canadian High Arctic.

    Science.gov (United States)

    Provencher, J F; Braune, B M; Gilchrist, H G; Forbes, M R; Mallory, M L

    2014-04-01

    Baseline data on trace element concentrations are lacking for many species of Arctic marine birds. We measured essential and non-essential element concentrations in Arctic tern (Sterna paradisaea) liver tissue and brain tissue (mercury only) from Canada's High Arctic, and recorded the presence/absence of gastrointestinal parasites during four different phases of the breeding season. Arctic terns from northern Canada had similar trace element concentrations to other seabird species feeding at the same trophic level in the same region. Concentrations of bismuth, selenium, lead and mercury in Arctic terns were high compared to published threshold values for birds. Selenium and mercury concentrations were also higher in Arctic terns from northern Canada than bird species sampled in other Arctic areas. Selenium, mercury and arsenic concentrations varied across the time periods examined, suggesting potential regional differences in the exposure of biota to these elements. For unknown reasons, selenium concentrations were significantly higher in birds with gastrointestinal parasites as compared to those without parasites, while bismuth concentrations were higher in Arctic terns not infected with gastrointestinal parasites.

  20. High serum uric acid concentration predicts poor survival in patients with breast cancer.

    Science.gov (United States)

    Yue, Cai-Feng; Feng, Pin-Ning; Yao, Zhen-Rong; Yu, Xue-Gao; Lin, Wen-Bin; Qian, Yuan-Min; Guo, Yun-Miao; Li, Lai-Sheng; Liu, Min

    2017-08-26

    Uric acid is a product of purine metabolism. Recently, uric acid has gained much attraction in cancer. In this study, we aim to investigate the clinicopathological and prognostic significance of serum uric acid concentration in breast cancer patients. A total of 443 female patients with histopathologically diagnosed breast cancer were included. After a mean follow-up time of 56months, survival was analysed using the Kaplan-Meier method. To further evaluate the prognostic significance of uric acid concentrations, univariate and multivariate Cox regression analyses were applied. Of the clinicopathological parameters, uric acid concentration was associated with age, body mass index, ER status and PR status. Univariate analysis identified that patients with increased uric acid concentration had a significantly inferior overall survival (HR 2.13, 95% CI 1.15-3.94, p=0.016). In multivariate analysis, we found that high uric acid concentration is an independent prognostic factor predicting death, but insufficient to predict local relapse or distant metastasis. Kaplan-Meier analysis indicated that high uric acid concentration is related to the poor overall survival (p=0.013). High uric acid concentration predicts poor survival in patients with breast cancer, and might serve as a potential marker for appropriate management of breast cancer patients. Copyright © 2017. Published by Elsevier B.V.

  1. Effects of feeding frequency on intake, ruminal fermentation, and feeding behavior in heifers fed high-concentrate diets.

    Science.gov (United States)

    Robles, V; González, L A; Ferret, A; Manteca, X; Calsamiglia, S

    2007-10-01

    Four ruminally fistulated Holstein heifers (BW = 385 +/- 6.2 kg) were used in a 4 x 4 Latin square experiment to determine the effect of feeding frequency on intake, water consumption, ruminal fermentation, and feeding and animal behavior. The treatments consisted of different feeding frequencies: a) once daily (T1); b) twice daily (T2); c) 3 times daily (T3); and d) 4 times daily (T4). Heifers were offered ad libitum access to concentrate and barley straw. Feeding frequency did not affect DMI (P >0.10), but water consumption tended to increase linearly as feeding frequency increased (P = 0.08). Average ruminal pH was not affected (P >0.10) by feeding frequency, but at 12 h after feeding ruminal pH was greater for T2 than for the other treatments. Total VFA concentration and VFA proportions were not affected (P >0.10) by feeding frequency, except valerate proportion, which increased linearly (P = 0.05) as feeding frequency increased. The concentration of ammonia-N was affected (P 0.05), except for observational behavior, for which there was a linear decrease as feeding frequency increased (P = 0.02). Heifers spent the same time on chewing activities, independent of feeding frequency. However, meal criteria tended to be affected (P = 0.07) by feeding frequency, with T2 (39.4 min) showing the longest intermeal interval. Total daily meal time, meal frequency, and meal size were not affected by feeding frequency (P >0.10), whereas meal length and eating rate showed cubic tendencies (P = 0.10 and P = 0.06, respectively) as feeding frequency increased. These results suggest that in the present experimental conditions, with heifers fed high-concentrate diets and with noncompetitive feeding, a smaller range of ruminal pH values was observed when feed was offered twice daily. Although heifers spent the same time on chewing activities, more stable ruminal conditions were probably achieved by feeding twice daily due to the rumination pattern, which was more constant during

  2. Axisymmetric instability of the Poiseuille-Couette flow between concentric cylinders at high Reynolds numbers

    Science.gov (United States)

    Savenkov, I. V.

    2015-02-01

    For the pressure-driven flow in an annular channel with a wall moving in the axial direction, its linear instability with respect to axisymmetric perturbations at high Reynolds numbers is investigated within the framework of the triple-deck theory. When the gap between the cylinders is sufficiently small (as compared to the radii of the cylinders), it is shown that the perturbations can split into two wave packets, the first of which grows faster and moves at a higher velocity.

  3. An incidence of very high phosphate concentrations in the waters around Andaman Islands

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, C.V.G.; Murty, P.S.N.; Sankaranarayanan, V.N.

    at stations close to coasts; 2) vertical distribution of phosphates in 200 metre column does not appear to correspond to any regular accepted pattern and 3) all the phosphates having the abnormally high phosphate concentration were found to be highly turbid...

  4. Influence of Mechanical Activation on Acid Leaching Dephosphorization of High-phosphorus Iron Ore Concentrates

    Institute of Scientific and Technical Information of China (English)

    De-qing ZHU; Hao WANG; Jian PAN; Cong-cong YANG

    2016-01-01

    High pressure roll grinding (HPRG)and ball milling were compared to investigate the influence of me-chanical activation on the acid leaching dephosphorization of a high-phosphorus iron ore concentrate,which was man-ufactured through magnetizing roasting-magnetic separation of high-phosphorus oolitic iron ores.The results indica-ted that when high-phosphorus iron ore concentrates containing 54·92 mass% iron and 0·76 mass% phosphorus were directly processed through acid leaching,iron ore concentrates containing 55·74 mass% iron and 0·33 mass%phosphorus with an iron recovery of 84·64% and dephosphorization of 63·79% were obtained.When high-phosphor-us iron ore concentrates activated by ball milling were processed by acid leaching,iron ore concentrates containing 56·03 mass% iron and 0·21 mass% phosphorus with an iron recovery of 85·65% and dephosphorization of 77·49%were obtained.Meanwhile,when high-phosphorus iron ore concentrates activated by HPRG were processed by acid leaching,iron ore concentrates containing 58·02 mass% iron and 0·10 mass% phosphorus were obtained,with the iron recovery reaching 88·42% and the dephosphorization rate reaching 88·99%.Mechanistic studies demonstrated that ball milling can reduce the particle size,demonstrating a prominent reunion phenomenon.In contrast,HPRG pretreatment contributes to the formation of more cracks within the particles and selective dissociation of iron and P bearing minerals,which can provide the favorable kinetic conditions to accelerate the solid-liquid reaction rate.As such,the crystal structure is destroyed and the surface energy of mineral particles is strengthened by mechanical ac-tivation,further strengthening the dephosphorization.

  5. Prodigious Effects of Concentration Intensification on Nanoparticle Synthesis: A High-Quality, Scalable Approach

    KAUST Repository

    Williamson, Curtis B.

    2015-12-23

    © 2015 American Chemical Society. Realizing the promise of nanoparticle-based technologies demands more efficient, robust synthesis methods (i.e., process intensification) that consistently produce large quantities of high-quality nanoparticles (NPs). We explored NP synthesis via the heat-up method in a regime of previously unexplored high concentrations near the solubility limit of the precursors. We discovered that in this highly concentrated and viscous regime the NP synthesis parameters are less sensitive to experimental variability and thereby provide a robust, scalable, and size-focusing NP synthesis. Specifically, we synthesize high-quality metal sulfide NPs (<7% relative standard deviation for Cu2-xS and CdS), and demonstrate a 10-1000-fold increase in Cu2-xS NP production (>200 g) relative to the current field of large-scale (0.1-5 g yields) and laboratory-scale (<0.1 g) efforts. Compared to conventional synthesis methods (hot injection with dilute precursor concentration) characterized by rapid growth and low yield, our highly concentrated NP system supplies remarkably controlled growth rates and a 10-fold increase in NP volumetric production capacity (86 g/L). The controlled growth, high yield, and robust nature of highly concentrated solutions can facilitate large-scale nanomanufacturing of NPs by relaxing the synthesis requirements to achieve monodisperse products. Mechanistically, our investigation of the thermal and rheological properties and growth rates reveals that this high concentration regime has reduced mass diffusion (a 5-fold increase in solution viscosity), is stable to thermal perturbations (64% increase in heat capacity), and is resistant to Ostwald ripening.

  6. Single neuron network PI control of high reliability linear induction motor for Maglev

    Institute of Scientific and Technical Information of China (English)

    FANG You-tong; FAN Cheng-zhi

    2007-01-01

    The paper deals with a new model of linear induction motor (LIM) to improve the reliability of the system. Based on the normal equation circuit of LIM considering the dynamic end effect, an equivalent circuit model with compensation of large end effect is constructed when the end effect force at synchronism is of braking character. The equivalent circuit model is used for secondary-flux oriented control of LIM. Single neuron network PI unit for LIM servo-drive is also discussed. The effectiveness of mathematical model for drive control is verified by simulations.

  7. High power dual-wavelength tunable fiber laser in linear and ring cavity configurations

    Institute of Scientific and Technical Information of China (English)

    H. Ahmad; A. A. Latif; M. Z. Zulkifli; N. A. Awang; S. W. Harun

    2012-01-01

    We describe and compare the performances of two crucial configurations for a tunable dual-wavelength fiber laser,namely,the linear and ring configurations.The performances of these two cavities and the tunability in the dual-wavelength output varied from 0.8 to 11.9 nm are characterized.The ring cavity provides a better performance,achieving an average output power of 0.5 dBm,with a power fluctuation of only 1.1 dB and a signal-to-noise ratio (SNR) of 66 dB.Moreover,the ring cavity has minimal or no background amplified spontaneous emission (ASE).

  8. An object oriented design for high performance linear algebra on distributed memory architectures

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J.J. [Oak Ridge National Lab., TN (United States)]|[Univ. of Tennessee, Knoxville, TN (United States). Dept. of Computer Science; Walker, D.W. [Oak Ridge National Lab., TN (United States); Pozo, R. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Computer Science

    1993-12-31

    We describe the design of ScaLAPACK++, an object oriented C++ library for implementing linear algebra computations on distributed memory multicomputers. This package, when complete, will support distributed dense, banded, sparse matrix operations for symmetric, positive-definite, and non-symmetric cases. In ScaLAPACK++ we have employed object oriented design methods to enchance scalability, portability, flexibility, and ease-of-use. We illustrate some of these points by describing the implementation of a right-looking LU factorization for dense systems in ScaLAPACK++.

  9. High-Gain Approach Based Full-Order Observers for Linear Systems with Unknown Inputs

    Institute of Scientific and Technical Information of China (English)

    韩冬; 刘俊

    2016-01-01

    In this paper, a full-order observer which can be fully decoupled from the unknown inputs as the con-ventional full-order observer does is designed by using auxiliary outputs, but the requirement of the matching con-dition is removed. The procedure of calculating the parameter matrices of the full-order observer is also presented. Compared with the existing auxiliary outputs based sliding-mode observers, the designed observer has a simpler design procedure, which is systematic and does not involve solving linear matrix inequalities. The simulation re-sults show that the proposed method is effective.

  10. Design and Evaluation of the Highly Concentrated Human IgG Formulation Using Cyclodextrin Polypseudorotaxane Hydrogels.

    Science.gov (United States)

    Higashi, Taishi; Tajima, Anna; Ohshita, Naoko; Hirotsu, Tatsunori; Abu Hashim, Irhan Ibrahim; Motoyama, Keiichi; Koyama, Sawako; Iibuchi, Ruriko; Mieda, Shiuhei; Handa, Kenji; Kimoto, Tomoaki; Arima, Hidetoshi

    2015-12-01

    To achieve the potent therapeutic effects of human immunoglobulin G (IgG), highly concentrated formulations are required. However, the stabilization for highly concentrated human IgG is laborious work. In the present study, to investigate the potentials of polypseudorotaxane (PPRX) hydrogels consisting of polyethylene glycol (PEG) and α- or γ-cyclodextrin (α- or γ-CyD) as pharmaceutical materials for highly concentrated human IgG, we designed the PPRX hydrogels including human IgG and evaluated their pharmaceutical properties. The α- and γ-CyDs formed PPRX hydrogels with PEG (M.W. 20,000) even in the presence of highly concentrated human IgG (>100 mg/mL). According to the results of (1)H-NMR, powder X-ray diffraction, and Raman microscopy, the formation of human IgG/CyD PPRX hydrogels was based on physical cross-linking arising from their columnar structures. The release profiles of human IgG from the hydrogels were in accordance with the non-Fickian diffusion model. Importantly, the stabilities of human IgG included into the hydrogels against thermal and shaking stresses were markedly improved. These findings suggest that PEG/CyD PPRX hydrogels are useful to prepare the formulation for highly concentrated human IgG.

  11. High Concentrating GaAs Cell Operation Using Optical Waveguide Solar Energy System

    Science.gov (United States)

    Nakamura, T.; Case, J. A.; Timmons, M. L.

    2004-01-01

    This paper discusses the result of the concentrating photovoltaic (CPV) cell experiments conducted with the Optical Waveguide (OW) Solar Energy System. The high concentration GaAs cells developed by Research Triangle Institute (RTI) were combined with the OW system in a "fiber-on-cell" configuration. The sell performance was tested up to the solar concentration of 327. Detailed V-I characteristics, power density and efficiency data were collected. It was shown that the CPV cells combined with the OW solar energy system will be an effective electric power generation device.

  12. Photorespiration and carbon concentrating mechanisms: two adaptations to high O2, low CO2 conditions.

    Science.gov (United States)

    Moroney, James V; Jungnick, Nadine; Dimario, Robert J; Longstreth, David J

    2013-11-01

    This review presents an overview of the two ways that cyanobacteria, algae, and plants have adapted to high O2 and low CO2 concentrations in the environment. First, the process of photorespiration enables photosynthetic organisms to recycle phosphoglycolate formed by the oxygenase reaction catalyzed by ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Second, there are a number of carbon concentrating mechanisms that increase the CO2 concentration around Rubisco which increases the carboxylase reaction enhancing CO2 fixation. This review also presents possibilities for the beneficial modification of these processes with the goal of improving future crop yields.

  13. Application of Hydrothermal Treatment to High Concentrated Sewage Sludge for Anaerobic Digestion Process

    Directory of Open Access Journals (Sweden)

    M. Orikawa

    2013-10-01

    Full Text Available Tomato and seaweed were produced by utilizing CO2 and heat discharged from power generation using biogas in Toyogawa biomass park, Japan. The biogas was obtained by anaerobic digestion with hydrothermal treatment. The hydrothermal treatment was applied to the high concentrated sewage sludge (22 % total solids (TS dewatered sludge. The purpose of this study is to clarify the effect of hydrothermal treatment on the qualities of high concentrated sewage sludge, by analyzing particulate organic carbon (POC and dissolved organic carbon (DOC. The hydrothermal treatment was investigated under 10-60 min of treatment time, 180-200 °C of temperature, 10-22 %-TS of sewage sludge concentration. The results showed that the DOC in each conditions increased through hydrothermal treatment. The highest DOC obtained was 67 % of total carbon concentration, when the temperature was 180 °C, treatment time was 60 min and sewage sludge concentration was 10 %-TS. Furthermore, the viscosity of treated sewage sludge was decreased by hydrothermal treatment. In batch anaerobic digestion test, methane gas production was confirmed. In addition, this study evaluated the energy balance of this system. Thus, the results of this study indicated that the possibility of application of hydrothermal treatment to high concentrated sewage sludge for anaerobic digestion process. Keywords: anaerobic reaction, hydrothermal treatment, sewage sludge, solubilization

  14. High concentrations of myeloperoxidase in the equine uterus as an indicator of endometritis.

    Science.gov (United States)

    Parrilla-Hernandez, Sonia; Ponthier, Jérôme; Franck, Thierry Y; Serteyn, Didier D; Deleuze, Stéfan C

    2014-04-15

    Intraluminal fluid and excessive abnormal hyperedema are regularly used for the diagnosis of endometritis in the mare, which is routinely confirmed by the presence of neutrophils on endometrial smears. Studies show a relation between neutrophils and myeloperoxidase (MPO), an enzyme contained in and released by neutrophils during degranulation or after cell lysis. This enzyme has been found in many fluids and tissues, and associated with different inflammatory pathologies in the horse. The aims of this study were to assess the presence and concentration of MPO in the equine uterus, and to investigate its relation with neutrophils, and other clinical signs of endometritis. Mares (n = 51) were evaluated for the presence of intraluminal fluid and excessive endometrial edema before breeding, and a small volume lavage and cytology samples were obtained. From 69 cycles, supernatant of the uterine flushes was analyzed with a specific equine MPO ELISA assay to measure MPO concentration. Cytology samples were used for the diagnosis of endometritis. Myeloperoxidase was present in the uterus of all estrus mares in highly variable concentrations. Myeloperoxidase concentrations were significantly (P < 0.05) higher in samples with positive cytologies and in the presence of intraluminal fluid. Occasionally, some samples with negative cytologies showed high MPO concentration, but the opposite was never observed. Cycles presenting hyperedema weren't associated with high concentration of MPO, intraluminal fluid, or positive cytology, making it a poor diagnostic tool of endometritis.

  15. Responses of the central nervous system to high linear energy transfer radiation: NSCOR project highlights

    Science.gov (United States)

    Nelson, Gregory; Fike, John; Limoli, Charles; Obenaus, André; Raber, Jacob; Soltesz, Ivan; Vlkolinský, Roman

    2014-01-01

    Overview: The five-university NSCOR project investigates the responses of the central nervous system to space-like charged particle exposure by evaluating: synaptic function, in vitro and in vivo neurogenesis, behavior and behaviorally induced gene expression, and oxidative stress of the mouse hippocampus and cultured neural precursor cells. To test the role of reactive oxygen species in mediating the effects of radiation exposure, we compare responses in a catalase overexpressing transgenic mouse strain to wild type. We also use computational models of the hippocampus in three dimensions, informed by experimental measurements, to provide insight into network behavior. Radiation exposure protocols include single, acute whole-body exposures to 1H, 28Si and 56Fe ions and mixed field exposures using 1H + 56Fe ions (24 h later). The animal models are 10-week-old C57BL/6J and MCATtg males which are evaluated at 30 and 90 days postirradiation. In vitro models are cultured murine and human neural stem cells irradiated with 1H, 16O, 28Si and 56Fe ions at multiple energies and are evaluated at times from days to weeks. Highlights: Neural stem cells organized into neurospheres were irradiated with several ions at doses as low as 0.75 cGy. Data show that significant oxidative stress occurs that alters survival, proliferation and differentiation. Overall trends indicate that changes in oxidative stress (persisting for weeks) correlate with particle linear energy transfer (LET). 56Fe ions elicited the largest and most persistent changes in stress markers, including antioxidant enzyme expression levels. The hippocampus-dependent contextual fear conditioning (CFC) and novel object recognition (NOR) paradigms were used to assess cognition and showed cognitive deficits after irradiation with the NOR paradigm more sensitive than CFC. Analysis of neurogenesis indicates that overall neurogenesis is inhibited at doses ≥1 Gy, but newly born activated microglia are significantly

  16. Highly Localized Acoustic Streaming and Size-Selective Submicrometer Particle Concentration Using High Frequency Microscale Focused Acoustic Fields.

    Science.gov (United States)

    Collins, David J; Ma, Zhichao; Ai, Ye

    2016-05-17

    Concentration and separation of particles and biological specimens are fundamental functions of micro/nanofluidic systems. Acoustic streaming is an effective and biocompatible way to create rapid microscale fluid motion and induce particle capture, though the >100 MHz frequencies required to directly generate acoustic body forces on the microscale have traditionally been difficult to generate and localize in a way that is amenable to efficient generation of streaming. Moreover, acoustic, hydrodynamic, and electrical forces as typically applied have difficulty manipulating specimens in the submicrometer regime. In this work, we introduce highly focused traveling surface acoustic waves (SAW) at high frequencies between 193 and 636 MHz for efficient and highly localized production of acoustic streaming vortices on microfluidic length scales. Concentration occurs via a novel mechanism, whereby the combined acoustic radiation and streaming field results in size-selective aggregation in fluid streamlines in the vicinity of a high-amplitude acoustic beam, as opposed to previous acoustic radiation induced particle concentration where objects typically migrate toward minimum pressure locations. Though the acoustic streaming is induced by a traveling wave, we are able to manipulate particles an order of magnitude smaller than possible using the traveling wave force alone. We experimentally and theoretically examine the range of particle sizes that can be captured in fluid streamlines using this technique, with rapid particle concentration demonstrated down to 300 nm diameters. We also demonstrate that locations of trapping and concentration are size-dependent, which is attributed to the combined effects of the acoustic streaming and acoustic forces.

  17. Co-generation system with a linear concentrator and thermoelectric elements; Senkei shukokei to netsuden henkan soshi wo mochiita netsuden heikyu system

    Energy Technology Data Exchange (ETDEWEB)

    Kachi, E.; Suzuki, A.; Fujibayashi, K. [Tokyo University of Agriculture and Technology, Tokyo (Japan)

    1996-10-27

    The co-generation system using a solar cell has the disadvantage that the performance of a cell element deteriorates when the temperature rises. Therefore, the co-generation system in which a BiTe thermoelectric element and linear Fresnel lens are used was constructed. Moreover, the basic characteristics were confirmed and the characteristics of a system model were analyzed. A thermoelectric element area must be reduced to improve the generating efficiency. The generating efficiency depends on the temperature difference between thermoelectric elements rather than the thermoelectric element area. As the thermoelectric area gets lower, the generating efficiency will get higher. This inclination is advantageous on the economic side. The generating efficiency becomes low during operation at high temperature. As a result, the temperature supplied to the thermal load is set to the lower position (100 to 200{degree}C) so as to advance the validity of the system. Even if the co-generation temperature is low, a heat supply capability of 150{degree}C is sufficient for an industrial heat supply system because it holds a large majority of the consumption demand for the whole industry. 3 refs., 8 figs., 3 tabs.

  18. Reduction of Temperature in Concentrator Photovoltaic Module Using Coating with High Thermal Emissivity and Conductivity

    Directory of Open Access Journals (Sweden)

    Nakamura Satoshi

    2016-01-01

    Full Text Available The temperature of solar cells considerably increases under light-concentrating operations, and the conversion efficiency of solar cells decreases with increasing temperature. It is very important to reduce the cell temperature in concentrator photovoltaic modules. The thermal radiation layers with high thermal emissivity and thermal conductivity was coated on the aluminum samples which is used for the chassis of concentrator photovoltaic and the effect was evaluated under the conditions with wind. The temperature of sample with coating showed lower temperature than that without coating. In the condition with wind, the coated sample with high thermal emissivity and high thermal conductivity showed the lowest temperature due to the effect of thermal radiation and thermal conduction.

  19. Experimental Study of Sorbitol Production by Zymomonas mobilis in High Sucrose Concentration

    Directory of Open Access Journals (Sweden)

    Rui Sérgio dos Santos Ferreira da Silva

    2004-01-01

    Full Text Available The sorbitol presents several industrial applications and its conventional production is of high cost and low yield. Sorbitol production by Zymomonas mobilis production has attracted attention as both production cost and environmental impact are low. The sorbitol plays an osmo-protective rule so that its production is promoted by high sugar concentrations. This work has evaluated the effect of high sucrose concentration in the sorbitol production. The raise of sucrose concentration from 100 to 300g/ L caused an increase in the sorbitol production from 4,979 to 20,633g/l. Statistic analysis showed that 95,5% in the variation in sorbitol production can be explained.

  20. The ability of Typha domingensis to accumulate and tolerate high concentrations of Cr, Ni, and Zn.

    Science.gov (United States)

    Mufarrege, M M; Hadad, H R; Di Luca, G A; Maine, M A

    2015-01-01

    The tolerance and removal efficiency of Typha domingensis exposed to high concentrations of Cr, Ni, and Zn in single and combined treatments were studied. Sediment and two plants were disposed in each plastic reactor. The treatments were 100 and 500 mg L(-1) of Cr, Ni, and Zn (single solutions); 100 mg L(-1) Cr + Ni + Zn (multi-metal solutions) and 500 mg L(-1) Cr + Ni + Zn (multi-metal solutions); and a control. Even though the concentrations studied were extremely high, simulating an accidental metal dump, the three metals were efficiently removed from water. The highest removal was registered for Cr. The presence of other metals favored Cr and did not favor Ni and Zn removal from water. After 25 days, senescence and chlorosis of plants were observed in Ni and Comb500 treatments, while Cr and Zn only caused growth inhibition. T. domingensis accumulated high metal concentrations in tissues. The roots showed higher metal concentration than submerged parts of leaves. Cr translocation to aerial parts was enhanced by the presence of Ni and Zn. Our results demonstrate that in the case of an accidental dump of high Cr, Ni, and Zn concentrations, a wetland system dominated by T. domingensis is able to retain metals, and the macrophyte is able to tolerate them the time necessary to remove them from water. Thus, the environment will be preserved since the wetland would act as a cushion.