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Sample records for profilogram reduction system

  1. Microgravity particle reduction system

    Science.gov (United States)

    Brandon, Vanessa; Joslin, Michelle; Mateo, Lili; Tubbs, Tracey

    1988-01-01

    The Controlled Ecological Life Support System (CELSS) project, sponsored by NASA, is assembling the knowledge required to design, construct, and operate a system which will grow and process higher plants in space for the consumption by crew members of a space station on a long term space mission. The problem of processing dry granular organic materials in microgravity is discussed. For the purpose of research and testing, wheat was chosen as the granular material to be ground into flour. Possible systems which were devised to transport wheat grains into the food processor, mill the wheat into flour, and transport the flour to the food preparation system are described. The systems were analyzed and compared and two satisfactory systems were chosen. Prototypes of the two preferred systems are to be fabricated next semester. They will be tested under simulated microgravity conditions and revised for maximum effectiveness.

  2. Bathymetric Data Reduction System.

    Science.gov (United States)

    1980-08-01

    accurately edited. In the Lineal Input System (LIS) no such method was employed, and the errors inherent in both the LIS day 𔃻’ and day ’n...points forming a side of the polygon. Using the slope it is possible to determine algebraically through which grid cells the line will pass for each...respectively. When comparing these angles, the algebraic minimum value is that of the 2’E longitude. This results in a sectioned area between 21E and 2

  3. Model Reduction of Hybrid Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    matrices are constructed based on the convex combinations of the generalized gramians. However this framework is less conservative than the first one, it does not guarantee the stability for all switching signals. The stability preservation is studied for this reduction technique. The third framework......High-Technological solutions of today are characterized by complex dynamical models. A lot of these models have inherent hybrid/switching structure. Hybrid/switched systems are powerful models for distributed embedded systems design where discrete controls are applied to continuous processes...... of hybrid systems, designing controllers and implementations is very high so that the use of these models is limited in applications where the size of the state space is large. To cope with complexity, model reduction is a powerful technique. This thesis presents methods for model reduction and stability...

  4. Infinitary Combinatory Reduction Systems: Confluence

    NARCIS (Netherlands)

    Ketema, J.; Simonsen, Jakob Grue

    2009-01-01

    We study confluence in the setting of higher-order infinitary rewriting, in particular for infinitary Combinatory Reduction Systems (iCRSs). We prove that fully-extended, orthogonal iCRSs are confluent modulo identification of hypercollapsing subterms. As a corollary, we obtain that fully-extended,

  5. Model reduction of parametrized systems

    CERN Document Server

    Ohlberger, Mario; Patera, Anthony; Rozza, Gianluigi; Urban, Karsten

    2017-01-01

    The special volume offers a global guide to new concepts and approaches concerning the following topics: reduced basis methods, proper orthogonal decomposition, proper generalized decomposition, approximation theory related to model reduction, learning theory and compressed sensing, stochastic and high-dimensional problems, system-theoretic methods, nonlinear model reduction, reduction of coupled problems/multiphysics, optimization and optimal control, state estimation and control, reduced order models and domain decomposition methods, Krylov-subspace and interpolatory methods, and applications to real industrial and complex problems. The book represents the state of the art in the development of reduced order methods. It contains contributions from internationally respected experts, guaranteeing a wide range of expertise and topics. Further, it reflects an important effor t, carried out over the last 12 years, to build a growing research community in this field. Though not a textbook, some of the chapters ca...

  6. Carbon Monoxide Silicate Reduction System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Carbon Monoxide Silicate Reduction System (COSRS) is an innovative method that for the first time uses the strong reductant carbon monoxide to both reduce iron...

  7. Infinitary Combinatory Reduction Systems: Confluence

    DEFF Research Database (Denmark)

    Ketema, Jeroen; Simonsen, Jakob Grue

    2009-01-01

    -extended, orthogonal iCRSs have the normal form property and the  unique normal form property (with respect to reduction). We also show that, unlike the case in first-order infinitary rewriting, almost non-collapsing iCRSs are not necessarily confluent....

  8. System model reduction for MBS optimization

    Directory of Open Access Journals (Sweden)

    Zavřel J.

    2007-11-01

    Full Text Available A disadvantage of optimization of flexible multibody systems (MBS is a computing time, mainly for large systems, especially designed by FEM. The computing time rises with the complexity of the model significantly. A reduction techniques allow decreasing of degrees of freedom and it contributes to the reduction of the computing time. These techniques can be used for the reduction from thousands and more degrees of freedom to tens, but some limits exist. A reduction degree (ratio between number of DOFs before and after the reduction is the most important feature because it predicts the final accuracy of the model. The next one is the selection of master and slave degrees of freedom that play an important role in connecting all bodies together within the MBS (e.g. by joints. There are many reduction methods, but they differ in available accuracy, speed, efficiency and suitability for the same reduction degree. A dimension of the original system is decisive for the reduction method suitability, many methods require an inversion matrix from the part of the stiffness matrix. The inversion matrix are than largeand the computing time grows up. This paper deals with the reduction techniques, their disadvantages, suitability and applicability.

  9. Carbon Monoxide Silicate Reduction System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Carbon Monoxide Silicate Reduction System (COSRS) is a novel technology for producing large quantities of oxygen on the Moon. Oxygen yields of 15 kilograms per...

  10. Reduction of Subjective and Objective System Complexity

    Science.gov (United States)

    Watson, Michael D.

    2015-01-01

    Occam's razor is often used in science to define the minimum criteria to establish a physical or philosophical idea or relationship. Albert Einstein is attributed the saying "everything should be made as simple as possible, but not simpler". These heuristic ideas are based on a belief that there is a minimum state or set of states for a given system or phenomena. In looking at system complexity, these heuristics point us to an idea that complexity can be reduced to a minimum. How then, do we approach a reduction in complexity? Complexity has been described as a subjective concept and an objective measure of a system. Subjective complexity is based on human cognitive comprehension of the functions and inter relationships of a system. Subjective complexity is defined by the ability to fully comprehend the system. Simplifying complexity, in a subjective sense, is thus gaining a deeper understanding of the system. As Apple's Jonathon Ive has stated," It's not just minimalism or the absence of clutter. It involves digging through the depth of complexity. To be truly simple, you have to go really deep". Simplicity is not the absence of complexity but a deeper understanding of complexity. Subjective complexity, based on this human comprehension, cannot then be discerned from the sociological concept of ignorance. The inability to comprehend a system can be either a lack of knowledge, an inability to understand the intricacies of a system, or both. Reduction in this sense is based purely on a cognitive ability to understand the system and no system then may be truly complex. From this view, education and experience seem to be the keys to reduction or eliminating complexity. Objective complexity, is the measure of the systems functions and interrelationships which exist independent of human comprehension. Jonathon Ive's statement does not say that complexity is removed, only that the complexity is understood. From this standpoint, reduction of complexity can be approached

  11. Symmetry Reduction For Stochastic Hybrid Systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Katoen, Joost P.

    2008-01-01

    This paper is focused on adapting symmetry reduction, a technique that is highly successful in traditional model checking, to stochastic hybrid systems. To that end, we first show that performability analysis of stochastic hybrid systems can be reduced to a stochastic reachability analysis (SRA).

  12. Symmetry reduction for stochastic hybrid systems

    NARCIS (Netherlands)

    Bujorianu, L.M.; Katoen, Joost P.

    2009-01-01

    This paper is focused on adapting symmetry reduction, a technique that is highly successful in traditional model checking, to stochastic hybrid systems. We first show that performability analysis of stochastic hybrid systems can be reduced to a stochastic reachability analysis (SRA). Then, we

  13. System reduction for nanoscale IC design

    CERN Document Server

    2017-01-01

    This book describes the computational challenges posed by the progression toward nanoscale electronic devices and increasingly short design cycles in the microelectronics industry, and proposes methods of model reduction which facilitate circuit and device simulation for specific tasks in the design cycle. The goal is to develop and compare methods for system reduction in the design of high dimensional nanoelectronic ICs, and to test these methods in the practice of semiconductor development. Six chapters describe the challenges for numerical simulation of nanoelectronic circuits and suggest model reduction methods for constituting equations. These include linear and nonlinear differential equations tailored to circuit equations and drift diffusion equations for semiconductor devices. The performance of these methods is illustrated with numerical experiments using real-world data. Readers will benefit from an up-to-date overview of the latest model reduction methods in computational nanoelectronics.

  14. Robotic system for glovebox size reduction

    Energy Technology Data Exchange (ETDEWEB)

    KWOK,KWAN S.; MCDONALD,MICHAEL J.

    2000-03-02

    The Intelligent Systems and Robotics Center (ISRC) at Sandia National Laboratories (SNL) is developing technologies for glovebox size reduction in the DOE nuclear complex. A study was performed for Kaiser-Hill (KH) at the Rocky Flats Environmental Technology Site (RFETS) on the available technologies for size reducing the glovebox lines that require size reduction in place. Currently, the baseline approach to these glovebox lines is manual operations using conventional mechanical cutting methods. The study has been completed and resulted in a concept of the robotic system for in-situ size reduction. The concept makes use of commercially available robots that are used in the automotive industry. The commercially available industrial robots provide high reliability and availability that are required for environmental remediation in the DOE complex. Additionally, the costs of commercial robots are about one-fourth that of the custom made robots for environmental remediation. The reason for the lower costs and the higher reliability is that there are thousands of commercial robots made annually, whereas there are only a few custom robots made for environmental remediation every year. This paper will describe the engineering analysis approach used in the design of the robotic system for glovebox size reduction.

  15. Advanced CO2 Removal and Reduction System

    Science.gov (United States)

    Alptekin, Gokhan; Dubovik, Margarita; Copeland, Robert J.

    2011-01-01

    An advanced system for removing CO2 and H2O from cabin air, reducing the CO2, and returning the resulting O2 to the air is less massive than is a prior system that includes two assemblies . one for removal and one for reduction. Also, in this system, unlike in the prior system, there is no need to compress and temporarily store CO2. In this present system, removal and reduction take place within a single assembly, wherein removal is effected by use of an alkali sorbent and reduction is effected using a supply of H2 and Ru catalyst, by means of the Sabatier reaction, which is CO2 + 4H2 CH4 + O2. The assembly contains two fixed-bed reactors operating in alternation: At first, air is blown through the first bed, which absorbs CO2 and H2O. Once the first bed is saturated with CO2 and H2O, the flow of air is diverted through the second bed and the first bed is regenerated by supplying it with H2 for the Sabatier reaction. Initially, the H2 is heated to provide heat for the regeneration reaction, which is endothermic. In the later stages of regeneration, the Sabatier reaction, which is exothermic, supplies the heat for regeneration.

  16. Model Reduction of Fuzzy Logic Systems

    Directory of Open Access Journals (Sweden)

    Zhandong Yu

    2014-01-01

    Full Text Available This paper deals with the problem of ℒ2-ℒ∞ model reduction for continuous-time nonlinear uncertain systems. The approach of the construction of a reduced-order model is presented for high-order nonlinear uncertain systems described by the T-S fuzzy systems, which not only approximates the original high-order system well with an ℒ2-ℒ∞ error performance level γ but also translates it into a linear lower-dimensional system. Then, the model approximation is converted into a convex optimization problem by using a linearization procedure. Finally, a numerical example is presented to show the effectiveness of the proposed method.

  17. Model reduction for discrete bilinear systems

    Science.gov (United States)

    King, A. M.; Skelton, R. E.

    1987-01-01

    A model reduction method for discrete bilinear systems is developed which matches q sets of Volterra and covariance parameters. These parameters are shown to represent both deterministic and stochastic attributes of the discrete bilinear system. A reduced order model which matches these q sets of parameters is defined to be a q-Volterra covariance equivalent realization (q-Volterra COVER). An algorithm is presented which constructs a class of q-Volterra COVERs parameterized by solutions to a Hermitian, quadratic, matrix equation. The algorithm is applied to a bilinear model of a robot manipulator.

  18. Active noise reduction systems in ducts

    Science.gov (United States)

    Tichy, J.; Poole, L. A.; Warnaka, G. E.

    1984-12-01

    Fundamentals of the theory of the sound propagation in ducts with perfectly reflecting walls, relevant to noise reduction systems, is summarized. A brief historical review of the active sound cancellation techniques is given. Systems based on time invariant parameters are analyzed and their inherited drawbacks outlined. A new generation of systems using controllers based on modified adaptive LMS algorithm is described. The measurements in an experimental duct show that the random noise can be reduced by 25-30 dB, while the noise with line spectra can be decreased by up to 40 dB. Good success is also reported with impulse signals which have random time intervals between the pulses.

  19. Cryogenic Boil-Off Reduction System

    Science.gov (United States)

    Plachta, David W.; Guzik, Monica C.

    2014-03-01

    A computational model of the cryogenic boil-off reduction system being developed by NASA as part of the Cryogenic Propellant Storage and Transfer technology maturation project has been applied to a range of propellant storage tanks sizes for high-performing in-space cryogenic propulsion applications. This effort focuses on the scaling of multi-layer insulation (MLI), cryocoolers, broad area cooling shields, radiators, solar arrays, and tanks for liquid hydrogen propellant storage tanks ranging from 2 to 10 m in diameter. Component scaling equations were incorporated into the Cryogenic Analysis Tool, a spreadsheet-based tool used to perform system-level parametric studies. The primary addition to the evolution of this updated tool is the integration of a scaling method for reverse turbo-Brayton cycle cryocoolers, as well as the development and inclusion of Self-Supporting Multi-Layer Insulation. Mass, power, and sizing relationships are traded parametrically to establish the appropriate loiter period beyond which this boil-off reduction system application reduces mass. The projected benefit compares passive thermal control to active thermal control, where active thermal control is evaluated for reduced boil-off with a 90 K shield, zero boil-off with a single heat interception stage at the tank wall, and zero boil-off with a second interception stage at a 90 K shield. Parametric studies show a benefit over passive storage at loiter durations under one month, in addition to showing a benefit for two-stage zero boil-off in terms of reducing power and mass as compared to single stage zero boil-off. Furthermore, active cooling reduces the effect of varied multi-layer insulation performance, which, historically, has been shown to be significant.

  20. The Space Technology 7 Disturbance Reduction System

    Science.gov (United States)

    O'Donnell, J. R., Jr.; Hsu, O. C.; Hanson, J.; Hruby, V.

    The Space Technology 7 Disturbance Reduction System (DRS) is an in-space technology demonstration designed to validate technologies that are required for future missions such as the Laser Interferometer Space Antenna (LISA) and the Micro-Arcsecond X-ray Imaging Mission (MAXIM). The primary sensors that will be used by DRS are two Gravitational Reference Sensors (GRSs) being developed by Stanford University. DRS will control the spacecraft so that it flies about one of the freely-floating Gravitational Reference Sensor test masses, keeping it centered within its housing. The other GRS serves as a cross-reference for the first as well as being used as a reference for the spacecraft's attitude control. Colloidal MicroNewton Thrusters being developed by the Busek Co. will be used to control the spacecraft's position and attitude using a six degree-of-freedom Dynamic Control System being developed by Goddard Space Flight Center. A laser interferometer being built by the Jet Propulsion Laboratory will be used to help validate the results of the experiment. The DRS will be launched in 2008 on the European Space Agency (ESA) LISA Pathfinder spacecraft along with a similar ESA experiment, the LISA Test Package.

  1. Model Reduction of Switched Systems Based on Switching Generalized Gramians

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza; Wisniewski, Rafal

    2012-01-01

    In this paper, a general method for model order reduction of discrete-time switched linear systems is presented. The proposed technique uses switching generalized gramians. It is shown that several classical reduction methods can be developed into the generalized gramian framework for the model...... reduction of linear systems and for the reduction of switched systems. Discrete-time balanced reduction within a specified frequency interval is taken as an example within this framework. To avoid numerical instability and to increase the numerical efficiency, a generalized gramian-based Petrov......-Galerkin projection is constructed instead of the similarity transform approach for reduction. It is proven that the proposed reduction framework preserves the stability of the original switched system. The performance of the method is illustrated by numerical examples....

  2. Bosch CO2 Reduction System Development

    Science.gov (United States)

    Holmes, R. F.; King, C. D.; Keller, E. E.

    1976-01-01

    Development of a Bosch process CO2 reduction unit was continued, and, by means of hardware modifications, the performance was substantially improved. Benefits of the hardware upgrading were demonstrated by extensive unit operation and data acquisition in the laboratory. This work was accomplished on a cold seal configuration of the Bosch unit.

  3. Power system coherency and model reduction

    CERN Document Server

    Chow, Joe H

    2014-01-01

    This book provides a comprehensive treatment for understanding interarea modes in large power systems and obtaining reduced-order models using the coherency concept and selective modal analysis method.

  4. Hydraulic Soft Yaw System Load Reduction and Prototype Results

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Markussen, Kristian

    2013-01-01

    Introducing a hydraulic soft yaw concept for wind turbines leads to significant load reductions in the wind turbine structure. The soft yaw system operates as a shock absorption system on a car, hence absorbing the loading from turbulent wind conditions instead of leading them into the stiff wind...... turbine structure. Results presented shows fatigue reductions of up to 40% and ultimate load reduction of up to 19%. The ultimate load reduction increases even more when the over load protection system in the hydraulic soft yaw system is introduced and results show how the exact extreme load cut off...... operates. Further it is analyzed how the soft yaw system influence the power production of the turbine. It is shown that the influence is minimal, but at larger yaw errors the effect is possitive. Due to the implemeted functions in the hydraulic soft yaw system such as even load distribution on the pinions...

  5. Turbine blade tip gap reduction system

    Science.gov (United States)

    Diakunchak, Ihor S.

    2012-09-11

    A turbine blade sealing system for reducing a gap between a tip of a turbine blade and a stationary shroud of a turbine engine. The sealing system includes a plurality of flexible seal strips extending from a pressure side of a turbine blade generally orthogonal to the turbine blade. During operation of the turbine engine, the flexible seal strips flex radially outward extending towards the stationary shroud of the turbine engine, thereby reducing the leakage of air past the turbine blades and increasing the efficiency of the turbine engine.

  6. Modeling Emergency Warning Systems for Disaster Reduction

    Science.gov (United States)

    Sorensen, J. H.

    2015-12-01

    Emergency warning systems are the last line of defense for reducing losses from natural hazards. Well-designed systems enable populations-at-risk in impending disasters to take appropriate protective actions. There have been a limited number of research efforts designed to quantify the performance of various types of warning systems and these have been primarily technology-specific. This paper describes the result of research on developing models of warning systems based of the 3 stages of warning: deciding to issue a warning, disseminating the warning to the population-at-risk and initiating a protective action. The warning issuance stage is the time between emergency warning officials being notified of the existence of a threat and reaching a decision to activate the warning system. The warning dissemination stage is the time between that decision and individuals receiving the first warning. The protective action stage is the time between receiving the warning and initiating a protective action. A fourth stage consisting of implementing the protective action is not discussed in this paper. The basic method used in developing models of each stage of the warning process was to first review previous modeling research. Second, assemble historic data on the timing of the warning process. This included point data as well as cumulative distributions. Third, develop a modeling approach to specify a diffusion equation. Fourth, compare the empirical data to the results of the simulation. The attached figure depicts a comparision between simulated warning diffusion and empirical data For each stage, best and worst case curves are develop. Several moderate or average curves are also developed. Factors associated with identifying which curves would be appropriate for a large range of potential event scenarios are identified and discussed. Potential application to lose of life modeling and hazard mitigation strategies are also discussed.

  7. Comodulation masking release in bit-rate reduction systems

    DEFF Research Database (Denmark)

    Vestergaard, Martin D.; Rasmussen, Karsten Bo; Poulsen, Torben

    1999-01-01

    It has been suggested that the level dependence of the upper masking slopebe utilised in perceptual models in bit-rate reduction systems. However,comodulation masking release (CMR) phenomena lead to a reduction of themasking effect when a masker and a probe signal are amplitude modulated withthe ...

  8. System Reduction and Damping of Flexible Structures

    DEFF Research Database (Denmark)

    Høgsberg, Jan Riess; Krenk, Steen

    2007-01-01

    An increasing number of flexible structures such as cable-stayed bridges, pedestrian bridges and high-rise buildings are fitted with local dampers to mitigate vibration problems. In principle the effect of local dampers can be analyzed by use of complex modes, e.g. in conjunction with an averaging...... technique for local linearization of the damper characteristics. However, the complex mode shapes and frequencies depend on the magnitude of the damper and therefore are less suitable for design of the damper system. An efficient alternative consists in the use of a two-component representation...... of the damped modes of the structure. The idea is to represent the damped mode as a linear combination of the modes that occur in two distinctly different situations representing extreme conditions: the mode shape of the structure without the damper(s), and the mode shape of the structure, when the damper...

  9. Systems and methods to reduce reductant consumption in exhaust aftertreament systems

    Science.gov (United States)

    Gupta, Aniket; Cunningham, Michael J.

    2017-02-14

    Systems, apparatus and methods are provided for reducing reductant consumption in an exhaust aftertreatment system that includes a first SCR device and a downstream second SCR device, a first reductant injector upstream of the first SCR device, and a second reductant injector between the first and second SCR devices. NOx conversion occurs with reductant injection by the first reductant injector to the first SCR device in a first temperature range and with reductant injection by the second reductant injector to the second SCR device when the temperature of the first SCR device is above a reductant oxidation conversion threshold.

  10. Model reduction for controller design for infinite-dimensional systems

    NARCIS (Netherlands)

    Opmeer, Mark Robertus

    2006-01-01

    The main aim of this thesis is, as the title suggests, the presentation of results on model reduction for controller design for infinite-dimensional systems. The obtained results are presented for both discrete-time systems and continuous-time systems. They are perfect generalizations of the

  11. Symmetry and reduction in implicit generalized Hamiltonian systems

    NARCIS (Netherlands)

    Blankenstein, G.; van der Schaft, Arjan

    In this paper we study the notion of symmetry for implicit generalized Hamiltonian systems, which are Hamiltonian systems with respect to a generalized Dirac structure. We investigate the reduction of these systems admitting a symmetry Lie group with corresponding quantities. Main features in this

  12. Symmetry and Reduction in Implicit Generalized Hamiltonian Systems

    NARCIS (Netherlands)

    Blankenstein, G.; Schaft, A.J. van der

    2001-01-01

    In this paper we study the notion of symmetry for implicit generalized Hamiltonian systems, which are Hamiltonian systems with respect to a generalized Dirac structure. We investigate the reduction of these systems admitting a symmetry Lie group with corresponding conserved quantities. Main features

  13. Application of system concept in vibration and noise reduction

    Directory of Open Access Journals (Sweden)

    SHENG Meiping

    2017-08-01

    Full Text Available Although certain vibration and noise control technologies are maturing, such as vibration absorption, vibration isolation, sound absorption and sound insulation, and new methods for specific frequency bands or special environments have been proposed unceasingly, there is still no guarantee that practical effective vibration and noise reduction can be obtained. An important constraint for vibration and noise reduction is the lack of a system concept, and the integrity and relevance of such practical systems as ship structure have not obtained enough attention. We have tried to use the system engineering theory in guiding vibration and noise reduction, and have already achieved certain effects. Based on the system concept, the noise control of a petroleum pipeline production workshop has been completed satisfactorily, and the abnormal noise source identification of an airplane has been accomplished successfully. We want to share our experience and suggestions to promote the popularization of the system engineering theory in vibration and noise control.

  14. Model reduction of nonlinear systems subject to input disturbances

    KAUST Repository

    Ndoye, Ibrahima

    2017-07-10

    The method of convex optimization is used as a tool for model reduction of a class of nonlinear systems in the presence of disturbances. It is shown that under some conditions the nonlinear disturbed system can be approximated by a reduced order nonlinear system with similar disturbance-output properties to the original plant. The proposed model reduction strategy preserves the nonlinearity and the input disturbance nature of the model. It guarantees a sufficiently small error between the outputs of the original and the reduced-order systems, and also maintains the properties of input-to-state stability. The matrices of the reduced order system are given in terms of a set of linear matrix inequalities (LMIs). The paper concludes with a demonstration of the proposed approach on model reduction of a nonlinear electronic circuit with additive disturbances.

  15. Approximate Bisimulation-Based Reduction of Power System Dynamic Models

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, AM; Dukic, SD; Saric, AT

    2015-05-01

    In this paper we propose approximate bisimulation relations and functions for reduction of power system dynamic models in differential- algebraic (descriptor) form. The full-size dynamic model is obtained by linearization of the nonlinear transient stability model. We generalize theoretical results on approximate bisimulation relations and bisimulation functions, originally derived for a class of constrained linear systems, to linear systems in descriptor form. An algorithm for transient stability assessment is proposed and used to determine whether the power system is able to maintain the synchronism after a large disturbance. Two benchmark power systems are used to illustrate the proposed algorithm and to evaluate the applicability of approximate bisimulation relations and bisimulation functions for reduction of the power system dynamic models.

  16. On the Reduction of Singularly-Perturbed Linear Differential Systems

    OpenAIRE

    Barkatou, Moulay; Maddah, Suzy S.; Abbas, Hassan

    2014-01-01

    In this article, we recover singularly-perturbed linear differential systems from their turning points and reduce the rank of the singularity in the parameter to its minimal integer value. Our treatment is Moser-based; that is to say it is based on the reduction criterion introduced for linear singular differential systems by Moser. Such algorithms have proved their utility in the symbolic resolution of the systems of linear functional equations, giving rise to the package ISOLDE, as well as ...

  17. Reduction of 4(5)-Methylimidazole Using Cookie Model Systems.

    Science.gov (United States)

    Jung, Min-Chul; Kim, Mina K; Lee, Kwang-Geun

    2017-10-01

    The objective of this study was to determine the reduction of 4(5)-methylimidazole (4-MI) under various baking conditions. For 4-MI analysis, an analytical method using gas chromatography-mass spectrometry was developed. The developed method was validated with linearity (r2 > 0.999), recovery (101% to 103%, 3 levels), and precision (1.5% to 4.3%, 3 levels). Limits of detection and quantification were 18.5 and 56.0 μg/kg, respectively. This method was used to monitor the level of 4-MI in 11 commercial cookies, which ranged from 71.5 to 1254.8 μg/kg. Time and temperature were modified in the cookie model system to reduce 4-MI. The largest reduction in 4-MI (56%) was achieved by baking at 140 °C for 8 min; however the cookies baked at this condition were not well accepted by consumers. With combination of consumer liking test result, baking cookies at 140 °C for 16 min is optimal for 4-MI reduction (28% reduction), while it has minimal impact on consumer acceptance. A strong correlation (r2 = 0.9981) was found between caramel colorant and 4-MI in the cookie model system. A consumer awareness toward toxicity of 4-MI has been arising, and method to reduce the levels of 4-MI in food products are being developed in many studies. Yet, these reduction studies in food model systems only focused on use of food additives for 4-MI reduction. Current study investigated the use of process modification on 4-MI reduction in cookie, and suggested that baking cookies longer at lower temperature, in turn, reduces the levels of 4-MI in cookies without compromising consumer acceptance. Finding from current study can practically aid bakery industry to ensure safety of bakery products without affecting consumer likings. © 2017 Institute of Food Technologists®.

  18. Extreme Cost Reductions with Multi-Megawatt Centralized Inverter Systems

    Energy Technology Data Exchange (ETDEWEB)

    Schwabe, Ulrich [Alencon LLC; Fishman, Oleg [Alencon LLC

    2015-03-20

    The objective of this project was to fully develop, demonstrate, and commercialize a new type of utility scale PV system. Based on patented technology, this includes the development of a truly centralized inverter system with capacities up to 100MW, and a high voltage, distributed harvesting approach. This system promises to greatly impact both the energy yield from large scale PV systems by reducing losses and increasing yield from mismatched arrays, as well as reduce overall system costs through very cost effective conversion and BOS cost reductions enabled by higher voltage operation.

  19. Reduction of Linear Functional Systems using Fuhrmann's Equivalence

    Directory of Open Access Journals (Sweden)

    Mohamed S. Boudellioua

    2016-11-01

    Full Text Available Functional systems arise in the treatment of systems of partial differential equations, delay-differential equations, multidimensional equations, etc. The problem of reducing a linear functional system to a system containing fewer equations and unknowns was first studied by Serre. Finding an equivalent presentation of a linear functional system containing fewer equations and fewer unknowns can generally simplify both the study of the structural properties of the linear functional system and of different numerical analysis issues, and it can sometimes help in solving the linear functional system. In this paper, Fuhrmann's equivalence is used to present a constructive result on the reduction of under-determined linear functional systems to a single equation involving a single unknown. This equivalence transformation has been studied by a number of authors and has been shown to play an important role in the theory of linear functional systems.

  20. Order reduction of linear discrete systems using a genetic algorithm

    National Research Council Canada - National Science Library

    Satakshi; Mukherjee, S; Mittal, R.C

    2005-01-01

    ... order reduction of linear systems using step and impulse response matching involves the error minimization problem which has been handled with classical techniques so far by different workers [2,5,6] . But all these suffer from the limitations of classical techniques. There are some common difficulties with most of the classical techniq...

  1. Reduction of Second-Order Network Systems with Structure Preservation

    NARCIS (Netherlands)

    Cheng, Xiaodong; Kawano, Yu; Scherpen, Jacquelien M.A.

    2017-01-01

    This paper proposes a general framework for structure-preserving model reduction of a second-order network system based on graph clustering. In this approach, vertex dynamics are captured by the transfer functions from inputs to individual states, and the dissimilarities of vertices are quantified

  2. Recursion Operators for CBC system with reductions. Geometric theory

    Science.gov (United States)

    Yanovski, A.; Vilasi, G.

    2016-09-01

    We discuss some recent developments of the geometric theory of the Recursion Operators (Generating Operators) for Caudrey-Beals-Coifman systems (CBC systems) on semisimple Lie algebras. As is well known the essence of this interpretation is that the Recursion Operators could be considered as adjoint to Nijenhuis tensors on certain infinite-dimensional manifolds. In particular, we discuss the case when there are Zp reductions of Mikhailov type.

  3. Systemic cost-effectiveness analysis of food hazard reduction

    DEFF Research Database (Denmark)

    Jensen, Jørgen Dejgård; Lawson, Lartey Godwin; Lund, Mogens

    2015-01-01

    stage are considered. Cost analyses are conducted for different risk reduction targets and for three alternative scenarios concerning the acceptable range of interventions. Results demonstrate that using a system-wide policy approach to risk reduction can be more cost-effective than a policy focusing......An integrated microbiological-economic framework for policy support is developed to determine the cost-effectiveness of alternative intervention methods and strategies to reduce the risk of Campylobacter in broilers. Four interventions at the farm level and four interventions at the processing...... purely on farm-level interventions. Allowing for chemical decontamination methods may enhance cost-effectiveness of intervention strategies further....

  4. Speckle reduction in THz imaging systems with multiple phase patterns

    Science.gov (United States)

    Jaeger, Irina; Stiens, Johan; Koers, Gaetan; Poesen, Gert; Vounckx, Roger

    2006-04-01

    THz technology makes possible imaging of phenomena, inaccessible to both visible and infrared radiation, but the imaging is still in its early stages of development. This paper draws attention to the aspects of speckle reduction to improve the image quality. Because all existing THz sources are coherent - speckle is an ultimate limiting factor of the free-space imaging techniques. Speckle arises when coherent light scattered from a rough surface is detected by an intensity detector with a finite aperture, hiding the image information. This problem is of special importance for THz imaging, because surface roughness is closer to the object dimension as in optical imaging. The reduction of speckle is highly desirable and we propose here a Hadamard matrix solution. Hadamard diffuser for mm-wave frequency range have been designed, built and tested. We report 50% speckle reduction measurements using a free-space vector network analyzer over the full W-band (75-110 GHz). The advantage of the mm-wave Hadamard technology over optical: the diffuser doesn't have to be moved (vibrated) any more to accomplish the technology of speckle reduction. Temporal optical effect is substituted here by spatial quasi-optical: Hadamard coding in each scan pixel. Second method delivers realistic system parameters for the speckle reduction with polychromatic light for aviation security.

  5. System Reduction in Nonlinear Multibody Dynamics of Wind Turbines

    DEFF Research Database (Denmark)

    Holm-Jørgensen, Kristian; Nielsen, Søren R.K.; Rubak, Rune

    2007-01-01

    In this paper the system reduction in nonlinear multibody dynamics of wind turbines is investigated for various updating schemes of the moving frame of reference. In one case, the moving frame of reference is updated to a stiff body, relative to which the elastic deformations are fixed at one end....... In the other case, the stiff body motion is defined as the chord line connecting the end points of the beam, and the elastic deformations are simply supported at the end points. The system reduction is performed by discretizing the spatial motion into a set of rigid body modes and linear elastic eigenmodes...... determined from an FE-beam model complying to the definitions of the stiff bodymotions. Moreover, certain nonlinear effects have been included. These encompass the non-conservative rotation of the aerodynamic load during large elastic deformations and application of the aerodynamic and inertial loads...

  6. Dimension reduction for the full Navier-Stokes-Fourier system

    Czech Academy of Sciences Publication Activity Database

    Březina, J.; Kreml, Ondřej; Mácha, Václav

    2017-01-01

    Roč. 19, č. 4 (2017), s. 659-683 ISSN 1422-6928 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : Navier–Stokes–Fourier system * dimension reduction * relative entropy Subject RIV: BA - General Mathematics Impact factor: 1.106, year: 2016 https://link.springer.com/article/10.1007%2Fs00021-016-0301-6

  7. An algorithm for model reduction in large electric power systems

    Directory of Open Access Journals (Sweden)

    A. I. Zecevic

    1998-01-01

    Full Text Available Model reduction has become an important issue in the analysis of electric power systems, due to their constantly increasing size and complexity. In this paper we present a decomposition algorithm which is capable of reducing the number of equations in the model, while preserving the potential for parallel computation. A variety of experimental results are provided to illustrate the performance of the algorithm.

  8. A Kaluza-Klein Reduction of Super-integrable Systems

    OpenAIRE

    Fordy, Allan P.

    2018-01-01

    Given a super-integrable system in $n$ degrees of freedom, possessing an integral which is linear in momenta, we use the "Kaluza-Klein construction" in reverse to reduce to a lower dimensional super-integrable system. We give two examples of a reduction from 3 to 2 dimensions. The constant curvature metric (associated with the kinetic energy) is the same in both cases, but with two different super-integrable extensions. For these, we use different elements of the algebra of isometries of the ...

  9. Charge transfer mediator based systems for electrocatalytic oxygen reduction

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Shannon S.; Gerken, James B.; Anson, Colin W.

    2017-11-07

    Disclosed are systems for the electrocatalytic reduction of oxygen, having redox mediator/redox catalyst pairs and an electrolyte solution in contact with an electrode. The redox mediator is included in the electrolyte solution, and the redox catalyst may be included in the electrolyte solution, or alternatively, may be in contact with the electrolyte solution. In one form a cobalt redox catalyst is used with a quinone redox mediator. In another form a nitrogen oxide redox catalyst is used with a nitroxyl type redox mediator. The systems can be used in electrochemical cells wherein neither the anode nor the cathode comprise an expensive metal such as platinum.

  10. Charge transfer mediator based systems for electrocatalytic oxygen reduction

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Shannon S.; Gerken, James B.; Anson, Colin W.

    2017-07-18

    Disclosed are systems for the electrocatalytic reduction of oxygen, having redox mediator/redox catalyst pairs and an electrolyte solution in contact with an electrode. The redox mediator is included in the electrolyte solution, and the redox catalyst may be included in the electrolyte solution, or alternatively, may be in contact with the electrolyte solution. In one form a cobalt redox catalyst is used with a quinone redox mediator. In another form a nitrogen oxide redox catalyst is used with a nitroxyl type redox mediator. The systems can be used in electrochemical cells wherein neither the anode nor the cathode comprise an expensive metal such as platinum.

  11. Output Current Ripple Reduction Algorithms for Home Energy Storage Systems

    Directory of Open Access Journals (Sweden)

    Jin-Hyuk Park

    2013-10-01

    Full Text Available This paper proposes an output current ripple reduction algorithm using a proportional-integral (PI controller for an energy storage system (ESS. In single-phase systems, the DC/AC inverter has a second-order harmonic at twice the grid frequency of a DC-link voltage caused by pulsation of the DC-link voltage. The output current of a DC/DC converter has a ripple component because of the ripple of the DC-link voltage. The second-order harmonic adversely affects the battery lifetime. The proposed algorithm has an advantage of reducing the second-order harmonic of the output current in the variable frequency system. The proposed algorithm is verified from the PSIM simulation and experiment with the 3 kW ESS model.

  12. A combined model reduction algorithm for controlled biochemical systems.

    Science.gov (United States)

    Snowden, Thomas J; van der Graaf, Piet H; Tindall, Marcus J

    2017-02-13

    Systems Biology continues to produce increasingly large models of complex biochemical reaction networks. In applications requiring, for example, parameter estimation, the use of agent-based modelling approaches, or real-time simulation, this growing model complexity can present a significant hurdle. Often, however, not all portions of a model are of equal interest in a given setting. In such situations methods of model reduction offer one possible approach for addressing the issue of complexity by seeking to eliminate those portions of a pathway that can be shown to have the least effect upon the properties of interest. In this paper a model reduction algorithm bringing together the complementary aspects of proper lumping and empirical balanced truncation is presented. Additional contributions include the development of a criterion for the selection of state-variable elimination via conservation analysis and use of an 'averaged' lumping inverse. This combined algorithm is highly automatable and of particular applicability in the context of 'controlled' biochemical networks. The algorithm is demonstrated here via application to two examples; an 11 dimensional model of bacterial chemotaxis in Escherichia coli and a 99 dimensional model of extracellular regulatory kinase activation (ERK) mediated via the epidermal growth factor (EGF) and nerve growth factor (NGF) receptor pathways. In the case of the chemotaxis model the algorithm was able to reduce the model to 2 state-variables producing a maximal relative error between the dynamics of the original and reduced models of only 2.8% whilst yielding a 26 fold speed up in simulation time. For the ERK activation model the algorithm was able to reduce the system to 7 state-variables, incurring a maximal relative error of 4.8%, and producing an approximately 10 fold speed up in the rate of simulation. Indices of controllability and observability are additionally developed and demonstrated throughout the paper. These provide

  13. DEVELOPMENT OF HIGH ACTIVITY, CATALYTIC SYSTEMS FOR NOx REDUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-12-01

    This project was directed at an investigation of catalytic NO{sub x} reduction on carbonaceous supports at low temperatures. The experimental work was conducted primarily in a packed bed reactor/gas flow system that was constructed for this work. The analytical techniques employed were mass spectrometry, NO{sub x} chemiluminescence, and gas chromatography. The experimental plan was focused on steady-state reactivity experiments, followed by temperature programmed desorption (TPD) of surface intermediates, and also selected temperature-programmed reaction (TPR) experiments. Both uncatalyzed and catalyzed (potassium-promoted) phenolic resin char, were investigated as well as the catalytic effect of additional CO in the gas phase.

  14. METHODOLOGY OF SYSTEM APPROACHE TO SEISMIC RISK ASSESSMENT AND REDUCTION

    Directory of Open Access Journals (Sweden)

    A. D. Abakarov

    2016-01-01

    Full Text Available Abstract. Ensuring of urban areas seismic safety is a task which do not require delay. But it cannot be solved by separate parts. It is essential that all components of the seismic hazard must be grouped together in one problem based on the system approach. In the present paper is presented not only the main flowchart of systems approach to ensuring the territory seismic safety but also the flowcharts of components of each main unit. They cover the whole package of measures for a full assessment of territory seismic hazard, seismic risk and its reduction.The proposed methodology can be carried out for design and implementation of regional territory seismic safety programs. 

  15. Energy, greenhouse gas, and cost reductions for municipal recycling systems.

    Science.gov (United States)

    Chester, Mikhail; Martin, Elliot; Sathaye, Nakul

    2008-03-15

    Curbside recycling programs can be more cost-effective than landfilling and lead to environmental benefits from the recovery of materials. Significant reductions in energy and emissions are derived from the decrease of energy-intensive production with virgin materials. In many cities, competing priorities can lead to limited consideration given to system optimal collection and processing strategies that can drive down costs and increase revenue while simultaneously reducing system energy consumption and greenhouse gas (GHG) emissions. We evaluate three alterations to a hypothetical California city's recycling network to discern the conditions under which the changes.constitute system improvements to cost, energy, and emissions. The system initially operates with a collection zoning scheme that does not mitigate the impact of seasonal variations in consumer tonnage. In addition, two collection organizations operate redundantly, collecting recyclables from different customer types on the same street network. Finally, the system is dual stream, meaning recyclables are separated at the curbside. In some scenarios, this practice can limit the consumer participation rate leading to lower collection quantities. First, we evaluate a "business as usual" (BAU) scenario and find that the system operates at a $1.7 M/yr loss but still avoids a net 18.7 GJ and 1700 kg of greenhouse gas equivalent (GGE) per ton of material recycled. Second, we apply an alternative zoning scheme for collection that creates a uniform daily pickup demand throughout the year reducing costs by $0.2 M/yr, energy by 30 MJ/ton, and GHG emissions by 2 kg GGE/ton. Next, the two collection organizations are consolidated into a single entity further reducing vehicle fleet size and weekly vehicle miles traveled resulting in savings from BAU of $0.3 M/yr, 100 MJ/ton, and 8 kg GGE/ton. Lastly, we evaluate a switch to a single-stream system (where recyclables are commingled). We showthat single-stream recycling

  16. Capability for Integrated Systems Risk-Reduction Analysis

    Science.gov (United States)

    Mindock, J.; Lumpkins, S.; Shelhamer, M.

    2016-01-01

    NASA's Human Research Program (HRP) is working to increase the likelihoods of human health and performance success during long-duration missions, and subsequent crew long-term health. To achieve these goals, there is a need to develop an integrated understanding of how the complex human physiological-socio-technical mission system behaves in spaceflight. This understanding will allow HRP to provide cross-disciplinary spaceflight countermeasures while minimizing resources such as mass, power, and volume. This understanding will also allow development of tools to assess the state of and enhance the resilience of individual crewmembers, teams, and the integrated mission system. We will discuss a set of risk-reduction questions that has been identified to guide the systems approach necessary to meet these needs. In addition, a framework of factors influencing human health and performance in space, called the Contributing Factor Map (CFM), is being applied as the backbone for incorporating information addressing these questions from sources throughout HRP. Using the common language of the CFM, information from sources such as the Human System Risk Board summaries, Integrated Research Plan, and HRP-funded publications has been combined and visualized in ways that allow insight into cross-disciplinary interconnections in a systematic, standardized fashion. We will show examples of these visualizations. We will also discuss applications of the resulting analysis capability that can inform science portfolio decisions, such as areas in which cross-disciplinary solicitations or countermeasure development will potentially be fruitful.

  17. Feedback Reduction in Uplink MIMO OFDM Systems by Chunk Optimization

    Science.gov (United States)

    Jorswieck, Eduard; Sezgin, Aydin; Ottersten, Björn; Paulraj, Arogyaswami

    2007-12-01

    The performance of multiuser MIMO systems can be significantly increased by channel-aware scheduling and signal processing at the transmitters based on channel state information. In the multipleantenna uplink multicarrier scenario, the base station decides centrally on the optimal signal processing and spectral power allocation as well as scheduling. An interesting challenge is the reduction of the overhead in order to inform the mobiles about their transmit strategies. In this work, we propose to reduce the feedback by chunk processing and quantization. We maximize the weighted sum rate of a MIMO OFDM MAC under individual power constraints and chunk size constraints. An efficient iterative algorithm is developed and convergence is proved. The feedback overhead as a function of the chunk size is considered in the rate computation and the optimal chunk size is determined by numerical simulations for various channel models. Finally, the issues of finite modulation and coding schemes as well as quantization of the precoding matrices are addressed.

  18. Characterization of the LISA Pathfinder Drag Reduction System

    Science.gov (United States)

    Slutsky, Jacob; LISA Pathfinder Team

    2016-03-01

    The LISA Pathfinder (LPF) mission launched in December 2015 with operations beginning March 2016. LPF is a technology demonstration mission built to prove and fully characterize the performance of the use of drag free test masses as Gravitational Reference Sensors (GRS) for future space based gravitational-wave observatories. As a joint ESA-NASA mission, LPF is comprised of both European and NASA payloads, the LISA Technology Package (LTP) and Disturbance Reduction System (DRS), respectively. DRS includes Colloid Micro-Newton Thruster (CMNT) systems, to precisely maneuver the spacecraft without disturbing the GRS, and a control system that directs spacecraft and test mass actuation. In order to fully characterize DRS/CMNT performance, we have developed a series of experiments, to take place during DRS operations beginning later this year. We have built analysis pipelines, validated on simulated data, to rapidly process experimental data and to identify any performance issues as they occur. European partners have developed the LTP Data Analysis (LTPDA) Matlab extension, and we have adapted and expanded this to DRS missions as the basis of our analysis pipelines. I will discuss the anticipated DRS performance and measurement accuracy, illustrated on simulated data.

  19. Reduction of Systemic Risk by Means of Pigouvian Taxation.

    Directory of Open Access Journals (Sweden)

    Vinko Zlatić

    Full Text Available We analyze the possibility of reduction of systemic risk in financial markets through Pigouvian taxation of financial institutions, which is used to support the rescue fund. We introduce the concept of the cascade risk with a clear operational definition as a subclass and a network related measure of the systemic risk. Using financial networks constructed from real Italian money market data and using realistic parameters, we show that the cascade risk can be substantially reduced by a small rate of taxation and by means of a simple strategy of the money transfer from the rescue fund to interbanking market subjects. Furthermore, we show that while negative effects on the return on investment (ROI are direct and certain, an overall positive effect on risk adjusted return on investments (ROIRA is visible. Please note that the taxation is introduced as a monetary/regulatory, not as a _scal measure, as the term could suggest. The rescue fund is implemented in a form of a common reserve fund.

  20. Reduction of Systemic Risk by Means of Pigouvian Taxation.

    Science.gov (United States)

    Zlatić, Vinko; Gabbi, Giampaolo; Abraham, Hrvoje

    2015-01-01

    We analyze the possibility of reduction of systemic risk in financial markets through Pigouvian taxation of financial institutions, which is used to support the rescue fund. We introduce the concept of the cascade risk with a clear operational definition as a subclass and a network related measure of the systemic risk. Using financial networks constructed from real Italian money market data and using realistic parameters, we show that the cascade risk can be substantially reduced by a small rate of taxation and by means of a simple strategy of the money transfer from the rescue fund to interbanking market subjects. Furthermore, we show that while negative effects on the return on investment (ROI) are direct and certain, an overall positive effect on risk adjusted return on investments (ROIRA) is visible. Please note that the taxation is introduced as a monetary/regulatory, not as a _scal measure, as the term could suggest. The rescue fund is implemented in a form of a common reserve fund.

  1. Strategies for the reduction of Legionella in biological treatment systems.

    Science.gov (United States)

    Nogueira, R; Utecht, K-U; Exner, M; Verstraete, W; Rosenwinkel, K-H

    A community-wide outbreak of Legionnaire's disease occurred in Warstein, Germany, in August 2013. The epidemic strain, Legionella pneumophila Serogruppe 1, was isolated from an industrial wastewater stream entering the municipal wastewater treatment plant (WWTP) in Wartein, the WWTP itself, the river Wäster and air/water samples from an industrial cooling system 3 km downstream of the WWTP. The present study investigated the effect of physical-chemical disinfection methods on the reduction of the concentration of Legionella in the biological treatment and in the treated effluent entering the river Wäster. Additionally, to gain insight into the factors that promote the growth of Legionella in biological systems, growth experiments were made with different substrates and temperatures. The dosage rates of silver micro-particles, hydrogen peroxide, chlorine dioxide and ozone and pH stress to the activated sludge were not able to decrease the number of culturable Legionella spp. in the effluent. Nevertheless, the UV treatment of secondary treated effluent reduced Legionella spp. on average by 1.6-3.4 log units. Laboratory-scale experiments and full-scale measurements suggested that the aerobic treatment of warm wastewater (30-35 °C) rich in organic nitrogen (protein) is a possible source of Legionella infection.

  2. Pesticide and toxicity reduction using an integrated vegetated treatment system.

    Science.gov (United States)

    Anderson, Brian; Phillips, Bryn; Hunt, John; Largay, Bryan; Shihadeh, Rami; Tjeerdema, Ronald

    2011-05-01

    The California, USA, central coast is one of the most productive agricultural areas in the world, and numerous stakeholders are working there to implement conservation practices to reduce contaminated runoff. Practices include vegetated treatment systems (VTS) designed to promote contaminant reduction and breakdown. The current study evaluated the effectiveness of a vegetated drainage ditch incorporating a sedimentation basin, a vegetated section, and a Landguard organophosphate-A (OP-A) enzyme dosing system. The VTS was constructed on a working farm and was designed to remove organophosphate and pyrethroid pesticides, the primary pesticides causing toxicity in Salinas Valley watersheds. The present study was conducted during five separate irrigation events on tailwater runoff containing mixtures of pesticides and suspended sediments. Water samples were collected at four stations within the system, and these were subjected to chemical analyses and tested for toxicity to Ceriodaphnia dubia. All inflow samples were highly toxic to C. dubia, and this was largely because of diazinon. Treatment of diazinon-contaminated runoff was only partially effective using aquatic vegetation. All diazinon remaining after vegetated treatment was effectively removed after treatment with the Landguard OP-A enzyme. Chemical analysis of the VTS water samples showed that pyrethroid and organochlorine pesticide concentrations in water were greatly reduced in the sedimentation section of the ditch, and these pesticides were further reduced in the vegetated section of the ditch. The overall conclusion from these analyses is that the VTS was effective at reducing the more hydrophobic organochlorine and pyrethroid pesticides from water. The water-soluble pesticide diazinon was not sufficiently removed during the VTS residence times observed in this study; however, residual diazinon was effectively removed using Landguard OP-A. Copyright © 2011 SETAC.

  3. Feedback Reduction in Uplink MIMO OFDM Systems by Chunk Optimization

    Directory of Open Access Journals (Sweden)

    Arogyaswami Paulraj

    2008-01-01

    Full Text Available The performance of multiuser MIMO systems can be significantly increased by channel-aware scheduling and signal processing at the transmitters based on channel state information. In the multipleantenna uplink multicarrier scenario, the base station decides centrally on the optimal signal processing and spectral power allocation as well as scheduling. An interesting challenge is the reduction of the overhead in order to inform the mobiles about their transmit strategies. In this work, we propose to reduce the feedback by chunk processing and quantization. We maximize the weighted sum rate of a MIMO OFDM MAC under individual power constraints and chunk size constraints. An efficient iterative algorithm is developed and convergence is proved. The feedback overhead as a function of the chunk size is considered in the rate computation and the optimal chunk size is determined by numerical simulations for various channel models. Finally, the issues of finite modulation and coding schemes as well as quantization of the precoding matrices are addressed.

  4. Thermal Load Reduction System Development in a Hyundai Sonata PHEV

    Energy Technology Data Exchange (ETDEWEB)

    Kreutzer, Cory J.; Rugh, John; Tomerlin, Jeff

    2017-03-28

    Increased market penetration of electric drive vehicles (EDVs) requires overcoming a number of hurdles, including limited vehicle range and the elevated cost in comparison to conventional vehicles. Climate control loads have a significant impact on range, cutting it by over 50% in both cooling and heating conditions. To minimize the impact of climate control on EDV range, the National Renewable Energy Laboratory has partnered with Hyundai America and key industry partners to quantify the performance of thermal load reduction technologies on a Hyundai Sonata plug-in hybrid electric vehicle. Technologies that impact vehicle cabin heating in cold weather conditions and cabin cooling in warm weather conditions were evaluated. Tests included thermal transient and steady-state periods for all technologies, including the development of a new test methodology to evaluate the performance of occupant thermal conditioning. Heated surfaces demonstrated significant reductions in energy use from steady-state heating, including a 29%-59% reduction from heated surfaces. Solar control glass packages demonstrated significant reductions in energy use for both transient and steady-state cooling, with up to a 42% reduction in transient and 12.8% reduction in steady-state energy use for the packages evaluated. Technologies that demonstrated significant climate control load reduction were selected for incorporation into a complete thermal load reduction package. The complete package is set to be evaluated in the second phase of the ongoing project.

  5. On PT Symmetry Systems: Invariance, Conservation Laws, and Reductions

    Directory of Open Access Journals (Sweden)

    P. Masemola

    2014-01-01

    results in a scalar cubic Schrödinger equation. We investigate the relationship between the conservation laws and Lie symmetries and investigate a Lagrangian, corresponding Noether symmetries, conserved vectors, and exact solutions via “double reductions.”

  6. Spatiotemporal system identification on nonperiodic domains using Chebyshev spectral operators and system reduction algorithms.

    Science.gov (United States)

    Khanmohamadi, Omid; Xu, Daolin

    2009-09-01

    A system identification methodology based on Chebyshev spectral operators and an orthogonal system reduction algorithm is proposed, leading to a new approach for data-driven modeling of nonlinear spatiotemporal systems on nonperiodic domains. A continuous model structure is devised allowing for terms of arbitrary derivative order and nonlinearity degree. Chebyshev spectral operators are introduced to realm of inverse problems to discretize that continuous structure and arrive with spectral accuracy at a discrete form. Finally, least squares combined with an orthogonal system reduction algorithm are employed to solve for the parameters and eliminate the redundancies to achieve a parsimonious model. A numerical case study of identifying the Allen-Cahn metastable equation demonstrates the superior accuracy of the proposed Chebyshev spectral identification over its finite difference counterpart.

  7. On distribution reduction and algorithm implementation in inconsistent ordered information systems.

    Science.gov (United States)

    Zhang, Yanqin

    2014-01-01

    As one part of our work in ordered information systems, distribution reduction is studied in inconsistent ordered information systems (OISs). Some important properties on distribution reduction are studied and discussed. The dominance matrix is restated for reduction acquisition in dominance relations based information systems. Matrix algorithm for distribution reduction acquisition is stepped. And program is implemented by the algorithm. The approach provides an effective tool for the theoretical research and the applications for ordered information systems in practices. For more detailed and valid illustrations, cases are employed to explain and verify the algorithm and the program which shows the effectiveness of the algorithm in complicated information systems.

  8. Generalized Gramian Framework for Model/Controller Order Reduction of Switched Systems

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza; Wisniewski, Rafal

    2011-01-01

    In this article, a general method for model/controller order reduction of switched linear dynamical systems is presented. The proposed technique is based on the generalised gramian framework for model reduction. It is shown that different classical reduction methods can be developed...... transform approach for reduction. The framework is developed for switched controller reduction. To the best of our knowledge, there is no other reported result on switched controller reduction in the literature. The method preserves the stability under an arbitrary switching signal for both model...... and controller reduction. Furthermore, it is applicable to both continuous and discrete time systems for different classical gramian-based reduction methods. The performance of the proposed method is illustrated by numerical examples....

  9. System Reduction in Multibody Dynamics of Wind Turbines

    DEFF Research Database (Denmark)

    Holm-Jørgensen, Kristian; Nielsen, Søren R.K.

    2009-01-01

    in the expansion via a quasi-static correction. The results show that by using the derived reduction scheme it is only necessary with 2 dynamical modes for the blade substructure when the remaining modes are treated as quasi-static. Moreover, it is shown that it has little to none effect if the gyroscopic...

  10. Frequency Weighted Model Order Reduction Technique and Error Bounds for Discrete Time Systems

    OpenAIRE

    Muhammad Imran; Abdul Ghafoor; Victor Sreeram

    2014-01-01

    Model reduction is a process of approximating higher order original models by comparatively lower order models with reasonable accuracy in order to provide ease in design, modeling and simulation for large complex systems. Generally, model reduction techniques approximate the higher order systems for whole frequency range. However, certain applications (like controller reduction) require frequency weighted approximation, which introduce the concept of using frequency weights in model reductio...

  11. Model Reduction via Time-Interval Balanced Stochastic Truncation for Linear Time Invariant Systems

    DEFF Research Database (Denmark)

    Tahavori, Maryamsadat; Shaker, Hamid Reza

    2013-01-01

    In this article, a new method for model reduction of linear dynamical systems is presented. The proposed technique is from the family of gramian-based relative error model reduction methods. The method uses time-interval gramians in the reduction procedure rather than ordinary gramians and in suc......In this article, a new method for model reduction of linear dynamical systems is presented. The proposed technique is from the family of gramian-based relative error model reduction methods. The method uses time-interval gramians in the reduction procedure rather than ordinary gramians...... accuracy and efficiency. In order to avoid numerical instability and also to further increase the numerical efficiency, projector matrices are constructed instead of the similarity transform approach for reduction. The method is illustrated by a numerical example and finally it is applied to a practical CD...

  12. On Balancing and Order Reduction of Unstable Periodic Systems

    OpenAIRE

    Varga, Andras

    2001-01-01

    Abstract: We consider the direct application of balancing techniques to unstable periodic systems by extending the balancing concepts to arbitrary periodic systems. We extend first the balancing concepts to unstable discrete-time systems by defining the reachability and observability grammians from appropriate right and left coprime factorizations with inner denominators. Further, we extend this new balancing method to unstable linear time-varying discrete-time systems with periodically vary...

  13. Noise exposure reduction of advanced high-lift systems

    Science.gov (United States)

    Haffner, Stephen W.

    1995-01-01

    The purpose of NASA Contract NAS1-20090 Task 3 was to investigate the potential for noise reduction that would result from improving the high-lift performance of conventional subsonic transports. The study showed that an increase in lift-to-drag ratio of 15 percent would reduce certification noise levels by about 2 EPNdB on approach, 1.5 EPNdB on cutback, and zero EPNdB on sideline. In most cases, noise contour areas would be reduced by 10 to 20 percent.

  14. Model Reduction of Linear Switched Systems by Restricting Discrete Dynamics

    DEFF Research Database (Denmark)

    Bastug, Mert; Petreczky, Mihaly; Wisniewski, Rafal

    2014-01-01

    We present a procedure for reducing the number of continuous states of discrete-time linear switched systems, such that the reduced system has the same behavior as the original system for a subset of switching sequences. The proposed method is expected to be useful for abstraction based control s...

  15. Incomplete information system and rough set theory models and attribute reductions

    CERN Document Server

    Yang, Xibei

    2012-01-01

    This study of the theory of generalizations of rough-set models in incomplete information systems discusses not only the regular attributes but also the criteria in these systems, and presents practical approaches to computing a number of reducts.

  16. Cholesterol Hydroperoxide Generation, Translocation, and Reductive Turnover in Biological Systems.

    Science.gov (United States)

    Girotti, Albert W; Korytowski, Witold

    2017-12-01

    Cholesterol is like other unsaturated lipids in being susceptible to peroxidative degradation upon exposure to strong oxidants like hydroxyl radical or peroxynitrite generated under conditions of oxidative stress. In the eukaryotic cell plasma membrane, where most of the cellular cholesterol resides, peroxidation leads to membrane structural and functional damage from which pathological states may arise. In low density lipoprotein, cholesterol and phospholipid peroxidation have long been associated with atherogenesis. Among the many intermediates/products of cholesterol oxidation, hydroperoxide species (ChOOHs) have a number of different fates and deserve special attention. These fates include (a) damage-enhancement via iron-catalyzed one-electron reduction, (b) damage containment via two-electron reduction, and (c) inter-membrane, inter-lipoprotein, and membrane-lipoprotein translocation, which allows dissemination of one-electron damage or off-site suppression thereof depending on antioxidant location and capacity. In addition, ChOOHs can serve as reliable and conveniently detected mechanistic reporters of free radical-mediated reactions vs. non-radical (e.g., singlet oxygen)-mediated reactions. Iron-stimulated peroxidation of cholesterol and other lipids underlies a newly discovered form of regulated cell death called ferroptosis. These and other deleterious consequences of radical-mediated lipid peroxidation will be discussed in this review.

  17. Structure-preserving tangential interpolation for model reduction of port-Hamiltonian Systems

    OpenAIRE

    Gugercin, Serkan; Polyuga, Rostyslav V.; Beattie, Christopher; van der Schaft, Arjan

    2011-01-01

    Port-Hamiltonian systems result from port-based network modeling of physical systems and are an important example of passive state-space systems. In this paper, we develop the framework for model reduction of large-scale multi-input/multi-output port-Hamiltonian systems via tangential rational interpolation. The resulting reduced-order model not only is a rational tangential interpolant but also retains the port-Hamiltonian structure; hence is passive. This reduction methodology is described ...

  18. Optimally Convex Controller and Model Reduction for a Dynamic System

    Directory of Open Access Journals (Sweden)

    P. S. KHUNTIA

    2008-07-01

    Full Text Available This paper presents analysis and design of a family of controllers based on numerical convex optimization for an aircraft pitch control system. A design method is proposed here to solve control system design problems in which a set of multiple closed loop performance specifications are simultaneously satisfied. The transfer matrix of the system is determined through the convex combination of the transfer matrices of the plant and the controllers. The present system with optimal convex controller has been tested for stability using Kharitonov’s Stability Criteria. The simulation deals here withthe problem of pitch control system of a BRAVO fighter aircraft which results in higher order close loop transfer function. So the order of the higher order transfer function is reduced to minimize the complexity of the system.

  19. Adaptive noise reduction circuit for a sound reproduction system

    Science.gov (United States)

    Engebretson, A. Maynard (Inventor); O'Connell, Michael P. (Inventor)

    1995-01-01

    A noise reduction circuit for a hearing aid having an adaptive filter for producing a signal which estimates the noise components present in an input signal. The circuit includes a second filter for receiving the noise-estimating signal and modifying it as a function of a user's preference or as a function of an expected noise environment. The circuit also includes a gain control for adjusting the magnitude of the modified noise-estimating signal, thereby allowing for the adjustment of the magnitude of the circuit response. The circuit also includes a signal combiner for combining the input signal with the adjusted noise-estimating signal to produce a noise reduced output signal.

  20. Singular perturbations introduction to system order reduction methods with applications

    CERN Document Server

    Shchepakina, Elena; Mortell, Michael P

    2014-01-01

    These lecture notes provide a fresh approach to investigating singularly perturbed systems using asymptotic and geometrical techniques. It gives many examples and step-by-step techniques, which will help beginners move to a more advanced level. Singularly perturbed systems appear naturally in the modelling of many processes that are characterized by slow and fast motions simultaneously, for example, in fluid dynamics and nonlinear mechanics. This book’s approach consists in separating out the slow motions of the system under investigation. The result is a reduced differential system of lesser order. However, it inherits the essential elements of the qualitative behaviour of the original system. Singular Perturbations differs from other literature on the subject due to its methods and wide range of applications. It is a valuable reference for specialists in the areas of applied mathematics, engineering, physics, biology, as well as advanced undergraduates for the earlier parts of the book, and graduate stude...

  1. A Romanian energy system model and a nuclear reduction strategy

    DEFF Research Database (Denmark)

    Gota, Dan-Ioan; Lund, Henrik; Miclea, Liviu

    2011-01-01

    This paper presents a model of the Romanian energy system with the purpose of providing a tool for the analysis of future sustainable energy strategies. The model represents the total national energy system and is detailed to the level of hourly demand and production in order to be able to analyse...... the consequences of adding fluctuating renewable energy sources to the system. The model has been implemented into the EnergyPLAN tool and has been validated in order to determine if it can be used as a reference model for other simulations. In EnergyPLAN, two different future strategy scenarios for the Romanian...... energy system are compared to the actual data of Romania of year 2008. First, a comparison is made between the 2008 model and the 2013 strategy scenario corresponding to the grid of the Romanian transmission system operator (TSO) Transelectrica. Then, a comparison is made to a second strategy scenario...

  2. Reduction of Flight Control System/Structural Mode Interaction Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel approach is proposed for reducing the degree of interaction of a high gain flight control system with the airframe structural vibration modes, representing a...

  3. Neural Network Target Identification System for False Alarm Reduction

    Science.gov (United States)

    Ye, David; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

    2009-01-01

    A multi-stage automated target recognition (ATR) system has been designed to perform computer vision tasks with adequate proficiency in mimicking human vision. The system is able to detect, identify, and track targets of interest. Potential regions of interest (ROIs) are first identified by the detection stage using an Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter combined with a wavelet transform. False positives are then eliminated by the verification stage using feature extraction methods in conjunction with neural networks. Feature extraction transforms the ROIs using filtering and binning algorithms to create feature vectors. A feed forward back propagation neural network (NN) is then trained to classify each feature vector and remove false positives. This paper discusses the test of the system performance and parameter optimizations process which adapts the system to various targets and datasets. The test results show that the system was successful in substantially reducing the false positive rate when tested on a sonar image dataset.

  4. Model Reduction of Nonlinear Aeroelastic Systems Experiencing Hopf Bifurcation

    KAUST Repository

    Abdelkefi, Abdessattar

    2013-06-18

    In this paper, we employ the normal form to derive a reduced - order model that reproduces nonlinear dynamical behavior of aeroelastic systems that undergo Hopf bifurcation. As an example, we consider a rigid two - dimensional airfoil that is supported by nonlinear springs in the pitch and plunge directions and subjected to nonlinear aerodynamic loads. We apply the center manifold theorem on the governing equations to derive its normal form that constitutes a simplified representation of the aeroelastic sys tem near flutter onset (manifestation of Hopf bifurcation). Then, we use the normal form to identify a self - excited oscillator governed by a time - delay ordinary differential equation that approximates the dynamical behavior while reducing the dimension of the original system. Results obtained from this oscillator show a great capability to predict properly limit cycle oscillations that take place beyond and above flutter as compared with the original aeroelastic system.

  5. The degenerate C. Neumann system I: symmetry reduction and convexity

    NARCIS (Netherlands)

    Dullin, H.R.; Hanssmann, H.|info:eu-repo/dai/nl/107757435

    2012-01-01

    The C. Neumann system describes a particle on the sphere Sn under the influence of a potential that is a quadratic form. We study the case that the quadratic form has ` +1 distinct eigenvalues with multiplicity. Each group of m equal eigenvalues gives rise to an O(m )-symmetry in configuration

  6. Structure-preserving tangential interpolation for model reduction of port-Hamiltonian systems

    NARCIS (Netherlands)

    Gugercin, Serkan; Polyuga, Rostyslav V.; Beattie, Christopher; Schaft, Arjan van der

    Port-Hamiltonian systems result from port-based network modeling of physical systems and are an important example of passive state-space systems. In this paper, we develop a framework for model reduction of large-scale multi-input/multi-output port-Hamiltonian systems via tangential rational

  7. Determination of Turboprop Reduction Gearbox System Fatigue Life and Reliability

    Science.gov (United States)

    Zaretsky, Erwin V.; Lewicki, David G.; Savage, Michael; Vlcek, Brian L.

    2007-01-01

    Two computational models to determine the fatigue life and reliability of a commercial turboprop gearbox are compared with each other and with field data. These models are (1) Monte Carlo simulation of randomly selected lives of individual bearings and gears comprising the system and (2) two-parameter Weibull distribution function for bearings and gears comprising the system using strict-series system reliability to combine the calculated individual component lives in the gearbox. The Monte Carlo simulation included the virtual testing of 744,450 gearboxes. Two sets of field data were obtained from 64 gearboxes that were first-run to removal for cause, were refurbished and placed back in service, and then were second-run until removal for cause. A series of equations were empirically developed from the Monte Carlo simulation to determine the statistical variation in predicted life and Weibull slope as a function of the number of gearboxes failed. The resultant L(sub 10) life from the field data was 5,627 hr. From strict-series system reliability, the predicted L(sub 10) life was 774 hr. From the Monte Carlo simulation, the median value for the L(sub 10) gearbox lives equaled 757 hr. Half of the gearbox L(sub 10) lives will be less than this value and the other half more. The resultant L(sub 10) life of the second-run (refurbished) gearboxes was 1,334 hr. The apparent load-life exponent p for the roller bearings is 5.2. Were the bearing lives to be recalculated with a load-life exponent p equal to 5.2, the predicted L(sub 10) life of the gearbox would be equal to the actual life obtained in the field. The component failure distribution of the gearbox from the Monte Carlo simulation was nearly identical to that using the strict-series system reliability analysis, proving the compatibility of these methods.

  8. Reduction and power losses in transmission and distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, J.I.; Reed, J.H.; Reddoch, T.W.

    1988-08-30

    The very real power crisis in many developing countries calls for both innovativeness and efficiency in meeting the needs for electric power posed by social and economic development. One of the key elements in such a strategy is improving the efficiency of electricity transmission and distribution (in other words, reducing unnecessary losses in these parts of a power system). United Nations data, self-reported by individual countries, suggest that average losses in transmission and distribution systems across the region are about 13%. Other data, however, indicate that losses in many countries are on the order of 50% higher than the UN figures; for example, recent data suggest that losses in one country within the region are more than 30%. 22 refs., 8 figs., 3 tabs.

  9. Engine Systems Ownership Cost Reduction - Aircraft Propulsion Subsystems Integration (APSI)

    Science.gov (United States)

    1975-08-01

    4343 A Figure 4.2.10--1. Comparison of Cas Flowpath for Co-Rotating Versus Counter- Rotating Engine lip and LP Shafts. 100 - - iI Teledyne CAE Report...requirement for an oil reservoir. In the case of the expendable oil system, the oil mist from the lip turbine bearing would be dumped into the LI’ turbine...span bumper bearing to alter the shaft critical speed. Using the cost and weight studies performed on the baseline engine and scaled versions of half

  10. Evaluation of the noise reduction system in a commercial digital hearing aid.

    Science.gov (United States)

    Alcántara, José L; Moore, Brian C J; Kühnel, Volker; Launer, Stefan

    2003-01-01

    We evaluated the effectiveness of a noise reduction system implemented in a commercial digital multichannel compression hearing aid. Eight experienced hearing aid wearers with moderate sensorineural hearing loss were fitted bilaterally according to the manufacturer's fitting guidelines. After a 3-month period of regular use of two programs, one with and one without the noise reduction system, speech recognition thresholds (SRTs) were measured in four types of background noise, including steady noise, and noises with spectral and/or temporal dips. SRTs were very similar with and without the noise reduction system; in both cases, SRTs were markedly lower than for unaided listening. SRTs were lower for the noises with dips than for the steady noise, especially for the aided conditions, indicating that amplification can help to 'listen in the dips'. Ratings of sound quality and listening comfort in the aided conditions were uniformly high and very similar with and without the noise reduction system.

  11. An Air Quality Data Analysis System for Interrelating Effects, Standards and Needed Source Reductions

    Science.gov (United States)

    Larsen, Ralph I.

    1973-01-01

    Makes recommendations for a single air quality data system (using average time) for interrelating air pollution effects, air quality standards, air quality monitoring, diffusion calculations, source-reduction calculations, and emission standards. (JR)

  12. Reduction of background clutter in structured lighting systems

    Science.gov (United States)

    Carlson, Jeffrey J.; Giles, Michael K.; Padilla, Denise D.; Davidson, Jr., Patrick A.; Novick, David K.; Wilson, Christopher W.

    2010-06-22

    Methods for segmenting the reflected light of an illumination source having a characteristic wavelength from background illumination (i.e. clutter) in structured lighting systems can comprise pulsing the light source used to illuminate a scene, pulsing the light source synchronously with the opening of a shutter in an imaging device, estimating the contribution of background clutter by interpolation of images of the scene collected at multiple spectral bands not including the characteristic wavelength and subtracting the estimated background contribution from an image of the scene comprising the wavelength of the light source and, placing a polarizing filter between the imaging device and the scene, where the illumination source can be polarized in the same orientation as the polarizing filter. Apparatus for segmenting the light of an illumination source from background illumination can comprise an illuminator, an image receiver for receiving images of multiple spectral bands, a processor for calculations and interpolations, and a polarizing filter.

  13. Creating Scenarios for Seismic Risk Reduction Using Geographic Information Systems

    Directory of Open Access Journals (Sweden)

    Florin Leon

    2007-01-01

    Full Text Available This paper presents a GIS-based methodology for monitoring the seismic performance, while taking into account the deteriorations revealed during GIS-based scenarios aiming at the identification of the seismic serviceability of the structure. By applying the geographical information system (GIS containing geo-spatial data, one can develop useful scenarios to improve the knowledge of structural vulnerability of the urban built infrastructure. Scenarios of modelling, simulation and non-linear seismic analysis are described and applied to a class of damaged models for some of the structures typical of the existing urban infrastructure of Jassy, Romania. The management of GIS-based seismic vulnerability of existing concrete structure is presented as a tool for awareness and mitigation of seismic effects of possible future events in the urban area.

  14. Frequency Weighted Model Order Reduction Technique and Error Bounds for Discrete Time Systems

    Directory of Open Access Journals (Sweden)

    Muhammad Imran

    2014-01-01

    for whole frequency range. However, certain applications (like controller reduction require frequency weighted approximation, which introduce the concept of using frequency weights in model reduction techniques. Limitations of some existing frequency weighted model reduction techniques include lack of stability of reduced order models (for two sided weighting case and frequency response error bounds. A new frequency weighted technique for balanced model reduction for discrete time systems is proposed. The proposed technique guarantees stable reduced order models even for the case when two sided weightings are present. Efficient technique for frequency weighted Gramians is also proposed. Results are compared with other existing frequency weighted model reduction techniques for discrete time systems. Moreover, the proposed technique yields frequency response error bounds.

  15. Waste reduction possibilities for manufacturing systems in the industry 4.0

    Science.gov (United States)

    Tamás, P.; Illés, B.; Dobos, P.

    2016-11-01

    The industry 4.0 creates some new possibilities for the manufacturing companies’ waste reduction for example by appearance of the cyber physical systems and the big data concept and spreading the „Internet of things (IoT)”. This paper presents in details the fourth industrial revolutions’ more important achievements and tools. In addition there will be also numerous new research directions in connection with the waste reduction possibilities of the manufacturing systems outlined.

  16. The Belle II PXD data acquisition and reduction system

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Soeren; Gessler, Thomas; Kuehn, Wolfgang; Muenchow, David; Spruck, Bjoern [Giessen Univ. (Germany). 2. Physikalisches Inst.; Lin, Haichuan; Liu, Zhen-An; Xu, Hao; Zhao, Jingzhou [IHEP Beijing (China); Collaboration: Belle II Collaboration

    2013-07-01

    The Belle II DEPFET pixel detector (PXD) will deliver high data rates of up to 21.6 Gbytes/s for 3% detector occupancy. Data of this high rate must be buffered for 5 seconds, corresponding to the HLT (High Level Trigger) latency, and then a region-of-interest (ROI) filter is applied to reduce the data rate by a factor of ≥10 by charged track extrapolation from other detectors (SVD, CDC). The PXD readout system is based upon ATCA (Advanced Telecommunications Architecture). The 3rd PCB iteration uses a concept with a xTCA carrier board (with a Virtex-4 FX60 FPGA for ATCA backplane routing) and 4 AMC modules (each with a Xilinx Virtex-5 FX70T FPGA). The FPGA firmware implementation comprises a receiver core for the high speed optical links (≤6.25 Gbps), a buffer management with lookup of ≤270.000 pointers/s, DDR2 memory write (native port interface, ≥1.5 Gbytes/s), Gigabit ethernet (UDP stack in VHDL) and a parallelized ROI selection algorithm. Test results of all the components are presented.

  17. Specification, construction, and exact reduction of state transition system models of biochemical processes.

    Science.gov (United States)

    Bugenhagen, Scott M; Beard, Daniel A

    2012-10-21

    Biochemical reaction systems may be viewed as discrete event processes characterized by a number of states and state transitions. These systems may be modeled as state transition systems with transitions representing individual reaction events. Since they often involve a large number of interactions, it can be difficult to construct such a model for a system, and since the resulting state-level model can involve a huge number of states, model analysis can be difficult or impossible. Here, we describe methods for the high-level specification of a system using hypergraphs, for the automated generation of a state-level model from a high-level model, and for the exact reduction of a state-level model using information from the high-level model. Exact reduction is achieved through the automated application to the high-level model of the symmetry reduction technique and reduction by decomposition by independent subsystems, allowing potentially significant reductions without the need to generate a full model. The application of the method to biochemical reaction systems is illustrated by models describing a hypothetical ion-channel at several levels of complexity. The method allows for the reduction of the otherwise intractable example models to a manageable size.

  18. Stiction, friction, and wear reduction in silicon microelectromechanical systems

    Science.gov (United States)

    Mantiziba, Fadziso Mabel

    Current reliability issues in silicon based microelectromechanical systems (MEMS) pose a challenge in the advancement of this pervasive technology. Silicon Microsystems are encumbered with adhesion induced catastrophic failures (stiction) during the final fabrication step where a wet chemical etch release is often conducted to produce functional, suspended microstructures. Irreversible adhesion of active device layer components to the substrate can drastically reduce yields of fully functional devices. Potential in-use problems of a tribological nature also limit the reliability and device lifetimes of these microstructures, particularly where intermittent or continuous contacting of surfaces occurs during a device's normal operation. Understanding the fundamental tribological properties such as friction coefficients and wear mechanisms that occur in the normal operation of these devices is a necessity in providing potential long term solutions to such reliability issues. A unique, simple, yet inexpensive solution to release related adhesion failures that utilizes a temporary physical barrier during the final rinsing stage of a typical silicon wet etch release process is presented. This temporary barrier is accomplished using polystyrene microspheres that prevent contact between the substrate and the components of the suspended device layer during drying. The microspheres are subsequently removed using a plasma etching process. Improvement of yields of stiction-free, functional devices >90% in comparison to rinse liquids have been demonstated using this process. To address tribological reliability issues for silicon MEMS, friction testing devices are utilized to measure the friction coefficients of silicon. Thin ceramic coatings of oxides of aluminum, zirconium, or titanium are applied to the silicon MEMS devices using the atomic layer deposition technique and tested for comparison to non-coated silicon surfaces. Testing conducted under controlled humidity shows

  19. Attribute Reduction Algorithm Based on Structure Discernibility Matrix in Composite Information Systems

    Directory of Open Access Journals (Sweden)

    Ge Mei-Jun

    2017-01-01

    Full Text Available Attribute reduction, as an important preprocessing step for knowledge acquiring in data mining, is one of the key issues in rough set theory. It can only deal with attributes of a specific type in the information system by using a specific binary relation. However, there may be attributes of multiple different types in information systems in real-life applications. A composite relation is proposed to process attributes of multiple different types simultaneously in composite information systems. In order to solve the time-consuming problem of traditional heuristic attribute reduction algorithms, a novel attribute reduction algorithm based on structure discernibility matrix was proposed in this paper. The proposed algorithms can choose the same attribute reduction as its previous version, but it can be used to accelerate a heuristic process of attribute reduction by avoiding the process of intersection and adopting the forward greedy attribute reduction approach. The theoretical analysis and experimental results with UCI data sets show that the proposed algorithm can accelerate the heuristic process of attribute reduction.

  20. Optimizing Blocking and Nonblocking Reduction Operations for Multicore Systems: Hierarchical Design and Implementation

    Energy Technology Data Exchange (ETDEWEB)

    Gorentla Venkata, Manjunath [ORNL; Shamis, Pavel [ORNL; Graham, Richard L [ORNL; Ladd, Joshua S [ORNL; Sampath, Rahul S [ORNL

    2013-01-01

    Many scientific simulations, using the Message Passing Interface (MPI) programming model, are sensitive to the performance and scalability of reduction collective operations such as MPI Allreduce and MPI Reduce. These operations are the most widely used abstractions to perform mathematical operations over all processes that are part of the simulation. In this work, we propose a hierarchical design to implement the reduction operations on multicore systems. This design aims to improve the efficiency of reductions by 1) tailoring the algorithms and customizing the implementations for various communication mechanisms in the system 2) providing the ability to configure the depth of hierarchy to match the system architecture, and 3) providing the ability to independently progress each of this hierarchy. Using this design, we implement MPI Allreduce and MPI Reduce operations (and its nonblocking variants MPI Iallreduce and MPI Ireduce) for all message sizes, and evaluate on multiple architectures including InfiniBand and Cray XT5. We leverage and enhance our existing infrastructure, Cheetah, which is a framework for implementing hierarchical collective operations to implement these reductions. The experimental results show that the Cheetah reduction operations outperform the production-grade MPI implementations such as Open MPI default, Cray MPI, and MVAPICH2, demonstrating its efficiency, flexibility and portability. On Infini- Band systems, with a microbenchmark, a 512-process Cheetah nonblocking Allreduce and Reduce achieves a speedup of 23x and 10x, respectively, compared to the default Open MPI reductions. The blocking variants of the reduction operations also show similar performance benefits. A 512-process nonblocking Cheetah Allreduce achieves a speedup of 3x, compared to the default MVAPICH2 Allreduce implementation. On a Cray XT5 system, a 6144-process Cheetah Allreduce outperforms the Cray MPI by 145%. The evaluation with an application kernel, Conjugate

  1. Switched Systems Reduction Framework Based on Convex Combination of Generalized Gramians

    Directory of Open Access Journals (Sweden)

    Hamid Reza Shaker

    2009-01-01

    Full Text Available A general method for model-order reduction of switched linear dynamical systems is presented. The proposed technique uses convex generalized gramian which is a convex combination of the generalized gramians. It is shown that different classical reduction methods can be developed into the generalized gramian framework for model reduction of linear systems and further for the reduction of switched systems by construction of the convex generalized gramian. Balanced reduction within specified frequency bound is taken as an example which is developed within this framework. In order to avoid numerical instability and also to increase the numerical efficiency, convex generalized gramian-based Petrov-Galerkin projection is constructed instead of the similarity transform approach for reduction. It is proven that the method preserves the stability of the original switched system at least for stabilizing switching signal and it is also less conservative than the method which is based on the common generalized gramian. Some discussions on the coefficient of the vertices of the convex variables are presented. The performance of the proposed method is illustrated by numerical examples.

  2. System Response Analysis and Model Order Reduction, Using Conventional Method, Bond Graph Technique and Genetic Programming

    Directory of Open Access Journals (Sweden)

    Lubna Moin

    2009-04-01

    Full Text Available This research paper basically explores and compares the different modeling and analysis techniques and than it also explores the model order reduction approach and significance. The traditional modeling and simulation techniques for dynamic systems are generally adequate for single-domain systems only, but the Bond Graph technique provides new strategies for reliable solutions of multi-domain system. They are also used for analyzing linear and non linear dynamic production system, artificial intelligence, image processing, robotics and industrial automation. This paper describes a unique technique of generating the Genetic design from the tree structured transfer function obtained from Bond Graph. This research work combines bond graphs for model representation with Genetic programming for exploring different ideas on design space tree structured transfer function result from replacing typical bond graph element with their impedance equivalent specifying impedance lows for Bond Graph multiport. This tree structured form thus obtained from Bond Graph is applied for generating the Genetic Tree. Application studies will identify key issues and importance for advancing this approach towards becoming on effective and efficient design tool for synthesizing design for Electrical system. In the first phase, the system is modeled using Bond Graph technique. Its system response and transfer function with conventional and Bond Graph method is analyzed and then a approach towards model order reduction is observed. The suggested algorithm and other known modern model order reduction techniques are applied to a 11th order high pass filter [1], with different approach. The model order reduction technique developed in this paper has least reduction errors and secondly the final model retains structural information. The system response and the stability analysis of the system transfer function taken by conventional and by Bond Graph method is compared and

  3. Physical chemistry of catalytic reduction of nitroarenes using various nanocatalytic systems: past, present, and future

    Energy Technology Data Exchange (ETDEWEB)

    Begum, Robina [University of the Punjab, Centre for Undergraduate Studies (Pakistan); Rehan, Rida; Farooqi, Zahoor H., E-mail: zhfarooqi@gmail.com; Butt, Zonarah; Ashraf, Sania [University of the Punjab, Institute of Chemistry (Pakistan)

    2016-08-15

    The catalytic reduction of nitroarenes under various catalytic systems has been widely reported in the flood of publications during last twenty years. This reaction has become a benchmark for testing catalytic activity of inorganic nanoparticles stabilized in various systems. This tutorial review presents design and classification of inorganic nanocatalysts along with their stabilizing agents used for catalytic reduction of nitroarenes. The techniques used for characterization of catalysts have been highlighted in this review. The mechanism of catalytic reduction has been described in a tutorial way. Factors affecting the rate of reduction of nitroarenes in the presence of metal nanoparticles stabilized in polyelectrolyte brushes, polyionic liquids, micelles, dendrimers, and microgels have been discussed for further development in this area.Graphical abstract.

  4. POD-DEIM APPROACH ON DIMENSION REDUCTION OF A MULTI-SPECIES HOST-PARASITOID SYSTEM

    Directory of Open Access Journals (Sweden)

    Gabriel Dimitriu

    2015-07-01

    Full Text Available In this study, we implement the DEIM algorithm (Discrete Empirical Interpolation Method combined with POD (Proper Orthogonal Decomposition to provide dimension reduction of a model describing the aggregative response of parasitoids to hosts in a coupled multi-species system. The model is defined by five reaction-diffusionchemotaxis equations. We show DEIM improves the efficiency of the POD approximation and achieves a complexity reduction of the nonlinear terms. Numerical results are presented.

  5. Highly selective NOx reduction for diesel engine exhaust via an electrochemical system

    DEFF Research Database (Denmark)

    Shao, Jing; Tao, Youkun; Kammer Hansen, Kent

    2016-01-01

    in current diesel after-treatment techniques. The electrochemical system consisted of an electrochemical cell modified with NOx adsorbents and a diesel oxidation catalyst placed upstream of the cell. The system offers highly selective NOx reduction and a strong resistance to oxygen interference with almost...... zero emission of secondary pollutants....

  6. Rash with DERMABOND PRINEO Skin Closure System Use in Bilateral Reduction Mammoplasty: A Case Series

    Directory of Open Access Journals (Sweden)

    R. W. Knackstedt

    2015-01-01

    Full Text Available Background. Bilateral reduction mammoplasty is a common plastic surgery procedure that can be complicated by unfavorable scar formation along incision sites. Surgical adhesives can be utilized as an alternative or as an adjunct to conventional suture closures to help achieve good wound tension and provide an adequate barrier with excellent cosmesis. The recently introduced DERMABOND PRINEO Skin Closure System Skin Closure System combines the skin adhesive 2-octyl cyanoacrylate with a self-adhering polyester-based mesh. Proposed benefits of wound closure with DERMABOND PRINEO Skin Closure System, used with or without sutures, include its watertight seal, easy removal, microbial barrier, even distribution of tension, and reduction in wound closure time. Although allergic reactions to 2-octyl cyanoacrylate have been reported, few allergic reactions to DERMABOND PRINEO Skin Closure System have been noted in the literature. This case series describes three patients who experienced an allergic reaction to DERMABOND PRINEO Skin Closure System after undergoing elective bilateral reduction mammoplasties at our institution to further explore this topic. Methods. Retrospective chart review of bilateral reduction mammoplasty patients who received DERMABOND PRINEO Skin Closure System dressing at our institution was performed. Results. Three patients were identified as having a rash in reaction to DERMABOND PRINEO Skin Closure System after bilateral reduction mammoplasty. All three patients required systemic steroid treatment to resolve the rash. One patient was identified as having a prior adhesive reaction. Conclusions. DERMABOND PRINEO Skin Closure System has demonstrated its efficacy in optimizing scar healing and appearance. However, as we demonstrate these three allergic reactions to DERMABOND PRINEO Skin Closure System, caution must be utilized in its usage, namely, in patients with a prior adhesive allergy and in sites where moisture or friction may

  7. Comparative performance of an adaptive directional microphone system and a multichannel noise reduction system.

    Science.gov (United States)

    Yuen, Kevin C P; Kam, Anna C S; Lau, Polly S H

    2006-04-01

    The amplification outcomes of two hearing aid prescriptions, NAL-NL1 and Digital Perception Processing (DPP), of nine moderate to moderately severe hearing-impaired adults were compared in the same digital hearing instrument. NAL-NL1 aims at optimizing speech intelligibility while amplifying the speech signal to a normal overall loudness level (Dillon, 1999). DPP focuses on restoring loudness based on normal and impaired cochlear excitation models (Launer and Moore, 2003). In this comparison, DPP resulted in better sentence recognition performance than the NAL-NL1 algorithm in the signal-front/noise-side condition, and the two prescriptions gave similar performance in the signal-front/noise-front condition. Subjective evaluations by the participants using the Abbreviated Profile for Hearing Aid Benefit and sound quality comparisons did not give conclusive results between the two prescriptions. With each hearing aid prescription, the ability of the hearing aid circuitry to reduce the effects of noise was evaluated by a sentence-in-noise test in three conditions: (1) adaptive directional microphone (DAZ), (2) multichannel noise reduction system (FNC), and (3) a combination of FNC and DAZ (FNC + DAZ). In the signal-front/noise-side condition, DAZ and FNC + DAZ gave better performance than FNC in nearly all participants, whereas in the signal-front and noise-front evaluation, the conditions revealed no significant differences.

  8. Numerical analysis of NOx reduction for compact design in marine urea-SCR system

    Directory of Open Access Journals (Sweden)

    Cheolyong Choi

    2015-11-01

    Full Text Available In order to design a compact urea selective catalytic reduction system, numerical simulation was conducted by computational fluid dynamics tool. A swirl type static mixer and a mixing chamber were considered as mixing units in the system. It had great influence on flow characteristics and urea decomposition into ammonia. The mixer caused flow recirculation and high level of turbulence intensity, and the chamber increased residence time of urea- water-solution injected. Because of those effects, reaction rates of urea decomposition were enhanced in the region. When those mixing units were combined, it showed the maximum because the recirculation zone was significantly developed. NH3 conversion was maximized in the zone due to widely distributed turbulence intensity and high value of uniformity index. It caused improvement of NOx reduction efficiency of the system. It was possible to reduce 55% length of the chamber and connecting pipe without decrease of NOx reduction efficiency.

  9. Numerical analysis of NOx reduction for compact design in marine urea-SCR system

    Science.gov (United States)

    Choi, Cheolyong; Sung, Yonmo; Choi, Gyung Min; Kim, Duck Jool

    2015-11-01

    In order to design a compact urea selective catalytic reduction system, numerical simulation was conducted by computational fluid dynamics tool. A swirl type static mixer and a mixing chamber were considered as mixing units in the system. It had great influence on flow characteristics and urea decomposition into ammonia. The mixer caused flow recirculation and high level of turbulence intensity, and the chamber increased residence time of urea-water-solution injected. Because of those effects, reaction rates of urea decomposition were enhanced in the region. When those mixing units were combined, it showed the maximum because the recirculation zone was significantly developed. NH3 conversion was maximized in the zone due to widely distributed turbulence intensity and high value of uniformity index. It caused improvement of NOx reduction efficiency of the system. It was possible to reduce 55% length of the chamber and connecting pipe without decrease of NOx reduction efficiency.

  10. Quantitative Cyber Risk Reduction Estimation Methodology for a Small Scada Control System

    Energy Technology Data Exchange (ETDEWEB)

    Miles A. McQueen; Wayne F. Boyer; Mark A. Flynn; George A. Beitel

    2006-01-01

    We propose a new methodology for obtaining a quick quantitative measurement of the risk reduction achieved when a control system is modified with the intent to improve cyber security defense against external attackers. The proposed methodology employs a directed graph called a compromise graph, where the nodes represent stages of a potential attack and the edges represent the expected time-to-compromise for differing attacker skill levels. Time-to-compromise is modeled as a function of known vulnerabilities and attacker skill level. The methodology was used to calculate risk reduction estimates for a specific SCADA system and for a specific set of control system security remedial actions. Despite an 86% reduction in the total number of vulnerabilities, the estimated time-to-compromise was increased only by about 3 to 30% depending on target and attacker skill level.

  11. Water splitting-biosynthetic system with CO₂ reduction efficiencies exceeding photosynthesis.

    Science.gov (United States)

    Liu, Chong; Colón, Brendan C; Ziesack, Marika; Silver, Pamela A; Nocera, Daniel G

    2016-06-03

    Artificial photosynthetic systems can store solar energy and chemically reduce CO2 We developed a hybrid water splitting-biosynthetic system based on a biocompatible Earth-abundant inorganic catalyst system to split water into molecular hydrogen and oxygen (H2 and O2) at low driving voltages. When grown in contact with these catalysts, Ralstonia eutropha consumed the produced H2 to synthesize biomass and fuels or chemical products from low CO2 concentration in the presence of O2 This scalable system has a CO2 reduction energy efficiency of ~50% when producing bacterial biomass and liquid fusel alcohols, scrubbing 180 grams of CO2 per kilowatt-hour of electricity. Coupling this hybrid device to existing photovoltaic systems would yield a CO2 reduction energy efficiency of ~10%, exceeding that of natural photosynthetic systems. Copyright © 2016, American Association for the Advancement of Science.

  12. A system dynamics-based environmental performance simulation of construction waste reduction management in China.

    Science.gov (United States)

    Ding, Zhikun; Yi, Guizhen; Tam, Vivian W Y; Huang, Tengyue

    2016-05-01

    A huge amount of construction waste has been generated from increasingly higher number of construction activities than in the past, which has significant negative impacts on the environment if they are not properly managed. Therefore, effective construction waste management is of primary importance for future sustainable development. Based on the theory of planned behaviors, this paper develops a system dynamic model of construction waste reduction management at the construction phase to simulate the environmental benefits of construction waste reduction management. The application of the proposed model is shown using a case study in Shenzhen, China. Vensim is applied to simulate and analyze the model. The simulation results indicate that source reduction is an effective waste reduction measure which can reduce 27.05% of the total waste generation. Sorting behaviors are a premise for improving the construction waste recycling and reuse rates which account for 15.49% of the total waste generated. The environmental benefits of source reduction outweigh those of sorting behaviors. Therefore, to achieve better environmental performance of the construction waste reduction management, attention should be paid to source reduction such as low waste technologies and on-site management performance. In the meantime, sorting behaviors encouragement such as improving stakeholders' waste awareness, refining regulations, strengthening government supervision and controlling illegal dumping should be emphasized. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. A 2+1-Dimensional Non-Isothermal Magnetogasdynamic System. Hamiltonian-Ermakov Integrable Reduction

    Directory of Open Access Journals (Sweden)

    Hongli An

    2012-08-01

    Full Text Available A 2+1-dimensional anisentropic magnetogasdynamic system with a polytropic gas law is shown to admit an integrable elliptic vortex reduction when γ=2 to a nonlinear dynamical subsystem with underlying integrable Hamiltonian-Ermakov structure. Exact solutions of the magnetogasdynamic system are thereby obtained which describe a rotating elliptic plasma cylinder. The semi-axes of the elliptical cross-section, remarkably, satisfy a Ermakov-Ray-Reid system.

  14. Capabilities Engineering:Promoting Change-Reduction and Constructing Change-Tolerant Systems

    OpenAIRE

    Ravichandar, Ramya

    2008-01-01

    We propose a Capabilities-based approach for constructing complex emergent systems such that they are change-tolerant, and the development effort promotes change-reduction. The inherent complexity of software systems increases their susceptibility to change when subjected to the vagaries of user needs, technology advances, market demands and other change inducing factors. Despite the inevitability of change, traditional Requirements Engineering strives to develop systems based on a fixed solu...

  15. An incremental approach to obtaining attribute reduction for dynamic decision systems

    Directory of Open Access Journals (Sweden)

    Wenjun Liu

    2016-01-01

    Full Text Available In the 1960s Professor Hu Guoding proposed a method of measuring information based on the idea that connotation and denotation of a concept satisfies inverse ratio rule. According to this information measure, firstly we put forward the information quantity for information systems and decision systems; then, we discuss the updating mechanism of information quantity for decision systems; finally, we give an attribute reduction algorithm for decision tables with dynamically varying attribute values.

  16. The longview diesel emission control system : emissions performance of a combined DPF and NOx reduction catalyst system

    Energy Technology Data Exchange (ETDEWEB)

    Edgar, B.; Streichsbier, M. [Cleaire Advanced Emissions Controls, San Leandro, CA (United States)]|[Cummins Emissions Solutions, Memphis, TN (United States)

    2006-07-01

    Diesel engines operating in underground mines must be equipped with diesel particulate filters (DPFs) to control particulate matter (PM). Although wall flow filters offer the desired levels of PM/EC control, the use of precious metals as part of the regeneration strategy has an adverse impact on nitrogen dioxide (NO{sub 2}) formation. Therefore, the reductions in PM/EC are offset by increases in NO{sub 2}. This study presented a new system that offers the benefits of a passive regeneration system without the disadvantage of high NO{sub 2} formation. The Longview{sup R} system was initially developed for above ground mine facilities concerned with PM and ozone levels. The system combines HC-SCR with catalyzed DPF to reduce nitrogen oxides, particulate matter, carbon monoxide and hydrocarbons. HC-SCR refers to active hydrocarbon dosing upstream of a NOx reduction catalyst. This paper presented details of the system design features as well as emission performance test results. The impact of fuel sulfur level on emissions was also investigated at a Cummins test laboratory. The cycle averaged emissions from the Longview system using ULSD were a 40 per cent reduction in NOx; a 50 per cent reduction in NO{sub 2}; nearly a complete removal of CO; and, a 5 per cent increase in CO{sub 2}. It was determined that the system's fuel injection and NOx reduction catalysts play an important role in NO, NO{sub 2} and NOx emissions. The catalyzed PDF plays an important role in CO, HC and PM reductions. The Longview system is currently being tested in underground mining field trials. tabs., figs.

  17. ON THE PAPR REDUCTION IN OFDM SYSTEMS: A NOVEL ZCT PRECODING BASED SLM TECHNIQUE

    Directory of Open Access Journals (Sweden)

    VARUN JEOTI

    2011-06-01

    Full Text Available High Peak to Average Power Ratio (PAPR reduction is still an important challenge in Orthogonal Frequency Division Multiplexing (OFDM systems. In this paper, we propose a novel Zadoff-Chu matrix Transform (ZCT precoding based Selected Mapping (SLM technique for PAPR reduction in OFDM systems. This technique is based on precoding the constellation symbols with ZCT precoder after the multiplication of phase rotation factor and before the Inverse Fast Fourier Transform (IFFT in the SLM based OFDM (SLM-OFDM Systems. Computer simulation results show that, the proposed technique can reduce PAPR up to 5.2 dB for N=64 (System subcarriers and V=16 (Dissimilar phase sequences, at clip rate of 10-3. Additionally, ZCT based SLM-OFDM (ZCT-SLM-OFDM systems also take advantage of frequency variations of the communication channel and can also offer substantial performance gain in fading multipath channels.

  18. Comparison of SHR Mode IPL System with Alexandrite and Nd: YAG Lasers For Leg Hair Reduction

    Directory of Open Access Journals (Sweden)

    Şemsettin Karaca

    2012-12-01

    Full Text Available Objective: Multiple lasers and light sources are currently available for hair removal and many studies comparing efficacy and safety exist. SHR mode IPL is a technique that gives the total energy in divided doses with fewer side effects. We compared a SHR mode IPL system with alexandrite and Nd: YAG lasers for leg hair reductionMaterial and Methods: Twenty-five female participants with skin types II–IV, underwent treatment of unwanted hair on the cruris. Three selected areas were randomly treated with the SHR mode IPL system, Alexandrite laser and Nd: YAG laser in three sessions. Hair reduction was evaluated with digital photography by a blinded assessor every 6 weeks and 6 months after the last session. Pain severity, side effects and patient satisfaction analysis were also investigated. Results: Twenty-one participants completed the trial. The mean hair reductions in 6 weeks after the last treatment were 50% for the IPL system, 53% for Alexandrite and 39% for the Nd: YAG lasers. However after 6 months; 40%, 49% and 34% hair reduction was observed, respectively. The Alexandrite laser was the least painful system. Conclusion: Although there is no obvious advantage of one laser system over the others in terms of treatment outcome, the Alexandrite laser is still the most efficient and reliable way of hair removal in fair skinned individuals.

  19. Comparison of SHR Mode IPL System with Alexandrite and Nd: YAG Lasers For Leg Hair Reduction.

    Science.gov (United States)

    Karaca, Semsettin; Kaçar, Seval Doğruk; Ozuğuz, Pınar

    2012-12-01

    Multiple lasers and light sources are currently available for hair removal and many studies comparing efficacy and safety exist. SHR mode IPL is a technique that gives the total energy in divided doses with fewer side effects. We compared a SHR mode IPL system with alexandrite and Nd: YAG lasers for leg hair reduction. Twenty-five female participants with skin types II-IV, underwent treatment of unwanted hair on the cruris. Three selected areas were randomly treated with the SHR mode IPL system, Alexandrite laser and Nd: YAG laser in three sessions. Hair reduction was evaluated with digital photography by a blinded assessor every 6 weeks and 6 months after the last session. Pain severity, side effects and patient satisfaction analysis were also investigated. Twenty-one participants completed the trial. The mean hair reductions in 6 weeks after the last treatment were 50% for the IPL system, 53% for Alexandrite and 39% for the Nd: YAG lasers. However after 6 months; 40%, 49% and 34% hair reduction was observed, respectively. The Alexandrite laser was the least painful system. Although there is no obvious advantage of one laser system over the others in terms of treatment outcome, the Alexandrite laser is still the most efficient and reliable way of hair removal in fair skinned individuals.

  20. On Bit Rate Reduction of Inter-Channel Communication for a Binaural Hearing Assistance System

    Science.gov (United States)

    Chisaki, Yoshifumi; Kawano, Ryouji; Usagawa, Tsuyoshi

    A binaural hearing assistance system based on the frequency domain binaural model has been previously proposed. The system can enhance a signal coming from a specific direction. Since the system utilizes a binaural signal, an inter-channel communication between left and right subsystems is required. The bit rate reduction in inter-channel communication is essential for the detachment of the headset from the processing system. In this paper, the performance of a system which uses a differential pulse code modulation codec is examined and the relationship between the bit rate and sound quality is discussed.

  1. Disaster Risk Reduction and Climate Change Adaptation—A Sustainable Development Systems Perspective

    Directory of Open Access Journals (Sweden)

    Tom R. Burns

    2017-02-01

    Full Text Available This article considers the concepts of sustainability and sustainable development in relation to disaster risk reduction and climate change adaptation. We conceptualize sustainability from a social systemic perspective, that is, from a perspective that encompasses the multiple functionalities of a social system and their interrelationships in particular environmental contexts. The systems perspective is applied in our consideration and analysis of disaster risk reduction (DRR, climate change adaptation (CCA, and sustainable development (SD. Section “Sustainability and Sustainable Development” introduces briefly sustainability and sustainable development, followed by a brief presentation of the theory of complex social systems (Section “Social System Model”. The theory conceptualizes interdependent subsystems, their multiple functionalities, and the agential and systemic responses to internal and external stressors on a social system. Section “Case Studies of Response to Stressors” considers disaster risk reduction (DRR and climate change adaptation (CCA, emerging in response to one or more systemic stressors. It illustrates these with disaster risk reduction in the cases of food and chemical security regulation in the EU. CCA is illustrated by initiatives and developments on the island of Gotland, Sweden and in the Gothenburg Metropolitan area, which go beyond a limited CCA perspective, taking into account long-term sustainability issues. Section “Sustainable Development as a Societal Development System” discusses the limitations of DRR and CCA, not only their technical limitations but economic, socio-cultural, and political limitations, as informed from a sustainability perspective. It is argued that DRRs are only partial subsystems and must be considered and assessed in the context of a more encompassing systemic perspective. Part of the discussion is focused on the distinction between sustainable and non-sustainable DRRs and

  2. Dynamic Control System Mode Performance of the Space Technology-7 Disturbance Reduction System

    Science.gov (United States)

    O'Donnell, James R., Jr.; Hsu, Oscar; Maghami, Peiman

    2017-01-01

    The Space Technology-7 (ST-7) Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft, launched on December 3, 2015. DRS consists of three primary components: Colloidal MicroNewton Thrusters (CMNTs), an Integrated Avionics Unit (IAU), and flight-software implementing the Command and Data Handling (C&DH) and Dynamic Control System (DCS) algorithms. The CMNTs were designed to provide thrust from 5 to 30 micro Newton, with thrust controllability and resolution of 0.1 micro Newton and thrust noise of 0.1 micro Newton/(square root of (Hz)) in the measurement band from 1-30 mHz. The IAU hosts the C&DH and DCS flight software, as well as interfaces with both the CMNT electronics and the LISA Pathfinder spacecraft. When in control, the DCS uses star tracker attitude data and capacitive or optically-measured position and attitude information from LISA Pathfinder and the LISA Technology Package (LTP) to control the attitude and position of the spacecraft and the two test masses inside the LTP. After completion of the nominal ESA LISA Pathfinder mission, the DRS experiment was commissioned followed by its nominal mission. DRS operations extended over the next five months, interspersed with station keeping, anomaly resolution, and periods where control was handed back to LISA Pathfinder for them to conduct further experiments. The primary DRS mission ended on December 6, 2016, with the experiment meeting all of its Level 1 requirements. The DCS, developed at the NASA Goddard Space Flight Center, consists of five spacecraft control modes and six test mass control modes, combined into six 'DRS Mission Modes'. Attitude Control and Zero-G were primarily used to control the spacecraft during initial handover and during many of the CMNT characterization experiments. The other Mission Modes, Drag Free Low Force, 18-DOF Transitional, and 18-DOF, were used to provide drag-free control of the spacecraft about the test

  3. Ultrasonic reduction of excess sludge from activated sludge system: energy efficiency improvement via operation optimization.

    Science.gov (United States)

    He, Junguo; Wan, Tian; Zhang, Guangming; Yang, Jing

    2011-01-01

    This paper studied the influences of operational parameters to improve the energy efficiency during 'ultrasonic lysis-cryptic growth' sludge reduction. Subsequent batch reactor with a hydraulic retention time of 8 h was used to treat urban sewage, and ultrasound wave with a specific energy of 20 kWh/kg TS was employed for sludge lysis. A new index, EE, was defined to evaluate the energy efficiency in ultrasonic lysis-cryptic growth sludge reduction system. Results showed that the most important operational parameter was the proportion of sonicated sludge (SP), which determined the energy consumption and significantly impacted the energy efficiency. The upper limit of SP in this study was 30%, beyond which the effluent quality was unacceptable. Higher SP caused heavier sludge reduction but more energy consumption; when SP was 30%, the excess sludge reduction was the greatest (67.6%) and the energy consumption was the highest (0.101 kWh/d). With a given SP, frequent sludge lysis was adverse to sludge reduction. In summary, the recommended conditions for 'ultrasonic lysis-cryptic growth' sludge reduction were SP of 15%, lysis frequency of 1 time/day. Under these conditions, the highest energy efficiency of 0.012 kg TS/kWh was achieved. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Reduction of , -Unsaturated Ketones Using a Zn/NiCl System in ...

    African Journals Online (AJOL)

    NJD

    system in H2O or H2O/EtOH media in the absence or presence of anionic and cationic surfactants have been investigated and have ... Zinc/nickel chloride/H2O, reduction, hydrogenation, surfactants, sodium dodecyl sulphate (SDS), cetyltrimethylammonium ..... cooled to room temperature, saturated with NaCl solution.

  5. Model reduction of second-order network systems using graph clustering

    NARCIS (Netherlands)

    Cheng, Xiaodong; Scherpen, Jacquelien M.A.; Kawano, Yu

    2016-01-01

    A general framework is proposed for structure-preserving model reduction of a second-order network system. The method is based on graph clustering, and a recursive algorithm is proposed to find an appropriate clustering. Behaviors of nodes are interpreted by transfer functions, and the similarities

  6. Balanced Realization and Model Order Reduction for Nonlinear Systems based on Singular Value Analysis

    NARCIS (Netherlands)

    Fujimoto, Kenji; Scherpen, Jacquelien M. A.

    2010-01-01

    This paper discusses balanced realization and model order reduction for both continuous-time and discrete-time general nonlinear systems based on singular value analysis of the corresponding Hankel operators. Singular value analysis clarifies the gain structure of a given nonlinear operator. Here it

  7. Quantitative assessment of resilience of a water supply system under rainfall reduction due to climate change

    Science.gov (United States)

    Amarasinghe, Pradeep; Liu, An; Egodawatta, Prasanna; Barnes, Paul; McGree, James; Goonetilleke, Ashantha

    2016-09-01

    A water supply system can be impacted by rainfall reduction due to climate change, thereby reducing its supply potential. This highlights the need to understand the system resilience, which refers to the ability to maintain service under various pressures (or disruptions). Currently, the concept of resilience has not yet been widely applied in managing water supply systems. This paper proposed three technical resilience indictors to assess the resilience of a water supply system. A case study analysis was undertaken of the Water Grid system of Queensland State, Australia, to showcase how the proposed indicators can be applied to assess resilience. The research outcomes confirmed that the use of resilience indicators is capable of identifying critical conditions in relation to the water supply system operation, such as the maximum allowable rainfall reduction for the system to maintain its operation without failure. Additionally, resilience indicators also provided useful insight regarding the sensitivity of the water supply system to a changing rainfall pattern in the context of climate change, which represents the system's stability when experiencing pressure. The study outcomes will help in the quantitative assessment of resilience and provide improved guidance to system operators to enhance the efficiency and reliability of a water supply system.

  8. The reduction of 4-chloronitrobenzene by Fe(II)-Fe(III) oxide systems - correlations with reduction potential and inhibition by silicate

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Adele M., E-mail: adele.jones1@unsw.edu.au; Kinsela, Andrew S.; Collins, Richard N.; Waite, T. David, E-mail: d.waite@unsw.edu.au

    2016-12-15

    Recent studies have demonstrated that the rate at which Fe(II)-Fe(III) oxyhydroxide systems catalyze the reduction of reducible contaminants, such as 4-chloronitrobenzene, is well correlated to their thermodynamic reduction potential. Here we confirm this effect in the presence of Fe(III) oxyhydroxide phases not previously assessed, namely ferrihydrite and nano-goethite, as well as Fe(III) oxyhydroxide phases previously examined. In addition, silicate is found to decrease the extent of Fe(II) sorption to the Fe(III) oxyhydroxide surface, increasing the reduction potential of the Fe(II)-Fe(III) oxyhydroxide suspension and, accordingly, decreasing the rate of 4-chloronitrobenzene reduction. A linear relationship between the reduction potential of the Fe(II)-Fe(III) oxyhydroxide suspensions and the reduction rate of 4-chloronitrobenzene (normalized to surface area and concentration of sorbed Fe(II)) was obtained in the presence and absence of silicate. However, when ferrihydrite was doped with Si (through co-precipitation) the reduction of 4-chloronitrobenzene was much slower than predicted from its reduction potential. The results obtained have significant implications to the likely effectiveness of naturally occurring contaminant degradation processes involving Fe(II) and Fe(III) oxyhydroxides in groundwater environments containing high concentrations of silicate, or other species which compete with Fe(II) for sorption sites.

  9. Sensory and Physical Effects of Sugar Reduction in a Caramel Coating System.

    Science.gov (United States)

    Mayhew, Emily J; Schmidt, Shelly J; Lee, Soo-Yeun

    2017-08-01

    Sugar reduction in processed foods is a pressing and complex problem, as sugars contribute important sensory and physical properties to foods. Composed of sugars and lipids, caramel coating systems, like the coating in caramel popcorns, exemplify this challenge. In order to probe the feasibility and consequences of sugar reduction, both sensory and physical properties were measured for 3 types of caramel coating systems. Four commonly used sugar alcohols, isomalt, maltitol, mannitol, and sorbitol, with different thermal properties and relative sweetness values were chosen to replace sugar in the caramel coating systems at 25% and 50% sugar reduction levels. Full sugar (control) and reduced sugar caramel coating samples were prepared in duplicate. Ten trained panelists participated in a 6-wk descriptive analysis panel to define and quantify the intensity of important sensory characteristics. All 24 sensory terms generated by the panel differed significantly across caramel type and sugar replacer. Thermal properties were measured through differential scanning calorimetry, and textural properties were measured through texture profile analysis. Replacement of sugar with sugar alcohols was found to decrease the glass transition temperature and systematically alter the hardness and resilience of caramel samples. Principal component analysis of sensory and physical data revealed that caramel coating type dictates caramel aroma, aroma by mouth, taste, and aftertaste, while sugar replacer and replacement level dictate texture. This research represents the first comprehensive study of the effects of sugar reduction in a caramel coating system and suggests successful strategies for sugar reduction and key parameters to control in reduced sugar systems. © 2017 Institute of Food Technologists®.

  10. Accuracy Enhanced Stability and Structure Preserving Model Reduction Technique for Dynamical Systems with Second Order Structure

    DEFF Research Database (Denmark)

    Tahavori, Maryamsadat; Shaker, Hamid Reza

    A method for model reduction of dynamical systems with the second order structure is proposed in this paper. The proposed technique preserves the second order structure of the system, and also preserves the stability of the original systems. The method uses the controllability and observability...... gramians within the time interval to build the appropriate Petrov-Galerkin projection for dynamical systems within the time interval of interest. The bound on approximation error is also derived. The numerical results are compared with the counterparts from other techniques. The results confirm...

  11. Selective catalytic reduction system and process using a pre-sulfated zirconia binder

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A.

    2010-06-29

    A selective catalytic reduction (SCR) process with a palladium catalyst for reducing NOx in a gas, using hydrogen as a reducing agent is provided. The process comprises contacting the gas stream with a catalyst system, the catalyst system comprising (ZrO.sub.2)SO.sub.4, palladium, and a pre-sulfated zirconia binder. The inclusion of a pre-sulfated zirconia binder substantially increases the durability of a Pd-based SCR catalyst system. A system for implementing the disclosed process is further provided.

  12. Performance of two swine manure treatment systems on chemical composition and on the reduction of pathogens.

    Science.gov (United States)

    Viancelli, A; Kunz, A; Steinmetz, R L R; Kich, J D; Souza, C K; Canal, C W; Coldebella, A; Esteves, P A; Barardi, C R M

    2013-01-01

    Swine effluents must be correctly handled to avoid negative environmental impacts. In this study, the profiles of two swine manure treatment systems were evaluated: a solid-liquid separation step, followed by an anaerobic reactor, and an aerobic step (System 1); and a biodigester followed by serial lagoons (System 2). Both systems were described by the assessment of chemical, bacterial and viral parameters. The results showed that in System 1, there was reduction of chemicals (COD, phosphorus, total Kjeldhal nitrogen - TKN - and NH(3)), total coliforms and Escherichia coli; however, the same reduction was not observed for Salmonella sp. Viral particles were significantly reduced but not totally eliminated from the effluent. In System 2, there was a reduction of chemicals, bacteria and viruses with no detection of Salmonella sp., circovirus, parvovirus, and torque teno virus in the effluent. The chemical results indicate that the treated effluent can be reused for cleaning swine facilities. However, the microbiological results show a need of additional treatment to achieve a complete inactivation for cases when direct contact with animals is required. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Analysis of Beamformer Directed Single-Channel Noise Reduction System for Hearing Aid Applications

    DEFF Research Database (Denmark)

    Jensen, Jesper; Pedersen, Michael Syskind

    2015-01-01

    We study multi-microphone noise reduction systems consisting of a beamformer and a single-channel (SC) noise reduction stage. In particular, we present and analyse a maximum likelihood (ML) method for jointly estimating the target and noise power spectral densities (psd's) entering the SC filter....... locations. In a hearing aid context, we analyze the performance of the estimators as a function of target angle-of-arrival and frequency. Finally, we demonstrate the advantage of the proposed method in a hearing aid situation with a target speaker in large-crowd noise....

  14. Device with Complex System for Heat Utilization and Reduction of Hazardous Air Emissions

    Directory of Open Access Journals (Sweden)

    O. Kascheeva

    2012-01-01

    Full Text Available Investigations concern heat utilization and reduction of hazardous emissions occurring in residential buildings and accompanying operation of a great number of industrial enterprises in particular heat and power objects, and firstly, heat-generating units of small power located in densely populated residential areas without centralized heat supply.The investigation target is to reduce cost of heat produced by independent system of building heat supply, reduction of air pollution  due to hazardous gas emissions and reduction of heat pollution of the environment as a result of building ventilation system operation, ventilation of their internal and external sewerage network and higher reliability of their operation.The target is achieved because the device with complex system for heat utilization and reduction of hazardous air emissions has additionally an assembly tank for mixing flue gases, ventilation emissions and atmospheric air, heat pump. Evaporation zone of the pump is a condensator of the gas mixture and its condensate zone contains a heat supply line for a heat consumer. The line is equipped with assembling  and distributing collectors, pipeline connecting the heat supply line with the system of direct and return delivery water from a boiler house, a separator for division of liquid and gaseous mixture phases, neutralizing devices for separate reduction of concentrations of hazardous and odorous substances being released in gaseous and liquid portions of the mixture, a pipeline for periodic supply of air with higher concentration of hazardous and odorous substances in the boiler furnace. The supplied air is obtained as a result of its passing through gas filters at their regeneration when their exchange capacity is exhausted.

  15. Reduction of Under-Determined Linear Systems by Sparce Block Matrix Technique

    DEFF Research Database (Denmark)

    Tarp-Johansen, Niels Jacob; Poulsen, Peter Noe; Damkilde, Lars

    1996-01-01

    Under-determined linear equation systems occur in different engineering applications. In structural engineering they typically appear when applying the force method. As an example one could mention limit load analysis based on The Lower Bound Theorem. In this application there is a set of under......-determined equilibrium equation restrictions in an LP-problem. A significant reduction of computer time spent on solving the LP-problem is achieved if the equilib rium equations are reduced before going into the optimization procedure. Experience has shown that for some structures one must apply full pivoting to ensure...... numerical stability of the aforementioned reduction. Moreover the coefficient matrix for the equilibrium equations is typically very sparse. The objective is to deal efficiently with the full pivoting reduction of sparse rectangular matrices using a dynamic storage scheme based on the block matrix concept....

  16. Polynomic nonlinear dynamical systems - A residual sensitivity method for model reduction

    Science.gov (United States)

    Yurkovich, S.; Bugajski, D.; Sain, M.

    1985-01-01

    The motivation for using polynomic combinations of system states and inputs to model nonlinear dynamics systems is founded upon the classical theories of analysis and function representation. A feature of such representations is the need to make available all possible monomials in these variables, up to the degree specified, so as to provide for the description of widely varying functions within a broad class. For a particular application, however, certain monomials may be quite superfluous. This paper examines the possibility of removing monomials from the model in accordance with the level of sensitivity displayed by the residuals to their absence. Critical in these studies is the effect of system input excitation, and the effect of discarding monomial terms, upon the model parameter set. Therefore, model reduction is approached iteratively, with inputs redesigned at each iteration to ensure sufficient excitation of remaining monomials for parameter approximation. Examples are reported to illustrate the performance of such model reduction approaches.

  17. Spectral Subtraction Approach for Interference Reduction of MIMO Channel Wireless Systems

    Directory of Open Access Journals (Sweden)

    Tomohiro Ono

    2005-08-01

    Full Text Available In this paper, a generalized spectral subtraction approach for reducing additive impulsive noise, narrowband signals, white Gaussian noise and DS-CDMA interferences in MIMO channel DS-CDMA wireless communication systems is investigated. The interference noise reduction or suppression is essential problem in wireless mobile communication systems to improve the quality of communication. The spectrum subtraction scheme is applied to the interference noise reduction problems for noisy MIMO channel systems. The interferences in space and time domain signals can effectively be suppressed by selecting threshold values, and the computational load with the FFT is not large. Further, the fading effects of channel are compensated by spectral modification with the spectral subtraction process. In the simulations, the effectiveness of the proposed methods for the MIMO channel DS-CDMA is shown to compare with the conventional MIMO channel DS-CDMA.

  18. Lifecycle CO2 Reduction by Implementing Double Window Casement Systems in Residential Units in Korea

    Directory of Open Access Journals (Sweden)

    Chang Heon Cheong

    2015-02-01

    Full Text Available This study investigated lifecycle CO2 (LCCO2 emission reductions through application of double-window casement systems (DWCS in residential units in Korea, compared with conventional single windows (SWs. The DWCS is a double window system that is energy-efficient, reducing energy consumption during operation. However, this system incorporates increased embodied CO2 emissions. We evaluated LCCO2 reductions associated with use of the DWCS by calculating CO2 emissions during space conditioning as well as the embodied CO2 emissions of the DWCS. The results showed that use of DWCS in a residential unit during the cooling season had 26.2 and 27.4 t CO2 fewer emissions than SWs in the natural ventilation and minimum ventilation modes, respectively. Although implementation of DWCS is expected to substantially reduce LCCO2 emissions, the large embodied CO2 emissions of the aluminum frame reduce the benefits of the DWCS.

  19. 42 CFR 433.113 - Reduction of FFP for failure to operate a system and obtain initial approval.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Reduction of FFP for failure to operate a system... ADMINISTRATION Mechanized Claims Processing and Information Retrieval Systems § 433.113 Reduction of FFP for failure to operate a system and obtain initial approval. (a) Except as waived under § 433.130 or 433.131...

  20. [Preparation of bovine hemoglobin-loaded nanoparticles used as blood substitutes and establishment of reduction system].

    Science.gov (United States)

    Zhang, Xiaolan; Yuan, Yuan; Shan, Xiaoqian; Sheng, Yan; Zhao, Jian; Liu, Changsheng

    2008-12-01

    Bovine Hb-loaded nanoparticles with modulated size of pores, for use as blood substitutes, were prepared and a nonenzymatic reduction system including two-step-reduction and process optimization was established to control the metHb level in the present study. After the first-step-reduction procedure was performed, the raw BHb, being oxidized severely, was encapsulated to form nanoparticles by the modified double emulsion method. The binary solvent of dichloromethane (DCM) and acetonitrile (Aci) showed properties such as minimizing Hb oxidation and enlarging the pores of nanopartilces. Based on the size of pores o f nanoparticles evaluated by the diffusion of various substances wi thdifferent molecular weights, reducing agents such as ascorbic acid and glutathione present in the plasma were selected to perform the second-step-reduction, i. e. to further reduce the metHb in nanoparticles. The metHb level was reduced from over 90% in the raw materials to 1.25% by the two-step-reduction and controlled preparation; this is near the level of native blood, possessing the ability of carrying/releasing oxygen.

  1. Technology Roadmap. Energy Loss Reduction and Recovery in Industrial Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2004-11-01

    To help guide R&D decision-making and gain industry insights on the top opportunities for improved energy systems, ITP sponsored the Energy Loss Reduction and Recoveryin Energy Systems Roadmapping Workshopin April 2004 in Baltimore, Maryland. This Technology Roadmapis based largely on the results of the workshop and additional industrial energy studies supported by ITP and EERE. It summarizes industry feedback on the top opportunities for R&D investments in energy systems, and the potential for national impacts on energy use and the environment.

  2. Transformative Reduction of Transportation Greenhouse Gas Emissions. Opportunities for Change in Technologies and Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vimmerstedt, Laura [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brown, Austin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Newes, Emily [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Markel, Tony [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schroeder, Alex [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Zhang, Yimin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chipman, Peter [U.S. Department of Transportation, Washington, D.C. (United States); Johnson, Shawn [U.S. Department of Transportation, Washington, D.C. (United States)

    2015-04-30

    The transportation sector is changing, influenced by concurrent, ongoing, dynamic trends that could dramatically affect the future energy landscape, including effects on the potential for greenhouse gas emissions reductions. Battery cost reductions and improved performance coupled with a growing number of electric vehicle model offerings are enabling greater battery electric vehicle market penetration, and advances in fuel cell technology and decreases in hydrogen production costs are leading to initial fuel cell vehicle offerings. Radically more efficient vehicles based on both conventional and new drivetrain technologies reduce greenhouse gas emissions per vehicle-mile. Net impacts also depend on the energy sources used for propulsion, and these are changing with increased use of renewable energy and unconventional fossil fuel resources. Connected and automated vehicles are emerging for personal and freight transportation systems and could increase use of low- or non-emitting technologies and systems; however, the net effects of automation on greenhouse gas emissions are uncertain. The longstanding trend of an annual increase in transportation demand has reversed for personal vehicle miles traveled in recent years, demonstrating the possibility of lower-travel future scenarios. Finally, advanced biofuel pathways have continued to develop, highlighting low-carbon and in some cases carbon-negative fuel pathways. We discuss the potential for transformative reductions in petroleum use and greenhouse gas emissions through these emerging transportation-sector technologies and trends and present a Clean Transportation Sector Initiative scenario for such reductions, which are summarized in Table ES-1.

  3. Usefulness of CRT system on mass survey for GI tract. Dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Asazaki, Manabu; Chiyasu, Shikibu; Tanaka, Takao [Tsurugamine Hospital, Yokohama (Japan)

    1998-09-01

    For the purpose of dose reduction, authors have utilized digital imaging and CRT (cathode ray tube) system in mass survey of the stomach. This paper described a comparison of results obtained by CRT system and CR film on 7,752 examinees in whom 3,600 cases were subjected to the dose reduction by using CRT. Imaging apparatus was Toshiba DBW220A with Fuji FCR9000 and HI-C654 for reading and displaying the image, respectively. The imaging plate was ST-Va and the dosimeter, Swedish UNFORS. At the S values, which, in Fuji FCR, being displayed as a measure of imaging dose, of 250, 1000, and 3000, the grain size and diagnostic utility were compared between CRT system and CR film. The surface dose was measured to see its relation to the S value. At S value 250 (surface dose: 2.3 mGy), no difference was recognized; at 1000 (0.8 mGy), grains in CR film were somewhat inferior; and at 3000, both grains and utility were inferior in CR film, which indicating that dose reduction to about 1/4 was possible when CRT system was used. Further, there was no difference in the diagnostic rates of stomach cancer. (K.H.)

  4. Quantitative Risk reduction estimation Tool For Control Systems, Suggested Approach and Research Needs

    Energy Technology Data Exchange (ETDEWEB)

    Miles McQueen; Wayne Boyer; Mark Flynn; Sam Alessi

    2006-03-01

    For the past year we have applied a variety of risk assessment technologies to evaluate the risk to critical infrastructure from cyber attacks on control systems. More recently, we identified the need for a stand alone control system risk reduction estimation tool to provide owners and operators of control systems with a more useable, reliable, and credible method for managing the risks from cyber attack. Risk is defined as the probability of a successful attack times the value of the resulting loss, typically measured in lives and dollars. Qualitative and ad hoc techniques for measuring risk do not provide sufficient support for cost benefit analyses associated with cyber security mitigation actions. To address the need for better quantitative risk reduction models we surveyed previous quantitative risk assessment research; evaluated currently available tools; developed new quantitative techniques [17] [18]; implemented a prototype analysis tool to demonstrate how such a tool might be used; used the prototype to test a variety of underlying risk calculational engines (e.g. attack tree, attack graph); and identified technical and research needs. We concluded that significant gaps still exist and difficult research problems remain for quantitatively assessing the risk to control system components and networks, but that a useable quantitative risk reduction estimation tool is not beyond reach.

  5. A Soft Computing Based Approach Using Modified Selection Strategy for Feature Reduction of Medical Systems

    Directory of Open Access Journals (Sweden)

    Kursat Zuhtuogullari

    2013-01-01

    Full Text Available The systems consisting high input spaces require high processing times and memory usage. Most of the attribute selection algorithms have the problems of input dimensions limits and information storage problems. These problems are eliminated by means of developed feature reduction software using new modified selection mechanism with middle region solution candidates adding. The hybrid system software is constructed for reducing the input attributes of the systems with large number of input variables. The designed software also supports the roulette wheel selection mechanism. Linear order crossover is used as the recombination operator. In the genetic algorithm based soft computing methods, locking to the local solutions is also a problem which is eliminated by using developed software. Faster and effective results are obtained in the test procedures. Twelve input variables of the urological system have been reduced to the reducts (reduced input attributes with seven, six, and five elements. It can be seen from the obtained results that the developed software with modified selection has the advantages in the fields of memory allocation, execution time, classification accuracy, sensitivity, and specificity values when compared with the other reduction algorithms by using the urological test data.

  6. Energy Reduction with Anticontrol of Chaos for Nonholonomic Mobile Robot System

    Directory of Open Access Journals (Sweden)

    Zahra Yaghoubi

    2012-01-01

    Full Text Available This paper presents energy reduction with anticontrol of chaos for nonholonomic mobile robot system. Anticontrol of chaos is also called chaotification, meaning to chaotify an originally non-chaotic system, and in this paper error of mobile robot system has been synchronized with chaotic gyroscope for reducing energy and increasing performance. The benefits of chaos synchronization with mechanical systems have led us to an innovation in this paper. The main purpose is that the control system in the presence of chaos work with lower control cost and control effort has been reduced. For comparison of proposed method, the feedback linearization controller has also been designed for mobile robot with noise. Finally, the efficacies of the proposed method have been illustrated by simulations, energy of control signals has been calculated, and effect of Alpha (: a constant coefficient is used beside of chaotic system variations on the energy of control signals has been checked.

  7. Solving differential–algebraic equation systems by means of index reduction methodology

    DEFF Research Database (Denmark)

    Sørensen, Kim; Houbak, Niels; Condra, Thomas

    2006-01-01

    of a number of differential equations and algebraic equations — a so called DAE system. Two of the DAE systems are of index 1 and they can be solved by means of standard DAE-solvers. For the actual application, the equation systems are integrated by means of MATLAB’s solver: ode23t, that solves moderately...... stiff ODEs and index 1 DAEs by means of the trapezoidal rule. The last sub-model that models the boilers steam drum consist of two differential and three algebraic equations. The index of this model is greater than 1, which means that ode23t cannot integrate this equation system. In this paper......, it is shown how the equation system, by means of an index reduction methodology, can be reduced to a system of ordinary differential equations — ODEs....

  8. Solving differential-algebraic equation systems by means of index reduction methodology

    DEFF Research Database (Denmark)

    Sørensen, Kim; Houbak, Niels; Condra, Thomas Joseph

    2006-01-01

    of a number of differential equations and algebraic equations - a so called DAE system. Two of the DAE systems are of index 1 and they can be solved by means of standard DAE-solvers. For the actual application, the equation systems are integrated by means of MATLAB’s solver: ode23t, that solves moderately...... stiff ODE’s and index 1 DAE’s by means of the trapezoidal rule. The last sub-model that models the boilers steam drum consist of two differential and three algebraic equations. The index of this model is greater than 1, which means that ode23t cannot integrate this equation system. In this paper......, it is shown how the equation system, by means of an index reduction methodology, can be reduced to a system of Ordinary- Differential-Equations - ODE’s....

  9. Initial Results from ST7-Disturbance Reduction System on LISA Pathfinder

    Science.gov (United States)

    Dunn, Charles; Barela, Phillip; Cutler, Curt; Denzin, Richard; Franklin, Garth; Gorelik, Jacb; Hsu, Oscar; Javidnia, Shahram; Li, Irena; Maghami, Peiman; Marrese-Reading, Colleen; Mehta, Jitendra; O'Donnell, James; Romero-Wolf, Andrew; Slutsky, Jacob; Thorpe, Ira; Umfress, S. Harper; Ziemer, John

    2017-01-01

    The European Space Agency LISA Pathfinder spacecraft was launched on December, 2, 2015 carrying the NASA contribution ST7-Disturbance Reduction System (ST7-DRS). The objective of ST7-DRS is to demonstrate drag-free control and noise reduction technologies for future missions, especially a future space-based gravitational wave observatory. The system consists of a pair of Colloid Micro-Newton Thruster clusters and a computer with control algorithms. Data from the host platform is used for inertial and attitude sensing. ST7-DRS was initially powered on in January 2016 for an on-orbit check out and was fully commissioned in late June and early July. This presentation will report results relative to the 0.1 micro-Newton/ rt Hertz thrust noise requirement and the 10 nanometer/rt Hertz position control requirement. Preliminary extended mission results will be discussed. The work described here was funded by NASA.

  10. Data Reduction and Control Software for Meteor Observing Stations Based on CCD Video Systems

    Science.gov (United States)

    Madiedo, J. M.; Trigo-Rodriguez, J. M.; Lyytinen, E.

    2011-01-01

    The SPanish Meteor Network (SPMN) is performing a continuous monitoring of meteor activity over Spain and neighbouring countries. The huge amount of data obtained by the 25 video observing stations that this network is currently operating made it necessary to develop new software packages to accomplish some tasks, such as data reduction and remote operation of autonomous systems based on high-sensitivity CCD video devices. The main characteristics of this software are described here.

  11. Zn(BH ) /2NaCl: A Novel Reducing System for Efficient Reduction of ...

    African Journals Online (AJOL)

    NICO

    Under this protocol, reduction of conju- gated ketones such as benzylidenacetone (Table 2, entry 24) and chalcone (Table 2, entry 25) were achieved efficiently with 1 mo- lar equivalents of Zn(BH4)2/2NaCl at room temperature in. CH3CN in excellent yields (95–97 %). In order to show the efficiency of this reducing system, ...

  12. Noncontact ECG recording system with real time capacitance measurement for motion artifact reduction.

    Science.gov (United States)

    Torfs, Tom; Chen, Yun-Hsuan; Kim, Hyejung; Yazicioglu, Refet Firat

    2014-10-01

    A system for noncontact ECG recording is proposed that measures the real time electrode-body capacitance concurrently with the ECG as a reference signal for motion artifact reduction. Simultaneous recordings of these two signals from the human body in the presence of electrode motion artifacts are shown and an adaptive least-mean-squares (LMS) filtering algorithm run on these signals is demonstrated to be able to reduce the severity of certain types of electrode motion artifacts.

  13. Comparison of SHR Mode IPL System with Alexandrite and Nd: YAG Lasers For Leg Hair Reduction

    OpenAIRE

    KARACA, Şemsettin; Kaçar, Seval Doğruk; Ozuğuz, Pınar

    2012-01-01

    Objective: Multiple lasers and light sources are currently available for hair removal and many studies comparing efficacy and safety exist. SHR mode IPL is a technique that gives the total energy in divided doses with fewer side effects. We compared a SHR mode IPL system with alexandrite and Nd: YAG lasers for leg hair reduction Material and Methods: Twenty-five female participants with skin types II–IV, underwent treatment of unwanted hair on the cruris. Three selecte...

  14. Comparison of SHR Mode IPL System with Alexandrite and Nd: YAG Lasers For Leg Hair Reduction

    OpenAIRE

    Şemsettin Karaca; Seval Doğruk Kaçar; Pınar Ozuğuz

    2012-01-01

    Objective: Multiple lasers and light sources are currently available for hair removal and many studies comparing efficacy and safety exist. SHR mode IPL is a technique that gives the total energy in divided doses with fewer side effects. We compared a SHR mode IPL system with alexandrite and Nd: YAG lasers for leg hair reduction Material and Methods: Twenty-five female participants with skin types II–IV, underwent treatment of unwanted hair on the cruris. Three selec...

  15. A Residual Approach for Balanced Truncation Model Reduction (BTMR of Compartmental Systems

    Directory of Open Access Journals (Sweden)

    William La Cruz

    2014-05-01

    Full Text Available This paper presents a residual approach of the square root balanced truncation algorithm for model order reduction of continuous, linear and time-invariante compartmental systems. Specifically, the new approach uses a residual method to approximate the controllability and observability gramians, whose resolution is an essential step of the square root balanced truncation algorithm, that requires a great computational cost. Numerical experiences are included to highlight the efficacy of the proposed approach.

  16. Phase-Reduction Approach to Synchronization of Spatiotemporal Rhythms in Reaction-Diffusion Systems

    Science.gov (United States)

    Nakao, Hiroya; Yanagita, Tatsuo; Kawamura, Yoji

    2014-04-01

    Reaction-diffusion systems can describe a wide class of rhythmic spatiotemporal patterns observed in chemical and biological systems, such as circulating pulses on a ring, oscillating spots, target waves, and rotating spirals. These rhythmic dynamics can be considered limit cycles of reaction-diffusion systems. However, the conventional phase-reduction theory, which provides a simple unified framework for analyzing synchronization properties of limit-cycle oscillators subjected to weak forcing, has mostly been restricted to low-dimensional dynamical systems. Here, we develop a phase-reduction theory for stable limit-cycle solutions of reaction-diffusion systems with infinite-dimensional state space. By generalizing the notion of isochrons to functional space, the phase-sensitivity function—a fundamental quantity for phase reduction—is derived. For illustration, several rhythmic dynamics of the FitzHugh-Nagumo model of excitable media are considered. Nontrivial phase-response properties and synchronization dynamics are revealed, reflecting their complex spatiotemporal organization. Our theory will provide a general basis for the analysis and control of spatiotemporal rhythms in various reaction-diffusion systems.

  17. Microvax-based data management and reduction system for the regional planetary image facilities

    Science.gov (United States)

    Arvidson, R.; Guinness, E.; Slavney, S.; Weiss, B.

    1987-01-01

    Presented is a progress report for the Regional Planetary Image Facilities (RPIF) prototype image data management and reduction system being jointly implemented by Washington University and the USGS, Flagstaff. The system will consist of a MicroVAX with a high capacity (approx 300 megabyte) disk drive, a compact disk player, an image display buffer, a videodisk player, USGS image processing software, and SYSTEM 1032 - a commercial relational database management package. The USGS, Flagstaff, will transfer their image processing software including radiometric and geometric calibration routines, to the MicroVAX environment. Washington University will have primary responsibility for developing the database management aspects of the system and for integrating the various aspects into a working system.

  18. Beyond Waste Reduction: Creating Value with Information Systems in Closed-Loop Supply Chains

    OpenAIRE

    Koppius, Otto; Ozdemir, Oznur; Laan, Erwin

    2011-01-01

    textabstractWe study the role of information systems in enabling closed-loop supply chains. Past research in green IS and closed-loop supply chains has shown that it can result in substantial cost savings and waste reduction. We complement this research by showing that the effects are more than that: using information systems can also create business value for a firm in closed-loop supply chains. We make a novel distinction between four types of value: sourcing value, environmental value, cus...

  19. Selectivity Control of CO2 Reduction in an Inorganic Artificial Photosynthesis System

    Science.gov (United States)

    Hashiba, Hiroshi; Yotsuhashi, Satoshi; Deguchi, Masahiro; Yamada, Yuka; Ohkawa, Kazuhiro

    2013-09-01

    We demonstrated that the selectivity of photo electrochemical CO2 reduction can be controlled in an inorganic artificial photosynthesis system using an AlGaN/GaN photo electrode. By increasing input light intensity and the use of a gold cathode, the Faradaic efficiency of CO dramatically increases from 30% to over 80% while that of H2 decreases. We observed that the cathode potential resulting from illumination determines the ratio of CO and H2. With this system, it is possible to switch the main reaction product from CO to HCOOH, which is also effective even under intense illumination.

  20. Controlled reduction of red mud waste to produce active systems for environmental applications: heterogeneous Fenton reaction and reduction of Cr(VI).

    Science.gov (United States)

    Costa, Regina C C; Moura, Flávia C C; Oliveira, Patrícia E F; Magalhães, Fabiano; Ardisson, José D; Lago, Rochel M

    2010-02-01

    In this work, controlled reduction of red mud with H(2) was used to produce active systems for two different environmental applications, i.e. the heterogeneous Fenton reaction and the reduction of Cr(VI). Mössbauer, powder X-ray diffraction, thermal analyses and scanning electron microscopy analyses showed that at different temperatures, i.e. 300, 400, 500 and 600 degrees C, H(2) reduces red mud to different phases, mainly Fe(3)O(4), Fe(0)/Fe(3)O(4) and Fe(0). These Fe phases are dispersed on Al, Si and Ti oxides present in the red mud and show high reactivity towards two environmental applications, i.e. the heterogeneous Fenton reaction and the reduction of Cr(VI). Reduction with H(2) at 400 degrees C showed the best results for the oxidation of the model dye methylene blue with H(2)O(2) at neutral pH due to the presence of the composite Fe(0)/Fe(3)O(4). The reduced red mud at 500-600 degrees C produced Fe(0) highly active for the reduction of Cr(VI) in aqueous medium. Another feature of these red mud based system is that after deactivation due to extensive use they can be completely regenerated by simple treatment with H(2). Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  1. Importance of silvopastoral systems on caloric stress reduction in tropical livestock productions

    Directory of Open Access Journals (Sweden)

    Alexander Navas Panadero

    2010-06-01

    Full Text Available Livestock systems in Colombia have been developed taking concepts and technologies from the green revolution, where gramineous monocrop is privileged over arboreal cover in grazing lands. This model has not taken into account the climatic conditions of the different tropical ecosystems, in which variables as temperature, relative humidity and evaporation can limit the animal´s productive and reproductive efficiency, besides being a risk factor for illness occurrence in the herd. Bos Taurus and Bos Indicus breeds show termoneutral ranges where its genetic potential can be express. However, out of this comfort area animals can enter in caloric stress which in consequence reduces its performance and sometimes can end up causing death. Silvopastoral systems comprise several functions; it contributes to lessen caloric stress since temperature under the tree canopy can reach between 2 and 9°C lower in comparison to open pastures. Differences in temperature reduction have been found among silvopastoral systems and species, being the tree group arrangements and the species with high density canopy, those with superior effect. Interactions among components should be analyzed in order to design systems that incorporate enough arboreal cover to achieve caloric stress reductions, but without affecting forage production in pastures. Silvopastoral systems contribute to improve animal welfare.

  2. Accuracy Analysis of a Robot System for Closed Diaphyseal Fracture Reduction

    Directory of Open Access Journals (Sweden)

    Changsheng Li

    2014-10-01

    Full Text Available We have developed a robot system for closed diaphyseal fracture reduction. Because accuracy is essential for the treatment effects of the robot system and for the safety of both the patients and surgeons, we analysed accuracy in a systematic way. Both the structure of the robot and the operation procedure are described. Using the transfer model of errors in series and the error differential solving method for parallel mechanisms, an error model was established, and the main influencing factors of errors were considered. The Monte Carlo method was used to perform the simulation based on the error model. Experiments of image registration, of the mechanism and of the whole robot system were tested in different aspects to verify that the results of the simulation are correct. The system accuracy was compared with clinical standards to show that the robot system fulfilled the requirements for closed diaphyseal fracture reduction. The accuracy analysis method also provides an efficient path for other medical robots.

  3. A fuzzy logic urea dosage controller design for two-cell selective catalytic reduction systems.

    Science.gov (United States)

    You, Kun; Wei, Lijiang; Jiang, Kai

    2017-12-22

    Diesel engines have dominated in the heavy-duty vehicular and marine power source. However, the induced air pollution is a big problem. As people's awareness of environmental protection increasing, the emission regulations of diesel-engine are becoming more stringent. In order to achieve the emission regulations, the after-treatment system is a necessary choice. Specifically, the selective catalytic reduction (SCR) system has been widely applied to reduce the NOX emissions of diesel engine. Different from single-cell SCR systems, the two-cell systems have various benefits from the modeling and control perspective. In this paper, the urea dosage controller design for two-cell SCR systems was investigated. Firstly, the two-cell SCR modeling was introduced. Based on the developed model, the design procedure for the fuzzy logic urea dosage controller was well addressed. Secondly, simulations and comparisons were employed via an experimental verification of the whole vehicle simulator. And the results showed that the designed controller simultaneously achieved high NOX reduction rate and low tail-pipe ammonia slip. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Monitoring of Basic Parameters for Selective Catalytic Reduction System Used in an Agricultural Tractor

    Directory of Open Access Journals (Sweden)

    Antonín Skřivánek

    2014-01-01

    Full Text Available Presented paper describes monitoring of basic parameters for selective catalytic reduction (SCR system used in an agricultural tractor. SCR systems are used to reduce emissions of nitrogen oxides (NOx produced by combustion of fuel. The usage of SCR catalytic converters entails certain disadvantages in the use of reducing agent and the necessity of suitable operating conditions to achieve optimum efficiency of the catalytic converter. This paper aims to predict consumption of AdBlue depending on the temperature of SCR catalytic converter, which reflects the engine load and monitoring the effectiveness of SCR catalytic converter when operating a tractor engine with a maximum dose of fuel. To fulfill those aims, the measurements have been performed on the Case Puma 185 CVX agricultural tractor. As the measurement results indicate, the lowest NOx emissions correspond to high consumption of AdBlue. Other studies imply that the catalytic converter operates at optimal operating temperature and with the highest efficiency of NOx emission reduction. The effectiveness of NOx emission reduction is thus affected not only by quantity of injected reagent but also by catalytic converter thermal load. Further measurement results indicate that the lowest amount of emissions of NOx (and the highest efficiency rate is achieved by catalytic converter in a range in which the engine operates with the highest engine efficiency.

  5. Decision-directed iterative methods for PAPR reduction in optical wireless OFDM systems

    Science.gov (United States)

    Azim, Ali W.; Le Guennec, Yannis; Maury, Ghislaine

    2017-04-01

    In this paper, we propose two iterative decision-directed methods for peak-to-average power ratio (PAPR) reduction in optical-orthogonal frequency division multiplexing (O-OFDM) systems. The proposed methods are applicable to state-of-the-art intensity modulation-direct detection (IM-DD) O-OFDM techniques for optical wireless communication (OWC) systems, including both direct-current (DC) biased O-OFDM (DCO-OFDM), and asymmetrically clipped O-OFDM (ACO-OFDM). Conventional O-OFDM suffers from high power consumption due to high PAPR. The high PAPR of the O-OFDM signal can be counteracted by clipping the signal to a predefined threshold. However, because of clipping an inevitable distortion occurs due to the loss of useful information, thus, clipping mitigation methods are required. The proposed iterative decision-directed methods operate at the receiver, and recover the lost information by mitigating the clipping distortion. Simulation results acknowledge that the high PAPR of O-OFDM can be significantly reduced using clipping, and the proposed methods can successfully circumvent the clipping distortions. Furthermore, the proposed PAPR reduction methods exhibit a much lower computational complexity compared to standard PAPR reduction methods.

  6. A study on the indirect urea dosing method in the Selective Catalytic Reduction system

    Science.gov (United States)

    Brzeżański, M.; Sala, R.

    2016-09-01

    This article presents the results of studies on concept solution of dosing urea in a gas phase in a selective catalytic reduction system. The idea of the concept was to heat-up and evaporate the water urea solution before introducing it into the exhaust gas stream. The aim was to enhance the processes of urea converting into ammonia, what is the target reductant for nitrogen oxides treatment. The study was conducted on a medium-duty Euro 5 diesel engine with exhaust line consisting of DOC catalyst, DPF filter and an SCR system with a changeable setup allowing to dose the urea in liquid phase (regular solution) and to dose it in a gas phase (concept solution). The main criteria was to assess the effect of physical state of urea dosed on the NOx conversion ratio in the SCR catalyst. In order to compare both urea dosing methods a special test procedure was developed which consisted of six test steps covering a wide temperature range of exhaust gas generated at steady state engine operation condition. Tests were conducted for different urea dosing quantities defined by the a equivalence ratio. Based on the obtained results, a remarkable improvement in NOx reduction was found for gas urea application in comparison to the standard liquid urea dosing. Measured results indicate a high potential to increase an efficiency of the SCR catalyst by using a gas phase urea and provide the basis for further scientific research on this type of concept.

  7. PAPR Reduction Approach Based on Channel Estimation Pilots for Next Generations Broadcasting Systems

    Directory of Open Access Journals (Sweden)

    Anh-Tai Ho

    2011-01-01

    Full Text Available A novel peak-to-average power ratio (PAPR reduction technique for orthogonal frequency division multiplexing (OFDM systems is addressed. Instead of using dedicated pilots for PAPR reduction as with tone reservation (TR method selected by the DVB-T2 standard, we propose to use existing pilots used for channel estimation. In this way, we avoid the use of reserved tone pilots and then improve the spectral efficiency of the system. In order to allow their recovery at the receiver, these pilots have to follow particular laws which permit their blind detection and avoid sending side information. In this work, we propose and investigate a multiplicative law operating in discrete frequency domain. The operation in discrete domain aims at reducing degradation due to detection and estimation error in continuous domain. Simulation results are performed using the new DVB-T2 standard parameters. Its performance is compared to the DVB-T2 PAPR gradient algorithm and to the second-order cone programming (SOCP competitive technique proposed in the literature. We show that the proposed technique is efficient in terms of PAPR reduction value and of spectral efficiency while the channel estimation performance is maintained.

  8. Accelerated Cyclic Reduction: A Distributed-Memory Fast Solver for Structured Linear Systems

    KAUST Repository

    Chávez, Gustavo

    2017-12-15

    We present Accelerated Cyclic Reduction (ACR), a distributed-memory fast solver for rank-compressible block tridiagonal linear systems arising from the discretization of elliptic operators, developed here for three dimensions. Algorithmic synergies between Cyclic Reduction and hierarchical matrix arithmetic operations result in a solver that has O(kNlogN(logN+k2)) arithmetic complexity and O(k Nlog N) memory footprint, where N is the number of degrees of freedom and k is the rank of a block in the hierarchical approximation, and which exhibits substantial concurrency. We provide a baseline for performance and applicability by comparing with the multifrontal method with and without hierarchical semi-separable matrices, with algebraic multigrid and with the classic cyclic reduction method. Over a set of large-scale elliptic systems with features of nonsymmetry and indefiniteness, the robustness of the direct solvers extends beyond that of the multigrid solver, and relative to the multifrontal approach ACR has lower or comparable execution time and size of the factors, with substantially lower numerical ranks. ACR exhibits good strong and weak scaling in a distributed context and, as with any direct solver, is advantageous for problems that require the solution of multiple right-hand sides. Numerical experiments show that the rank k patterns are of O(1) for the Poisson equation and of O(n) for the indefinite Helmholtz equation. The solver is ideal in situations where low-accuracy solutions are sufficient, or otherwise as a preconditioner within an iterative method.

  9. Reductive defluorination of perfluorooctanoic acid by hydrated electrons in a sulfite-mediated UV photochemical system

    Energy Technology Data Exchange (ETDEWEB)

    Song, Zhou [Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074 (China); College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Tang, Heqing, E-mail: tangheqing@mail.scuec.edu.cn [Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, College of Chemistry and Materials Science, South-Central University for Nationalities, Wuhan 430074 (China); Wang, Nan, E-mail: nwang83@sina.com [College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhu, Lihua [College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-11-15

    Highlights: • A new reductive method for PFOA defluorination was established by sulfite-mediated photolysis. • The defluorination of PFOA was dependent on sulfite concentration and solution pH. • A defluorination ratio of PFOA as high as 88.5% was achieved after reaction of 24 h. • A few of perfluorinated sulfonates were detected as intermediates during the degradation of PFOA. • A mechanism was proposed for the reductive defluorination of PFOA by hydrated electrons. -- Abstract: A method for reductive degradation of perfluorooctanoic acid (PFOA) was established by using a sulfite/UV process. This process led to a PFOA removal of 100% at about 1 h and a defluorination ratio of 88.5% at reaction time of 24 h under N{sub 2} atmosphere, whereas the use of either UV irradiation or SO{sub 3}{sup 2−} alone induced little defluorination of PFOA under the same conditions. It was confirmed that the reductive defluorination of PFOA was achieved by hydrated electrons being generated from the photo-conversion of SO{sub 3}{sup 2−} as a mediator. Theoretical reaction kinetic analysis demonstrated that the generation of hydrated electrons was promoted by increasing either SO{sub 3}{sup 2−} concentration or solution pH, leading to the acceleration of the PFOA defluorination. Accompanying the reduction of PFOA, a small amount of short-chain perfluorocarboxylic acids, less fluorinated carboxylic acids and perfluorinated alkyl sulfonates were generated, all of which were able to be further degraded with further releasing of fluoride ions. Based on the generation, accumulation and distribution of intermediates, hydrated electrons induced defluorination pathway of PFOA was proposed in a sulfite-mediated UV photochemical system.

  10. Stability Analysis and H∞ Model Reduction for Switched Discrete-Time Time-Delay Systems

    Directory of Open Access Journals (Sweden)

    Zheng-Fan Liu

    2014-01-01

    Full Text Available This paper is concerned with the problem of exponential stability and H∞ model reduction of a class of switched discrete-time systems with state time-varying delay. Some subsystems can be unstable. Based on the average dwell time technique and Lyapunov-Krasovskii functional (LKF approach, sufficient conditions for exponential stability with H∞ performance of such systems are derived in terms of linear matrix inequalities (LMIs. For the high-order systems, sufficient conditions for the existence of reduced-order model are derived in terms of LMIs. Moreover, the error system is guaranteed to be exponentially stable and an H∞ error performance is guaranteed. Numerical examples are also given to demonstrate the effectiveness and reduced conservatism of the obtained results.

  11. The Proper Orthogonal Decomposition for Dimensionality Reduction in Mode-Locked Lasers and Optical Systems

    Directory of Open Access Journals (Sweden)

    Eli Shlizerman

    2012-01-01

    energy delivered per pulse. Managing the nonlinear penalties in the cavity becomes crucial for increasing the energy and suppressing the multipulsing instability. A proper orthogonal decomposition (POD allows for the reduction of governing equations of a mode-locked laser onto a low-dimensional space. The resulting reduced system is able to capture correctly the experimentally observed pulse transitions. Analysis of these models is used to explain the sequence of bifurcations that are responsible for the multipulsing instability in the master mode-locking and the waveguide array mode-locking models. As a result, the POD reduction allows for a simple and efficient way to characterize and optimize the cavity parameters for achieving maximal energy output.

  12. Optimized phase mask to realize retro-reflection reduction for optical systems

    Science.gov (United States)

    He, Sifeng; Gong, Mali

    2017-10-01

    Aiming at the threats to the active laser detection systems of electro-optical devices due to the cat-eye effect, a novel solution is put forward to realize retro-reflection reduction in this paper. According to the demands of both cat-eye effect reduction and the image quality maintenance of electro-optical devices, a symmetric phase mask is achieved from a stationary phase method and a fast Fourier transform algorithm. Then, based on a comparison of peak normalized cross-correlation (PNCC) between the different defocus parameters, the optimal imaging position can be obtained. After modification with the designed phase mask, the cat-eye effect peak intensity can be reduced by two orders of magnitude while maintaining good image quality and high modulation transfer function (MTF). Furthermore, a practical design example is introduced to demonstrate the feasibility of our proposed approach.

  13. Reduction of Fuel Consumption and Exhaust Pollutant Using Intelligent Transport Systems

    Directory of Open Access Journals (Sweden)

    Mostofa Kamal Nasir

    2014-01-01

    Full Text Available Greenhouse gas emitted by the transport sector around the world is a serious issue of concern. To minimize such emission the automobile engineers have been working relentlessly. Researchers have been trying hard to switch fossil fuel to alternative fuels and attempting to various driving strategies to make traffic flow smooth and to reduce traffic congestion and emission of greenhouse gas. Automobile emits a massive amount of pollutants such as Carbon Monoxide (CO, hydrocarbons (HC, carbon dioxide (CO2, particulate matter (PM, and oxides of nitrogen (NOx. Intelligent transport system (ITS technologies can be implemented to lower pollutant emissions and reduction of fuel consumption. This paper investigates the ITS techniques and technologies for the reduction of fuel consumption and minimization of the exhaust pollutant. It highlights the environmental impact of the ITS application to provide the state-of-art green solution. A case study also advocates that ITS technology reduces fuel consumption and exhaust pollutant in the urban environment.

  14. Reduction of fuel consumption and exhaust pollutant using intelligent transport systems.

    Science.gov (United States)

    Nasir, Mostofa Kamal; Md Noor, Rafidah; Kalam, M A; Masum, B M

    2014-01-01

    Greenhouse gas emitted by the transport sector around the world is a serious issue of concern. To minimize such emission the automobile engineers have been working relentlessly. Researchers have been trying hard to switch fossil fuel to alternative fuels and attempting to various driving strategies to make traffic flow smooth and to reduce traffic congestion and emission of greenhouse gas. Automobile emits a massive amount of pollutants such as Carbon Monoxide (CO), hydrocarbons (HC), carbon dioxide (CO2), particulate matter (PM), and oxides of nitrogen (NO x ). Intelligent transport system (ITS) technologies can be implemented to lower pollutant emissions and reduction of fuel consumption. This paper investigates the ITS techniques and technologies for the reduction of fuel consumption and minimization of the exhaust pollutant. It highlights the environmental impact of the ITS application to provide the state-of-art green solution. A case study also advocates that ITS technology reduces fuel consumption and exhaust pollutant in the urban environment.

  15. Multi scale Disaster Risk Reduction Systems Space and Community based Experiences over HKH Region

    Science.gov (United States)

    Gurung, D. R.; Shrestha, M.; Shrestha, N.; Debnath, B.; Jishi, G.; Bajracharya, R.; Dhonju, H. K.; Pradhan, S.

    2014-11-01

    An increasing trend in the recurrence of natural disasters and associated impacts due to Floods, Glacier Lake out bursts, landslides and forest fire is reported over Hindu Kush Himalyan (HKH) region. Climate change and anthropogenic coupled factors are identified as primary factors for such increased vulnerability. The large degree of poverty, lack of infrastructure, poor accessibility and uncertainties involved in understanding high altitude land surface and climate dynamics poses serious challenges in reducing disaster vulnerability and mitigating disaster impacts. In this context effective development of Disaster Risk Reduction (DRR) protocols and mechanisms have been realized as an urgent need. The paper presents the adoption and experiences of multi scale DRR systems across different Himalayan member countries ranging from community based indigenous early warning to space based emergency response and decision support systems. The Establishment of a Regional Flood Information System (HKH-HYCOS) over Ganges-Brahmaputra-Meghna (GBM) and Indus river basins promoted the timely exchange of flood data and information for the reduction of flood vulnerability within and among the participating countries. Satellite based forest fire alert systems evoked significant response among diverse stakeholders to optimize fire incidence and control. Satellite rainfall estimation products, satellite altimetry based flood early warning systems, flood inundation modelling and products, model derived hydrology flow products from different global data-sharing networks constitutes diverse information to support multi scale DRR systems. Community-based Flood Early Warning System (FEWS) enabled by wireless technology established over the Singara and Jiadhal rivers in Assam also stands as one of the promising examples of minimizing flood risk. Disaster database and information system and decision support tools in Nepal serves as potential tool to support diverse stakeholders.

  16. Performance Evaluation of a Thermal Load Reduction System in a Hyundai Sonata PHEV

    Energy Technology Data Exchange (ETDEWEB)

    Kreutzer, Cory J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rugh, John P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Titov, Eugene V [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gallagher, James [Gentherm, Inc.; Scott, Matthew [Hyundai America Technical Center, Inc.

    2017-11-28

    Increased adoption of electric-drive vehicles (EDVs) requires overcoming hurdles including limited vehicle range. Vehicle cabin heating and cooling demand for occupant climate control requires energy from the main battery and has been shown to significantly degrade vehicle range. During peak cooling and heating conditions, climate control can require as much or more energy as propulsion. As part of an ongoing project, NREL and project partners Hyundai America Technical Center, Inc. (HATCI), Gentherm , Pittsburgh Glass Works (PGW), PPG Industries, Sekisui, 3M, and Hanon Systems developed a thermal load reduction system in order to reduce the range penalty associated with electric vehicle climate control. Solar reflective paint, solar control glass, heated and cooled/ventilated seats, heated surfaces, and heated windshield with door demisters were integrated into a Hyundai Sonata plug-in hybrid electric vehicle (PHEV). Cold weather field-testing was conducted in Fairbanks, Alaska while warm weather testing was conducted in Death Valley, California to assess the system performance in comparison to the baseline production vehicle. In addition, environmental chamber testing at peak heating and cooling conditions was performed to assess the performance of the system in standardized conditions compared to the baseline. Experimental results are presented in this paper providing quantitative data to automobile manufacturers on the impact of climate control thermal load reduction technologies to increase the advanced thermal technology adoption and market penetration of electric drive vehicles.

  17. Design and Analysis of the ST7 Disturbance Reduction System (DRS) Spacecraft Controller

    Science.gov (United States)

    Maghami, P. G.; Markley, F. L.; Houghton, M. B.; Dennehy, C. J.

    2003-01-01

    The Space Technology 7 experiment will perform an on-orbit system-level validation of two specific Disturbance Reduction System technologies: a gravitational reference sensor employing a free-floating test mass and a set of micronewton colloidal thrusters. The Disturbance Reduction System is designed to maintain a spacecraft's position with respect to the free-floating test mass to less than 10 nm/square root of Hz, over the frequency range 10(exp -3) Hz to 10(exp -2) Hz. This paper presents the design and analysis of the coupled drag-free and attitude control system that closes the loop between the gravitational reference sensor and the micronewton thrusters while incorporating star tracker data at low frequencies. The effects of actuation and measurement noise and disturbances on the spacecraft and test masses are evaluated in a seven-degree-of-freedom planar model incorporating two translational and one rotational degrees of freedom for the spacecraft and two translational degrees of freedom for each test mass.

  18. Control of a selective catalytic reduction system based on NARMA-L2 model

    Science.gov (United States)

    Han, W. M.; Wang, Y. J.; Zheng, T. X.; Zhou, T. L.; Zhang, Y.; Tan, R.

    2017-03-01

    The plant of the selective catalytic reduction (SCR) system is characterized by significant nonlinearity, time delay and temperature sensitivity. In order to control the urea injection accurately, the (nonlinear auto regressive moving average) NARMA-L2 model based control is applied to the SCR system. In this paper, a data-based technique is taken and a model of the plant is identified on the basis of input-output data. Then the identified model is used to the design of a NARMA-L2 controller. Simulation of the NARMA-L2 model based control for the SCR system is presented to demonstrate the effectiveness and superiority. The comparison results show better performance over the traditional PID control.

  19. Persistent model order reduction for complex dynamical systems using smooth orthogonal decomposition

    Science.gov (United States)

    Ilbeigi, Shahab; Chelidze, David

    2017-11-01

    Full-scale complex dynamic models are not effective for parametric studies due to the inherent constraints on available computational power and storage resources. A persistent reduced order model (ROM) that is robust, stable, and provides high-fidelity simulations for a relatively wide range of parameters and operating conditions can provide a solution to this problem. The fidelity of a new framework for persistent model order reduction of large and complex dynamical systems is investigated. The framework is validated using several numerical examples including a large linear system and two complex nonlinear systems with material and geometrical nonlinearities. While the framework is used for identifying the robust subspaces obtained from both proper and smooth orthogonal decompositions (POD and SOD, respectively), the results show that SOD outperforms POD in terms of stability, accuracy, and robustness.

  20. Thermal stress reduction of bilayered systems by means of linearly graded interlayer

    Science.gov (United States)

    Wang, Binglian; Li, Yizeng; Huo, Yongzhong

    2009-07-01

    The technique of introducing graded interlayers has been used extensively to mitigate residual thermal stresses in joining dissimilar materials. The case-to-case numerical methods have often been used to discuss the effectiveness of the graded interlayers, because it is always a mathematical difficulty in analytical analysis. In this work, thermal stress reduction of bilayered systems with linearly graded interlayer is considered with analytical approaches. It has been found that the maximal stress in the system will always be lowered with a thick enough interlayer. However, if the interlayer thickness is restricted, a critical range of the elastic modulus and layer thicknesses of the original bilayered system can be identified only in which the maximal stress can be reduced. An even smaller range is found within which the maximal stress always decreases with the increase of the interlayer thickness.

  1. Evaluation of a biological wastewater treatment system combining an OSA process with ultrasound for sludge reduction.

    Science.gov (United States)

    Romero-Pareja, P M; Aragon, C A; Quiroga, J M; Coello, M D

    2017-05-01

    Sludge production is an undesirable by-product of biological wastewater treatment. The oxic-settling-anaerobic (OSA) process constitutes one of the most promising techniques for reducing the sludge produced at the treatment plant without negative consequences for its overall performance. In the present study, the OSA process is applied in combination with ultrasound treatment, a lysis technique, in a lab-scale wastewater treatment plant to assess whether sludge reduction is enhanced as a result of mechanical treatment. Reported sludge reductions of 45.72% and 78.56% were obtained for the two regimes of combined treatment tested in this study during two respective stages: UO1 and UO2. During the UO1 stage, the general performance and nutrient removal improved, obtaining 47.28% TN removal versus 21.95% in the conventional stage. However, the performance of the system was seriously damaged during the UO2 stage. Increases in dehydrogenase and protease activities were observed during both stages. The advantages of the combined process are not necessarily economic, but operational, as US treatment acts as contributing factor in the OSA process, inducing mechanisms that lead to sludge reduction in the OSA process and improving performance parameters. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Reductive defluorination of perfluorooctanoic acid by hydrated electrons in a sulfite-mediated UV photochemical system.

    Science.gov (United States)

    Song, Zhou; Tang, Heqing; Wang, Nan; Zhu, Lihua

    2013-11-15

    A method for reductive degradation of perfluorooctanoic acid (PFOA) was established by using a sulfite/UV process. This process led to a PFOA removal of 100% at about 1h and a defluorination ratio of 88.5% at reaction time of 24h under N2 atmosphere, whereas the use of either UV irradiation or SO3(2-) alone induced little defluorination of PFOA under the same conditions. It was confirmed that the reductive defluorination of PFOA was achieved by hydrated electrons being generated from the photo-conversion of SO3(2-) as a mediator. Theoretical reaction kinetic analysis demonstrated that the generation of hydrated electrons was promoted by increasing either SO3(2-) concentration or solution pH, leading to the acceleration of the PFOA defluorination. Accompanying the reduction of PFOA, a small amount of short-chain perfluorocarboxylic acids, less fluorinated carboxylic acids and perfluorinated alkyl sulfonates were generated, all of which were able to be further degraded with further releasing of fluoride ions. Based on the generation, accumulation and distribution of intermediates, hydrated electrons induced defluorination pathway of PFOA was proposed in a sulfite-mediated UV photochemical system. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Reduction of aflatoxins (B₁, B₂, G₁, and G₂) in soybean-based model systems.

    Science.gov (United States)

    Lee, Jongin; Her, Jae-Young; Lee, Kwang-Geun

    2015-12-15

    The effects of chemical, physical, and cooking treatments on the reduction of aflatoxin B1 (AFB1), B2, G1, and G2 in soybean matrix were investigated. A HPLC-FLD with a Kobra cell system was used for the quantitative analysis of aflatoxins (AFs). To decrease the level of AFs during the soaking process, the contaminated soybeans were submerged in organic acid solutions. The reduction rates of AFB1 in 1.0N citric acid, lactic acid, succinic acid, and tartaric acid for 18h were 94.1%, 92.7%, 62.0%, and 95.1%, respectively. In the case of pH and autoclave treatment, the level of AFB1 was significantly decreased during autoclaving process at pH 7.4, 9.0, and 11.1, compared with the non-autoclaved samples (p<0.05). In the case of physical treatment, the heating process at 100 and 150°C for 90min significantly decreased the level of AFB1 by 41.9% and 81.2%, respectively (p<0.05). The reduction rate of AFB1 after cooking was 97.9% for soybean milk and 33.6% for steamed soybeans. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Evaluation of Clipping Based Iterative PAPR Reduction Techniques for FBMC Systems

    Directory of Open Access Journals (Sweden)

    Zsolt Kollár

    2014-01-01

    to conventional orthogonal frequency division multiplexing (OFDM technique. The low ACLR of the transmitted FBMC signal makes it especially favorable in cognitive radio applications, where strict requirements are posed on out-of-band radiation. Large dynamic range resulting in high peak-to-average power ratio (PAPR is characteristic of all sorts of multicarrier signals. The advantageous spectral properties of the high-PAPR FBMC signal are significantly degraded if nonlinearities are present in the transceiver chain. Spectral regrowth may appear, causing harmful interference in the neighboring frequency bands. This paper presents novel clipping based PAPR reduction techniques, evaluated and compared by simulations and measurements, with an emphasis on spectral aspects. The paper gives an overall comparison of PAPR reduction techniques, focusing on the reduction of the dynamic range of FBMC signals without increasing out-of-band radiation. An overview is presented on transmitter oriented techniques employing baseband clipping, which can maintain the system performance with a desired bit error rate (BER.

  5. Rational design of an on-site volume reduction system for source-separated urine.

    Science.gov (United States)

    Pahore, Muhammad Masoom; Ito, Ryusei; Funamizu, Naoyuki

    2010-04-01

    Human urine contains nitrogen, phosphorus and potassium, which can be applied as fertilizer in agriculture, replacing commercial fertilizer. However, owing to the low nutrient content of the urine, huge quantities must be transported to farmland to meet the nutrient demand of crops. This highly increases the transportation cost for the farmers. To address the transportation issue, a new on-site volume reduction system was tested at the laboratory scale based on water evaporation from vertical gauze sheets. A mathematical water transport model was proposed to evaluate the performance of the system. The mass transfer coefficient and the resistance of water flow through the sheet in the water transport model were obtained from the experiments. The results agreed with the simulated data, thereby confirming the proposed model. The model was then applied to the dry climate of southern Pakistan, having an air temperature of 30-40 degrees C and air humidity of 20-40%, for an 80% volume reduction of 10 L urine per day, which corresponds to a family of 10 members (average for a household in Pakistan). The findings revealed that the estimated size of the vertical sheet is 440-2060 cm2, which is only a small area for setting up the system at a household level.

  6. Main Properties of the THERAFLEX MB-Plasma System for Pathogen Reduction

    Science.gov (United States)

    Seghatchian, Jerard; Struff, Wilhelm G.; Reichenberg, Stefan

    2011-01-01

    Summary Methylene blue (MB) treated plasma has been in clinical use for 18 years. The current THERAFLEX MB-Plasma has a number of improved features compared with the original Springe methodology. This overview embodies: the biochemical characteristics of MB, the mechanism of the technology, toxicology, pathogen reduction capacity, current position in clinical setting and status within Europe. The THERAFLEX MB (TMB) procedure is a robust, well standardised system lending itself to transfusion setting and meets the current guidelines. The pathogen kill power of the TMB system, like the other available technologies, is not limitless, probably in order of 6 log for most enveloped viruses and considerably less for non-enveloped ones. It does not induce either new antigen or grossly reducing the function and life span of active principle in fresh frozen plasma (FFP). The removal of the residual MB at the end of the process has the beneficial effect of reducing potential toxic impacts. Clinical haemovigilance data, so far, indicate that cell-free MB plasma is effective in all therapeutic setting requiring FFP, besides inconsistent thrombotic thrombocytopenia purpura data, without serious side-effects or toxicity. The current system is in continuous improvement e.g. regarding virus reduction range, illumination device, software used, and process integration in the blood bank setting. PMID:21779206

  7. Reduction of nitrobenzene and formation of corrosion coatings in zerovalent iron systems.

    Science.gov (United States)

    Huang, Yong H; Zhang, Tian C

    2006-09-01

    Batch tests were conducted to investigate reduction of nitrobenzene in a zerovalent iron system (Fe0) under various conditions. The results indicated that a limited amount of nitrobenzene (ArNO2) could be reduced to aniline by Fe0, but formation of a lepidocrocite (gamma-FeOOH) coating could significantly slow down the reaction. However, augmenting Fe0 with substoichiometric FeCl2 could dramatically accelerate the reaction. Surface-adsorbed Fe(II), not pH nor Cl-, was found to be responsible for rejuvenating the system. O2 and nitrobenzene could be concomitantly reduced by Fe0 in the presence of Fe2+. In the Fe0 system, both nitrobenzene and O2 favored formation of lepidocrocite; in the presence of aq. Fe(II), a stratified corrosion coating could develop, with magnetite (Fe3O4) as the inner layer and lepidocrocite as the outer layer. Fe2+ was not the main reductant for the reactions, but might accelerate the autoreduction of lepidocrocite to magnetite by the underlying Fe0. Our understanding on the role of Fe(II) in conjunction with a stratified, evolving corrosion coating may be useful for establishing an iron aquatic corrosion model.

  8. Radiation dosage reduction in general dental practice using digital intraoral radiographic systems

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Yoshihiko; Shibuya, Hiroshi; Kuroyanagi, Kinya [Tokyo Dental Coll., Chiba (Japan); Ota, Yoshiko

    1997-02-01

    This report describes the radiation dosage reduction possible in the general dental practice with two CCD (charge-coupled device)-based intraoral radiographic systems; the RVG-S (Trophy Radiologie, Vincennes, France) and the Sens-A-Ray (Regam Medical Systems, Sundsvall, Sweden). Radiation dosages (air-kerma; Gy) necessary for obtaining clinically acceptable images were measured at the cone tip using an ionization chamber type 660-1 (Nuclear Associates, Victoreen, Inc., Carle Place, New York, USA). When the RVG-S was used with an Oramatic 70 (Trophy Radiologie) X-ray generator, dosages at the cone tip ranged from 322 to 612 {mu}Gy. These corresponded to 40-60% of the dosages necessary when using Ektaspeed dental X-ray film (Eastman Kodak, Rochester, New York, USA) with a Heliodent 70 (Siemens, Erlangen, Germany) X-ray generator. At 60 kVp, the Sens-A-Ray reduced the dosage in the order of 30% compared with Ektaspeed dental X-ray film. Reduction in radiation dosage is one of the benefits of digital intraoral radiographic systems in general dental clinics. The RVG-S provides greater dose savings than does the Sens-A-Ray. (author)

  9. [Reduction of nitrobenzene by iron oxides bound Fe(II) system at different pH values].

    Science.gov (United States)

    Luan, Fu-Bo; Xie, Li; Li, Jun; Zhou, Qi

    2009-07-15

    Batch tests were conducted to investigate the reductive transformation of nitrobenzene by goethite, hematite, magnetite and steel converter slag bound Fe(II) system. And the reduction mechanism was explored at different pH values. Experimental results showed that hematite, magnetite and steel converter slag could adsorb Fe(II) on surfaces and form iron oxides bound Fe(II) system at pH from 6.5 to 7.0. The systems had strong reductive capacity and could reduce nitrobenzene to aniline. The reduction efficiency of nitrobenzene in surface bound Fe(II) system followed the sequence of magnetite, hematite and steel converter slag from high to low. The reduction efficiency of hematite and magnetite system increased with pH increasing. While it was almost pH independent in steel converter slag system. Although goethite adsorbed most of Fe(II) in solution, the adsorbed Fe(II) had no reductive activity for nitrobenzene. At pH 6.0, small amount of Fe(II) was adsorbed on magnetite and hematite and the systems did not show reductive activity for nitrobenzene. However, steel converter slag could adsorb Fe(II) at pH 6.0 and reduction efficiency almost equaled to the value at pH 7.0. When pH was above 7.5, dissolved Fe(II) could be converted to Fe(OH)2 and the newly formed Fe(OH)2 became the main redactor in the system. Under alkali condition, the presence of iron oxides inhibited the reduction capacity of system.

  10. Update on Risk Reduction Activities for a Liquid Advanced Booster for NASA's Space Launch System

    Science.gov (United States)

    Crocker, Andrew M.; Greene, William D.

    2017-01-01

    The stated goals of NASA's Research Announcement for the Space Launch System (SLS) Advanced Booster Engineering Demonstration and/or Risk Reduction (ABEDRR) are to reduce risks leading to an affordable Advanced Booster that meets the evolved capabilities of SLS and enable competition by mitigating targeted Advanced Booster risks to enhance SLS affordability. Dynetics, Inc. and Aerojet Rocketdyne (AR) formed a team to offer a wide-ranging set of risk reduction activities and full-scale, system-level demonstrations that support NASA's ABEDRR goals. During the ABEDRR effort, the Dynetics Team has modified flight-proven Apollo-Saturn F-1 engine components and subsystems to improve affordability and reliability (e.g., reduce parts counts, touch labor, or use lower cost manufacturing processes and materials). The team has built hardware to validate production costs and completed tests to demonstrate it can meet performance requirements. State-of-the-art manufacturing and processing techniques have been applied to the heritage F-1, resulting in a low recurring cost engine while retaining the benefits of Apollo-era experience. NASA test facilities have been used to perform low-cost risk-reduction engine testing. In early 2014, NASA and the Dynetics Team agreed to move additional large liquid oxygen/kerosene engine work under Dynetics' ABEDRR contract. Also led by AR, the objectives of this work are to demonstrate combustion stability and measure performance of a 500,000 lbf class Oxidizer-Rich Staged Combustion (ORSC) cycle main injector. A trade study was completed to investigate the feasibility, cost effectiveness, and technical maturity of a domestically-produced engine that could potentially both replace the RD-180 on Atlas V and satisfy NASA SLS payload-to-orbit requirements via an advanced booster application. Engine physical dimensions and performance parameters resulting from this study provide the system level requirements for the ORSC risk reduction test article

  11. Combined heat and power systems for commercial buildings: investigating cost, emissions, and primary energy reduction based on system components

    Science.gov (United States)

    Smith, Amanda D.

    Combined heat and power (CHP) systems produce electricity and useful heat from fuel. When power is produced near a building which consumes power, transmission losses are averted, and heat which is a byproduct of power production may be useful to the building. That thermal energy can be used for hot water or space heating, among other applications. This dissertation focuses on CHP systems using natural gas, a common fuel, and systems serving commercial buildings in the United States. First, the necessary price difference between purchased electricity and purchased fuel is analyzed in terms of the efficiencies of system components by comparing CHP with a conventional separate heat and power (SHP) configuration, where power is purchased from the electrical grid and heat is provided by a gas boiler. Similarly, the relationship between CDE due to electricity purchases and due to fuel purchases is analyzed as well as the relationship between primary energy conversion factors for electricity and fuel. The primary energy conversion factor indicates the quantity of source energy necessary to produce the energy purchased at the site. Next, greenhouse gas emissions are investigated for a variety of commercial buildings using CHP or SHP. The relationship between the magnitude of the reduction in emissions and the parameters of the CHP system is explored. The cost savings and reduction in primary energy consumption are evaluated for the same buildings. Finally, a CHP system is analyzed with the addition of a thermal energy storage (TES) component, which can store excess thermal energy and deliver it later if necessary. The potential for CHP with TES to reduce cost, emissions, and primary energy consumption is investigated for a variety of buildings. A case study is developed for one building for which TES does provide additional benefits over a CHP system alone, and the requirements for a water tank TES device are examined.

  12. The DATCON system of the Belle II experiment. Tracking and data reduction

    Energy Technology Data Exchange (ETDEWEB)

    Wessel, Christian; Dingfelder, Jochen; Marinas, Carlos; Deschamps, Bruno [Universitaet Bonn (Germany). Physikalisches Institut

    2016-07-01

    The SuperKEKB e{sup +}e{sup -} accelerator at KEK in Japan will have a luminosity which is a factor of 40 higher than the luminosity of its predecessor KEKB. The Belle II detector at SuperKEKB will contain a two-layer pixel detector at radii of 1.421 and 2.179 cm from the interaction point, based on the DEPFET (DEpleted P-channel Field Effect Transistor) technology. It is surrounded by four layers of strip detectors. Due to the high collision rate, the data rate of the pixel detector needs to by drastically reduced by an online data reduction system. The DATCON (Data Acquisition Tracking and Concentrator Online Node) system performs track reconstruction in the SVD (Strip Vertex Detector) and extrapolates to the PXD (PiXel Detector) to calculate ROI and to keep only hits in the ROI. The track reconstruction algorithm is based on a Hough transform, which reduces track finding to finding intersection points in the Hough parameter space. In this talk the employed algorithm for fast online track reconstruction on FPGA, ROI finding and the performance of the data reduction are presented.

  13. Vibration reduction using autoparametric resonance in a high-Tc superconducting levitation system

    Science.gov (United States)

    Yamasaki, Hiroshi; Takazakura, Toyoki; Sakaguchi, Ryunosuke; Sugiura, Toshihiko

    2014-05-01

    High-Tc superconducting levitation systems have very small damping and enable stable levitation without control. Therefore, they can be applied to various kinds of application. However, there are some problems that small damping produces large vibration and nonlinearity of magnetic force can generate complicated phenomena. Accordingly, analysis of these phenomena and reduction of vibration occurring in the system are important. In this study, we examined reduction of vibration without using any absorbers, but utilizing autoparametric resonance caused by nonlinear coupling between vertical oscillation and horizontal oscillation. We conducted numerical analysis and experiments in order to investigate motions of a rigid bar levitated by the electromagnetic force from high-Tc superconductors. As a result, if the ratio of the natural frequency of vertical oscillation and that of horizontal oscillation is two to one, the vertical oscillation decreases while the horizontal oscillation is excited. Thus, it was confirmed that the amplitude of a primary resonance can be reduced by occurrence of autoparametric resonance without using any absorbers.

  14. Self-duality of the compactified Ruijsenaars-Schneider system from quasi-Hamiltonian reduction

    Energy Technology Data Exchange (ETDEWEB)

    Feher, L., E-mail: lfeher@rmki.kfki.hu [Department of Theoretical Physics, WIGNER RCP, RMKI, H-1525 Budapest, P.O.B. 49 (Hungary); Department of Theoretical Physics, University of Szeged, Tisza Lajos krt 84-86, H-6720 Szeged (Hungary); Klimcik, C., E-mail: klimcik@univmed.fr [Institut de mathematiques de Luminy, 163, Avenue de Luminy, F-13288 Marseille (France)

    2012-07-21

    The Delzant theorem of symplectic topology is used to derive the completely integrable compactified Ruijsenaars-Schneider III{sub b} system from a quasi-Hamiltonian reduction of the internally fused double SU(n) Multiplication-Sign SU(n). In particular, the reduced spectral functions depending respectively on the first and second SU(n) factor of the double engender two toric moment maps on the III{sub b} phase space CP(n-1) that play the roles of action-variables and particle-positions. A suitable central extension of the SL(2,Z) mapping class group of the torus with one boundary component is shown to act on the quasi-Hamiltonian double by automorphisms and, upon reduction, the standard generator S of the mapping class group is proved to descend to the Ruijsenaars self-duality symplectomorphism that exchanges the toric moment maps. We give also two new presentations of this duality map: one as the composition of two Delzant symplectomorphisms and the other as the composition of three Dehn twist symplectomorphisms realized by Goldman twist flows. Through the well-known relation between quasi-Hamiltonian manifolds and moduli spaces, our results rigorously establish the validity of the interpretation [going back to Gorsky and Nekrasov] of the III{sub b} system in terms of flat SU(n) connections on the one-holed torus.

  15. Simultaneous arsenite oxidation and nitrate reduction at the electrodes of bioelectrochemical systems.

    Science.gov (United States)

    Nguyen, Van Khanh; Park, Younghyun; Yu, Jaecheul; Lee, Taeho

    2016-10-01

    Arsenic and nitrate contaminations in the soil and groundwater have urged the scientific community to explore suitable technologies for treatment of both contaminants. This study reports, for the first time, a novel application of bioelectrochemical systems for coupling As detoxification at the anode and denitrification at the cathode. A similar As(III) oxidation efficiency was achieved when anode potential was controlled by a potentiostat or a direct current (DC) power supply. However, a slightly lower nitrate reduction rate was obtained in reactors using DC power supply during simultaneous operation of nitrate reduction and As(III) oxidation. Microbial community analysis by denaturing gradient gel electrophoresis indicated the presence of some autotrophic As(III)-oxidizing bacteria, including Achromobacter spp., Ensifer spp., and Sinorhizobium spp., that can flexibly switch their original metabolism of using oxygen as sole electron acceptor to a new metabolism mode of using solid-state anode as sole electron acceptor driving for As(III) oxidation under anaerobic conditions. Although further research is required for validating their applicability, bioelectrochemical systems represent a brilliant technology for remediation of groundwater contaminated with nitrate and/or arsenite.

  16. Energy-efficient data reduction techniques for wireless seizure detection systems.

    Science.gov (United States)

    Chiang, Joyce; Ward, Rabab K

    2014-01-24

    The emergence of wireless sensor networks (WSNs) has motivated a paradigm shift in patient monitoring and disease control. Epilepsy management is one of the areas that could especially benefit from the use of WSN. By using miniaturized wireless electroencephalogram (EEG) sensors, it is possible to perform ambulatory EEG recording and real-time seizure detection outside clinical settings. One major consideration in using such a wireless EEG-based system is the stringent battery energy constraint at the sensor side. Different solutions to reduce the power consumption at this side are therefore highly desired. The conventional approach incurs a high power consumption, as it transmits the entire EEG signals wirelessly to an external data server (where seizure detection is carried out). This paper examines the use of data reduction techniques for reducing the amount of data that has to be transmitted and, thereby, reducing the required power consumption at the sensor side. Two data reduction approaches are examined: compressive sensing-based EEG compression and low-complexity feature extraction. Their performance is evaluated in terms of seizure detection effectiveness and power consumption. Experimental results show that by performing low-complexity feature extraction at the sensor side and transmitting only the features that are pertinent to seizure detection to the server, a considerable overall saving in power is achieved. The battery life of the system is increased by 14 times, while the same seizure detection rate as the conventional approach (95%) is maintained.

  17. System for the Reduction of Substances in Reject Water from Reed-Bed Sludge Mineralization Plants

    DEFF Research Database (Denmark)

    2004-01-01

    The invention is a system for the reduction of substances in reject water from reed-bed sludge mineralization plants (also referred to as sludge dewatering reed-beds). The systems utilizes the composition of substances in reject water from reed-beds and that of sludge to reduce substance mass from...... the reject water via recirculation into a mixed reactor and back onto the reed-beds. The mixed rector consists of a container in which sludge (that is typically loaded directly on to reed-beds) is mixed with recirculated reject water from reed-beds. The sludge mixture has a definable hydraulic retention time...... within the container. The solution is then applied to the reed-beds, which dewaters, converts, and partially mineralize the sludge mixture. The reject water from the reed-beds is split where up to100% of the reject water is recirculated back to the mixed reactor and the remaining usually disposed...

  18. DEMONSTRATION OF AN ADVANCED INTEGRATED CONTROL SYSTEM FOR SIMULTANEOUS EMISSIONS REDUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Suzanne Shea; Randhir Sehgal; Ilga Celmins; Andrew Maxson

    2002-02-01

    The primary objective of the project titled ''Demonstration of an Advanced Integrated Control System for Simultaneous Emissions Reduction'' was to demonstrate at proof-of-concept scale the use of an online software package, the ''Plant Environmental and Cost Optimization System'' (PECOS), to optimize the operation of coal-fired power plants by economically controlling all emissions simultaneously. It combines physical models, neural networks, and fuzzy logic control to provide both optimal least-cost boiler setpoints to the boiler operators in the control room, as well as optimal coal blending recommendations designed to reduce fuel costs and fuel-related derates. The goal of the project was to demonstrate that use of PECOS would enable coal-fired power plants to make more economic use of U.S. coals while reducing emissions.

  19. Dynamic Control System Performance during Commissioning of the Space Technology 7-Disturbance Reduction System Experiment of LISA Pathfinder

    Science.gov (United States)

    Hsu, Oscar; Maghami, Peiman; O’Donnell, James R., Jr.; Ziemer, John; Romero-Wolf, Andrew

    2017-01-01

    The Space Technology-7 Disturbance Reduction System (DRS) launched aboard the European Space Agency's LISA Pathfinder spacecraft on December 3, 2015, after more than a decade in development. DRS consists of three primary components: an Integrated Avionics Unit (IAU), Colloidal MicroNewton Thrusters, and Dynamic Control System (DCS) algorithms implemented on the IAU. During the portions of the mission in which the DRS was under control, the DCS was responsible for controlling the spacecraft and the free-floating test masses that were part of the LISA Test Package. The commissioning period was originally divided into two periods: before propulsion separation and after propulsion separation. A recommissioning period was added after an anomaly occurred in the thruster system. The paper will describe the activities used to commission DRS, present results from the commissioning of the DCS and the recommissioning activities per-formed after the thruster anomaly.

  20. Application of variance reduction technique to nuclear transmutation system driven by accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Sasa, Toshinobu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    In Japan, it is the basic policy to dispose the high level radioactive waste arising from spent nuclear fuel in stable deep strata after glass solidification. If the useful elements in the waste can be separated and utilized, resources are effectively used, and it can be expected to guarantee high economical efficiency and safety in the disposal in strata. Japan Atomic Energy Research Institute proposed the hybrid type transmutation system, in which high intensity proton accelerator and subcritical fast core are combined, or the nuclear reactor which is optimized for the exclusive use for transmutation. The tungsten target, minor actinide nitride fuel transmutation system and the melted minor actinide chloride salt target fuel transmutation system are outlined. The conceptual figures of both systems are shown. As the method of analysis, Version 2.70 of Lahet Code System which was developed by Los Alamos National Laboratory in USA was adopted. In case of carrying out the analysis of accelerator-driven subcritical core in the energy range below 20 MeV, variance reduction technique must be applied. (K.I.)

  1. Integrable reductions of the Bogoyavlenskij-Itoh Lotka-Volterra systems

    Science.gov (United States)

    Damianou, P. A.; Evripidou, C. A.; Kassotakis, P.; Vanhaecke, P.

    2017-03-01

    Given a constant skew-symmetric matrix A, it is a difficult open problem whether the associated Lotka-Volterra system is integrable or not. We solve this problem in a special case when A is a Toeplitz matrix where all off-diagonal entries are plus or minus one. In this case, the associated Lotka-Volterra system turns out to be a reduction of Liouville integrable systems, whose integrability was shown by Bogoyavlenskij and Itoh. We prove that the reduced systems are also Liouville integrable and that they are also non-commutative integrable by constructing a set of independent first integrals, having the required involutive properties (with respect to the Poisson bracket). These first integrals fall into two categories. One set consists of polynomial functions that are restriction of the Bogoyavlenskij-Itoh integrals; their involutivity was already pointed out by Bogoyavlenskij. The other set consists of rational functions which are obtained through a Poisson map from the first integrals of some recently discovered superintegrable Lotka-Volterra systems. The fact that these polynomial and rational first integrals, combined, have the required properties for Liouville and non-commutative integrability is quite remarkable; the quite technical proof of functional independence of the first integrals is given in detail.

  2. The impact of BPO on cost reduction in mid-sized health care systems.

    Science.gov (United States)

    Perry, Andy; Kocakülâh, Mehmet C

    2010-01-01

    At the convergence of two politico-economic "hot topics" of the day--outsourcing and the cost of health care-lie opportunities for mid-sized health systems to innovate, collaborate, and reduce overhead. Competition in the retail health care market can serve as both an impetus and an inhibitor to such measures, though. Here we are going to address the motivations, influences, opportunities, and limitations facing mid-sized, US non-profit health systems in business process outsourcing (BPO). Advocates cite numerous benefits to BPO, particularly in cost reduction and strategy optimization. BPO can elicit cost savings due to specialization among provider firms, returns to scale and technology, standardization and automation, and gains in resource arbitrage (off-shoring capabilities). BPO can also free an organization of non-critical tasks and focus resources on core competencies (treating patients). The surge in BPO utilization has rarely extended to the back-office functions of many mid-sized health systems. Health care providers, still a largely fragmented bunch with many rural, independent non-profit systems, have not experienced the consolidation and organizational scale growth to make BPO as attractive as other industries. Smaller firms, spurning merger and acquisition pressure from large, tertiary health systems, often wish to retain their autonomy and identity; hence, they face a competitive cost disadvantage compared to their larger competitors. This article examines the functional areas for these health systems in which BPO is not currently utilized and dissects the various methods available in which to practice BPO. We assess the ongoing adoption of BPO in these areas as well as the barriers to adoption, and identify the key processes that best represent opportunity for success. An emphasis is placed on a collaborative model with other health systems compared to a single system, unilateral BPO arrangement.

  3. Effectiveness of an ultraviolet-C disinfection system for reduction of healthcare-associated pathogens.

    Science.gov (United States)

    Yang, Jui-Hsuan; Wu, Un-In; Tai, Huei-Min; Sheng, Wang-Huei

    2017-09-18

    Healthcare-associated infections caused by multidrug-resistant (MDR) pathogens are significantly associated with increased mortality and morbidity. Environmental cleaning can reduce transmission of these pathogens but is often inadequate. Adjunctive methods are warranted to enhance the effectiveness of disinfection particularly in hospital settings where healthcare-associated infections are of major concern. We conducted a study to examine the effectiveness of a mobile, automatic device, Hyper Light Disinfection Robot (model: Hyper Light P3), which utilized ultraviolet-C (UV-C) to kill MDR-Pseudomonas aeruginosa, MDR- Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium (VRE), Mycobacterium abscessus and Aspergillus fumigatus. The performance of this device in disinfecting hospital rooms previously admitted by patients harboring MRSA and VRE was also assessed. Except for VRE and M. abscessus, more than 3 log 10 reduction of vegetative bacteria colonies was observed after UV-C irradiation of 5 min at a distance of 3 m from the device. At the distance of 1 m, substantial and comparable reduction of colonies was observed across all tested microorganisms regardless of exposure time. The killing effect was less pronounced for A. fumigatus particularly at the distance of 2-3 m. In uncleaned hospital rooms, there was significant reduction in the number of bacteria colonies sampled from different surfaces after UV-C irradiation for 15 min. UV-C disinfection system was effective in killing MDR pathogens. Further study is warranted to confirm its effectiveness as an adjunctive method in disinfecting hospital environment. Copyright © 2017. Published by Elsevier B.V.

  4. Nitrate reduction in a simulated free-water surface wetland system.

    Science.gov (United States)

    Misiti, Teresa M; Hajaya, Malek G; Pavlostathis, Spyros G

    2011-11-01

    The feasibility of using a constructed wetland for treatment of nitrate-contaminated groundwater resulting from the land application of biosolids was investigated for a site in the southeastern United States. Biosolids degradation led to the release of ammonia, which upon oxidation resulted in nitrate concentrations in the upper aquifer in the range of 65-400 mg N/L. A laboratory-scale system was constructed in support of a pilot-scale project to investigate the effect of temperature, hydraulic retention time (HRT) and nitrate and carbon loading on denitrification using soil and groundwater from the biosolids application site. The maximum specific reduction rates (MSRR), measured in batch assays conducted with an open to the atmosphere reactor at four initial nitrate concentrations from 70 to 400 mg N/L, showed that the nitrate reduction rate was not affected by the initial nitrate concentration. The MSRR values at 22 °C for nitrate and nitrite were 1.2 ± 0.2 and 0.7 ± 0.1 mg N/mg VSS(COD)-day, respectively. MSRR values were also measured at 5, 10, 15 and 22 °C and the temperature coefficient for nitrate reduction was estimated at 1.13. Based on the performance of laboratory-scale continuous-flow reactors and model simulations, wetland performance can be maintained at high nitrogen removal efficiency (>90%) with an HRT of 3 days or higher and at temperature values as low as 5 °C, as long as there is sufficient biodegradable carbon available to achieve complete denitrification. The results of this study show that based on the climate in the southeastern United States, a constructed wetland can be used for the treatment of nitrate-contaminated groundwater to low, acceptable nitrate levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. ANP system activity predicts variability of fat mass reduction and insulin sensitivity during weight loss.

    Science.gov (United States)

    Brachs, Maria; Wiegand, Susanna; Leupelt, Verena; Ernert, Andrea; Kintscher, Ulrich; Jumpertz von Schwarzenberg, Reiner; Decker, Anne-Marie; Bobbert, Thomas; Hübner, Norbert; Chen, Wei; Krude, Heiko; Spranger, Joachim; Mai, Knut

    2016-06-01

    In weight loss trials, a considerable inter-individual variability in reduction of fat mass and changes of insulin resistance is observed, even under standardized study conditions. The underlying mechanisms are not well understood. Given the metabolic properties of the atrial natriuretic peptide (ANP) system, we hypothesized that ANP signaling might be involved in this phenomenon by changes of ANP secretion or receptor balance. Therefore, we investigated the impact of systemic, adipose and myocellular ANP system on metabolic and anthropometric improvements during weight loss. We comprehensively investigated 143 subjects (31 male, 112 female) before and after a 3 month-standardized weight loss program. The time course of BMI, fat mass, insulin sensitivity, circulating mid-regional proANP (MR-proANP) levels as well as adipose and myocellular natriuretic receptor A (NPR-A) and C (NPR-C) mRNA expression were investigated. BMI decreased by -12.6±3.7%. This was accompanied by a remarkable decrease of adipose NPR-C expression (1005.0±488.4 vs. 556.7±465.6; pANP receptor expression predicted the degree of weight loss induced fat mass reduction. Our comprehensive human data support that peripheral ANP signalling is involved in control of adipose tissue plasticity and function during weight loss. (Funded by the Deutsche Forschungsgemeinschaft (KFO281/2), the Berlin Institute of Health (BIH) and the German Centre for Cardiovascular Research (DZHK/BMBF); ClinicalTrials.gov number: NCT00850629). Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Stability Optimization of a Disc Brake System with Hybrid Uncertainties for Squeal Reduction

    Directory of Open Access Journals (Sweden)

    Hui Lü

    2016-01-01

    Full Text Available A hybrid uncertain model is introduced to deal with the uncertainties existing in a disc brake system in this paper. By the hybrid uncertain model, the uncertain parameters of the brake with enough sampling data are treated as probabilistic variables, while the uncertain parameters with limited data are treated as interval probabilistic variables whose distribution parameters are expressed as interval variables. Based on the hybrid uncertain model, the reliability-based design optimization (RBDO of a disc brake with hybrid uncertainties is proposed to explore the optimal design for squeal reduction. In the optimization, the surrogate model of the real part of domain unstable eigenvalue of the brake system is established, and the upper bound of its expectation is adopted as the optimization objective. The lower bounds of the functions related to system stability, the mass, and the stiffness of design component are adopted as the optimization constraints. The combinational algorithm of Genetic Algorithm and Monte-Carlo method is employed to perform the optimization. The results of a numerical example demonstrate the effectiveness of the proposed optimization on improving system stability and reducing squeal propensity of a disc brake under hybrid uncertainties.

  7. Formation and reduction of furan in a soy sauce model system.

    Science.gov (United States)

    Kim, Min Yeop; Her, Jae-Young; Kim, Mina K; Lee, Kwang-Geun

    2015-12-15

    The formation and reduction of furan using a soy sauce model system were investigated in the present study. The concentration of furan fermented up to 30 days increased by 211% after sterilization compared to without sterilization. Regarding fermentation temperature, furan level after 30 days' fermentation was the highest at 30°C (86.21 ng/mL). The furan levels in the soy sauce fermentation at 20°C and 40°C were reduced by 45% and 88%, respectively compared to 30°C fermentation. Five metal ions (iron sulfate, zinc sulfate, manganese sulfate, magnesium sulfate, and calcium sulfate), sodium sulfite, ascorbic acid, dibutyl hydroxyl toluene (BHT), and butylated hydroxyanisole (BHA) were added in a soy sauce model system. The addition of metal ions such as magnesium sulfate and calcium sulfate reduced the furan concentration significantly by 36-90% and 27-91%, respectively in comparison to furan level in the control sample (psauce model system by 278% and 87%, respectively. In the case of the BHT and BHA, furan formation generally was reduced in the soy sauce model system by 84%, 56%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. INVESTIGATION OF AMMONIA ADSORPTION ON FLY ASH DUE TO INSTALLATION OF SELECTIVE CATALYTIC REDUCTION SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    G.F. Brendel; J.E. Bonetti; R.F. Rathbone; R.N. Frey Jr.

    2000-11-01

    This report summarizes an investigation of the potential impacts associated with the utilization of selective catalytic reduction (SCR) systems at coal-fired power plants. The study was sponsored by the U.S. Department of Energy Emission Control By-Products Consortium, Dominion Generation, the University of Kentucky Center for Applied Energy Research and GAI Consultants, Inc. SCR systems are effective in reducing nitrogen oxides (NOx) emissions as required by the Clean Air Act (CAA) Amendments. However, there may be potential consequences associated with ammonia contamination of stack emissions and combustion by-products from these systems. Costs for air quality, landfill and pond environmental compliance may increase significantly and the marketability of ash may be seriously reduced, which, in turn, may also lead to increased disposal costs. The potential impacts to air, surface water, groundwater, ash disposal, ash utilization, health and safety, and environmental compliance can not be easily quantified based on the information presently available. The investigation included: (1) a review of information and data available from published and unpublished sources; (2) baseline ash characterization testing of ash samples produced from several central Appalachian high-volatile bituminous coals from plants that do not currently employ SCR systems in order to characterize the ash prior to ammonia exposure; (3) an investigation of ammonia release from fly ash, including leaching and thermal studies; and (4) an evaluation of the potential impacts on plant equipment, air quality, water quality, ash disposal operations, and ash marketing.

  9. Using Dimensionality Reduction Techniques for Refining Passive Indoor Positioning Systems Based on Radio Fingerprinting.

    Science.gov (United States)

    Lopez-de-Teruel, Pedro E; Canovas, Oscar; Garcia, Felix J

    2017-04-15

    Indoor positioning methods based on fingerprinting and radio signals rely on the quality of the radio map. For example, for room-level classification purposes, it is required that the signal observations related to each room exhibit significant differences in their RSSI values. However, it is difficult to verify and visualize that separability since radio maps are constituted by multi-dimensional observations whose dimension is directly related to the number of access points or monitors being employed for localization purposes. In this paper, we propose a refinement cycle for passive indoor positioning systems, which is based on dimensionality reduction techniques, to evaluate the quality of a radio map. By means of these techniques and our own data representation, we have defined two different visualization methods to obtain graphical information about the quality of a particular radio map in terms of overlapping areas and outliers. That information will be useful to determine whether new monitors are required or some existing ones should be moved. We have performed an exhaustive experimental analysis based on a variety of different scenarios, some deployed by our own research group and others corresponding to a well-known existing dataset widely analyzed by the community, in order to validate our proposal. As we will show, among the different combinations of data representation methods and dimensionality reduction techniques that we discuss, we have found that there are some specific configurations that are more useful in order to perform the refinement process.

  10. Rules of thumb for assessing reductive dechlorination pathways of PCDDs in specific systems.

    Science.gov (United States)

    Lu, Gui-Ning; Dang, Zhi; Fennell, Donna E; Huang, Weilin; Li, Zhong; Liu, Cong-Qiang

    2010-05-15

    This paper reports a theoretical validation and proposition of the reductive dechlorination pathways for polychlorinated dibenzo-p-dioxin (PCDD) congeners. Density functional theory (DFT) calculations were carried out at the B3LYP/6-31G(d) level for all PCDDs and Mulliken atomic charges on chlorine atoms were adopted as the probe of the dechlorination reaction activity. The experimentally substantiated dechlorination pathways of 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD) and its daughter products in the presence of zero-valent zinc were validated and the complete pathway of dechlorination of octachlorodibenzo-p-dioxin (OCDD) was proposed. The proposed pathways were found to be consistent with anaerobic biotransformation of several PCDD congeners. Four rules of thumb arrived from this study include (1) the chlorine atoms in the longitudinal (1,4,6,9) positions are removed in preference to the chlorine atoms on lateral (2,3,7,8) positions; (2) the chlorine atom that has more neighboring chlorine atoms at ortho-, meta- and para-positions is to be eliminated; (3) reductive dechlorination prefers to take place on the benzene ring having more chlorine substitutions; and (4) a chlorine atom on the side of the longitudinal symmetry axis containing more chlorine atoms is preferentially eliminated. These rules of thumb can be conveniently used for rapidly predicting the major dechlorination pathway for a given PCDD in specific systems. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  11. FUGITIVE EMISSION REDUCTIONS DUE TO THE USE OF ENCLOSED DOCTOR BLADE SYSTEMS IN THE FLEXOGRAPHIC AND ROTOGRAVURE PRINTING INDUSTRIES

    Science.gov (United States)

    The report gives results of a quantification of the level of fugitive emission reductions resulting from the use of enclosed doctor blade (EDB) systems in place of traditional ink feed systems at flexographic and rotogravure printing operations. An EDB system is an innovative ink...

  12. Reduction in alert fatigue in an assisted electronic prescribing system, through the Lean Six Sigma methodology.

    Science.gov (United States)

    Cuéllar Monreal, Mª Jesús; Reig Aguado, Jorge; Font Noguera, Isabel; Poveda Andrés, José Luis

    2017-01-01

    To reduce the alert fatigue in our Assisted Electronic Prescribing System (AEPS), through the Lean Six Sigma (LSS) methodology. An observational (transversal) and retrospective study, in a general hospital with 850 beds and AEPS. The LSS methodology was followed in order to evaluate the alert fatigue situation in the AEPS system, to implement improvements, and to assess outcomes. The alerts generated during two trimesters studied (before and after the intervention) were analyzed. In order to measure the qualitative indicators, the most frequent alert types were analyzed, as well as the molecules responsible for over 50% of each type of alert. The action by the prescriber was analyzed in a sample of 496 prescriptions that generated such alerts. For each type of alert and molecule, there was a prioritization of the improvements to be implemented according to the alert generated and its quality. A second survey evaluated the pharmacist action for the alerts most highly valued by physicians. The problem, the objective, the work team and the project schedule were defined. A survey was designed in order to understand the opinion of the client about the alert system in the program. Based on the surveys collected (n = 136), the critical characteristics and the quanti/qualitative indicators were defined. Sixty (60) fields in the alert system were modified, corresponding to 32 molecules, and this led to a 28% reduction in the total number of alerts. Regarding quality indicators, false po sitive results were reduced by 25% (p < 0.05), 100% of those alerts ignored with justification were sustained, and there were no significant differences in user adherence to the system. The project improvements and outcomes were reviewed by the work team. LSS methodology has demonstrated being a valid tool for the quantitative and qualitative improvement of the alert system in an Assisted Electronic Prescription Program, thus reducing alert fatigue. Copyright AULA MEDICA EDICIONES 2014

  13. Puncture Reduction in Percutaneous Transforaminal Endoscopic Discectomy with HE's Lumbar LOcation (HELLO) System: A Cadaver Study.

    Science.gov (United States)

    Fan, Guoxin; Guan, Xiaofei; Sun, Qi; Hu, Annan; Zhu, Yanjie; Gu, Guangfei; Zhang, Hailong; He, Shisheng

    2015-01-01

    Percutaneous transforaminal endoscopic discectomy (PTED) usually requires numerous punctures under X-ray fluoroscopy. Repeated puncture will lead to more radiation exposure and reduce the beginners' confidence. This cadaver study aimed to investigate the efficacy of HE's Lumbar Location (HELLO) system in puncture reduction of PTED. Cadaver study. Comparative groups. HELLO system consists of self-made surface locator and puncture locator. One senior surgeon conducted the puncture procedure of PTED on the left side of 20 cadavers at L4/L5 and L5/S1 level with the assistance of HELLO system (Group A). Additionally, the senior surgeon conducted the puncture procedure of PTED on the right side of the cadavers at L4/L5 and L5/S1 level with traditional methods (Group B). On the other hand, an inexperienced surgeon conducted the puncture procedure of PTED on the left side of the cadavers at L4/L5 and L5/S1 level with the assistance of our HELLO system (Group C). At L4/L5 level, there was significant difference in puncture times between Group A and Group B (PHELLO system reduced 39%-45% radiation dosage when comparing Group A and Group B, but there was no significant difference in radiation exposure between Group A and Group C whatever at L4/L5 level or L5/S1 level (P>0.05). There was no difference in location time between Group A and Group B or Group A and Group C either at L4/L5 level or L5/S1 level (P>0.05). Small-sample preclinical study. HELLO system was effective in reducing puncture times, fluoroscopy time and radiation exposure, as well as the difficulty of learning PTED. (2015-RES-127).

  14. Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS)

    Science.gov (United States)

    Alexander, Tiffaney Miller

    2017-01-01

    Research results have shown that more than half of aviation, aerospace and aeronautics mishaps incidents are attributed to human error. As a part of Safety within space exploration ground processing operations, the identification and/or classification of underlying contributors and causes of human error must be identified, in order to manage human error. This research provides a framework and methodology using the Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS), as an analysis tool to identify contributing factors, their impact on human error events, and predict the Human Error probabilities (HEPs) of future occurrences. This research methodology was applied (retrospectively) to six (6) NASA ground processing operations scenarios and thirty (30) years of Launch Vehicle related mishap data. This modifiable framework can be used and followed by other space and similar complex operations.

  15. Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS)

    Science.gov (United States)

    Alexander, Tiffaney Miller

    2017-01-01

    Research results have shown that more than half of aviation, aerospace and aeronautics mishaps incidents are attributed to human error. As a part of Quality within space exploration ground processing operations, the identification and or classification of underlying contributors and causes of human error must be identified, in order to manage human error.This presentation will provide a framework and methodology using the Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS), as an analysis tool to identify contributing factors, their impact on human error events, and predict the Human Error probabilities (HEPs) of future occurrences. This research methodology was applied (retrospectively) to six (6) NASA ground processing operations scenarios and thirty (30) years of Launch Vehicle related mishap data. This modifiable framework can be used and followed by other space and similar complex operations.

  16. Reduction of a linear complex model for respiratory system during Airflow Interruption.

    Science.gov (United States)

    Jablonski, Ireneusz; Mroczka, Janusz

    2010-01-01

    The paper presents methodology of a complex model reduction to its simpler version - an identifiable inverse model. Its main tool is a numerical procedure of sensitivity analysis (structural and parametric) applied to the forward linear equivalent designed for the conditions of interrupter experiment. Final result - the reduced analog for the interrupter technique is especially worth of notice as it fills a major gap in occlusional measurements, which typically use simple, one- or two-element physical representations. Proposed electrical reduced circuit, being structural combination of resistive, inertial and elastic properties, can be perceived as a candidate for reliable reconstruction and quantification (in the time and frequency domain) of dynamical behavior of the respiratory system in response to a quasi-step excitation by valve closure.

  17. Final report LDRD project 105816 : model reduction of large dynamic systems with localized nonlinearities.

    Energy Technology Data Exchange (ETDEWEB)

    Lehoucq, Richard B.; Segalman, Daniel Joseph; Hetmaniuk, Ulrich L. (University of Washington, Seattle, WA); Dohrmann, Clark R.

    2009-10-01

    Advanced computing hardware and software written to exploit massively parallel architectures greatly facilitate the computation of extremely large problems. On the other hand, these tools, though enabling higher fidelity models, have often resulted in much longer run-times and turn-around-times in providing answers to engineering problems. The impediments include smaller elements and consequently smaller time steps, much larger systems of equations to solve, and the inclusion of nonlinearities that had been ignored in days when lower fidelity models were the norm. The research effort reported focuses on the accelerating the analysis process for structural dynamics though combinations of model reduction and mitigation of some factors that lead to over-meshing.

  18. NOAA's Joint Polar Satellite System's Proving Ground and Risk Reduction Program - Bringing New Capabilities to Operations!

    Science.gov (United States)

    Sjoberg, B.

    2015-12-01

    This presentation will focus on the NOAA Joint Polar Satellite System (JPSS) Program's Proving Ground and Risk Reduction (PGRR) initiative and how it has prepared NOAA users to effectively utilize new polar-orbiting capabilities. The PGRR Program was established in 2012, following the launch of the Suomi National Polar Partnership (SNPP) satellite. Two sets of PGRR Projects have been established grouped together in thirteen different initiatives. Details about how these projects have been continually tailored through the years to meet user requirements, will be highlighted. The presenter will focus on how the success of the first set of PGRR projects have been used to evaluate a follow-on set of projects and focus on exactly what the JPSS user community needs to meet their mission requirements. Details on the Dec 2014 PGRR Call-for-Proposals and the projects selected for funding will be discussed.

  19. Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS)

    Science.gov (United States)

    Alexander, Tiffaney Miller

    2017-01-01

    Research results have shown that more than half of aviation, aerospace and aeronautics mishaps/incidents are attributed to human error. As a part of Safety within space exploration ground processing operations, the identification and/or classification of underlying contributors and causes of human error must be identified, in order to manage human error. This research provides a framework and methodology using the Human Error Assessment and Reduction Technique (HEART) and Human Factor Analysis and Classification System (HFACS), as an analysis tool to identify contributing factors, their impact on human error events, and predict the Human Error probabilities (HEPs) of future occurrences. This research methodology was applied (retrospectively) to six (6) NASA ground processing operations scenarios and thirty (30) years of Launch Vehicle related mishap data. This modifiable framework can be used and followed by other space and similar complex operations.

  20. Active noise reduction systems: Their interaction with very low frequency acoustical energy

    Science.gov (United States)

    Crabtree, R. Brian

    1994-08-01

    Active noise reduction (ANR) is used for reducing noise at the ears of an observer through the action of interfering sound waves. Noise sensed by a microphone built into the observer's headset or helmet is processed and reintroduced into the ear cup cavity out of phase with the original sound, thus cancelling the noise at the ear. Recent field experience has shown that system exposure to very high amplitude low-frequency sound, such as during the operation of helicopters, can lead to saturation or overload of the ANR electronics. Experiments using acoustical maniquins were conducted to assess the low-frequency behavior of ANR equipment. Results of measurement of the threshold of overload indicated large differences in the saturation thresholds among systems tested. Performance strongly depended on the integrity of the ear seal. Those systems offering active attenuation into the infrasound region tended to saturate most easily, but did create the best listening condition for the user when operated below the saturation threshold.

  1. Estimation of Conservation Voltage Reduction Factors Using Measurement Data of KEPCO System

    Directory of Open Access Journals (Sweden)

    Kwan-Shik Shim

    2017-12-01

    Full Text Available This paper describes a method to estimate conservation voltage reduction (CVR factors using data measured in power distribution systems. A direct method is proposed to estimate CVR factors using only data measured at the moment of the transformer tap change. The mean absolute deviation (MAD direct method is proposed to consider direct methods and load variations. The proposed methods do not necessitate intentional tap changes for testing purposes. Instead, the voltage and load changes that occur when the tap changes, for voltage regulation purposes, are measured and utilized in the CVR factor calculation. The proposed methods were tested using data obtained from the Korea Electric Power Corporation (KEPCO system, and the results revealed that CVR factors for both active power and reactive power could be estimated using data measured in power distribution systems. Results of the CVR factor estimation for the active power revealed that the highest CVR factors occurred in winter, during which a large quantity of heating loads exist. In addition, the estimated CVR factors for the reactive power were higher than the estimated CVR factors for the active power because reactive power is more sensitive to voltage changes.

  2. Optimized design of suspension systems for hand-arm transmitted vibration reduction

    Science.gov (United States)

    Saggin, Bortolino; Scaccabarozzi, Diego; Tarabini, Marco

    2012-05-01

    This paper describes a systematic approach for optimizing suspension systems to reduce the vibrations transmitted to workers by hand-held power tools. The optimization is based on modeling tool-operator interactions using a mobility scheme. The tool is modeled as a vibration generator, and its internal impedance is included. A hand-arm impedance matrix is used to model the operator upper limbs. The mobility model is used to identify the optimal suspension characteristics, which in our study were the set of parameters that minimizes the frequency-weighted acceleration at the hand-tool interface. Different handling conditions (one and two hands) and different working cycles with the same tools can be included in the optimization process. The constraints derived from the limitation on the increase in the tool mass and the static deflection of the mounting system under the working loads are also considered. The proposed method has been applied to the reduction of the vibrations transmitted to the operator by a small pneumatic hammer. The designed system reduced the worker's exposure so that it is within the limits of the EU directive. The agreement between the model predictions and the measured suspension performances validates the effectiveness of this approach.

  3. Improved Kalman filter method for measurement noise reduction in multi sensor RFID systems.

    Science.gov (United States)

    Eom, Ki Hwan; Lee, Seung Joon; Kyung, Yeo Sun; Lee, Chang Won; Kim, Min Chul; Jung, Kyung Kwon

    2011-01-01

    Recently, the range of available radio frequency identification (RFID) tags has been widened to include smart RFID tags which can monitor their varying surroundings. One of the most important factors for better performance of smart RFID system is accurate measurement from various sensors. In the multi-sensing environment, some noisy signals are obtained because of the changing surroundings. We propose in this paper an improved Kalman filter method to reduce noise and obtain correct data. Performance of Kalman filter is determined by a measurement and system noise covariance which are usually called the R and Q variables in the Kalman filter algorithm. Choosing a correct R and Q variable is one of the most important design factors for better performance of the Kalman filter. For this reason, we proposed an improved Kalman filter to advance an ability of noise reduction of the Kalman filter. The measurement noise covariance was only considered because the system architecture is simple and can be adjusted by the neural network. With this method, more accurate data can be obtained with smart RFID tags. In a simulation the proposed improved Kalman filter has 40.1%, 60.4% and 87.5% less mean squared error (MSE) than the conventional Kalman filter method for a temperature sensor, humidity sensor and oxygen sensor, respectively. The performance of the proposed method was also verified with some experiments.

  4. Peak-to-average power ratio reduction in interleaved OFDMA systems

    KAUST Repository

    Al-Shuhail, Shamael

    2015-12-07

    Orthogonal frequency division multiple access (OFDMA) systems suffer from several impairments, and communication system engineers use powerful signal processing tools to combat these impairments and to keep up with the capacity/rate demands. One of these impairments is high peak-to-average power ratio (PAPR) and clipping is the simplest peak reduction scheme. However, in general, when multiple users are subjected to clipping, frequency domain clipping distortions spread over the spectrum of all users. This results in compromised performance and hence clipping distortions need to be mitigated at the receiver. Mitigating these distortions in multiuser case is not simple and requires complex clipping mitigation procedures at the receiver. However, it was observed that interleaved OFDMA presents a special structure that results in only self-inflicted clipping distortions (i.e., the distortions of a particular user do not interfere with other users). In this work, we prove analytically that distortions do not spread over multiple users (while utilizing interleaved carrier assignment in OFDMA) and construct a compressed sensing system that utilizes the sparsity of the clipping distortions and recovers it on each user. We provide numerical results that validate our analysis and show promising performance for the proposed clipping recovery scheme.

  5. Improved Kalman Filter Method for Measurement Noise Reduction in Multi Sensor RFID Systems

    Directory of Open Access Journals (Sweden)

    Min Chul Kim

    2011-10-01

    Full Text Available Recently, the range of available Radio Frequency Identification (RFID tags has been widened to include smart RFID tags which can monitor their varying surroundings. One of the most important factors for better performance of smart RFID system is accurate measurement from various sensors. In the multi-sensing environment, some noisy signals are obtained because of the changing surroundings. We propose in this paper an improved Kalman filter method to reduce noise and obtain correct data. Performance of Kalman filter is determined by a measurement and system noise covariance which are usually called the R and Q variables in the Kalman filter algorithm. Choosing a correct R and Q variable is one of the most important design factors for better performance of the Kalman filter. For this reason, we proposed an improved Kalman filter to advance an ability of noise reduction of the Kalman filter. The measurement noise covariance was only considered because the system architecture is simple and can be adjusted by the neural network. With this method, more accurate data can be obtained with smart RFID tags. In a simulation the proposed improved Kalman filter has 40.1%, 60.4% and 87.5% less Mean Squared Error (MSE than the conventional Kalman filter method for a temperature sensor, humidity sensor and oxygen sensor, respectively. The performance of the proposed method was also verified with some experiments.

  6. Puncture Reduction in Percutaneous Transforaminal Endoscopic Discectomy with HE's Lumbar LOcation (HELLO System: A Cadaver Study.

    Directory of Open Access Journals (Sweden)

    Guoxin Fan

    Full Text Available Percutaneous transforaminal endoscopic discectomy (PTED usually requires numerous punctures under X-ray fluoroscopy. Repeated puncture will lead to more radiation exposure and reduce the beginners' confidence.This cadaver study aimed to investigate the efficacy of HE's Lumbar Location (HELLO system in puncture reduction of PTED.Cadaver study.Comparative groups.HELLO system consists of self-made surface locator and puncture locator. One senior surgeon conducted the puncture procedure of PTED on the left side of 20 cadavers at L4/L5 and L5/S1 level with the assistance of HELLO system (Group A. Additionally, the senior surgeon conducted the puncture procedure of PTED on the right side of the cadavers at L4/L5 and L5/S1 level with traditional methods (Group B. On the other hand, an inexperienced surgeon conducted the puncture procedure of PTED on the left side of the cadavers at L4/L5 and L5/S1 level with the assistance of our HELLO system (Group C.At L4/L5 level, there was significant difference in puncture times between Group A and Group B (P0.05. There was no difference in location time between Group A and Group B or Group A and Group C either at L4/L5 level or L5/S1 level (P>0.05.Small-sample preclinical study.HELLO system was effective in reducing puncture times, fluoroscopy time and radiation exposure, as well as the difficulty of learning PTED. (2015-RES-127.

  7. A perspective on cost-effectiveness of greenhouse gas reduction solutions in water distribution systems

    Science.gov (United States)

    Hendrickson, Thomas P.; Horvath, Arpad

    2014-01-01

    Water distribution systems (WDSs) face great challenges as aging infrastructures require significant investments in rehabilitation, replacement, and expansion. Reducing environmental impacts as WDSs develop is essential for utility managers and policy makers. This study quantifies the existing greenhouse gas (GHG) footprint of common WDS elements using life-cycle assessment (LCA) while identifying the greatest opportunities for emission reduction. This study addresses oversights of the related literature, which fails to capture several WDS elements and to provide detailed life-cycle inventories. The life-cycle inventory results for a US case study utility reveal that 81% of GHGs are from pumping energy, where a large portion of these emissions are a result of distribution leaks, which account for 270 billion l of water losses daily in the United States. Pipe replacement scheduling is analyzed from an environmental perspective where, through incorporating leak impacts, a tool reveals that optimal replacement is no more than 20 years, which is in contrast to the US average of 200 years. Carbon abatement costs (CACs) are calculated for different leak reduction scenarios for the case utility that range from -130 to 35 t-1 CO2(eq). Including life-cycle modeling in evaluating pipe materials identified polyvinyl chloride (PVC) and cement-lined ductile iron (DICL) as the Pareto efficient options, however; utilizing PVC presents human health risks. The model developed for the case utility is applied to California and Texas to determine the CACs of reducing leaks to 5% of distributed water. For California, annual GHG savings from reducing leaks alone (3.4 million tons of CO2(eq)) are found to exceed California Air Resources Board’s estimate for energy efficiency improvements in the state’s water infrastructure.

  8. A Study of Shrinkage Stress Reduction and Mechanical Properties of Nanogel-Modified Resin Systems.

    Science.gov (United States)

    Liu, Jiancheng; Howard, Gregory D; Lewis, Steven H; Barros, Matthew D; Stansbury, Jeffrey W

    2012-11-01

    A series of nanogel compositions were prepared from urethane dimethacrylate (UDMA) and isobornyl methacrylate (IBMA) in the presence of a thiol chain transfer agent. The linear oligomer of IBMA was synthesized by a similar solution polymerization technique. The nanogels were prepared with different crosslinker concentrations to achieve varied branching densities and molecular weights. The prepolymers were dispersed in triethylene glycol dimethacrylate at loading levels ranging from 10 wt% to 50 wt%. Photopolymerization reaction kinetics of all prepolymer modified systems were enhanced relative to the nanogel-free control during early stage polymerization while limiting conversion was similar for most samples. Volumetric polymerization shrinkage was reduced proportionally with the prepolymer content while the corresponding decrease in polymerization stress was potentially greater than an additive linear behavior. Flexural strength for inert linear polymer-modified systems decreased significantly with the increase in the prepolymer content; however, with an increase in the crosslinker concentration within the nanogel additives, and an increase in the concentration of residual pendant reactive sites, flexural strength was maintained or improved regardless of the nanogel loading level. This demonstrates that covalent attachment rather than just physical entanglement with the polymer matrix is important for effective polymer mechanical reinforcement by nanogel additives. Reactive nanogel additives can be considered as a practical, generic means to achieve substantial reductions in polymerization shrinkage and shrinkage stress in common polymers.

  9. Nonlinear model reduction for dynamical systems using sparse sensor locations from learned libraries.

    Science.gov (United States)

    Sargsyan, Syuzanna; Brunton, Steven L; Kutz, J Nathan

    2015-09-01

    We demonstrate the synthesis of sparse sampling and dimensionality reduction to characterize and model nonlinear dynamical systems over a range of bifurcation parameters. First, we construct modal libraries using the classical proper orthogonal decomposition in order to expose the dominant low-rank coherent structures. Here, libraries of the nonlinear terms are also constructed in order to take advantage of the discrete empirical interpolation method and projection that allows for the approximation of nonlinear terms from a sparse number of grid points. The selected grid points are shown to be effective sensing and measurement locations for characterizing the underlying dynamics, stability, and bifurcations of nonlinear dynamical systems. The use of empirical interpolation points and sparse representation facilitates a family of local reduced-order models for each physical regime, rather than a higher-order global model, which has the benefit of physical interpretability of energy transfer between coherent structures. The method advocated also allows for orders-of-magnitude improvement in computational speed and memory requirements. To illustrate the method, the discrete interpolation points and nonlinear modal libraries are used for sparse representation in order to classify and reconstruct the dynamic bifurcation regimes in the complex Ginzburg-Landau equation. It is also shown that point measurements of the nonlinearity are more effective than linear measurements when sensor noise is present.

  10. Reduction of cogging torque in dual rotor permanent magnet generator for direct coupled wind energy systems.

    Science.gov (United States)

    Paulsamy, Sivachandran

    2014-01-01

    In wind energy systems employing permanent magnet generator, there is an imperative need to reduce the cogging torque for smooth and reliable cut in operation. In a permanent magnet generator, cogging torque is produced due to interaction of the rotor magnets with slots and teeth of the stator. This paper is a result of an ongoing research work that deals with various methods to reduce cogging torque in dual rotor radial flux permanent magnet generator (DRFPMG) for direct coupled stand alone wind energy systems (SAWES). Three methods were applied to reduce the cogging torque in DRFPMG. The methods were changing slot opening width, changing magnet pole arc width and shifting of slot openings. A combination of these three methods was applied to reduce the cogging torque to a level suitable for direct coupled SAWES. Both determination and reduction of cogging torque were carried out by finite element analysis (FEA) using MagNet Software. The cogging torque of DRFPMG has been reduced without major change in induced emf. A prototype of 1 kW, 120 rpm DRFPMG was fabricated and tested to validate the simulation results. The test results have good agreement with the simulation predictions.

  11. A Conservation Voltage Reduction Scheme for a Distribution Systems with Intermittent Distributed Generators

    Directory of Open Access Journals (Sweden)

    Pyeong-Ik Hwang

    2016-08-01

    Full Text Available In this paper, a conservation voltage reduction (CVR scheme is proposed for a distribution system with intermittent distributed generators (DGs, such as photovoltaics and wind turbines. The CVR is a scheme designed to reduce energy consumption by lowering the voltages supplied to customers. Therefore, an unexpected under-voltage violation can occur due to the variation of active power output from the intermittent DGs. In order to prevent the under-voltage violation and improve the CVR effect, a new reactive power controller which complies with the IEEE Std. 1547TM, and a parameter determination method for the controller are proposed. In addition, an optimal power flow (OPF problem to determine references for the resources of CVR is formulated with consideration of the intermittent DGs. The proposed method is validated using a modified IEEE 123-node test feeder. With the proposed method, the voltages of the test system are maintained to be greater than the lower bound, even though the active power outputs of the DGs are varied. Moreover, the CVR effect is improved compared to that used with the conventional reactive power control methods.

  12. Model order reduction and composite control for a class of slow-fast systems around a non-hyperbolic point

    NARCIS (Netherlands)

    Jardón Kojakhmetov, H.; Scherpen, Jacquelien M.A.

    In this letter we investigate a class of slow-fast systems for which the classical model order reduction technique based on singular perturbations does not apply due to the lack of a Normally Hyperbolic critical manifold. We show, however, that there exists a class of slow-fast systems that after a

  13. Facultative nitrate reduction by electrode-respiring Geobacter metallireducens biofilms as a competitive reaction to electrode reduction in a bioelectrochemical system.

    Science.gov (United States)

    Kashima, Hiroyuki; Regan, John M

    2015-03-03

    Alternative metabolic options of exoelectrogenic biofilms in bioelectrochemical systems (BESs) are important not only to explain the fundamental ecology and performance of these systems but also to develop reliable integrated nutrient removal strategies in BESs, which potentially involve substrates or intermediates that support/induce those alternative metabolisms. This research focused on dissimilatory nitrate reduction as an alternative metabolism to dissimilatory anode reduction. Using the exoelectrogenic nitrate reducer Geobacter metallireducens, the critical conditions controlling those alternative metabolisms were investigated in two-chamber, potentiostatically controlled BESs at various anode potentials and biofilm thicknesses and challenged over a range of nitrate concentrations. Results showed that anode-reducing biofilms facultatively reduced nitrate at all tested anode potentials (-150 to +900 mV vs Standard Hydrogen Electrode) with a rapid metabolic shift. The critical nitrate concentration that triggered a significant decrease in BES performance was a function of anode biofilm thickness but not anode potential. This indicates that these alternative metabolisms were controlled by the availability of nitrate, which is a function of nitrate concentration in bulk solution and its diffusion into an anode-reducing biofilm. Coulombic recovery decreased as a function of nitrate dose due to electron-acceptor substrate competition, and nitrate-induced suspended biomass growth decreased the effluent quality.

  14. Systemic non-malignant osteoporosis and reduction of edentulous alveolar ridges

    Directory of Open Access Journals (Sweden)

    Poštić Srđan D

    2014-01-01

    Full Text Available Introduction. Systemic osteoporosis damages skeletal bones to different degrees. The aim of this study was to determine the intensity and correlation of the osteoporotic changes in the bone density of the skeleton and body mass index (BMI with a reduction in edentulous mandibles, and to assess possibility of reparation of layers of mandibles with increase of mineral content in jaws of patients affected by osteoporosis. Material and Methods. In this study, 99 edentulous patients with decreased bone density comprised the experimental group, and 48 edentulous patients with normal bone densities formed the control. The age of the examined patients was 69.02 ± 7,9, range 53-74 of females and 69.11 ± 7.1, range 59-76 years. Radiographs of the hands and panoramic radiographs were done for all the patients. The values of BMI, metacarpal index, density of lumbar spine (L2-L4, in the phalanx and in segments of the mandibles as well as the edentulous alveolar ridges heights were measured, assessed and calculated. Results. The lowest value of the total skeletal density was established in the osteoporotic patients on the basis of the average T-score of- 2.5 in men, and - 2.6 in women. Minimum values of the edentulous ridges heights (right/left, in mm were measured in both osteoporotic females (21.84/22.39 and males 24.90/24.96 patients. By comparison of the densities of the metacarpal bones, proximal phalanx, segments of the edentulous mandibles and based on the numerical values of the edentulous ridges heights, x2 = 3.81 was found in men and x2 = 4.03 was found in women with normal bone densities; x2 = 5.92 was found in men and x2 = 6.25 was found in women with osteopenia; x2 = 2.63 was found in men and x2 = 3.85 was found in women with osteoporosis, on the level of probability of 0.05. After application of calcium and calcitonin in solutions, moderate increment of density (p < 0.05; p < 0.01 was verified, compensating up to 4% of total loss of mass

  15. Development of respiratory motion reduction device system (RMRDs) for radiotherapy in moving tumors.

    Science.gov (United States)

    Lee, Suk; Yang, Dae Sik; Choi, Myung Sun; Kim, Chul Yong

    2004-11-01

    The internal target volume (ITV) for tumors in the abdomen or thorax includes sufficient margin for breathing-related movement of tumor volumes during treatment. Depending on the location of the tumor, the magnitude of the ITV margin extends from 1 to 3 cm, which increases substantially the volume of the irradiated normal tissue, hence resulting in an increase in normal tissue complication probability (NTCP). We developed a simple and handy method which can reduce ITV margins in patients with moving tumors: the respiratory motion reduction device system (RMRDs). The patient's clinical database was structured for moving tumor patients and patient set-up error measurement and immobilization device effects were investigated. The system is composed of the respiration presser device (RPD) utilized in the prone position and the abdominal strip device (ASD) utilized in the supine position, and the analysis program, which enables analysis of patient set-up reproducibility. It was tested for analyzing the diaphragm movement from patients with RMRDs, the magnitude of the ITV margin was determined and the dose-volume histogram (DVH) was computed using treatment planning software. The dose to normal tissue in patients with and without RMRDs was analyzed by comparing the fraction of the normal liver receiving 50% of the isocenter dose. Average diaphragm movement due to respiration was 16 +/- 1.9 mm in the case of the supine position, and 12 +/- 1.9 mm in the case of the prone position. When utilizing the RMRDs, which was personally developed in our hospital, the value was reduced to 5 +/- 1.4 mm, and in the case in which the belt immobilization device was utilized, the value was reduced to 3 +/- 0.9 mm. In the case where the strip device was utilized, the value was proven to reduce to 4 +/- 0.3 mm. As a result of analyzing the volume of normal liver where 50% of the prescription dose is irradiated in DVH according to the radiation treatment planning, the use of the RMRD can

  16. On the stability of perchlorate ions against reductive attacks in electrochemical systems and in the environment

    Directory of Open Access Journals (Sweden)

    GYŐZŐ G. LÁNG

    2011-08-01

    Full Text Available The problems related to the electrochemical/electrocatalytic stability of perchlorate ions are reviewed in the light of recent experimental results. The electrocatalytic, catalytic, and electrochemical reduction processes are presented and the links between them are outlined. Some possible mechanisms of the complicated reduction processes are discussed. Various methods for the detection of reduction process are presented, e.g. voltammetry, impedance spectroscopy, and radiotracer methods. Environmental aspects and some methods for perchlorate removal and wastewater treatment are briefly summarized.

  17. Hexavalent chromium reduction with scrap iron in continuous-flow system. Part 2: Effect of scrap iron shape and size.

    Science.gov (United States)

    Gheju, M; Balcu, I

    2010-10-15

    Hexavalent chromium reduction with scrap iron has the advantage that two wastes are treated simultaneously. The reduction of hexavalent chromium by scrap iron was investigated in continuous system, using as reducing agent the following scrap iron shapes and sizes: (1) spiral fibers, (2) shavings, and (3) powder. The shape and size of scrap iron were found to have a significant influence on chromium and iron species concentration in column effluent, on column effluent pH and on Cr(VI) reduction mechanism. While for large scrap iron particles (spiral fibers) homogeneous reduction is the dominant Cr(VI) reduction process, for small scrap iron particles (powder) heterogeneous reduction appears to be the dominant reaction contributing to Cr(VI) reduction. All three shapes and sizes investigated in this work have both advantages and disadvantages. If found in sufficient quantities, scrap iron powder seem to be the optimum shape and size for the continuous reduction of Cr(VI), due to the following advantages: (1) the greatest reduction capacity, (2) the most important pH increase in column effluent (up to 6.3), (3) no chromium was detected in the column effluent during the first 60 h of the experiment, and (4) the lowest steady-state Cr(VI) concentration observed in column effluent (3.7 mg/L). But, despite of a lower reduction capacity in comparison with powder particles, spiral fibers and shavings have the advantage to result in large quantities from the mechanic processing of steel. 2010 Elsevier B.V. All rights reserved.

  18. Reduction of Airborne Bacterial Burden in the OR by Installation of Unidirectional Displacement Airflow (UDF) Systems.

    Science.gov (United States)

    Fischer, Sebastian; Thieves, Martin; Hirsch, Tobias; Fischer, Klaus-Dieter; Hubert, Helmine; Beppler, Steffen; Seipp, Hans-Martin

    2015-08-13

    Intraoperative bacterial contamination is a major risk factor for postoperative wound infections. This study investigated the influence of type of ventilation system on intraoperative airborne bacterial burden before and after installation of unidirectional displacement air flow systems. We microbiologically monitored 1286 surgeries performed by a single surgical team that moved from operating rooms (ORs) equipped with turbulent mixing ventilation (TMV, according to standard DIN-1946-4 [1999], ORs 1, 2, and 3) to ORs with unidirectional displacement airflow (UDF, according to standard DIN-1946-4, annex D [2008], ORs 7 and 8). The airborne bacteria were collected intraoperatively with sedimentation plates. After incubation for 48 h, we analyzed the average number of bacteria per h, peak values, and correlation to surgery duration. In addition, we compared the last 138 surgeries in ORs 1-3 with the first 138 surgeries in ORs 7 and 8. Intraoperative airborne bacterial burden was 5.4 CFU/h, 5.5 CFU/h, and 6.1 CFU/h in ORs 1, 2, and 3, respectively. Peak values of burden were 10.7 CFU/h, 11.1 CFU/h, and 11.0 CFU/h in ORs 1, 2, and 3, respectively). With the UDF system, the intraoperative airborne bacterial burden was reduced to 0.21 CFU/h (OR 7) and 0.35 CFU/h (OR 8) on average (pUDF system in ORs 7 and 8 kept bacterial levels constantly low (<3 CFU/h). A comparison of the last 138 surgeries before with the first 138 surgeries after changing ORs revealed a 94% reduction in average airborne bacterial burden (5 CFU/h vs. 0.29 CFU/h, p<0.01). The unidirectional displacement airflow, which fulfills the requirements of standard DIN-1946-4 annex D of 2008, is an effective ventilation system that reduces airborne bacterial burden under real clinical conditions by more than 90%. Although decreased postoperative wound infection incidence was not specifically assessed, it is clear that airborne microbiological burden contributes to surgical infections.

  19. Ecohealth System Dynamic Model as a Planning Tool for the Reduction of Breeding Sites

    Science.gov (United States)

    Respati, T.; Raksanagara, A.; Djuhaeni, H.; Sofyan, A.; Shandriasti, A.

    2017-03-01

    Dengue is still one of major health problem in Indonesia. Dengue transmission is influenced by dengue prevention and eradication program, community participation, housing environment and climate. The complexity of the disease coupled with limited resources necessitates different approach for prevention methods that include factors contribute to the transmission. One way to prevent the dengue transmission is by reducing the mosquito’s breeding sites. Four factors suspected to influence breeding sites are dengue prevention and eradication program, community participation, housing environment, and weather condition. In order to have an effective program in reducing the breeding site it is needed to have a model which can predict existence of the breeding sites while the four factors under study are controlled. The objective of this study is to develop an Ecohealth model using system dynamic as a planning tool for the reduction of breeding sites to prevent dengue transmission with regard to dengue prevention and eradication program, community participation, housing environment, and weather condition. The methodology is a mixed method study using sequential exploratory design. The study comprised of 3 stages: first a qualitative study to 14 respondents using in-depth interview and 6 respondents for focus group discussion. The results from the first stage was used to develop entomology and household survey questionnaires for second stage conducted in 2036 households across 12 sub districts in Bandung City. Ecohealth system dynamic model was developed using data from first and second stages. Analyses used are thematic analysis for qualitative data; spatial, generalized estimating equation (GEE) and structural equation modeling for quantitative data; also average mean error (AME) and average variance error (AVE) for dynamic system model validation. System dynamic model showed that the most effective approach to eliminate breeding places was by ensuring the availability

  20. Reduction of nitrobenzene by steel convert slag with Fe(II) system: The role of calcium in steel slag

    Energy Technology Data Exchange (ETDEWEB)

    Luan, Fubo [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai (China); Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA (United States); Xie, Li, E-mail: sally.xieli2008@gmail.com [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai (China); Sheng, Jie; Li, Jun; Zhou, Qi; Zhai, Guiming [State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai (China)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Steel convert slag (SCS) adsorbed Fe(II) by ion replacement with Ca(II) in SCS. Black-Right-Pointing-Pointer Adsorbed Fe(II) on SCS were able to reduce nitrobenzene to aniline. Black-Right-Pointing-Pointer A three-step model was proposed for nitrobenzene reduction in SCS-Fe(II) system. - Abstract: Experiments were conducted to examine of nitrobenzene reduction by steel convert slag (SCS) with Fe(II) system. The results showed SCS with Fe(II) was an effective reductant for nitrobenzene at pH 5.5-6.5. Further analysis suggested Fe(II) was adsorbed by SCS through ion replacement with SCS-bound Ca(II). More than 81% of the total Ca(II) in SCS was replaced with dissolved Fe(II), indicating a high adsorption capacity for Fe(II) (more than 5.82 mmol Fe(II)/g SCS). A three step mechanism (replacement process, conversion process and electron transfer process) was proposed for nitrobenzene reduction by SCS with Fe(II) system. The amount of Ca(II) in SCS determined the adsorption capacity for Fe(II) and further determined the reduction capacity of SCS with Fe(II) system.

  1. The systems approach to error reduction: factors influencing inoculation injury reporting in the operating theatre.

    Science.gov (United States)

    Cutter, Jayne; Jordan, Sue

    2013-11-01

    To examine the frequency of, and factors influencing, reporting of mucocutaneous and percutaneous injuries in operating theatres. Surgeons and peri-operative nurses risk acquiring blood-borne viral infections during surgical procedures. Appropriate first-aid and prophylactic treatment after an injury can significantly reduce the risk of infection. However, studies indicate that injuries often go unreported. The 'systems approach' to error reduction relies on reporting incidents and near misses. Failure to report will compromise safety. A postal survey of all surgeons and peri-operative nurses engaged in exposure prone procedures in nine Welsh hospitals, face-to-face interviews with selected participants and telephone interviews with Infection Control Nurses. The response rate was 51.47% (315/612). Most respondents reported one or more percutaneous (183/315, 58.1%) and/or mucocutaneous injuries (68/315, 21.6%) in the 5 years preceding the study. Only 54.9% (112/204) reported every injury. Surgeons were poorer at reporting: 70/133 (52.6%) reported all or >50% of their injuries compared with 65/71 nurses (91.5%). Injuries are frequently under-reported, possibly compromising safety in operating theatres. A significant number of inoculation injuries are not reported. Factors influencing under-reporting were identified. This knowledge can assist managers in improving reporting and encouraging a robust safety culture within operating departments. © 2012 John Wiley & Sons Ltd.

  2. Two-level system noise reduction for Microwave Kinetic Inductance Detectors

    Science.gov (United States)

    Noroozian, Omid; Gao, Jiansong; Zmuidzinas, Jonas; LeDuc, Henry G.; Mazin, Benjamin A.

    2009-12-01

    Noise performance is one of the most crucial aspects of any detector. Superconducting Microwave Kinetic Inductance Detectors (MKIDs) have an "excess" frequency noise that shows up as a small time dependent jitter of the resonance frequency characterized by the frequency noise power spectrum measured in units of Hz2/Hz. Recent studies have shown that this noise almost certainly originates from a surface layer of two-level system (TLS) defects on the metallization or substrate. Fluctuation of these TLSs introduces noise in the resonator due to coupling of the TLS electric dipole moments to the resonator's electric field. Motivated by a semi-empirical quantitative theory of this noise mechanism, we have designed and tested new resonator geometries in which the high-field "capacitive" portion of the CPW resonator is replaced by an interdigitated capacitor (IDC) structure with 10-20 μm electrode spacing, as compared to the 2 μm spacing used for our more conventional CPW resonators. Measurements show that this new IDC design has dramatically lower TLS noise, currently by about a factor of ˜29 in terms of the frequency noise power spectrum, corresponding to an improvement of about a factor of √29 in NEP. These new devices are replacing the CPW resonators in our next design iteration in progress for MKIDCam. Opportunities and prospects for future reduction of the TLS noise will be discussed.

  3. Distributed Reactive Power Control based Conservation Voltage Reduction in Active Distribution Systems

    Directory of Open Access Journals (Sweden)

    EMIROGLU, S.

    2017-11-01

    Full Text Available This paper proposes a distributed reactive power control based approach to deploy Volt/VAr optimization (VVO / Conservation Voltage Reduction (CVR algorithm in a distribution network with distributed generations (DG units and distribution static synchronous compensators (D-STATCOM. A three-phase VVO/CVR problem is formulated and the reactive power references of D-STATCOMs and DGs are determined in a distributed way by decomposing the VVO/CVR problem into voltage and reactive power control. The main purpose is to determine the coordination between voltage regulator (VR and reactive power sources (Capacitors, D-STATCOMs and DGs based on VVO/CVR. The study shows that the reactive power injection capability of DG units may play an important role in VVO/CVR. In addition, it is shown that the coordination of VR and reactive power sources does not only save more energy and power but also reduces the power losses. Moreover, the proposed VVO/CVR algorithm reduces the computational burden and finds fast solutions. To illustrate the effectiveness of the proposed method, the VVO/CVR is performed on the IEEE 13-node test system feeder considering unbalanced loading and line configurations. The tests are performed taking the practical voltage-dependent load modeling and different customer types into consideration to improve accuracy.

  4. Peak Power Demand and Energy Consumption Reduction Strategies for Trains under Moving Block Signalling System

    Directory of Open Access Journals (Sweden)

    Qing Gu

    2013-01-01

    Full Text Available In the moving block signalling (MBS system where the tracking target point of the following train is moving forward with its leading train, overload of the substations occurs when a dense queue of trains starts (or restarts in very close distance interval. This is the peak power demand problem. Several methods have been attempted in the literature to deal with this problem through changing train’s operation strategies. However, most existing approaches reduce the service quality. In this paper, two novel approaches—“Service Headway Braking” (SHB and “Extending Stopping Distance Interval” (ESDI—are proposed according to available and unavailable extra station dwell times, respectively. In these two methods, the restarting times of the trains are staggered and traction periods are reduced, which lead to the reduction of peak power demand and energy consumption. Energy efficient control switching points are seen as the decision parameters. Nonlinear programming method is used to model the process. Simulation results indicate that, compared with ARL, peak power demands are reduced by 40% and 20% by applying SHB and ESDI without any arrival time delay, respectively. At the same time, energy consumptions are also reduced by 77% and 50% by applying SHB and ESDI, respectively.

  5. Contribution of Spartina maritima to the reduction of eutrophication in estuarine systems

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Ana I. [IO - Institute of Oceanography, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon (Portugal); IMAR - Institute of Marine Research, Department of Zoology, University of Coimbra, 3004-517 Coimbra (Portugal)], E-mail: aisousa@fc.ul.pt; Lillebo, Ana I. [CESAM - Centro de Estudos do Ambiente e do Mar, Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Cacador, Isabel [IO - Institute of Oceanography, Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016 Lisbon (Portugal); Pardal, Miguel A. [IMAR - Institute of Marine Research, Department of Zoology, University of Coimbra, 3004-517 Coimbra (Portugal)

    2008-12-15

    Salt marshes are among the most productive ecosystems in the world, performing important ecosystem functions, particularly nutrient recycling. In this study, a comparison is made between Mondego and Tagus estuaries in relation to the role of Spartina maritima in nitrogen retention capacity and cycling. Two mono-specific S. maritima stands per estuary were studied during 1 yr (biomass, nitrogen (N) pools, litter production, decomposition rates). Results showed that the oldest Tagus salt marsh population presented higher annual belowground biomass and N productions, and a slower decomposition rate for litter, contributing to the higher N accumulation in the sediment, whereas S. maritima younger marshes had higher aboveground biomass production. Detritus moved by tides represented a huge amount of aboveground production, probably significant when considering the N balance of these salt marshes. Results reinforce the functions of salt marshes as contributing to a reduction of eutrophication in transitional waters, namely through sedimentation processes. - The crucial capacity of salt marshes to retain nitrogen, thus reducing eutrophication, greatly depends on the salt marsh maturity, rather than the estuarine system.

  6. Drift Reduction in Pedestrian Navigation System by Exploiting Motion Constraints and Magnetic Field

    Directory of Open Access Journals (Sweden)

    Muhammad Ilyas

    2016-09-01

    Full Text Available Pedestrian navigation systems (PNS using foot-mounted MEMS inertial sensors use zero-velocity updates (ZUPTs to reduce drift in navigation solutions and estimate inertial sensor errors. However, it is well known that ZUPTs cannot reduce all errors, especially as heading error is not observable. Hence, the position estimates tend to drift and even cyclic ZUPTs are applied in updated steps of the Extended Kalman Filter (EKF. This urges the use of other motion constraints for pedestrian gait and any other valuable heading reduction information that is available. In this paper, we exploit two more motion constraints scenarios of pedestrian gait: (1 walking along straight paths; (2 standing still for a long time. It is observed that these motion constraints (called “virtual sensor”, though considerably reducing drift in PNS, still need an absolute heading reference. One common absolute heading estimation sensor is the magnetometer, which senses the Earth’s magnetic field and, hence, the true heading angle can be calculated. However, magnetometers are susceptible to magnetic distortions, especially in indoor environments. In this work, an algorithm, called magnetic anomaly detection (MAD and compensation is designed by incorporating only healthy magnetometer data in the EKF updating step, to reduce drift in zero-velocity updated INS. Experiments are conducted in GPS-denied and magnetically distorted environments to validate the proposed algorithms.

  7. Reduction of carcinogenic 4(5)-methylimidazole in a caramel model system: influence of food additives.

    Science.gov (United States)

    Seo, Seulgi; Ka, Mi-Hyun; Lee, Kwang-Geun

    2014-07-09

    The effect of various food additives on the formation of carcinogenic 4(5)-methylimidazole (4-MI) in a caramel model system was investigated. The relationship between the levels of 4-MI and various pyrazines was studied. When glucose and ammonium hydroxide were heated, the amount of 4-MI was 556 ± 1.3 μg/mL, which increased to 583 ± 2.6 μg/mL by the addition of 0.1 M of sodium sulfite. When various food additives, such as 0.1 M of iron sulfate, magnesium sulfate, zinc sulfate, tryptophan, and cysteine were added, the amount of 4-MI was reduced to 110 ± 0.7, 483 ± 2.0, 460 ± 2.0, 409 ± 4.4, and 397 ± 1.7 μg/mL, respectively. The greatest reduction, 80%, occurred with the addition of iron sulfate. Among the 12 pyrazines, 2-ethyl-6-methylpyrazine with 4-MI showed the highest correlation (r = -0.8239).

  8. Impact of well intake systems on bacterial, algae, and organic carbon reduction in SWRO desalination systems, SAWACO, Jeddah, Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah

    2014-07-18

    The intake system can play a significant role in improving the feed water quality and ultimately influence the performance of downstream components of the seawater reverse osmosis desalination processes. In most cases, open-ocean intakes produce poor feed water quality in terms of the abundance of naturally occurring organic matter, which increases the risk of membrane fouling. An alternative intake is the subsurface system, which is based on the riverbank filtration concept that provides natural filtration and biological treatment of the feed water prior to the entry of the water into the desalination plant. The use of subsurface intakes normally improves the raw water quality by reducing suspended solids, algae, bacterial, and dissolved organic carbon concentrations. Therefore, the risk of biofouling caused by these substances can be reduced by implementing the appropriate type of intake system. The use of well intake systems was investigated along the Red Sea shoreline of Saudi Arabia in the Jeddah region. Data were collected from a seawater reverse osmosis (SWRO) plant with a capacity of 10,000 m3/d. The well system produces feed water from an artificial-fill peninsula that was constructed atop of the seabed. Ten wells have been constructed on the peninsula for extracting raw seawater. Water samples were collected from nearby surface seawater as a reference and from selected individual wells. The percentage of algae and bacterial removal by induced filtration process was evaluated by comparison of the seawater concentrations with the well discharges. Transparent exopolymer particles and organic carbon fractions reduction was also measured. The quality of raw water extracted from the well systems was highly improved compared with the raw seawater source. It was observed that algae were virtually 100% removed and the bacterial concentration was significantly removed by the aquifer matrix. The detailed analysis of organic carbon fraction using liquid

  9. Adaptive Model Predictive Control of Diesel Engine Selective Catalytic Reduction (SCR) Systems

    Science.gov (United States)

    McKinley, Thomas L.

    2009-01-01

    Selective catalytic reduction or SCR is coming into worldwide use for diesel engine emissions reduction for on- and off-highway vehicles. These applications are characterized by broad operating range as well as rapid and unpredictable changes in operating conditions. Significant nonlinearity, input and output constraints, and stringent performance…

  10. Design and Implementation of a Thermal Load Reduction System in a Hyundai PHEV

    Energy Technology Data Exchange (ETDEWEB)

    Kreutzer, Cory J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rugh, John P [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-08

    Increased market penetration of electric drive vehicles (EDVs) requires overcoming a number of hurdles including limited vehicle range and the elevated cost of EDVs as compared to conventional vehicles. Climate control loads have a significant impact on range, cutting it by over 50% in both cooling and heating conditions. In order to minimize the impact of climate control on EDV range, the National Renewable Energy Laboratory has partnered with Hyundai America and key industry partners to quantify the performance of thermal load reduction technologies on a Hyundai Sonata PHEV. Technologies that impact vehicle cabin heating in cold weather conditions and cabin cooling in warm weather conditions were evaluated. Tests included thermal transient and steady-state periods for all technologies, including the development of a new test methodology to evaluate the performance of occupant thermal conditioning. Heated surfaces and increased insulation demonstrated significant reductions in energy use from steady-state heating, including a 29% - 59% reduction from heated surfaces. Solar control glass packages demonstrated significant reductions in energy use for both transient and steady-state cooling, with up to a 42% reduction in transient and 12.8% reduction in steady-state energy use for the packages evaluated. Technologies that demonstrated significant climate control load reduction were selected for incorporation into a complete thermal load reduction package. The complete package is set to be evaluated in the second phase of the ongoing project.

  11. Modelling environmental cooperation on reciprocal emission reduction via virtual market system

    NARCIS (Netherlands)

    Nentjes, Andries; Shibayev, Sergey; Meijer, G; Heijman, WJM; VanOphem, JAC; Verstegen, BHJ

    2006-01-01

    Mainstream economic theory views international agreements on reduction of trans-boundary pollution as a Pareto-optimal outcome of negotiations among self-interested parties. This paper elaborates that notion by modelling negotiation as a multilateral trade in reciprocal emission reductions within

  12. A Robust Computational Technique for Model Order Reduction of Two-Time-Scale Discrete Systems via Genetic Algorithms

    OpenAIRE

    Alsmadi, Othman M.K.; Zaer S. Abo-Hammour

    2015-01-01

    A robust computational technique for model order reduction (MOR) of multi-time-scale discrete systems (single input single output (SISO) and multi-input multioutput (MIMO)) is presented in this paper. This work is motivated by the singular perturbation of multi-time-scale systems where some specific dynamics may not have significant influence on the overall system behavior. The new approach is proposed using genetic algorithms (GA) with the advantage of obtaining a reduced order model, maint...

  13. Colloid Microthruster Flight Performance Results from Space Technology 7 Disturbance Reduction System

    Science.gov (United States)

    Ziemer, John; Marrese-Reading, Colleen; Dunn, Charley; Romero-Wolf, Andrew; Cutler, Curt; Javidnia, Shahram; Li, Thanh; Li, Irena; Franklin, Garth; Barela, Phil; hide

    2017-01-01

    Space Technology 7 Disturbance Reduction System (ST7-DRS) is a NASA technology demonstration payload as part of the ESA LISA Pathfinder (LPF) mission, which launched on December 3, 2015. The ST7-DRS payload includes colloid microthrusters as part of a drag-free dynamic control system (DCS) hosted on an integrated avionics unit (IAU) with spacecraft attitude and test mass position provided by the LPF spacecraft computer and the highly sensitive gravitational reference sensor (GRS) as part of the LISA Technology Package (LTP). The objective of the DRS was to validate two technologies: colloid micro-Newton thrusters (CMNT) to provide low-noise control capability of the spacecraft, and drag-free flight control. The CMNT were developed by Busek Co., Inc., in a partnership with NASA Jet Propulsion Laboratory (JPL), and the DCS algorithms and flight software were developed at NASA Goddard Space Flight Center (GSFC). ST7-DRS demonstrated drag-free operation with 10nmHz level precision spacecraft position control along the primary axis of the LTP using eight CMNTs that provided 5-30 N each with 0.1 N precision. The DCS and CMNTs performed as required and as expected from ground test results, meeting all Level 1 requirements based on on-orbit data and analysis. DRS microthrusters operated for 2400 hours in flight during commissioning activities, a 90-day experiment and the extended mission. This mission represents the first validated demonstration of electrospray thrusters in space, providing precision spacecraft control and drag-free operation in a flight environment with applications to future gravitational wave observatories like LISA.

  14. Pathogen-reduction systems for blood components: the current position and future trends.

    Science.gov (United States)

    Seghatchian, Jerard; de Sousa, Gracinda

    2006-12-01

    characteristics; including the potential impacts of their metabolites and photo-adducts; their effects on the spectrum of pathogens affected and the log reductions in culture infective studies. Accordingly, any strategy that involves addition of an extraneous agent or physicochemical manipulation of blood must balance the benefits of pathogen reduction against the loss or alteration to the cells and plasma functional integrity, short and long term toxicity to the cells and to the recipients, as well as the risk to the personnel involved and the community at large. Moreover, it must be noted that each method will have a different profile of adverse reactions and may differ in terms of the risk to particularly vulnerable groups of patients, requiring in depth clinical trials, while taking into consideration the cost benefit of the final process. Newer diagnostic procedures must be in place to establish the storage stability of products that have undergone pathogen inactivation, in particular tests reflecting the release of platelet-derived cytokines, cellular apoptosis or microvesiculation and their role in immunosupressiveness. This overview aims to provide an update on the continual improvements in blood component safety, in particular using methods that target pathogen nucleic acid. Emphasis is placed on methylene blue light treatment (MBLT) and Intercept or Mirasol PRT systems for platelets and plasma. The status of pathogen reduction of whole blood and red cells is also highlighted, though the progress in this area has been virtually stopped after the finding of antibody development in the clinical trial.

  15. The U.S. geological survey rass-statpac system for management and statistical reduction of geochemical data

    Science.gov (United States)

    VanTrump, G.; Miesch, A.T.

    1977-01-01

    RASS is an acronym for Rock Analysis Storage System and STATPAC, for Statistical Package. The RASS and STATPAC computer programs are integrated into the RASS-STATPAC system for the management and statistical reduction of geochemical data. The system, in its present form, has been in use for more than 9 yr by scores of U.S. Geological Survey geologists, geochemists, and other scientists engaged in a broad range of geologic and geochemical investigations. The principal advantage of the system is the flexibility afforded the user both in data searches and retrievals and in the manner of statistical treatment of data. The statistical programs provide for most types of statistical reduction normally used in geochemistry and petrology, but also contain bridges to other program systems for statistical processing and automatic plotting. ?? 1977.

  16. A projected landmark method for reduction of registration error in image-guided surgery systems.

    Science.gov (United States)

    Serej, Nasim Dadashi; Ahmadian, Alireza; Mohagheghi, Saeed; Sadrehosseini, Seyed Musa

    2015-05-01

    Image-guided surgery systems are limited by registration error, so practical and effective methods to improve accuracy are necessary. A projection point-based method for reducing the surface registration error in image-guided surgery was developed and tested. Checkerboard patterns are projected on visible surfaces to create projected landmarks over a region of interest. Surface information thus becomes available in the form of point clouds of surface point coordinates with submillimeter resolution. The reconstructed 3D point cloud is registered using iterative closest point (ICP) approximation to a 3D point cloud extracted from preoperative CT images of the same region of interest. The projected landmark surface registration method was compared with two other methods using a facial surface phantom: (a) landmark registration using anatomical features, and (b) surface matching based on an additional 40 surface points. The mean error for the projected landmark surface registration method was 0.64 mm, which was 47.4 and 35.3 % lower relative to mean errors of the anatomical landmark registration and the surface-matching methods, respectively. After applying the proposed method, using target registration error as a gold standard, the resulting mean error was 1.1 mm or a reduction of 61.2 % compared to the anatomical landmark registration. Optical checkerboard pattern projection onto visible surfaces was used to acquire surface point clouds for image-guided surgery registration. A projected landmark method eliminated the effects of unwanted and overlapping points by acquiring the desired points at specific locations. The results were more accurate than conventional landmark or surface registration.

  17. Innovative Surveillance and Risk Reduction Systems for Family Maltreatment, Suicidality and Substance Problems in the USAF

    National Research Council Canada - National Science Library

    Slep, Amy

    2004-01-01

    This project aims to enhance the capacity of the Air Force (AP) to reduce death, injury, and degraded force readiness via reduction of he prevalence and impact of family - maltreatment, suicidality, and alcohol/drug problems...

  18. A grid-tied PV system for commercial load and peak load reduction: South African case study

    CSIR Research Space (South Africa)

    Senatla, Mamahloko

    2017-08-01

    Full Text Available in the analysis with the objective of reducing both the load demand and peak load for a South African commercial entity. The results show load and peak load reductions of 3.4% and 4.5 % respectively. This shows that if such or similar systems are adopted...

  19. Do different cow types respond differently to a reduction on concentrate supplementation in an Alpine low-input dairy system?

    DEFF Research Database (Denmark)

    Horn, Marco; Steinwidder, Andreas; Pfister, Rupert

    2014-01-01

    Forage based low-input dairy systems include a certain risk of a temporary undersupply with nutrients and energy. Therefore the aim of the present study was to investigate the productive, reproductive and metabolic response of two different dairy cow types to a reduction of concentrate supplement...

  20. Determining the storage, availability and reactivity of NH3 within Cu-Chabazite-based Ammonia Selective Catalytic Reduction systems

    NARCIS (Netherlands)

    Lezcano-Gonzalez, I; Deka, U; Arstad, B; Van Yperen-De Deyne, A; Hemelsoet, K; Waroquier, M; Van Speybroeck, V; Weckhuysen, B M; Beale, A M

    2014-01-01

    Three different types of NH3 species can be simultaneously present on Cu(2+)-exchanged CHA-type zeolites, commonly used in Ammonia Selective Catalytic Reduction (NH3-SCR) systems. These include ammonium ions (NH4(+)), formed on the Brønsted acid sites, [Cu(NH3)4](2+) complexes, resulting from NH3

  1. Problem shifting in transport systems. Analysing and balancing unintended consequences of CO2 emission reduction in Dutch transport.

    NARCIS (Netherlands)

    Gebler, Malte

    2013-01-01

    Summary Transport systems face significant input- and output-related challenges in the upcoming decades. To tackle climate change – the major output challenge - an 80% CO2 reduction has to be achieved by 2050 (base year 1990). This requires a sustainabi

  2. Higher harmonic control analysis for vibration reduction of helicopter rotor systems

    Science.gov (United States)

    Nguyen, Khanh Q.

    1994-01-01

    An advanced higher harmonic control (HHC) analysis has been developed and applied to investigate its effect on vibration reduction levels, blade and control system fatigue loads, rotor performance, and power requirements of servo-actuators. The analysis is based on a finite element method in space and time. A nonlinear time domain unsteady aerodynamic model, based on the indicial response formulation, is used to calculate the airloads. The rotor induced inflow is computed using a free wake model. The vehicle trim controls and blade steady responses are solved as one coupled solution using a modified Newton method. A linear frequency-domain quasi-steady transfer matrix is used to relate the harmonics of the vibratory hub loads to the harmonics of the HHC inputs. Optimal HHC is calculated from the minimization of the vibratory hub loads expressed in term of a quadratic performance index. Predicted vibratory hub shears are correlated with wind tunnel data. The fixed-gain HHC controller suppresses completely the vibratory hub shears for most of steady or quasi-steady flight conditions. HHC actuator amplitudes and power increase significantly at high forward speeds (above 100 knots). Due to the applied HHC, the blade torsional stresses and control loads are increased substantially. For flight conditions where the blades are stalled considerably, the HHC input-output model is quite nonlinear. For such cases, the adaptive-gain controller is effective in suppressing vibratory hub loads, even though HHC may actually increase stall areas on the rotor disk. The fixed-gain controller performs poorly for such flight conditions. Comparison study of different rotor systems indicates that a soft-inplane hingeless rotor requires less actuator power at high speeds (above 130 knots) than an articulated rotor, and a stiff-inplane hingeless rotor generally requires more actuator power than an articulated or a soft-inplane hingeless rotor. Parametric studies for a hingeless rotor

  3. Effect of the cathode potential and sulfate ions on nitrate reduction in a microbial electrochemical denitrification system.

    Science.gov (United States)

    Nguyen, Van Khanh; Park, Younghyun; Yang, Heechun; Yu, Jaecheul; Lee, Taeho

    2016-06-01

    Recently, bioelectrochemical systems have been demonstrated as advantageous for denitrification. Here, we investigated the nitrate reduction rate and bacterial community on cathodes at different cathode potentials [-300, -500, -700, and -900 mV vs. standard hydrogen electrode (SHE)] in a two-chamber microbial electrochemical denitrification system and effects of sulfate, a common nitrate co-contaminant, on denitrification efficiency. The results indicated that the highest nitrate reduction rates (3.5 mg L(-1) days(-1)) were obtained at a cathode potential of -700 mV, regardless of sulfate presence, while a lower rate was observed at a more negative cathode potential (-900 mV). Notably, although sulfate ions generally inhibited nitrate reduction, this effect was absent at a cathode potential of -700 mV. Polymerase chain reaction-denaturing gradient gel electrophoresis revealed that bacterial communities on the graphite-felt cathode were significantly affected by the cathode potential change and sulfate presence. Shinella-like and Alicycliphilus-like bacterial species were exclusively observed on cathodes in reactors without sulfate. Ochrobactrum-like and Sinorhizobium-like bacterial species, which persisted at different cathode potentials irrespective of sulfate presence, were shown to contribute to bioelectrochemical denitrification. This study suggested that a cathode potential of around -700 mV versus SHE would ensure optimal nitrate reduction rate and counteract inhibitory effects of sulfate. Additionally, sulfate presence considerably affects denitrification efficiency and microbial community of microbial electrochemical denitrification systems.

  4. Towards Energy Demand Reduction in Social Housing Buildings: Envelope System Optimization Strategies

    Directory of Open Access Journals (Sweden)

    Paula M. Esquivias

    2012-07-01

    Full Text Available This work evaluates the potential for the reduction of energy demand in residential buildings by acting on the exterior envelope, both in newly constructed buildings and in the retrofitting of existing stock. It focuses on analysing social housing buildings in Mediterranean areas and on quantifying the scope of that reduction in the application of different envelope design strategies, with the purpose of prioritizing their application based on their energy efficiency. The analyses and quantifications were made by means of the generation of energy models with the TRNSYS tool for simple or combined solutions, identifying possible potentials for reduction of the energy demand from 20% to 25%, basically by acting on the windows. The case study was a newly built social housing building of a closed block type located in Seville (Spain. Its constructive techniques and the insulation level of its envelope are standardized for current buildings widespread across Mediterranean Europe.

  5. A Technique for Reduction of Edentulous Fractures Using Dentures and SMARTLock Hybrid Fixation System

    Directory of Open Access Journals (Sweden)

    Anna Rose Carlson, MD

    2017-09-01

    Full Text Available Summary:. Establishing anatomic reduction of an edentulous mandible fracture is a frequently acknowledged challenge in craniomaxillofacial trauma surgery. In this study, we report a novel method for the reduction of the edentulous mandible fracture, via fabrication of modified Gunning splints using existing dentures and SMARTLock hybrid arch bars. This technique dramatically simplifies the application of an arch bar to dentures, obviates the need for the fabrication of impressions and custom splints, and eliminates the lag time associated with the creation of splints. Furthermore, this method may be used with or without adjunctive rigid internal fixation. The technique described herein of creating Gunning splints with SMARTLock hybrid arch bars provides surgeons with a simple, rapid, single-stage solution for reduction of mandibular fractures in the edentulous patient.

  6. Biotechnological reduction of sulfide in an industrial primary wastewater treatment system: A sustainable and successful case study

    Energy Technology Data Exchange (ETDEWEB)

    Rajamani, S. [Central Leather Research Institute, Madras (India)

    1996-12-31

    The leather industry is an important export-oriented industry in India, with more than 3,000 tanneries located in different clusters. Sodium sulfide, a toxic chemical, is used in large quantities to remove hair and excess flesh from hides and skins. Most of the sodium sulfide used in the process is discharged as waste in the effluent, which causes serious environmental problems. Reduction of sulfide in the effluent is generally achieved by means of chemicals in the pretreatment system, which involves aerobic mixing using large amounts of chemicals and high energy, and generating large volumes of sludge. A simple biotechnological system that uses the residual biosludge from the secondary settling tank was developed, and the commercial-scale application established that more than 90% of the sulfide could be reduced in the primary treatment system. In addition to the reduction of sulfide, foul smells, BOD and COD are reduced to a considerable level. 3 refs., 2 figs., 1 tab.

  7. The application of an analytical probabilistic model for estimating the rainfall-runoff reductions achieved using a rainwater harvesting system.

    Science.gov (United States)

    Kim, Hyoungjun; Han, Mooyoung; Lee, Ju Young

    2012-05-01

    Rainwater harvesting systems cannot only supplement on-site water needs, but also reduce water runoff and lessen downstream flooding. In this study, an existing analytic model for estimating the runoff in urban areas is modified to provide a more economical and effective model that can be used for describing rainwater harvesting. This model calculates the rainfall-runoff reduction by taking into account the catchment, storage tank, and infiltration facility of a water harvesting system; this calculation is based on the water balance equation, and the cumulative distribution, probability density, and average rainfall-runoff functions. This model was applied to a water harvesting system at the Seoul National University in order to verify its practicality. The derived model was useful for evaluating runoff reduction and for designing the storage tank capacity. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. A method of ‘speed coefficients’ for biochemical model reduction applied to the NF-κB system.

    Science.gov (United States)

    West, Simon; Bridge, Lloyd J; White, Michael R H; Paszek, Pawel; Biktashev, Vadim N

    2015-02-01

    The relationship between components of biochemical network and the resulting dynamics of the overall system is a key focus of computational biology. However, as these networks and resulting mathematical models are inherently complex and non-linear, the understanding of this relationship becomes challenging. Among many approaches, model reduction methods provide an avenue to extract components responsible for the key dynamical features of the system. Unfortunately, these approaches often require intuition to apply. In this manuscript we propose a practical algorithm for the reduction of biochemical reaction systems using fast-slow asymptotics. This method allows the ranking of system variables according to how quickly they approach their momentary steady state, thus selecting the fastest for a steady state approximation. We applied this method to derive models of the Nuclear Factor kappa B network, a key regulator of the immune response that exhibits oscillatory dynamics. Analyses with respect to two specific solutions, which corresponded to different experimental conditions identified different components of the system that were responsible for the respective dynamics. This is an important demonstration of how reduction methods that provide approximations around a specific steady state, could be utilised in order to gain a better understanding of network topology in a broader context.

  9. Reduction of Life Cycle CO2 Emission in Public Welfare Facilities Equipped with PV/Solar Heat/Cogeneration System

    Science.gov (United States)

    Oke, Shinichiro; Kemmoku, Yoshishige; Takikawa, Hirofumi; Sakakibara, Tateki

    The reduction effect of life cycle CO2 emission is examined in case of introducing a PV/solar heat/cogeneration system into public welfare facilities(hotel and hospital). Life cycle CO2 emission is calculated as the sum of that when operating and that when manufacturing equipments. The system is operated with the dynamic programming method, into which hourly data of electric and heat loads, solar insolation, and atmospheric temperature during a year are input. The proposed system is compared with a conventional system and a cogeneration system. The life cycle CO2 emission of the PV/solar heat/cogeneration system is lower than that of the conventional system by 20% in hotel and by 14% in hospital.

  10. Model reduction for the dynamics and control of large structural systems via neutral network processing direct numerical optimization

    Science.gov (United States)

    Becus, Georges A.; Chan, Alistair K.

    1993-01-01

    Three neural network processing approaches in a direct numerical optimization model reduction scheme are proposed and investigated. Large structural systems, such as large space structures, offer new challenges to both structural dynamicists and control engineers. One such challenge is that of dimensionality. Indeed these distributed parameter systems can be modeled either by infinite dimensional mathematical models (typically partial differential equations) or by high dimensional discrete models (typically finite element models) often exhibiting thousands of vibrational modes usually closely spaced and with little, if any, damping. Clearly, some form of model reduction is in order, especially for the control engineer who can actively control but a few of the modes using system identification based on a limited number of sensors. Inasmuch as the amount of 'control spillover' (in which the control inputs excite the neglected dynamics) and/or 'observation spillover' (where neglected dynamics affect system identification) is to a large extent determined by the choice of particular reduced model (RM), the way in which this model reduction is carried out is often critical.

  11. Harm reduction as a complex adaptive system: A dynamic framework for analyzing Tanzanian policies concerning heroin use.

    Science.gov (United States)

    Ratliff, Eric A; Kaduri, Pamela; Masao, Frank; Mbwambo, Jessie K K; McCurdy, Sheryl A

    2016-04-01

    Contrary to popular belief, policies on drug use are not always based on scientific evidence or composed in a rational manner. Rather, decisions concerning drug policies reflect the negotiation of actors' ambitions, values, and facts as they organize in different ways around the perceived problems associated with illicit drug use. Drug policy is thus best represented as a complex adaptive system (CAS) that is dynamic, self-organizing, and coevolving. In this analysis, we use a CAS framework to examine how harm reduction emerged around heroin trafficking and use in Tanzania over the past thirty years (1985-present). This account is an organizational ethnography based on of the observant participation of the authors as actors within this system. We review the dynamic history and self-organizing nature of harm reduction, noting how interactions among system actors and components have coevolved with patterns of heroin us, policing, and treatment activities over time. Using a CAS framework, we describe harm reduction as a complex process where ambitions, values, facts, and technologies interact in the Tanzanian sociopolitical environment. We review the dynamic history and self-organizing nature of heroin policies, noting how the interactions within and between competing prohibitionist and harm reduction policies have changed with patterns of heroin use, policing, and treatment activities over time. Actors learn from their experiences to organize with other actors, align their values and facts, and implement new policies. Using a CAS approach provides researchers and policy actors a better understanding of patterns and intricacies in drug policy. This knowledge of how the system works can help improve the policy process through adaptive action to introduce new actors, different ideas, and avenues for communication into the system. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Efficiency Improvement through Reduction in Friction and Wear in Powertrain Systems

    Energy Technology Data Exchange (ETDEWEB)

    Michael Killian

    2009-09-30

    The objective of this project is to improve the efficiency of truck drivelines through reduction of friction and parasitic losses in transmission and drive axles. Known efficiencies for these products exceeded 97 percent, so the task was not trivial. The project relied on a working relationship between modeling and hardware testing. Modeling was to shorten the development cycle by guiding the selection of materials, processes and strategies. Bench top and fixture tests were to validate the models. Modeling was performed at a world class, high academic level, but in the end, modeling did not impact the hardware development as much as intended. Insights leading to the most significant accomplishments came from bench top and fixture tests and full scale dynamometer tests. A key development in the project was the formulation of the implementation strategy. Five technical elements with potential to minimize friction and parasitic losses were identified. These elements included churning, lubrication, surface roughness, coatings and textures. An interesting fact is that both Caterpillar and Eaton independently converged on the same set of technical elements in formulating their implementation strategies. Exploiting technical elements of the implementation strategy had a positive impact on transmission and drive axle efficiencies. During one dynamometer test of an Eaton Best Tech 1 transmission, all three gear ranges tested: Under drive, direct drive and over drive, showed efficiencies greater than 99 percent. Technology boosts to efficiency for transmissions reached 1 percent, while efficiency improvements to drive axle pushed 2 percent. These advancements seem small, but the accomplishment is large considering that these products normally run at greater than 97 percent efficiency. Barriers and risks to implementing these technology elements are clear. Schemes using a low fill sump and spray tubes endanger the gears and bearings by lubricant starvation. Gear coatings have

  13. Heavy Class Helicopter Fuselage Model Drag Reduction by Active Flow Control Systems

    Science.gov (United States)

    De Gregorio, F.

    2017-08-01

    A comprehensive experimental investigation of helicopter blunt fuselage drag reduction using active flow control is being carried out within the European Clean Sky program. The objective is to demonstrate the capability of several active flow technologies to decrease fuselage drag by alleviating the flow separation occurring in the rear area of some helicopters. The work is performed on a simplified blunt fuselage at model-scale. Two different flow control actuators are considered for evaluation: steady blowing, unsteady blowing (or pulsed jets). Laboratory tests of each individual actuator are first performed to assess their performance and properties. The fuselage model is then equipped with these actuators distributed in 3 slots located on the ramp bottom edge. This paper addresses the promising results obtained during the wind-tunnel campaign, since significant drag reductions are achieved for a wide range of fuselage angles of attack and yaw angles without detriment of the other aerodynamic characteristics.

  14. Second-Order Harmonic Reduction Technique for Photovoltaic Power Conditioning Systems Using a Proportional-Resonant Controller

    Directory of Open Access Journals (Sweden)

    Hae-Gwang Jeong

    2013-01-01

    Full Text Available This paper proposes a second-order harmonic reduction technique using a proportional-resonant (PR controller for a photovoltaic (PV power conditioning system (PCS. In a grid-connected single-phase system, inverters create a second-order harmonic at twice the fundamental frequency. A ripple component unsettles the operating points of the PV array and deteriorates the operation of the maximum power point tracking (MPPT technique. The second-order harmonic component in PV PCS is analyzed using an equivalent circuit of the DC/DC converter and the DC/AC inverter. A new feed-forward compensation technique using a PR controller for ripple reduction is proposed. The proposed algorithm is advantageous in that additional devices are not required and complex calculations are unnecessary. Therefore, this method is cost-effective and simple to implement. The proposed feed-forward compensation technique is verified by simulation and experimental results.

  15. Advanced Exploration Systems (AES) Logistics Reduction and Repurposing Project: Advanced Clothing Ground Study Final Report

    Science.gov (United States)

    Byrne, Vicky; Orndoff, Evelyne; Poritz, Darwin; Schlesinger, Thilini

    2013-01-01

    All human space missions require significant logistical mass and volume that will become an excessive burden for long duration missions beyond low Earth orbit. The goal of the Advanced Exploration Systems (AES) Logistics Reduction & Repurposing (LRR) project is to bring new ideas and technologies that will enable human presence in farther regions of space. The LRR project has five tasks: 1) Advanced Clothing System (ACS) to reduce clothing mass and volume, 2) Logistics to Living (L2L) to repurpose existing cargo, 3) Heat Melt Compactor (HMC) to reprocess materials in space, 4) Trash to Gas (TTG) to extract useful gases from trash, and 5) Systems Engineering and Integration (SE&I) to integrate these logistical components. The current International Space Station (ISS) crew wardrobe has already evolved not only to reduce some of the logistical burden but also to address crew preference. The ACS task is to find ways to further reduce this logistical burden while examining human response to different types of clothes. The ACS task has been broken into a series of studies on length of wear of various garments: 1) three small studies conducted through other NASA projects (MMSEV, DSH, HI-SEAS) focusing on length of wear of garments treated with an antimicrobial finish; 2) a ground study, which is the subject of this report, addressing both length of wear and subject perception of various types of garments worn during aerobic exercise; and 3) an ISS study replicating the ground study, and including every day clothing to collect information on perception in reduced gravity in which humans experience physiological changes. The goal of the ground study is first to measure how long people can wear the same exercise garment, depending on the type of fabric and the presence of antimicrobial treatment, and second to learn why. Human factors considerations included in the study consist of the Institutional Review Board approval, test protocol and participants' training, and a web

  16. Autoantibodies Affect Brain Density Reduction in Nonneuropsychiatric Systemic Lupus Erythematosus Patients

    Directory of Open Access Journals (Sweden)

    Jian Xu

    2015-01-01

    Full Text Available This study explores the relationship between autoantibodies and brain density reduction in SLE patients without major neuropsychiatric manifestation (NPSLE. Ninety-five NPSLE patients without obvious cerebral deficits, as determined by conventional MRI, as well as 89 control subjects, underwent high-resolution structural MRI. Whole-brain density of grey matter (GMD and white matter (WMD were calculated for each individual, and correlations between the brain density, symptom severity, immunosuppressive agent (ISA, and autoantibody levels were assessed. The GMD and WMD of the SLE group decreased compared to controls. GMD was negatively associated with SLE activity. The WMD of patients who received ISA treatment were higher than that in the patients who did not. The WMD of patients with anticardiolipin (ACL or anti-SSB/La antibodies was lower than in patients without these antibodies, while the GMD was lower in patients with anti-SM or anti-U1RNP antibodies. Thus, obvious brain atrophy can occur very early even before the development of significant symptoms and specific autoantibodies might contribute to the reduction of GMD or WMD in NPSLE patients. However, ISAs showed protective effects in minimizing GMD and WMD reduction. The presence of these specific autoantibodies might help identify early brain damage in NPSLE patients.

  17. A Harmonic Impedance Measurement System for Reduction of Harmonics in the Electricity Grid

    NARCIS (Netherlands)

    Heskes, P.J.M.; Myrzik, J.M.A.; Kling, W.L.

    2009-01-01

    This paper describes the development of a Complex Harmonic Impedance Measurement system, called the CHIME-system. This system performs on-line impedance measurements in the electricity grid and will be designed for implementation in Digital Signal Processor (DSP) control systems of grid-connected

  18. Introducing network Gramians to undirected network systems for structure-preserving model reduction

    NARCIS (Netherlands)

    Cheng, Xiaodong; Scherpen, Jacquelien M.A.

    2016-01-01

    In this paper, we propose the notion of controllability Gramian for linear network systems. In contrast to the conventional Gramians defined for asymptotically stable systems, the new Gramian is generalized to semi-stable systems and can be computed for network systems with imaginary axis poles. We

  19. Greenhouse gas emission reduction and environmental quality improvement from implementation of aerobic waste treatment systems in swine farms.

    Science.gov (United States)

    Vanotti, M B; Szogi, A A; Vives, C A

    2008-01-01

    Trading of greenhouse gas (GHG) emission reductions is an attractive approach to help producers implement cleaner treatment technologies to replace current anaerobic lagoons. Our objectives were to estimate greenhouse gas (GHG) emission reductions from implementation of aerobic technology in USA swine farms. Emission reductions were calculated using the approved United Nations framework convention on climate change (UNFCCC) methodology in conjunction with monitoring information collected during full-scale demonstration of the new treatment system in a 4360-head swine operation in North Carolina (USA). Emission sources for the project and baseline manure management system were methane (CH4) emissions from the decomposition of manure under anaerobic conditions and nitrous oxide (N2O) emissions during storage and handling of manure in the manure management system. Emission reductions resulted from the difference between total project and baseline emissions. The project activity included an on-farm wastewater treatment system consisting of liquid-solid separation, treatment of the separated liquid using aerobic biological N removal, chemical disinfection and soluble P removal using lime. The project activity was completed with a centralized facility that used aerobic composting to process the separated solids. Replacement of the lagoon technology with the cleaner aerobic technology reduced GHG emissions 96.9%, from 4972 tonnes of carbon dioxide equivalents (CO2-eq) to 153 tonnes CO2-eq/year. Total net emission reductions by the project activity in the 4360-head finishing operation were 4776.6 tonnes CO2-eq per year or 1.10 tonnes CO2-eq/head per year. The dollar value from implementation of this project in this swine farm was US$19,106/year using current Chicago Climate Exchange trading values of US$4/t CO2. This translates into a direct economic benefit to the producer of US$1.75 per finished pig. Thus, GHG emission reductions and credits can help compensate for the

  20. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    Science.gov (United States)

    Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

    2013-11-01

    This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

  1. Analytical design and evaluation of an active control system for helicopter vibration reduction and gust response alleviation

    Science.gov (United States)

    Taylor, R. B.; Zwicke, P. E.; Gold, P.; Miao, W.

    1980-01-01

    An analytical study was conducted to define the basic configuration of an active control system for helicopter vibration and gust response alleviation. The study culminated in a control system design which has two separate systems: narrow band loop for vibration reduction and wider band loop for gust response alleviation. The narrow band vibration loop utilizes the standard swashplate control configuration to input controller for the vibration loop is based on adaptive optimal control theory and is designed to adapt to any flight condition including maneuvers and transients. The prime characteristics of the vibration control system is its real time capability. The gust alleviation control system studied consists of optimal sampled data feedback gains together with an optimal one-step-ahead prediction. The prediction permits the estimation of the gust disturbance which can then be used to minimize the gust effects on the helicopter.

  2. Power System Mass Analysis for Hydrogen Reduction Oxygen Production on the Lunar Surface

    Science.gov (United States)

    Colozza, Anthony J.

    2009-01-01

    The production of oxygen from the lunar regolith requires both thermal and electrical power in roughly similar proportions. This unique power requirement is unlike most applications on the lunar surface. To efficiently meet these requirements, both solar PV array and solar concentrator systems were evaluated. The mass of various types of photovoltaic and concentrator based systems were calculated to determine the type of power system that provided the highest specific power. These were compared over a range of oxygen production rates. Also a hybrid type power system was also considered. This system utilized a photovoltaic array to produce the electrical power and a concentrator to provide the thermal power. For a single source system the three systems with the highest specific power were a flexible concentrator/Stirling engine system, a rigid concentrator/Stirling engine system and a tracking triple junction solar array system. These systems had specific power values of 43, 34, and 33 W/kg, respectively. The hybrid power system provided much higher specific power values then the single source systems. The best hybrid combinations were the triple junction solar array with the flexible concentrator and the rigid concentrator. These systems had a specific power of 81 and 68 W/kg, respectively.

  3. Innovations in Medication Preparation Safety and Wastage Reduction: Use of a Workflow Management System in a Pediatric Hospital.

    Science.gov (United States)

    Davis, Stephen Jerome; Hurtado, Josephine; Nguyen, Rosemary; Huynh, Tran; Lindon, Ivan; Hudnall, Cedric; Bork, Sara

    2017-01-01

    Background: USP regulatory requirements have mandated that pharmacies improve aseptic techniques and cleanliness of the medication preparation areas. In addition, the Institute for Safe Medication Practices (ISMP) recommends that technology and automation be used as much as possible for preparing and verifying compounded sterile products. Objective: To determine the benefits associated with the implementation of the workflow management system, such as reducing medication preparation and delivery errors, reducing quantity and frequency of medication errors, avoiding costs, and enhancing the organization's decision to move toward positive patient identification (PPID). Methods: At Texas Children's Hospital, data were collected and analyzed from January 2014 through August 2014 in the pharmacy areas in which the workflow management system would be implemented. Data were excluded for September 2014 during the workflow management system oral liquid implementation phase. Data were collected and analyzed from October 2014 through June 2015 to determine whether the implementation of the workflow management system reduced the quantity and frequency of reported medication errors. Data collected and analyzed during the study period included the quantity of doses prepared, number of incorrect medication scans, number of doses discontinued from the workflow management system queue, and the number of doses rejected. Data were collected and analyzed to identify patterns of incorrect medication scans, to determine reasons for rejected medication doses, and to determine the reduction in wasted medications. Results: During the 17-month study period, the pharmacy department dispensed 1,506,220 oral liquid and injectable medication doses. From October 2014 through June 2015, the pharmacy department dispensed 826,220 medication doses that were prepared and checked via the workflow management system. Of those 826,220 medication doses, there were 16 reported incorrect volume errors. The

  4. Potential Occupant Injury Reduction in Pre-Crash System Equipped Vehicles in the Striking Vehicle of Rear-end Crashes.

    Science.gov (United States)

    Kusano, Kristofer D; Gabler, Hampton C

    2010-01-01

    To mitigate the severity of rear-end and other collisions, Pre-Crash Systems (PCS) are being developed. These active safety systems utilize radar and/or video cameras to determine when a frontal crash, such as a front-to-back rear-end collisions, is imminent and can brake autonomously, even with no driver input. Of these PCS features, the effects of autonomous pre-crash braking are estimated. To estimate the maximum potential for injury reduction due to autonomous pre-crash braking in the striking vehicle of rear-end crashes, a methodology is presented for determining 1) the reduction in vehicle crash change in velocity (ΔV) due to PCS braking and 2) the number of injuries that could be prevented due to the reduction in collision severity. Injury reduction was only performed for belted drivers, as unbelted drivers have an unknown risk of being thrown out of position. The study was based on 1,406 rear-end striking vehicles from NASS / CDS years 1993 to 2008. PCS parameters were selected from realistic values and varied to examine the effect on system performance. PCS braking authority was varied from 0.5 G's to 0.8 G's while time to collision (TTC) was held at 0.45 seconds. TTC was then varied from 0.3 second to 0.6 seconds while braking authority was held constant at 0.6 G's. A constant braking pulse (step function) and ramp-up braking pulse were used. The study found that automated PCS braking could reduce the crash ΔV in rear-end striking vehicles by an average of 12% - 50% and avoid 0% - 14% of collisions, depending on PCS parameters. Autonomous PCS braking could potentially reduce the number of injured drivers who are belted by 19% to 57%.

  5. Design and testing of an independently controlled urea SCR retrofit system for the reduction of NOx emissions from marine diesels.

    Science.gov (United States)

    Johnson, Derek R; Bedick, Clinton R; Clark, Nigel N; McKain, David L

    2009-05-15

    Diesel engine emissions for on-road, stationary and marine applications are regulated in the United States via standards set by the Environmental Protection Agency (EPA). A major component of diesel exhaust that is difficult to reduce is nitrogen oxides (NOx). Selective catalytic reduction (SCR) has been in use for many years for stationary applications, including external combustion boilers, and is promising for NOx abatement as a retrofit for mobile applications where diesel compression ignition engines are used. The research presented in this paper is the first phase of a program focused on the reduction of NOx by use of a stand-alone urea injection system, applicable to marine diesel engines typical of work boats (e.g., tugs). Most current urea SCR systems communicate with engine controls to predict NOx emissions based on signals such as torque and engine speed, however many marine engines in use still employ mechanical injection technology and lack electronic communication abilities. The system developed and discussed in this paper controls NOx emissions independentof engine operating parameters and measures NOx and exhaust flow using the following exhaust sensor inputs: absolute pressure, differential pressure, temperature, and NOx concentration. These sensor inputs were integrated into an independent controller and open loop architecture to estimate the necessary amount of urea needed, and the controller uses pulse width modulation (PWM) to power an automotive fuel injector for airless urea delivery. The system was tested in a transient test cell on a 350 hp engine certified at 4 g/bhp-hr of NOx, with a goal of reducing the engine out NOx levels by 50%. NOx reduction capabilities of 41-67% were shown on the non road transient cycle (NRTC) and ICOMIA E5 steady state cycles with system optimization during testing to minimize the dilute ammonia slip to cycle averages of 5-7 ppm. The goal of 50% reduction of NOx can be achieved dependent upon cycle. Further

  6. Update on Risk Reduction Activities for a Liquid Advanced Booster for NASA's Space Launch System

    Science.gov (United States)

    Crocker, Andy; Greene, William D.

    2017-01-01

    Goals of NASA's Advanced Booster Engineering Demonstration and/or Risk Reduction (ABEDRR) are to: (1) Reduce risks leading to an affordable Advanced Booster that meets the evolved capabilities of SLS. (2) Enable competition by mitigating targeted Advanced Booster risks to enhance SLS affordability. SLS Block 1 vehicle is being designed to carry 70 mT to LEO: (1) Uses two five-segment solid rocket boosters (SRBs) similar to the boosters that helped power the space shuttle to orbit. Evolved 130 mT payload class rocket requires an advanced booster with more thrust than any existing U.S. liquid-or solid-fueled boosters

  7. Generation IV Nuclear Energy Systems Construction Cost Reductions Through the Use of Virtual Environments

    Energy Technology Data Exchange (ETDEWEB)

    Timothy Shaw; Vaugh Whisker

    2004-02-28

    The objective of this multi-phase project is to demonstrate the feasibility and effectiveness of using full-scale virtual reality simulation in the design, construction, and maintenance of future nuclear power plants. The project will test the suitability of immersive virtual reality technology to aid engineers in the design of the next generation nuclear power plant and to evaluate potential cost reductions that can be realized by optimization of installation and construction sequences. The intent is to see if this type of information technology can be used in capacities similar to those currently filled by full-scale physical mockups. This report presents the results of the completed project.

  8. Evaluation of Mirasol pathogen reduction system by artificially contaminating platelet concentrates with Staphylococcus epidermidis: A pilot study from India

    Directory of Open Access Journals (Sweden)

    Kabita Chatterjee

    2016-01-01

    Full Text Available Background and Objectives: This study was conducted to assess the efficacy of Mirasol pathogen reduction system for platelets aimed at preventing bacterial regrowth by spiking buffy coat pooled platelets (BCPP with clinically relevant load of Staphylococous epidermidis. Materials and Methods: BCPP units were prepared using Teruflex BP-kit with Imugard III-S-PL (Terumo BCT, Tokyo, Japan. Two BCPP units were pooled, of which 40 ml of negative control (NC was removed. The remaining volume of the platelet unit was inoculated with clinically relevant load of bacteria (total of 30 CFU of S. epidermidis in 1 ml; following this the platelet unit was split into two parts. One part served as positive control (PC and the other part was subjected to pathogen reduction technique (Mirasol PRT, CaridianBCT Biotechnologies, Lakewood, CO, USA. Bacterial detection was performed using BacT/ALERT system, controls after day 1 and day 7 following inoculation of bacteria and on day 7 for Mirasol-treated unit. Results: Of the 32 treatment cycles, 28 were valid and 4 were invalid. No regrowth was observed in 96.4% (27 of 28 after treatment with Mirasol pathogen reduction system. Of four invalid tests, on two instances the NC showed growth, whereas in other 2 no regrowth was detected in 7th day PC. Bacterial screening of PCs by BacT/ALERT after 24 h of incubation was 28.6%, whereas the effectiveness increased to 100% when incubated for 7 days. Conclusions: Mirasol system was effective in inactivating S.epidermidis when it was deliberately inoculated into BCPP at clinically relevant concentrations. Such systems may significantly improve blood safety by inactivating traditional and emerging transfusion-transmitted pathogens.

  9. Ambient nitrogen reduction cycle using a hybrid inorganic–biological system

    Science.gov (United States)

    Liu, Chong; Sakimoto, Kelsey K.; Colón, Brendan C.; Silver, Pamela A.

    2017-01-01

    We demonstrate the synthesis of NH3 from N2 and H2O at ambient conditions in a single reactor by coupling hydrogen generation from catalytic water splitting to a H2-oxidizing bacterium Xanthobacter autotrophicus, which performs N2 and CO2 reduction to solid biomass. Living cells of X. autotrophicus may be directly applied as a biofertilizer to improve growth of radishes, a model crop plant, by up to ∼1,440% in terms of storage root mass. The NH3 generated from nitrogenase (N2ase) in X. autotrophicus can be diverted from biomass formation to an extracellular ammonia production with the addition of a glutamate synthetase inhibitor. The N2 reduction reaction proceeds at a low driving force with a turnover number of 9 × 109 cell–1 and turnover frequency of 1.9 × 104 s–1⋅cell–1 without the use of sacrificial chemical reagents or carbon feedstocks other than CO2. This approach can be powered by renewable electricity, enabling the sustainable and selective production of ammonia and biofertilizers in a distributed manner. PMID:28588143

  10. A continuous system for Fe0 reduction of nitrobenzene in synthetic wastewater.

    Science.gov (United States)

    Mantha, R; Taylor, K E; Biswas, N; Bewtra, J K

    2001-08-01

    Nitrobenzene is a major environmental pollutant, and its degradation is difficultto achieve. Hence, a chemical reduction pretreatment is sought in this research, before the resulting aniline can be treated by enzyme-mediated oxidative polymerization. Zerovalent iron (Fe0) has been successfully employed to reduce nitrobenzene to aniline in synthetic wastewater in both batch and continuous flow reactors. The concentration of nitrobenzene studied was thatwhich would be present in industrial wastewater streams (millimolar, 123 ppm), a concentration range considerably higher than those studied previously with groundwater by other researchers. Anaerobic conditions were maintained in the reactors by including Na2SO3 as an oxygen scavenger in the presence of CoCl2.6H2O, which acted as a catalyst. Batch reactors exhibited adsorption of aniline on the Fe0, which could be described by a langmuir isotherm. A 200 g Fe0 (particle size: 1-2 mm) bed completely converted 1 mM of nitrobenzene flowing upward for about 600 pore-volumes before experiencing flow reduction due to clogging due to corrosion products. Green-black precipitates (Fe0 corrosion products) were formed at the influent end of the column which were identified as maghemite.

  11. Ambient nitrogen reduction cycle using a hybrid inorganic-biological system.

    Science.gov (United States)

    Liu, Chong; Sakimoto, Kelsey K; Colón, Brendan C; Silver, Pamela A; Nocera, Daniel G

    2017-06-20

    We demonstrate the synthesis of NH 3 from N 2 and H 2 O at ambient conditions in a single reactor by coupling hydrogen generation from catalytic water splitting to a H 2 -oxidizing bacterium Xanthobacter autotrophicus , which performs N 2 and CO 2 reduction to solid biomass. Living cells of X. autotrophicus may be directly applied as a biofertilizer to improve growth of radishes, a model crop plant, by up to ∼1,440% in terms of storage root mass. The NH 3 generated from nitrogenase (N 2 ase) in X. autotrophicus can be diverted from biomass formation to an extracellular ammonia production with the addition of a glutamate synthetase inhibitor. The N 2 reduction reaction proceeds at a low driving force with a turnover number of 9 × 10 9 cell -1 and turnover frequency of 1.9 × 10 4 s -1 ⋅cell -1 without the use of sacrificial chemical reagents or carbon feedstocks other than CO 2 This approach can be powered by renewable electricity, enabling the sustainable and selective production of ammonia and biofertilizers in a distributed manner.

  12. The Henry ford production system: effective reduction of process defects and waste in surgical pathology.

    Science.gov (United States)

    Zarbo, Richard J; D'Angelo, Rita

    2007-12-01

    By adopting a cultural transformation in its employees' approach to work and using manufacturing based continuous quality improvement methods, the surgical pathology division of Henry Ford Hospital, Detroit, MI, focused on reducing commonly encountered defects and waste in processes throughout the testing cycle. At inception, the baseline in-process defect rate was measured at nearly 1 in 3 cases (27.9%). After the year-long efforts of 77 workers implementing more than 100 process improvements, the number of cases with defects was reduced by 55% to 1 in 8 cases (12.5%), with a statistically significant reduction in the overall distribution of defects (P = .0004). Comparison with defects encountered in the pre-improvement period showed statistically significant reductions in pre-analytic (P = .0007) and analytic (P = .0002) test phase processes in the post-improvement period that included specimen receipt, specimen accessioning, grossing, histology slides, and slide recuts. We share the key improvements implemented that were responsible for the overall success in reducing waste and re-work in the broad spectrum of surgical pathology processes.

  13. System and method for selective catalytic reduction of nitrogen oxides in combustion exhaust gases

    Science.gov (United States)

    Sobolevskiy, Anatoly; Rossin, Joseph A

    2014-04-08

    A multi-stage selective catalytic reduction (SCR) unit (32) provides efficient reduction of NOx and other pollutants from about 50-550.degree. C. in a power plant (19). Hydrogen (24) and ammonia (29) are variably supplied to the SCR unit depending on temperature. An upstream portion (34) of the SCR unit catalyzes NOx+NH.sub.3 reactions above about 200.degree. C. A downstream portion (36) catalyzes NOx+H.sub.2 reactions below about 260.degree. C., and catalyzes oxidation of NH.sub.3, CO, and VOCs with oxygen in the exhaust above about 200.degree. C., efficiently removing NOx and other pollutants over a range of conditions with low slippage of NH.sub.3. An ammonia synthesis unit (28) may be connected to the SCR unit to provide NH.sub.3 as needed, avoiding transport and storage of ammonia or urea at the site. A carbonaceous gasification plant (18) on site may supply hydrogen and nitrogen to the ammonia synthesis unit, and hydrogen to the SCR unit.

  14. Model Order Reduction of Large-Scale Finite Element Systems in an MPI Parallelized Environment for Usage in Multibody Simulation

    Directory of Open Access Journals (Sweden)

    Volzer Thomas

    2016-12-01

    Full Text Available The use of elastic bodies within a multibody simulation became more and more important within the last years. To include the elastic bodies, described as a finite element model in multibody simulations, the dimension of the system of ordinary differential equations must be reduced by projection. For this purpose, in this work, the modal reduction method, a component mode synthesis based method and a moment-matching method are used. Due to the always increasing size of the non-reduced systems, the calculation of the projection matrix leads to a large demand of computational resources and cannot be done on usual serial computers with available memory. In this paper, the model reduction software Morembs++ is presented using a parallelization concept based on the message passing interface to satisfy the need of memory and reduce the runtime of the model reduction process. Additionally, the behaviour of the Block-Krylov-Schur eigensolver, implemented in the Anasazi package of the Trilinos project, is analysed with regard to the choice of the size of the Krylov base, the block size and the number of blocks. Besides, an iterative solver is considered within the CMS-based method.

  15. A genetic system for Geobacter metallireducens: role of the flagellin and pilin in the reduction of Fe(III) oxide

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, PL; Aklujkar, M; Leang, C; Nevin, KP; Lovley, D

    2011-11-27

    Geobacter metallireducens is an important model organism for many novel aspects of extracellular electron exchange and the anaerobic degradation of aromatic compounds, but studies of its physiology have been limited by a lack of techniques for gene deletion and replacement. Therefore, a genetic system was developed for G. metallireducens by making a number of modifications in the previously described approach for homologous recombination in Geobacter sulfurreducens. Critical modifications included, among others, a 3.5-fold increased in the quantity of electrotransformed linear DNA and the harvesting of cells at early-log. The Cre-lox recombination system was used to remove an antibiotic resistance cassette from the G. metallireducens chromosome permitting the generation of multiple mutations in the same strain. Deletion of the gene fliC, which encodes the flagellin protein, resulted in a strain that did not produce flagella, was non-motile, and was defective for the reduction of insoluble Fe(III). Deletion of pilA, which encodes the structural protein of the type IV pili, inhibited the production of lateral pili as well as Fe(III) oxide reduction and electron transfer to an electrode. These results demonstrate the importance of flagella and pili in the reduction of insoluble Fe(III) by G. metallireducens and provide methods for additional genetic-based approaches for the study of G. metallireducens.

  16. Improvement and prediction of OSA system performance in sludge reduction through integration with thermal and mechanical treatment.

    Science.gov (United States)

    Nazif, Sara; Mehrdadi, Naser; Zare, Sajad; Mosavari, Sarvenaz

    2016-11-01

    The oxic-settling-anoxic (OSA) process is one of the sludge production reduction methods in the activated sludge process. In this method, sludge is stored in an anaerobic tank within the sludge return line before entrance into an aeration tank. Due to this method's flexibility in application to operating treatment plants and not being energy-consuming, its application is developing. In this research, the improvement of the OSA process is investigated via thermal and mechanical treatment in a sequencing batch reactor (SBR). A pilot-scale reactor and domestic wastewater are used. Sludge was subjected to high temperature in an anaerobic tank using a heat transformer and it was subjected to mechanical shear through mechanical mixing in the anaerobic tank. Different temperatures and voltages were tested. The OSA process reduced sludge production by 24% while the chemical oxygen demand (COD) removal rate decreased from 90% to 86%. Thermal treatment combined with the OSA process caused a maximum of 46% sludge production reduction. However temperatures above 90 °C are not recommended due to a high level of decrease in COD removal. Mechanical mixing in combination with the OSA process led to 34% sludge production reduction. The effluent quality is not affected by the OSA process itself but is slightly reduced by thermal treatment and mechanical mixing. Therefore, for reaching the maximum sludge reduction in OSA plus thermal and mechanical treatment it would be necessary to evaluate the effect of different sets of parameters on effluent quality beside the sludge reduction. For this purpose multi-layer perceptron artificial neural network models are developed to predict the effluent total suspended solids and COD removal efficiency as well as sludge production rate. The models perform well and would be useful tools in determining the optimal set of system operation parameters.

  17. The reductive degradation of 1,1,1-trichloroethane by Fe(0) in a soil slurry system.

    Science.gov (United States)

    Wu, Xiaoliang; Lu, Shuguang; Qiu, Zhaofu; Sui, Qian; Lin, Kuangfei; Du, Xiaoming; Luo, Qishi

    2014-01-01

    Most studies on the treatment of chlorinated contaminants by Fe(0) focus on aqueous system tests. However, few is known about the effectiveness of these tests for degrading chlorinated contaminants such as 1,1,1-trichloroethane (TCA) in soil. In this work, the reductive degradation performance of 1,1,1-TCA by Fe(0) was thoroughly investigated in a soil slurry system. The effects of various factors including acid-washed iron, the initial 1,1,1-TCA concentration, Fe(0) dosage, slurry pH, and common constituents in groundwater and soil such as Cl(-), HCO3 (-), SO4 (2-), and NO3 (-) anions and humic acid (HA) were evaluated. The experimental results showed that 1,1,1-TCA could be effectively degraded in 12 h for an initial Fe(0) dosage of 10 g L(-1) and a soil/water mass ratio of 1:5. The soil slurry experiments showed two-stage degradation kinetics: a slow reaction in the first stage and a fast reductive degradation of 1,1,1-TCA in the second stage. The reductive degradation of 1,1,1-TCA was expedited as the mass concentration of Fe(0) increased. In addition, high pHs adversely affected the degradation of 1,1,1-TCA over a pH range of 5.4-8.0 and the reductive degradation efficiency decreased with increasing slurry pH. The initial 1,1,1-TCA concentration and the presence of Cl(-) and SO4(2-) anions had negligible effects. HCO3(-) anions had a accelerative effect on 1,1,1-TCA removal, and both NO3(-) and HA had inhibitory effects. A Cl(-) mass balance showed that the amount of Cl(-) ions released into the soil slurry system during the 1,1,1-TCA degradation increased with increasing reaction time, suggesting that the main degradation mechanism of 1,1,1-TCA by Fe(0) in a soil slurry system was reductive dechlorination with 1,1-DCA as the main intermediate. In conclusion, this study provides a theoretical basis for the practical application of the remediation of contaminated sites containing chlorinated solvent.

  18. The effectiveness of lane departure warning systems-A reduction in real-world passenger car injury crashes.

    Science.gov (United States)

    Sternlund, Simon; Strandroth, Johan; Rizzi, Matteo; Lie, Anders; Tingvall, Claes

    2017-02-17

    The objective of this study was to estimate the safety benefits of in vehicle lane departure warning (LDW) and lane keeping aid (LKA) systems in reducing relevant real-world passenger car injury crashes. The study used an induced exposure method, where LDW/LKA-sensitive and nonsensitive crashes were compared for Volvo passenger cars equipped with and without LDW/LKA systems. These crashes were matched by car make, model, model year, and technical equipment; that is, low-speed autonomous emergency braking (AEB) called City Safety (CS). The data were extracted from the Swedish Traffic Accident Data Acquisition database (STRADA) and consisted of 1,853 driver injury crashes that involved 146 LDW-equipped cars, 11 LKA-equipped cars, and 1,696 cars without LDW/LKA systems. The analysis showed a positive effect of the LDW/LKA systems in reducing lane departure crashes. The LDW/LKA systems were estimated to reduce head-on and single-vehicle injury crashes on Swedish roads with speed limits between 70 and 120 km/h and with dry or wet road surfaces (i.e., not covered by ice or snow) by 53% with a lower limit of 11% (95% confidence interval [CI]). This reduction corresponded to a reduction of 30% with a lower limit of 6% (95% CI) for all head-on and single-vehicle driver injury crashes (including all speed limits and all road surface conditions). LDW/LKA systems were estimated to lower the driver injury risk in crash types that the systems are designed to prevent; that is, head-on and single-vehicle crashes. Though these are important findings, they were based on a small data set. Therefore, further research is desirable to evaluate the effectiveness of LDW/LKA systems under real-world conditions and to differentiate the effectiveness between technical solutions (i.e., LDW and LKA) proposed by different manufacturers.

  19. Vibration reduction for vision systems on board unmanned aerial vehicles using a neuro-fuzzy controller

    OpenAIRE

    Marichal, N.; Tomas-Rodriguez, M.; Hernandez, A.; Castillo, S; Campoy, P.

    2014-01-01

    In this paper, an intelligent control approach based on neuro-fuzzy systems performance is presented, with the objective of counteracting the vibrations that affect the low-cost vision platform onboard an unmanned aerial system of rotating nature. A scaled dynamical model of a helicopter is used to simulate vibrations on its fuselage. The impact of these vibrations on the low-cost vision system will be assessed and an intelligent control approach will be derived in order to reduce its detrime...

  20. Energy storage in drive systems of servo presses for reduction of peak power and energy recovery

    OpenAIRE

    Putz, Matthias; Blau, Peter; Kolesnikov, Artem; Richter, Mark; Pierer, Alexander

    2016-01-01

    The development approach for energy storage systems focuses on optimally sized capacitor modules to reduce peak power and to avoid energy recovery of production machines. Using servo presses as an example, the application of two different energy storage systems in the DC link is practically examined. A simulation model in Matlab/Simulink and a test stand of a servo press are proposed for representing the power flows between the mains supply, the electric drives and the storage systems. The de...

  1. A novel generic hebbian ordering-based fuzzy rule base reduction approach to mamdani neuro-fuzzy system.

    Science.gov (United States)

    Liu, Feng; Quek, Chai; Ng, Geok See

    2007-06-01

    There are two important issues in neuro-fuzzy modeling: (1) interpretability--the ability to describe the behavior of the system in an interpretable way--and (2) accuracy--the ability to approximate the outcome of the system accurately. As these two objectives usually exert contradictory requirements on the neuro-fuzzy model, certain compromise has to be undertaken. This letter proposes a novel rule reduction algorithm, namely, Hebb rule reduction, and an iterative tuning process to balance interpretability and accuracy. The Hebb rule reduction algorithm uses Hebbian ordering, which represents the degree of coverage of the samples by the rule, as an importance measure of each rule to merge the membership functions and hence reduces the number of the rules. Similar membership functions (MFs) are merged by a specified similarity measure in an order of Hebbian importance, and the resultant equivalent rules are deleted from the rule base. The rule with a higher Hebbian importance will be retained among a set of rules. The MFs are tuned through the least mean square (LMS) algorithm to reduce the modeling error. The tuning of the MFs and the reduction of the rules proceed iteratively to achieve a balance between interpretability and accuracy. Three published data sets by Nakanishi (Nakanishi, Turksen, & Sugeno, 1993), the Pat synthetic data set (Pal, Mitra, & Mitra, 2003), and the traffic flow density prediction data set are used as benchmarks to demonstrate the effectiveness of the proposed method. Good interpretability, as well as high modeling accuracy, are derivable simultaneously and are suitably benchmarked against other well-established neuro-fuzzy models.

  2. Photocatalytic water reduction and study of the formation of Fe(i)Fe(0) species in diiron catalyst systems.

    Science.gov (United States)

    Li, Xueqiang; Wang, Mei; Chen, Lin; Wang, Xiuna; Dong, Jingfeng; Sun, Licheng

    2012-05-01

    Noble-metal-free systems with bio-inspired diiron dithiolate mimics of the [FeFe]-hydrogenase active site, namely, [(μ-pdt)Fe(2) (CO)(5) L] [pdt=propanedithiolate; L=P(CH(2) OH)(3) (1), P(CH(3) )(3) (2)], as water reduction catalysts with xanthene dyes as photosensitizers and triethylamine as a sacrificial electron donor were studied for visible-light-driven water reduction to hydrogen. These systems display good catalytic activities with the efficiencies in hydrogen evolution of up to 226 turnovers for 1, if Eosin Y was used as the photosensitizer in an environmentally benign solvent (EtOH/H(2) O) after 15 h of irradiation (λ>450 nm) under optimal conditions. Under all of the conditions adopted, 1 that has a water soluble phosphine ligand, P(CH(2) OH)(3) displayed a higher efficiency than 2, which bears a PMe(3) ligand. The photoinduced electron transfer in the systems was studied using fluorescence, transient absorption, time-resolved UV/Vis, and in situ electron paramagnetic resonance (EPR) spectroscopy. A new electron-transfer mechanism is proposed for hydrogen evolution by these iron-based photocatalytic systems. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A robust computational technique for model order reduction of two-time-scale discrete systems via genetic algorithms.

    Science.gov (United States)

    Alsmadi, Othman M K; Abo-Hammour, Zaer S

    2015-01-01

    A robust computational technique for model order reduction (MOR) of multi-time-scale discrete systems (single input single output (SISO) and multi-input multioutput (MIMO)) is presented in this paper. This work is motivated by the singular perturbation of multi-time-scale systems where some specific dynamics may not have significant influence on the overall system behavior. The new approach is proposed using genetic algorithms (GA) with the advantage of obtaining a reduced order model, maintaining the exact dominant dynamics in the reduced order, and minimizing the steady state error. The reduction process is performed by obtaining an upper triangular transformed matrix of the system state matrix defined in state space representation along with the elements of B, C, and D matrices. The GA computational procedure is based on maximizing the fitness function corresponding to the response deviation between the full and reduced order models. The proposed computational intelligence MOR method is compared to recently published work on MOR techniques where simulation results show the potential and advantages of the new approach.

  4. A Robust Computational Technique for Model Order Reduction of Two-Time-Scale Discrete Systems via Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Othman M. K. Alsmadi

    2015-01-01

    Full Text Available A robust computational technique for model order reduction (MOR of multi-time-scale discrete systems (single input single output (SISO and multi-input multioutput (MIMO is presented in this paper. This work is motivated by the singular perturbation of multi-time-scale systems where some specific dynamics may not have significant influence on the overall system behavior. The new approach is proposed using genetic algorithms (GA with the advantage of obtaining a reduced order model, maintaining the exact dominant dynamics in the reduced order, and minimizing the steady state error. The reduction process is performed by obtaining an upper triangular transformed matrix of the system state matrix defined in state space representation along with the elements of B, C, and D matrices. The GA computational procedure is based on maximizing the fitness function corresponding to the response deviation between the full and reduced order models. The proposed computational intelligence MOR method is compared to recently published work on MOR techniques where simulation results show the potential and advantages of the new approach.

  5. A systems approach for data compression and latency reduction in cortically controlled brain machine interfaces.

    Science.gov (United States)

    Oweiss, Karim G

    2006-07-01

    This paper suggests a new approach for data compression during extracutaneous transmission of neural signals recorded by high-density microelectrode array in the cortex. The approach is based on exploiting the temporal and spatial characteristics of the neural recordings in order to strip the redundancy and infer the useful information early in the data stream. The proposed signal processing algorithms augment current filtering and amplification capability and may be a viable replacement to on chip spike detection and sorting currently employed to remedy the bandwidth limitations. Temporal processing is devised by exploiting the sparseness capabilities of the discrete wavelet transform, while spatial processing exploits the reduction in the number of physical channels through quasi-periodic eigendecomposition of the data covariance matrix. Our results demonstrate that substantial improvements are obtained in terms of lower transmission bandwidth, reduced latency and optimized processor utilization. We also demonstrate the improvements qualitatively in terms of superior denoising capabilities and higher fidelity of the obtained signals.

  6. Modified PTS-based PAPR Reduction for FBMC-OQAM Systems

    Science.gov (United States)

    Deng, Honggui; Ren, Shuang; Liu, Yan; Tang, Chengying

    2017-10-01

    The filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) has been raised great concern in the 5G communication research. However FBMC-OQAM has also the inherent drawback of high peak-to-average power ratio (PAPR) that should be addressed. Due to the overlapping structure of FBMC-OQAM signals, it is proven that directly employing conventional partial transmit sequence (PTS) scheme proposed for OFDM to FBMC-OQAM is ineffective. In this paper, we propose a modified PTS-based scheme by employing phase rotation factors to optimize only the phase of the sparse peak signals, called as sparse PTS (S-PTS) scheme. Theoretical analysis and simulation results show that the proposed S-PTS scheme provides a significant PAPR reduction performance with lower computational complexity.

  7. Procedures for sampling and sample reduction within quality assurance systems for solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The objective of this experimental study on sampling was to determine the size and number of samples of biofuels required (taken at two sampling points in each case) and to compare two methods of sampling. The first objective of the sample-reduction exercise was to compare the reliability of various sampling methods, and the second objective was to measure the variations introduced as a result of reducing the sample size to form suitable test portions. The materials studied were sawdust, wood chips, wood pellets and bales of straw, and these were analysed for moisture, ash, particle size and chloride. The sampling procedures are described. The study was conducted in Scandinavia. The results of the study were presented in Leipzig in October 2004. The work was carried out as part of the UK's DTI Technology Programme: New and Renewable Energy.

  8. Recent Advances in Transition-Metal-Mediated Electrocatalytic CO2 Reduction: From Homogeneous to Heterogeneous Systems

    KAUST Repository

    Feng, Da-Ming

    2017-12-01

    Global climate change and increasing demands for clean energy have brought intensive interest in the search for proper electrocatalysts in order to reduce carbon dioxide (CO2) to higher value carbon products such as hydrocarbons. Recently, transition-metal-centered molecules or organic frameworks have been reported to show outstanding electrocatalytic activity in the liquid phase. Their d-orbital electrons are believed to be one of the key factors to capture and convert CO2 molecules to value-added low-carbon fuels. In this review, recent advances in electrocatalytic CO2 reduction have been summarized based on the targeted products, ranging from homogeneous reactions to heterogeneous ones. Their advantages and fallbacks have been pointed out and the existing challenges, especially with respect to the practical and industrial application are addressed.

  9. Recent Advances in Transition-Metal-Mediated Electrocatalytic CO2 Reduction: From Homogeneous to Heterogeneous Systems

    Directory of Open Access Journals (Sweden)

    Da-Ming Feng

    2017-12-01

    Full Text Available Global climate change and increasing demands for clean energy have brought intensive interest in the search for proper electrocatalysts in order to reduce carbon dioxide (CO2 to higher value carbon products such as hydrocarbons. Recently, transition-metal-centered molecules or organic frameworks have been reported to show outstanding electrocatalytic activity in the liquid phase. Their d-orbital electrons are believed to be one of the key factors to capture and convert CO2 molecules to value-added low-carbon fuels. In this review, recent advances in electrocatalytic CO2 reduction have been summarized based on the targeted products, ranging from homogeneous reactions to heterogeneous ones. Their advantages and fallbacks have been pointed out and the existing challenges, especially with respect to the practical and industrial application are addressed.

  10. PEAK-TO-AVERAGE POWER RATIO REDUCTION USING CODING AND HYBRID TECHNIQUES FOR OFDM SYSTEM

    Directory of Open Access Journals (Sweden)

    Bahubali K. Shiragapur

    2016-03-01

    Full Text Available In this article, the research work investigated is based on an error correction coding techniques are used to reduce the undesirable Peak-to-Average Power Ratio (PAPR quantity. The Golay Code (24, 12, Reed-Muller code (16, 11, Hamming code (7, 4 and Hybrid technique (Combination of Signal Scrambling and Signal Distortion proposed by us are used as proposed coding techniques, the simulation results shows that performance of Hybrid technique, reduces PAPR significantly as compared to Conventional and Modified Selective mapping techniques. The simulation results are validated through statistical properties, for proposed technique’s autocorrelation value is maximum shows reduction in PAPR. The symbol preference is the key idea to reduce PAPR based on Hamming distance. The simulation results are discussed in detail, in this article.

  11. Biofeedback systems for stress reduction : Towards a bright future for a revitalized field

    NARCIS (Netherlands)

    Broek, E.L. van den; Westerink, J.H.D.M.

    2012-01-01

    Stress has recently been baptized as the black death of the 21st century, which illustrates its threat to current health standards. This article proposes biofeedback systems as a means to reduce stress. A concise state-of-the-art introduction on biofeedback systems is given. The field of mental

  12. Biofeedback systems for stress reduction: Towards a Bright Future for a Revitalized Field

    NARCIS (Netherlands)

    van den Broek, Egon; Westerink, Joyce H.D.M.; Conchon, E.; Correia, C.; Fred, A.; Gamboa, H.

    2012-01-01

    Stress has recently been baptized as the black death of the 21st century, which illustrates its threat to current health standards. This article proposes biofeedback systems as a means to reduce stress. A concise state-ofthe-art introduction on biofeedback systems is given. The field of mental

  13. Peak reduction in decentralised electricity systems : Markets and prices for flexible planning

    NARCIS (Netherlands)

    Höning, N.F.

    2016-01-01

    In contemporary societies, industrial processes as well as domestic activities rely to a large degree on a well-functioning electricity system. This reliance exists both structurally (the system should always be available) and economically (the prices for electricity affect the costs of operating a

  14. On Solving Systems of Equations by Successive Reduction Using 2×2 Matrices

    Science.gov (United States)

    Carley, Holly

    2014-01-01

    Usually a student learns to solve a system of linear equations in two ways: "substitution" and "elimination." While the two methods will of course lead to the same answer they are considered different because the thinking process is different. In this paper the author solves a system in these two ways to demonstrate the…

  15. Memory and computation reduction for least-square channel estimation of mobile OFDM systems

    NARCIS (Netherlands)

    Xu, T.; Tang, Z.; Lu, H.; Leuken, R van

    2012-01-01

    Mobile OFDM refers to OFDM systems with fast moving transceivers, contrastive to traditional OFDM systems whose transceivers are stationary or have a low velocity. In this paper, we use Basis Expansion Models (BEM) to model the time-variation of channels, based on which two least-squares (LS)

  16. Innovative cross-flow membrane system for volume reduction of mixed waste

    Energy Technology Data Exchange (ETDEWEB)

    Greene, W. [SpinTek Membrane Systems, Huntington Beach, CA (United States)

    1997-10-01

    In this task, SpinTek Membrane Systems, Inc., and the Institute of Gas Technology are completing engineering development leading to a full-scale demonstration of the SpinTek ST-II High Shear Rotary Membrane Filtration System (ST-II) under a Program Research and Development Agreement (PRDA) with the Federal Energy Technology Center-Morgantown. The SpinTek ST-II technology will be scaled-up, and a two-stage ST-II system will be designed, constructed, and operated on both surrogate and actual feed at the Los Alamos National Laboratory (LANL) Liquid Radioactive Waste Treatment Facility (LRWTF). Results from these studies on both surrogate and actual wastewater streams will also be used by LANL personnel to produce a model for determining the applicability and economics of the SpinTek ST-II system to other DOE waste and process streams. The ST-II is a unique, compact cross-flow membrane system having several advantages in performance and cost compared to currently available systems. Staff at LANL have performed pilot-scale testing with the SpinTek technology to evaluate its feasibility for enhanced radionuclide removal from wastewater at its 5- to 8-million-gallon-per-year LRWTF. Recent data have shown the system`s capabilities to remove radionuclides from the waste stream at concentration factors greater than 2000:1, and performance has exceeded both conventional and all other advanced technologies examined.

  17. ASSESSMENT PROTOCOLS - DURABILITY OF PERFORMANCE OF A HOME RADON REDUCTION SYSTEM FOR SUB-SLAB DEPRESSURIZA- TION SYSTEMS

    Science.gov (United States)

    This handbook contains protocols that compare the immediate performance of subslab depressurization (SSD) mitigation system with performance months or years later. These protocols provide a methodology to test SSD radon mitigation systems in situ to determine long-term performanc...

  18. Efficient Model Order Reduction of Structural Dynamic Systems with Local Nonlinearities under Periodic Motion

    Directory of Open Access Journals (Sweden)

    M. Mohammadali

    2014-01-01

    Full Text Available In many nonlinear structural systems, compared with the local regions with induced nonlinear effects, the main portions of the structures are linear. An exact condensation technique based on the harmonic balance method (HBM in conjunction with the modal expansion technique is employed to convert the motion equations of such a system to a set of nonlinear algebraic equations that are considerably small and adequately accurate to determine periodic responses. To demonstrate the capability of the suggested method, few case studies consisting of discrete systems with weak and essential nonlinearities are studied, and the results are compared to other methodologies results.

  19. PAPR Reduction in All-optical OFDM Systems Based on Phase Pre-emphasis

    Energy Technology Data Exchange (ETDEWEB)

    He Zhou; Li, Wei; Shao Jing; Liang Xiaojun; Huang Dexiu [Wuhan National Lab for Optoelectronics, Department of Optoelectronics Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Tao Zhiyong [State Key Laboratory of Optical Communication Technologies and Networks, Wuhan Research Institute of Posts and Telecommunications, Wuhan 430074 (China); Deng Zhuanhua, E-mail: hezhou@wri.com.cn, E-mail: weilee@mail.hust.edu.cn [School of Computer Science and Technology, Hubei University of Economics, Wuhan 430205 (China)

    2011-02-01

    This paper investigates the peak-to-average power ratio (PAPR) theory in all-optical orthogonal frequency division multiplexing (OFDM) optical fibre communication systems. We find out that phase pre-emphasis could effectively reduce PAPR in all-optical OFDM communication systems which employ intensity modulation-direct detection (IM-DD) method. An equation is developed and proposed to calculate suitable phasing values for pre-emphasis. Furthermore, we find out that phase pre-emphasis cannot reduce PAPR effectively in all-optical OFDM systems that employ Phase Shift Keying (PSK) or Quadracture Amplitude Modulation (QAM) method.

  20. Common-mode Voltage Reduction in a Motor Drive System with a Power Factor Correction

    DEFF Research Database (Denmark)

    Adabi, J.; Boora, A.A.; Zare, F.

    2012-01-01

    to reduce shaft voltage in a three-phase AC motor drive system. In this topology, the AC-DC diode rectifier influences the common-mode voltage generated by the inverter because the placement of the neutral point is changing in different rectifier circuit states. A pulse width modulation technique......Common-mode voltage generated by a power converter in combination with parasitic capacitive couplings is a potential source of shaft voltage in an AC motor drive system. In this study, a three-phase motor drive system supplied with a single-phase AC-DC diode rectifier is investigated in order...

  1. Stabilizing a CFD model of an unstable system through model reduction

    Directory of Open Access Journals (Sweden)

    Svein Hovland

    2006-07-01

    Full Text Available We demonstate stabilization of a computational fluid dynamics model of an unstable system. The unstable heating of a two-dimensional plate is used as a case study. Active control is introduced by cooling parts of the boundaries of the plate. The high order of the original model is reduced by proper orthogonal decomposition, giving an unstable reduced order model with a state space structure convenient for controller design. A stabilizing controller based on pole placement is designed for the reduced order model and integral action is included to enhance performance. The controller is then applied to the full model, where it is shown through simulations to stabilize the system. The demonstrated procedure makes it possible to analyze stability properties and design control systems for a class of systems that would otherwise be very computationally demanding.

  2. PAPR reduction based on improved Nyquist pulse shaping technology in OFDM-RoF systems

    Science.gov (United States)

    Liu, Jian-fei; Li, Ning; Lu, Jia; Zeng, Xiang-ye; Li, Jie; Wang, Meng-jun

    2013-01-01

    High peak-to-average power ratio (PAPR) is the main disadvantage in orthogonal frequency-division multiplexing (OFDM) communication systems, which also exists in OFDM-radio over fiber (RoF) systems. In this paper, we firstly analyze the impact of high PAPR on a 40 GHz OFDM-RoF system, and then describe the theory of Nyquist pulse shaping technology for reducing PAPR. To suppress PAPR further, an improved Nyquist pulse shaping technology is proposed, in which the distribution of original-data amplitude is changed by properly selecting the time-limited waveforms of the different subcarriers. We firstly apply the improved Nyquist pulse shaping technology to an OFDM-RoF system. The simulation results show that PAPR is effectively reduced by more than 2 dB with the bit error rate (BER) declining by about 0.125%.

  3. A choice reduction model for the concept phase of a weapon system

    Directory of Open Access Journals (Sweden)

    C.M. Erasmus

    2003-12-01

    Full Text Available During the concept phase of a weapon system it is often necessary to decide between a number of different development or purchasing options. This typically involves using a multidimensional value system that incorporates aspects such as performance, cost, risk, logistics and time-scales. This paper describes a model which assists in the choice in the performance dimension by including application battlefield scenarios in the analysis, and calculating the relative worth of competing systems based on the expected utility of the component weapon system attributes. The author would like to acknowledge the contributions of Mr B L Logan and Mr A E Heijdenrijch in the development of the model. This project would not have been possible without their suggestions and support, especially on the detail procedures for implementing the model.

  4. Implications of the international reduction pledges on long-term energy system changes and costs in China and India

    DEFF Research Database (Denmark)

    Lucas, Paul L.; Shukla, P.R.; Chen, Wenying

    2013-01-01

    India and China with respect to the timing of emission reductions and the choice of mitigation measures relate to differences in projections of rapid economic change, capital stock turnover and technological development. Furthermore, depending on the way it is implemented, climate policy could increase......This paper analyses the impact of postponing global mitigation action on abatement costs and energy systems changes in China and India. It compares energy-system changes and mitigation costs from a global and two national energy-system models under two global emission pathways with medium...... indoor air pollution, but it is likely to provide synergies for energy security. These relations should be taken into account when designing national climate policies. © 2013 Elsevier Ltd. All rights reserved....

  5. Fe-N-doped carbon catalysts prepared by hybrid PECVD/sputtering system for oxygen reduction reaction

    Science.gov (United States)

    Hotozuka, Kozue; Yoshie, Ryo; Murata, Hidenobu; Tateno, Akira; Ito, Gen; Kawaguchi, Norihito; Matsuo, Takahiro; Ito, Hitomi; Kinoshita, Ikuo; Tachibana, Masaru

    2017-07-01

    A hybrid plasma-enhanced chemical vapor deposition (PECVD)/sputtering system was developed to prepare iron (Fe)-nitrogen (N)-doped carbon catalysts for oxygen reduction reaction (ORR). This hybrid system combines PECVD effective for the synthesis of nanocarbons with sputtering technique for the doping of metals such as Fe where the amount of the doping can be independently controlled during synthesizing nanocarbons. By using this system, Fe-N-doped carbon catalysts are directly synthesized on carbon papers which have been widely used as a gas diffusion layer in fuel cells. The synthesized catalysts with carbon papers exhibit high ORR activity. This is attributed to Fe-N coordination bonds which are stably formed in the synthesized catalysts.

  6. The impact of ODA microadditions into secondary system on corrosion rate reduction in VVER steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Avdeev, A.A.; Kukushkin, A.N.; Repin, D.A. [All-Russia Research and Design Inst. of Nuclear Power Machine Building (VNIIAM), Moscow (Russian Federation); Omelchuk, V.V.; Barmin, L.F. [Kola Nuclear Power Plant, Polyarnye Zori, Murmansk region (Russian Federation); Yurmanov, V.A. [N.A. Dollezhal Research and Development Inst. of Power Engineering (NIKIET), Moscow (Russian Federation); Czempik, E. [RECON GmbH, Leipzig (Germany)

    2010-07-01

    Injection of film-forming corrosion inhibitors is a challenging way of suppressing erosion-corrosion and crud induced corrosion in power stations. Films of surface-active inhibitors, such as octadecylamine (ODA) provide a diffusion barrier to penetration of corrosion-aggressive ions onto the metal surface. Erosion and corrosion tests were conducted in autoclaves and on a pilot steam generator (SG) design to look into the impact of ODA. To accelerate corrosion process tests were conducted in a more aggressive environment as compared to actual operating conditions, including high chloride concentration and stress levels. It is not only important to reduce deposition growth, but also to wash out deposits previously formed on heat exchanger surfaces. This allows to reduce the risk of local corrosion and corrosion cracking development. A number of VVER plants have conducted full-scale testing that confirmed the impact of ODA microadditions on local corrosion mitigation. Some PWR plants are testing injection of surface-active dispersants to loosen SG deposits. Multiple studies proved ODA ability to remove chlorides from smooth surfaces which allowed to reduce the rate of microcrack growth. Trial testing has shown that the rate of corrosion cracking on SG tubes was reduced by 60-70% owing to ODA injections. Such effect was due to significant reduction in chlorides absorption by the metal surface during the year of ODA injection. Tests on a pilot SG design have shown that ODA could be used for partially wash out deposits from a heating surface. This also minimizes local corrosion. The tests showed that ODA microadditions remove chlorides from microcracks and crevices on SG tubing spacer grids. The ability to wash out previously formed deposits allows to reduce risk of local corrosion and cracking. The abilities of microadditions of film-forming corrosion inhibitors identified through the above mentioned testing could be used under the VVER plant life extension program. The

  7. Comparison of Expected Crash and Injury Reduction from Production Forward Collision and Lane Departure Warning Systems.

    Science.gov (United States)

    Kusano, Kristofer D; Gabler, Hampton C

    2015-01-01

    The U.S. New Car Assessment Program (NCAP) now tests for forward collision warning (FCW) and lane departure warning (LDW). The design of these warnings differs greatly between vehicles and can result in different real-world field performance in preventing or mitigating the effects of collisions. The objective of this study was to compare the expected number of crashes and injured drivers that could be prevented if all vehicles in the fleet were equipped with the FCW and LDW systems tested under the U.S. NCAP. To predict the potential crashes and serious injury that could be prevented, our approach was to computationally model the U.S. crash population. The models simulated all rear-end and single-vehicle road departure collisions that occurred in a nationally representative crash database (NASS-CDS). A sample of 478 single-vehicle crashes from NASS-CDS 2012 was the basis for 24,822 simulations for LDW. A sample of 1,042 rear-end collisions from NASS-CDS years 1997-2013 was the basis for 7,616 simulations for FCW. For each crash, 2 simulations were performed: (1) without the system present and (2) with the system present. Models of each production safety system were based on 54 model year 2010-2014 vehicles that were evaluated under the NCAP confirmation procedure for LDW and/or FCW. NCAP performed 40 LDW and 45 FCW tests of these vehicles. The design of the FCW systems had a dramatic impact on their potential to prevent crashes and injuries. Between 0 and 67% of crashes and 2 and 69% of moderately to fatally injured drivers in rear-end impacts could have been prevented if all vehicles were equipped with the FCW systems. Earlier warning times resulted in increased benefits. The largest effect on benefits, however, was the lower operating speed threshold of the systems. Systems that only operated at speeds above 20 mph were less than half as effective as those that operated above 5 mph with similar warning times. The production LDW systems could have prevented

  8. Enhancement and performance evaluation for heat transfer of air cooling zone for reduction system of sponge titanium

    Science.gov (United States)

    Wang, Wenhao; Wu, Fuzhong; Jin, Huixin

    2017-02-01

    Since the magnesiothermic reduction employed in current sponge titanium is a highly exothermic reaction, the TiCl4 feed rate is carried out slowly to keep a suitable temperature in reduction reactor, which accounts for an extremely low level of productivity and energy efficiency. In order to shorten the production cycle and improve the energy efficiency, an enhancing scheme is proposed to enhance the heat transfer of air cooling zone for reduction system. The air cooling zone and enhancing scheme are firstly introduced. And then, the heat transfer characteristics of cooling zone are obtained by theoretical analysis and experimental date without enhancing scheme. Finally, the enhancement is analyzed and evaluated. The results show that the fitting results of heat transfer coefficients can be used to evaluate the heat transfer enhancement of cooling zone. Heat sources temperatures have a limited decreasing, heat transfer rate increases obviously with the enhanced cooling, and the TiCl4 feed rate can be increased significantly by 9.61 %. And the measured and calculated results are good enough to meet the design requirements.

  9. Reduction of anesthesia process times after the introduction of an internal transfer pricing system for anesthesia services.

    Science.gov (United States)

    Schuster, Martin; Standl, Thomas; Reissmann, Hajo; Kuntz, Ludwig; Am Esch, Jochen Schulte

    2005-07-01

    To improve operating room workflow, an internal transfer pricing system (ITPS) for anesthesia services was introduced in our hospital in 2001. The basic principle of the ITPS is that the department of anesthesia receives reimbursement only for the surgically controlled time, not for anesthesia-controlled time (ACT). A reduction in anesthesia process times is therefore beneficial for the anesthesia department. In this study, we analyzed the ACT (with its parts: preparation before induction, induction, extubation, and recovery room transfer) for 3 yr before and 3 yr after the introduction of the ITPS in 55,776 cases. Furthermore, the anesthesia cases were subsegmented into 10 different anesthesia techniques, and the process times were studied. The average total ACT was reduced from 40.4 +/- 23.5 min in 1998 to 34.3 +/- 21.7 min in 2003. The main effect came from reductions in anesthesia preparation time and recovery room transfer time, whereas induction and extubation time changed little. A significant reduction in average ACT was seen in 7 of 10 analyzed anesthesia techniques, ranging from 4 to 18 min. We conclude that transfer pricing of anesthesia services based on the surgically controlled time can be a successful approach to reduce anesthesia process times.

  10. Reductions in electricity losses in the distribution power system in case of the mass use of compact fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Trifunovic, J.; Mikulovic, J.; Djurisic, Z.; Kostic, M. [Faculty of Electrical Engineering, University of Belgrade, Bulevar kralja Aleksandra 73, 11000 Belgrade (RS)

    2011-02-15

    The paper presents a method for the evaluation of the reductions in the technical and non-technical distribution losses in case of the mass use of compact fluorescent lamps (CFLs) in buildings in Serbia. The evaluation was based on an assumption that the two most used incandescent lamps in each of the 25-50% of the total number of dwellings in Serbia will be replaced with adequate CFLs, and that the same total number of lamps will be replaced in residential and non-residential sectors. A general methodology for the hourly estimation of the distribution loss reduction in case of reduced electricity consumption, based on the statistical processing of available data and on an integral (macroscopic) approach, is presented and used in the calculations. Such a methodology is appropriate because the electricity cost rate in the region changes on an hourly basis, being highest during hours when peaks of both the power demand and the decrease of distribution power losses occur. The paper illustrates that considerable reductions in both the technical and non-technical losses in the Serbian distribution power system can be achieved by applying energy efficient light sources. (author)

  11. In situ calibration of atmospheric-infrasound sensors including the effects of wind-noise-reduction pipe systems.

    Science.gov (United States)

    Gabrielson, Thomas B

    2011-09-01

    A worldwide network of more than 40 infrasound monitoring stations has been established as part of the effort to ensure compliance with the Comprehensive Nuclear Test Ban Treaty. Each station has four to eight individual infrasound elements in a kilometer-scale array for detection and bearing determination of acoustic events. The frequency range of interest covers a three-decade range-roughly from 0.01 to 10 Hz. A typical infrasound array element consists of a receiving transducer connected to a multiple-inlet pipe network to average spatially over the short-wavelength turbulence-associated "wind noise." Although the frequency response of the transducer itself may be known, the wind-noise reduction system modifies that response. In order to understand the system's impact on detection and identification of acoustical events, the overall frequency response must be determined. This paper describes a technique for measuring the absolute magnitude and phase of the frequency response of an infrasound element including the wind-noise-reduction piping by comparison calibration using ambient noise and a reference-microphone system. Measured coherence between the reference and the infrasound element and the consistency between the magnitude and the phase provide quality checks on the process. © 2011 Acoustical Society of America

  12. Drag-Free Performance of the ST7 Disturbance Reduction System Flight Experiment on the LISA Pathfinder

    Science.gov (United States)

    Maghami, Peiman; O'Donnell, James, Jr.; Hsu, Oscar; Ziemer, John; Dunn, Charles

    2017-01-01

    The Space Technology-7 Disturbance Reduction System (DRS) is an experiment package aboard the European Space Agency (ESA) LISA Pathfinder spacecraft. LISA Pathfinder launched from Kourou, French Guiana on December 3, 2015. The DRS is tasked to validate two specific technologies: colloidal micro-Newton thrusters (CMNT) to provide low-noise control capability of the spacecraft, and drag-free control flight. This validation is performed using highly sensitive drag-free sensors, which are provided by the LISA Technology Package of the European Space Agency. The Disturbance Reduction System is required to maintain the spacecrafts position with respect to a free-floating test mass to better than 10nmHz, along its sensitive axis (axis in optical metrology). It also has a goal of limiting the residual accelerations of any of the two test masses to below 30 (1 + [f3 mHz]) fmsHz, over the frequency range of 1 to 30 mHz.This paper briefly describes the design and the expected on-orbit performance of the control system for the two modes wherein the drag-free performance requirements are verified. The on-orbit performance of these modes are then compared to the requirements, as well as to the expected performance, and discussed.

  13. SWRO-PRO System in “Mega-ton Water System” for Energy Reduction and Low Environmental Impact

    Directory of Open Access Journals (Sweden)

    Masaru Kurihara

    2018-01-01

    Full Text Available Reverse osmosis (RO membranes have been widely applied in seawater desalination (SWRO and wastewater reclamation as the main desalination technology since 2000. SWRO plants face challenges to reduce energy consumption and brine disposal to lessen marine pollution. To tackle these challenges, a SWRO-PRO (Pressure Retarded Osmosis System was proposed in the “Mega-ton Water System” project under the Japanese national project of the “Funding Program for World-Leading Innovative R&D on Science and Technology” (FIRST Program. To reduce the energy consumption of the main SWRO plant, an innovative low-pressure SWRO membrane and a next generation energy recovery device (ERD were developed by the “Mega-ton Water System” project. In addition to this research and development, a new membrane process has been proposed and confirmed as a low-pressure multi-stage SWRO (LMS. A brine conversion two-stage SWRO system was invented 20 years ago, and has been in operation for over 15 years. Application of the SWRO membrane process to actual commercial plants was an important research theme. The low-pressure multi-stage SWRO System (LMS was an innovative method of introducing a low-pressure membrane and the membrane element in the pressure vessel was designed to avoid heavy fouling of lead elements. As a result of these developments at mega-ton scale SWRO plants, a 20% energy reduction was possible in the SWRO system of the “Mega-ton Water System”. In the development of the PRO process, a PRO hollow fiber membrane module with a maximum 13.3 w/m2 of membrane power density using a 10-inch module was established at a prototype PRO plant. Thus, a 30% energy reduction was possible using the SWRO-PRO System in the “Mega-ton Water System” at mega-ton scale SWRO plants. The brine disposal problem was also solved by this system.

  14. Intelligent Data Reduction (IDARE)

    Science.gov (United States)

    Brady, D. Michael; Ford, Donnie R.

    1990-01-01

    A description of the Intelligent Data Reduction (IDARE) expert system and an IDARE user's manual are given. IDARE is a data reduction system with the addition of a user profile infrastructure. The system was tested on a nickel-cadmium battery testbed. Information is given on installing, loading, maintaining the IDARE system.

  15. Reduction of beam-induced pattern placement errors in MEBES systems

    Science.gov (United States)

    Alexander, David W.; Veneklasen, Lee; Weaver, Suzanne; Varner, Jeffrey K.; Cole, Damon M.

    1999-12-01

    Analysis of pattern placement errors has shown a pattern and exposure sequence dependent component of placement error exists that cannot be accounted for by beam and stage positioning errors alone. The interaction of the electron beam (e-beam) with the resist can cause displacement of the e-beam from its desired position. This is commonly referred to as mask charging. A special pattern was created to enhance this effect in order to study its functional dependencies, including resist thickness, resist type, and exposure sequence. These errors are noticeable when writing in multipass strategies and where there are large gradients in pattern density. Customer and acceptance test patterns are included in the matrix to determine the magnitude of the errors with more production-oriented patterns. To further characterize this placement error phenomenon, the MEBES e-beam column was modified to minimize the distance between the exit location of the electrons from the electron optics and the surface of the resist-coated mask. Preliminary test results indicate pattern placement error is reduced by approximately 25% with this 'reduced gap' design. We are currently assessing the long-term effects of this new design. Of more importance, choice of resist and process are key components in reducing the charging effect. Reduction of more than 50% in placement errors using ZEP 7000 resist is detailed in this paper.

  16. Analysis of The Propulsion System Towards The Speed Reduction of Vessels Type PC-43

    Directory of Open Access Journals (Sweden)

    Arica Dwi Susanto

    2017-05-01

    Full Text Available (PC-43 is an Indonesian navy vessel type limited patrol craft made in Indonesian. The vessel was designed using a steel material with a maximum speed of 27 knots and using engine power by 3 x 1800 HP, T = 1.40 at the empty draft and T = 1.70 at full draft. The speed is decreased in the current conditions by 22 knots at 1.50 meters draft within 1 year after its launching. This fact is very interesting to be used as a paper project by analyzing the effect of changes in vessel’s draft to the resistance and analyze the current installed engine power, This paper carried two methods of calculation, namely: resistance and power calculation numerically along with resistance and power calculation using software maxsurf. The results from the manual calculations of power at T = 1.65 meters in 27 knots, the power needed is BHPscr = 4245.04 HP. From the data of power installed in the vessel, it was stated that the power is 3 x 1800 = 5400 HP, means a mathematical/theoretical speed of 27 knots can be achieved. Thus, the resistance and power is not one of the causes of speed reduction in Vessel Type PC- 43.

  17. Application of NO Reduction Dynamical Model in SNCR Denitration System Based on Biomass

    Directory of Open Access Journals (Sweden)

    Feng Ran

    2016-06-01

    Full Text Available In recent years, studies on denitration by applying biomass reburning method has drawn the attention of many researchers due to the characteristics of low sulfur and nitrogen content, high volatile, high ash focal activity, zero CO2 net emissions, etc. Based on Chemkin software and selective non-catalytic reduction (SNCR denitration chemical kinetic model, this paper conducted SNCR denitration chemical kinetic modeling. And the results showed that: with the increase of residence time, under the different initial concentration of NO, SNCR denitration efficiency tends to stabilize after the first increase. Moreover, the higher the initial concentration of NO, the longer the residence time which is required to achieve the greatest denitration efficiency. With the increase of ammonia nitrogen ratio, SNCR denitration efficiency increases step by step. When the normalized stoichiometric ratio (NSR is greater than 1.5, the denitration efficiency is at a basic stable state. Under the same conditions, simulation results of the SNCR results agree well with the test results. Therefore, it can be concluded that carrying out the SNCR denitration chemical dynamics simulation using Chemkin software can provide a reference for tests and mechanism researches on SNCR, biomass reburning and advanced reburning denitration.

  18. Reduction of Fe and Ni in Fe-Ni-O systems

    Directory of Open Access Journals (Sweden)

    Zhang Y.

    2013-01-01

    Full Text Available A Cu-Co ore from Katinga Province, the Republic of Congo containing 1.5% Co and 1.6% Cu was tested to determine the leachability of Cu and Co using sulphuric acid and hydrogen peroxide mixtures at different conditions. Without hydrogen peroxide, the maximum extraction of copper and cobalt were found to be ~80% and ~15%, respectively when the acid concentration was varied between 0.36 - 1.1M. When hydrogen peroxide was added (0.008-0.042M, Cu recovery was enhanced to ~90%. Recoveries of ~90% of Co could be achieved at 20ºC, using leachants consisting of 0.36M sulphuric acid and 0.025M hydrogen peroxide after 3 hours. The reaction time to reach 90% Co extraction was reduced to less than 2 hours at 30ºC. Stabcal modelling of the Eh-pH diagrams shows the importance of hydrogen peroxide as a reductant. The decrease of solution potential (300-350 mV by adding hydrogen peroxide was confirmed by Eh measurements during the tests. The leaching follows the shrinking core model kinetics, where the rate constant is linearly dependent on hydrogen peroxide concentration in the range 0-0.025M and proportional to (1/r2 where r is the average radius of the mineral particles. The activation energy for the leaching process is 72.3 kJ/mol.

  19. Reductive dechlorination of hexachlorobenzene subjected to several conditions in a bioelectrochemical system.

    Science.gov (United States)

    Wang, Hui; Yi, Shuyu; Cao, Xian; Fang, Zhou; Li, Xianning

    2017-05-01

    A microbial fuel cell (MFC) is a very promising way to remove organic pollutants. Hexachlorobenzene (HCB) is a widely used agricultural pesticide. In this study, single-chamber and membrane-less soil MFCs were constructed. The HCB was degraded to pentachlorobenzene (PeCB), tetrachlorobenzene (TeCB), and trichlorobenzene (TCB) in sequence by a reductive dechlorination process in soil MFCs. The influences of the external resistance, concentration of phosphate buffer, and electrode spacing in soil MFCs on the degradation rate and removal efficiency of HCB were analyzed. The results showed that the degradation rate and removal efficiency of HCB were increased when the external resistance decreased from 2000 to 20Ω, and also when the concentration of phosphate buffer increased. The anode area played a significant role in dechlorination of HCB. Altering the spacing of the reducing electrode resulted in a lower ohmic resistance in the soil MFCs. The ohmic resistance was negatively correlated with the removal efficiency and degradation rate (Premoval efficiency could be enhanced by soil MFCs, the performance of which was improved by a decrease in external resistance and internal resistance, and an increase in phosphate buffer concentration, rather than just by shortening the electrode spacing. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. BACKORDER AND LOST SALES CONTINUOUS REVIEW RAW MATERIAL INVENTORY CONTROL SYSTEM WITH LEAD TIME AND ORDERING COST REDUCTION

    Directory of Open Access Journals (Sweden)

    Tiena Gustina Amran

    2012-06-01

    Full Text Available The purpose of this research is to suggest the optimal raw material inventory system alternatives synchronized with the stock out characteristics and the condition can be occurred, the backorder raw material inventory control, beside that it also can reduce lead time and raw material ordering cost. In this case, the inventory models also extent (Q, R Inventory Model Under lead Time and Ordering Cost Reduction with lead time and ordering cost can be reduced. After the calculation, the optimal solution of inventory models can be obtained; those are with backorder condition which produced the annual inventory total cost for the company.

  1. Data reduction in the ITMS system through a data acquisition model with self-adaptive sampling rate

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, M. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain)], E-mail: mariano.ruiz@upm.es; Lopez, JM.; Arcas, G. de [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain); Barrera, E. [Departamento de Sistemas Electronicos y de Control, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain); Melendez, R. [Grupo de Investigacion en Instrumentacion y Acustica Aplicada, Universidad Politecnica de Madrid (UPM), Crta. Valencia Km-7, Madrid 28031 (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para Fusion, Madrid (Spain)

    2008-04-15

    Long pulse or steady state operation of fusion experiments require data acquisition and processing systems that reduce the volume of data involved. The availability of self-adaptive sampling rate systems and the use of real-time lossless data compression techniques can help solve these problems. The former is important for continuous adaptation of sampling frequency for experimental requirements. The latter allows the maintenance of continuous digitization under limited memory conditions. This can be achieved by permanent transmission of compressed data to other systems. The compacted transfer ensures the use of minimum bandwidth. This paper presents an implementation based on intelligent test and measurement system (ITMS), a data acquisition system architecture with multiprocessing capabilities that permits it to adapt the system's sampling frequency throughout the experiment. The sampling rate can be controlled depending on the experiment's specific requirements by using an external dc voltage signal or by defining user events through software. The system takes advantage of the high processing capabilities of the ITMS platform to implement a data reduction mechanism based in lossless data compression algorithms which are themselves based in periodic deltas.

  2. Hexavalent chromium reduction with scrap iron in continuous-flow system Part 1: effect of feed solution pH.

    Science.gov (United States)

    Gheju, M; Iovi, A; Balcu, I

    2008-05-01

    The reduction of hexavalent chromium by scrap iron was investigated in continuous system, using long-term column experiments, for aqueous Cr(VI) solutions having low buffering capacities, over the pH range of 2.00-7.30. The results showed that the initial pH of Cr(VI) solution significantly affects the reduction capacity of scrap iron. The highest reduction capacity was determined to be 19.2 mg Cr(VI)/g scrap iron, at pH 2.50, and decreased with increasing the initial pH of Cr(VI) solution. A considerable decrease in scrap iron reduction capacity (25%) was also observed at pH 2.00, as compared to pH 2.50, due to the increased contribution of H(+) ions to the corrosion of scrap iron, which leads to a rapid decrease in time of the scrap iron volume. Over the pH range of 2.50-7.30, hexavalent chromium concentration increases slowly in time after its breakthrough in column effluent, until a steady-state concentration was observed; similarly, over the same pH range, the amount of solubilized Cr(III) in treated column effluent decreases in time, until a steady-state concentration was observed. The steady-state concentration in column effluent decreased for Cr(VI) and increased for Cr(III) with decreasing the initial pH of Cr(VI) solution. No steady-state Cr(VI) or Cr(III) concentrations in column effluent were observed at pH 2.00. Over the entire studied pH range, the amount of Fe(total) in treated solution increases as the initial pH of column influent is decreased; the results show also a continuously decrease in time of Fe(total) concentration, for a constant initial pH, due to a decrease in time of iron corrosion rate. Cr(III) concentration in column effluent also continuously decreased in time, for a constant initial pH, over the pH range of 2.50-7.30. This represents an advantage, because the amount of precipitant agent used to remove Fe(total) and Cr(III) from the column effluent will also decrease in time. The optimum pH for Cr(VI) reduction with scrap iron in

  3. Optimal placement of water-lubricated rubber bearings for vibration reduction of flexible multistage rotor systems

    Science.gov (United States)

    Liu, Shibing; Yang, Bingen

    2017-10-01

    Flexible multistage rotor systems with water-lubricated rubber bearings (WLRBs) have a variety of engineering applications. Filling a technical gap in the literature, this effort proposes a method of optimal bearing placement that minimizes the vibration amplitude of a WLRB-supported flexible rotor system with a minimum number of bearings. In the development, a new model of WLRBs and a distributed transfer function formulation are used to define a mixed continuous-and-discrete optimization problem. To deal with the case of uncertain number of WLRBs in rotor design, a virtual bearing method is devised. Solution of the optimization problem by a real-coded genetic algorithm yields the locations and lengths of water-lubricated rubber bearings, by which the prescribed operational requirements for the rotor system are satisfied. The proposed method is applicable either to preliminary design of a new rotor system with the number of bearings unforeknown or to redesign of an existing rotor system with a given number of bearings. Numerical examples show that the proposed optimal bearing placement is efficient, accurate and versatile in different design cases.

  4. Reduction of acid rock drainage using steel slag in cover systems over sulfide rock waste piles.

    Science.gov (United States)

    de Almeida, Rodrigo Pereira; Leite, Adilson do Lago; Borghetti Soares, Anderson

    2015-04-01

    The extraction of gold, coal, nickel, uranium, copper and other earth-moving activities almost always leads to environmental damage. In metal and coal extraction, exposure of sulfide minerals to the atmosphere leads to generation of acid rock drainage (ARD) and in underground mining to acid mine drainage (AMD) due to contamination of infiltrating groundwater. This study proposes to develop a reactive cover system that inhibits infiltration of oxygen and also releases alkalinity to increase the pH of generated ARD and attenuate metal contaminants at the same time. The reactive cover system is constructed using steel slag, a waste product generated from steel industries. This study shows that this type of cover system has the potential to reduce some of the adverse effects of sulfide mine waste disposal on land. Geochemical and geotechnical characterization tests were carried out. Different proportions of sulfide mine waste and steel slag were studied in leachate extraction tests. The best proportion was 33% of steel slag in dry weight. Other tests were conducted as follows: soil consolidation, saturated permeability and soil water characteristic curve. The cover system was numerically modeled through unsaturated flux analysis using Vadose/w. The solution proposed is an oxygen transport barrier that allows rain water percolation to treat the ARD in the waste rock pile. The results showed that the waste pile slope is an important factor and the cover system must have 5 m thickness to achieve an acceptable effectiveness. © The Author(s) 2015.

  5. Analysing Infinite-State Systems by Combining Equivalence Reduction and the Sweep-Line Method

    DEFF Research Database (Denmark)

    Mailund, Thomas

    2002-01-01

    The sweep-line method is a state space exploration method for on-the-fly verification aimed at systems exhibiting progress. Presence of progress in the system makes it possible to delete certain states during state space generation, which reduces the memory used for storing the states....... Unfortunately, the same progress that is used to improve memory performance in state space exploration often leads to an infinite state space: The progress in the system is carried over to the states resulting in infinitely many states only distinguished through the progress. A finite state space can...... property essential for the sweep-line method. We evaluate the new method on two case studies, showing significant improvements in performance, and we briefly discuss the new method in the context of Timed Coloured Petri Nets, where the “increasing global time” semantics can be exploited for more efficient...

  6. Carbon dioxide reduction potential of solar district heating systems; CO{sub 2}-Reduktionspotential solarer Nahwaermesysteme

    Energy Technology Data Exchange (ETDEWEB)

    Tepe, R. [Institut fuer Solarenergieforschung GmbH Hameln/Emmerthal (ISFH), Emmerthal (Germany)

    1998-02-01

    Ecological balances for systems and products attract increasingly interest because of the discussion about climate change caused by anthropogenic greenhouse gas emissions. Investigations into energy payback time and yield have shown that solar thermal systems can contribute considerably towards protecting our environment. But, because methodologies are approximate and data bases are not precise, ecological balances must be discussed with caution. (orig.) [Deutsch] Oekobilanzen fuer Systeme und Produkte unterschiedlicher Art haben in den letzten Jahren aufgrund der Diskussion um die Klimagefaehrdung durch treibhausrelevante Gase erheblich an Bedeutung gewonnen. Untersuchungen bezueglich der charakteristischen Kennwerte energetische Amortisationszeit und Erntefaktor haben ergeben, dass solare Kollektoranlagen zur Schonung unserer Umwelt erheblich beitragen koennen. Die Analysen zur Oekobilanzierung beduerfen allerdings groesster Sorgfalt, da die Verfahren fuer und die verfuegbaren Daten ueber die materialbezogenen Primaerenergieaufwendungen ein erhebliches Fehlerpotential beinhalten. (orig.)

  7. Single-use surgical clothing system for reduction of airborne bacteria in the operating room.

    Science.gov (United States)

    Tammelin, A; Ljungqvist, B; Reinmüller, B

    2013-07-01

    It is desirable to maintain a low bacterial count in the operating room air to prevent surgical site infection. This can be achieved by ventilation or by all staff in the operating room wearing clothes made from low-permeable material (i.e. clean air suits). We investigated whether there was a difference in protective efficacy between a single-use clothing system made of polypropylene and a reusable clothing system made of a mixed material (cotton/polyester) by testing both in a dispersal chamber and during surgical procedures. Counts of colony-forming units (cfu)/m(3) air were significantly lower when using the single-use clothing system in both settings. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  8. Effects of pulsation dampers in piping systems in terms of pressure surge reduction

    Energy Technology Data Exchange (ETDEWEB)

    Keller, C. [AREVA NP GmbH (Germany)

    2010-05-15

    Pulsation dampers working with a compressible gas volume have the capability of reducing pressure surges in piping systems if they are properly dimensioned and positioned. This is also valid for piping systems with high pressure levels. Even if they show promising pressure peak mitigation effects the application of pulsation dampers in nuclear power plants will still remain on an exceptional basis. However with the help of computer simulations it is possible to predict the effect of such devices much more precisely then in the past. This is the reason why the application of pulsation dampers for special cases should be considered as possibility. (orig.)

  9. Methods of Cost Reduction for United States Coast Guard Telephone Systems.

    Science.gov (United States)

    1981-03-01

    Polling----------------------------------- 49 3. Facsimile (FAX)--------------------------- 52 C. ALTERNATIVES TO TELCO ------------------------- 54 VI. WIDE...Network (AUTOVON) , Automatic Secure Voice Communications CAUTOSEVOCOM), and other special circuitry and connecting hardware are often billed via TELCO ...company ( TELCO ) leased systems. Collectively, the common carriers, government agencies, and the newly arrived interconnect industry now exist in a new

  10. Predictive Pulse Pattern Current Modulation Scheme for Harmonic Reduction in Three-Phase Multidrive Systems

    DEFF Research Database (Denmark)

    Davari, Pooya; Yang, Yongheng; Zare, Firuz

    2016-01-01

    The majority of the industrial motor drive systems are equipped with the conventional line-commutated front-end rectifiers, and being one of the main sources of harmonics in the power line. While a parallel combination of these drive units elevates current quality issues, a proper arrangement...

  11. Complexity reduction in MPC for stochastic max-plus-linear discrete event systems by variability expansion

    NARCIS (Netherlands)

    Heidergott, B.F.; van den Boom, T.J.J.; de Schutter, B.

    2007-01-01

    Model predictive control (MPC) is a popular controller design technique in the process industry. Recently, MPC has been extended to a class of discrete event systems that can be described by a model that is "linear" in the max-plus algebra. In this context both the perturbations-free case and for

  12. Neonatal Facial Coding System for Assessing Postoperative Pain in Infants: Item Reduction is Valid and Feasible

    NARCIS (Netherlands)

    Peters, J.W.B.; Koot, H.M.; Grunau, R.E.; Boer, J. de; Druenen, M.J. van; Tibboel, D.; Duivenvoorden, H.J.

    2003-01-01

    Objective: The objectives of this study were to: (1) evaluate the validity of the Neonatal Facial Coding System (NFCS) for assessment of postoperative pain and (2) explore whether the number of NFCS facial actions could be reduced for assessing postoperative pain. Design: Prospective, observational

  13. Single char particle model for naphthalene reduction in a biomass gasification system

    NARCIS (Netherlands)

    Abu El-Rub, Ziad; Brem, Gerrit; Bramer, Eduard A.

    2015-01-01

    Tar removal in biomass gasification systems is one of the key challenges to overcome for the successful commercialization of this technology. This study focused on tar conversion over the active char particle besides the simultaneous carbon conversion of the char particle. In the presented model,

  14. Reduction method with system analysis for multiobjective optimization-based design

    Science.gov (United States)

    Azarm, S.; Sobieszczanski-Sobieski, J.

    1993-01-01

    An approach for reducing the number of variables and constraints, which is combined with System Analysis Equations (SAE), for multiobjective optimization-based design is presented. In order to develop a simplified analysis model, the SAE is computed outside an optimization loop and then approximated for use by an operator. Two examples are presented to demonstrate the approach.

  15. Terabytes to Megabytes: Data Reduction Onsite for Remote Limited Bandwidth Systems

    Science.gov (United States)

    Hirsch, M.

    2016-12-01

    Inexpensive, battery-powerable embedded computer systems such as the Intel Edison and Raspberry Pi have inspired makers of all ages to create and deploy sensor systems. Geoscientists are also leveraging such inexpensive embedded computers for solar-powered or other low-resource utilization systems for ionospheric observation. We have developed OpenCV-based machine vision algorithms to reduce terabytes per night of high-speed aurora video data down to megabytes of data to aid in automated sifting and retention of high-value data from the mountains of less interesting data. Given prohibitively expensive data connections in many parts of the world, such techniques may be generalizable to more than just the auroral video and passive FM radar implemented so far. After the automated algorithm decides which data to keep, automated upload and distribution techniques are relevant to avoid excessive delay and consumption of researcher time. Open-source collaborative software development enables data audiences from experts through citizen enthusiasts to access the data and make exciting plots. Open software and data aids in cross-disciplinary collaboration opportunities, STEM outreach and increasing public awareness of the contributions each geoscience data collection system makes.

  16. Edge Reduction for EVMDDs to Speed Up Analysis of Multi-State Systems

    Science.gov (United States)

    2015-01-01

    breakdown), 1 (partially supply), and 2 (full supply). And, the system has six states which correspond to the percentage of area of a town that is blacked... erogeneous MDDs,” IEEE Trans. on CAD, Vol. 24, No. 11, pp. 1645–1659, Nov. 2005. [12] S. Nagayama, T. Sasao, and J. T. Butler, “A systematic design method

  17. Reduction of soil compaction in a cotton and peanut rotation using conservation systems

    Science.gov (United States)

    Southern Coastal Plain soils benefit from the adoption of conservation tillage systems as water retention and organic matter increase which improves soil structure. However, some coastal plain soils are prone to compaction and tend to form hardpans which restrict root growth and reduce yields. The a...

  18. Control of Linear Systems with Preisach Hysteresis Output with Application to Damage Reduction

    DEFF Research Database (Denmark)

    Barradas Berglind, Jose de Jesus; Wisniewski, Rafal

    2015-01-01

    The focus of this work is on the Preisach hysteresis operator which has been widely used in fields such as ferromagnetics, phase transitions, filtration through porous media, and shape memory alloys. The main purpose is to incorporate discrete linear time invariant systems with discretized Preisach...

  19. Application of Autonomous Smart Inverter Volt-VAR Function for Voltage Reduction Energy Savings and Power Quality in Electric Distribution Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Fei; Nagarajan, Adarsh; Baggu, Murali; Chakraborty, Sudipta; Nguyen, Andu; Walinga, Sarah; McCarty, Michael; Bell, Frances

    2017-05-01

    This paper evaluated the impact of smart inverter Volt-VAR function on voltage reduction energy saving and power quality in electric power distribution systems. A methodology to implement the voltage reduction optimization was developed by controlling the substation LTC and capacitor banks, and having smart inverters participate through their autonomous Volt-VAR control. In addition, a power quality scoring methodology was proposed and utilized to quantify the effect on power distribution system power quality. All of these methodologies were applied to a utility distribution system model to evaluate the voltage reduction energy saving and power quality under various PV penetrations and smart inverter densities.

  20. Experimental Study of Selective Catalytic Reduction System On CI Engine Fuelled with Diesel-Ethanol Blend for NOx Reduction with Injection of Urea Solutions

    OpenAIRE

    R. Praveen; Natarajan, S.

    2014-01-01

    Nowadays exhaust emission control from internal combustion engines have become one of the most important challenges. Oxides of nitrogen (NOx) are one of the major hazardous pollutants that come out from diesel engines. There are various techniques existing for NOx control but each techniques has its own advantages and disadvantages. Technologies available for NOx reductions either increase other polluting gas emission or increase fuel consumption. The objective of this paper is to determine t...

  1. High-level synthesis for reduction of WCET in real-time systems

    DEFF Research Database (Denmark)

    Kristensen, Andreas Toftegaard; Pezzarossa, Luca; Sparsø, Jens

    2017-01-01

    The increasing design complexity of systems-on-chip (SoCs) requires designers to work at higher levels of abstraction. High-level synthesis (HLS) is one approach towards this. It allows designers to synthesize hardware directly from code written in a high-level programming language and to more...... quickly explore alternative implementations by re-running the synthesis with different optimization parameters and pragmas. HLS is particularly interesting for FPGA circuits, where different hardware implementations can easily be loaded into the target device. Another perspective on HLS is performance....... Compared to executing the high-level language code on a processor, HLS can be used to create hardware that accelerates critical parts of the code. When discussing performance in the context or real-time systems, it is the worst-case execution time (WCET) of a task that matters. WCET obviously benefits from...

  2. Challenges in Gaining Large Scale Carbon Reductions through Wireless Home Automation Systems

    DEFF Research Database (Denmark)

    Larsen, Peter Gorm; Rovsing, Poul Ejnar; Toftegaard, Thomas Skjødeberg

    2010-01-01

    wireless but also powerline communication in a home automation setting. For many years, home automation has been visible to many, but accessible to only a few, because of inadequate integration of systems. A vast number of both standard and proprietary communication protocols are used, and systems......Buildings account for more than a 35 % of the energy consumption in Europe. Therefore a step towards more sustainable lifestile is to use home automation to optimize the energy consumption “automatically”. This paper reports about the usage and some of the remaining challenges of especially...... are often difficult to install and configure so professional assistance is needed. In this paper we report about our experience in constructing an open universal home automation framework enabling interoperability of multiple communication protocols. The framework can easily be expanded in order to support...

  3. Alternative Drive Systems as a Part of a GHG Emission Reduction

    Directory of Open Access Journals (Sweden)

    Jevto Lučić

    2011-09-01

    Full Text Available Air pollution as a consequence of a modern way of life contaminates the natural environment and brings us the global warming which poses a clear and present danger to civilization. The main causes of global warming are greenhouse gasses, which arise of reliance on fossil fuels, deforestation, agriculture, industrial processes and transport. The transport itself makes 14% of the main causes of greenhouse gasses. Its dependence on fossil fuels, together with the decrease of a world fossil fuels reserves, force us to look for alternative fuels and to develop alternative drive systems, which can stabilize and reduce the greenhouse effect, and at the same time offer us new technologies, independent on a fossil fuels. This paper will try to present potential solutions for this problem, and to show the development of alternative drive systems

  4. Furnace veneering systems of special design help achieve energy reduction goals at Armco

    Energy Technology Data Exchange (ETDEWEB)

    Caspersen, L.J.

    1982-12-01

    A steel company conserves energy by veneering reheat furnaces with a ceramic fiber modular system. The furnace lining system incorporates several grades of veneering materials (modules, cements, coatings) whose application is matched to the exact conditions in the furnace. Zoned linings utilize a combination of grades of alumina-silica modules to achieve thermally efficient yet durable performance. High temperature cements exhibit good tackiness, easy module penetration and high strength retention after firing. A protective coating is sprayed in a thin layer over the modules and can be easily reapplied at a later date should it be necessary. Benefits include greater thermal control (temperature responsiveness and heating uniformity), less over-firing, less fuel use, and less heat loss. Fuel efficiency is increased by 20 to 50%.

  5. Self-sustained reduction of multiple metals in a microbial fuel cell-microbial electrolysis cell hybrid system.

    Science.gov (United States)

    Li, Yan; Wu, Yining; Liu, Bingchuan; Luan, Hongwei; Vadas, Timothy; Guo, Wanqian; Ding, Jie; Li, Baikun

    2015-09-01

    A self-sustained hybrid bioelectrochemical system consisting of microbial fuel cell (MFC) and microbial electrolysis cell (MEC) was developed to reduce multiple metals simultaneously by utilizing different reaction potentials. Three heavy metals representing spontaneous reaction (chromium, Cr) and unspontaneous reaction (lead, Pb and nickel, Ni) were selected in this batch-mode study. The maximum power density of the MFC achieved 189.4 mW m(-2), and the energy recovery relative to the energy storage circuit (ESC) was ∼ 450%. At the initial concentration of 100 mg L(-1), the average reduction rate of Cr(VI) was 30.0 mg L(-1) d(-1), Pb(II) 32.7 mg L(-1) d(-1), and Ni(II) 8.9 mg L(-1) d(-1). An electrochemical model was developed to predict the change of metal concentration over time. The power output of the MFC was sufficient to meet the requirement of the ESC and MEC, and the "self-sustained metal reduction" was achieved in this hybrid system. Published by Elsevier Ltd.

  6. PowerFilm PowerShade Fixed Site Solar System Cost Reduction Plan

    Science.gov (United States)

    2014-07-31

    hardware operation. First, modules must be sheated from roll and laid out in proper side-by- side position. Second, busbar tape must be placed on the...soldered to the busbar strips. Fourth, the assembled module must be fed in to the roll lamination system with proper spacing to allow efficient use...above the two tables. This head has a feed for conductive adhesive coated copper busbar and applies that busbar down the length joining the two

  7. Polysulfide reduction using sulfate-reducing bacteria in a photocatalytic hydrogen generation system.

    Science.gov (United States)

    Takahashi, Yui; Suto, Koichi; Inoue, Chihiro; Chida, Tadashi

    2008-09-01

    A hydrogen generation process using photocatalytic reactions has been proposed. In this process, hydrogen sulfide is a source of hydrogen and is turned into polysulfide. In order to establish the cyclic operation of a photocatalytic hydrogen generation system, it is necessary to convert polysulfide back into hydrogen sulfide with a small energy input. This paper proposes the use of sulfate-reducing bacteria (SRB) for the regeneration of hydrogen sulfide. Batch cultivation of natural source SRB samples were carried out using a culture medium containing polysulfide as the only sulfur compound source. SRB produced hydrogen sulfide from several kinds of polysulfide sources, including a photocatalytic hydrogen generation-produces solution. Production lag phase and production rate of hydrogen sulfide were affected by initial polysulfide concentration. SRB activity was inhibited at high initial polysulfide concentrations. SRB enrichment culture T2, exhibited the highest hydrogen sulfide production rate, and was able to utilize several kinds of organic matter as the electron donor. The results suggest the possibility of using large biomass sources, such as sewage sludge and the raw garbage in a hydrogen generation system. We developed speculative estimates that an SRB based hydrogen generation system is feasible.

  8. Optimal Energy Reduction Schedules for Ice Storage Air-Conditioning Systems

    Directory of Open Access Journals (Sweden)

    Whei-Min Lin

    2015-09-01

    Full Text Available This paper proposes a hybrid algorithm to solve the optimal energy dispatch of an ice storage air-conditioning system. Based on a real air-conditioning system, the data, including the return temperature of chilled water, the supply temperature of chilled water, the return temperature of ice storage water, and the supply temperature of ice storage water, are measured. The least-squares regression (LSR is used to obtain the input-output (I/O curve for the cooling load and power consumption of chillers and ice storage tank. The objective is to minimize overall cost in a daily schedule while satisfying all constraints, including cooling loading under the time-of-use (TOU rate. Based on the Radial Basis Function Network (RBFN and Ant Colony Optimization, an Ant-Based Radial Basis Function Network (ARBFN is constructed in the searching process. Simulation results indicate that reasonable solutions provide a practical and flexible framework allowing the economic dispatch of ice storage air-conditioning systems, and offering greater energy efficiency in dispatching chillers.

  9. Stator Current Harmonic Reduction in a Novel Half Quasi-Z-Source Wind Power Generation System

    Directory of Open Access Journals (Sweden)

    Shoudao Huang

    2016-09-01

    Full Text Available The generator stator current gets distorted with unacceptable levels of total harmonic distortion (THD because impedance-source wind power generation systems use three-phase diode rectifiers. The stator current harmonics will cause increasing losses and torque ripple, which reduce the efficiency and stability of the system. This paper proposes a novel half quasi-Z-source inverter (H-qZSI for grid-connected wind power generation systems, which can reduce the generator stator current harmonics a great deal. When H-qZSI operates in the shoot-through zero state, the derivative of the generator stator current is only determined by the instantaneous value of the generator stator voltage, so the nonlinear relationship between generator stator current and stator voltage is improved compared with the traditional impedance-source inverter. Theoretically, it is indicated that the stator current harmonics can be reduced effectively by means of the proposed H-qZSI. Finally, simulation and experimental results are given to verify the theoretical analysis.

  10. Low-Gain, Low-Noise Integrated Neuronal Amplifier for Implantable Artifact-Reduction Recording System

    Directory of Open Access Journals (Sweden)

    Abdelhamid Benazzouz

    2013-09-01

    Full Text Available Brain neuroprostheses for neuromodulation are being designed to monitor the neural activity of the brain in the vicinity of the region being stimulated using a single macro-electrode. Using a single macro-electrode, recent neuromodulation studies show that recording systems with a low gain neuronal amplifier and successive amplifier stages can reduce or reject stimulation artifacts. These systems were made with off-the-shelf components that are not amendable for future implant design. A low-gain, low-noise integrated neuronal amplifier (NA with the capability of recording local field potentials (LFP and spike activity is presented. In vitro and in vivo characterizations of the tissue/electrode interface, with equivalent impedance as an electrical model for recording in the LFP band using macro-electrodes for rodents, contribute to the NA design constraints. The NA occupies 0.15 mm2 and dissipates 6.73 µW, and was fabricated using a 0.35 µm CMOS process. Test-bench validation indicates that the NA provides a mid-band gain of 20 dB and achieves a low input-referred noise of 4 µVRMS. Ability of the NA to perform spike recording in test-bench experiments is presented. Additionally, an awake and freely moving rodent setup was used to illustrate the integrated NA ability to record LFPs, paving the pathway for future implantable systems for neuromodulation.

  11. Advancedmonitoring Systems for Landslide Risk Reduction in THE'SIQ' of PETRA (jordan)

    Science.gov (United States)

    Delmonaco, G.; Brini, M.; Cesaro, G.

    2017-08-01

    The UNESCO World Heritage Site of Petra is characterized by a spectacular geo-archaeological landscape that lead to its inscription as World Heritage Site in 1985. Petra is also a fragile site facing a wide diversity of risks, ranging from those posed by environmental factors as well as those attributed to tourism. In recent years, hazardous natural phenomena were registered as increasingly impacting the site, and most specifically the 'Siq', a 1.2 km naturally formed gorge serving as the only tourist entrance to the archaeological park, posing a major threat to cultural heritage and visitors. These recent events have prompted UNESCO Amman Office, in cooperation with the national authorities, to develop a strategy towards prevention and mitigation of instability phenomena at the 'Siq' and, thus, further contribute to the management and conservation of the site through the implementation of the multi-year Italian funded "Siq Stability" project Actions have been primarily focusing on the analysis of the stability conditions of the 'Siq' slopes, the installation of an integrated monitoring system and the definition and implementation of mitigation measures against rock instability. This paper reports a detailed description of the integrated monitoring system installed paying particular attention on the wireless monitoring devices and the EASA applications, which proved to be some of the most successful systems implemented in the framework of the project. Some preliminary results regarding the data retrieved, policies applied and actions taken to ensure long-term sustainability and capacity development of the national authorities are also reported.

  12. A low-cost, goal-oriented ‘compact proper orthogonal decomposition’ basis for model reduction of static systems

    KAUST Repository

    Carlberg, Kevin

    2010-12-10

    A novel model reduction technique for static systems is presented. The method is developed using a goal-oriented framework, and it extends the concept of snapshots for proper orthogonal decomposition (POD) to include (sensitivity) derivatives of the state with respect to system input parameters. The resulting reduced-order model generates accurate approximations due to its goal-oriented construction and the explicit \\'training\\' of the model for parameter changes. The model is less computationally expensive to construct than typical POD approaches, since efficient multiple right-hand side solvers can be used to compute the sensitivity derivatives. The effectiveness of the method is demonstrated on a parameterized aerospace structure problem. © 2010 John Wiley & Sons, Ltd.

  13. Radiation dose reduction and new image modalities development for interventional C-arm imaging system

    Science.gov (United States)

    Niu, Kai

    Cardiovascular disease and stroke are the leading health problems and causes of death in the US. Due to the minimally invasive nature of the evolution of image guided techniques, interventional radiological procedures are becoming more common and are preferred in treating many cardiovascular diseases and strokes. In addition, with the recent advances in hardware and device technology, the speed and efficacy of interventional treatment has significantly improved. This implies that more image modalities can be developed based on the current C-arm system and patients treated in interventional suites can potentially experience better health outcomes. However, during the treatment patients are irradiated with substantial amounts of ionizing radiation with a high dose rate (digital subtraction angiography (DSA) with 3muGy/frame and 3D cone beam CT image with 0.36muGy/frame for a Siemens Artis Zee biplane system) and/or a long irradiation time (a roadmapping image sequence can be as long as one hour during aneurysm embolization). As a result, the patient entrance dose is extremely high. Despite the fact that the radiation dose is already substantial, image quality is not always satisfactory. By default a temporal average is used in roadmapping images to overcome poor image quality, but this technique can result in motion blurred images. Therefore, reducing radiation dose while maintaining or even improving the image quality is an important area for continued research. This thesis is focused on improving the clinical applications of C-arm cone beam CT systems in two ways: (1) Improve the performance of current image modalities on the C-arm system. (2) Develop new image modalities based on the current system. To be more specific, the objectives are to reduce radiation dose for current modalities (e.g., DSA, fluoroscopy, roadmapping, and cone beam CT) and enable cone beam CT perfusion and time resolved cone beam CT angiography that can be used to diagnose and triage acute

  14. Lung volume reduction surgery in canine model of predominantly upper lobe emphysema: advantages of new surgical system.

    Science.gov (United States)

    Mink, Steven N; Gonzalez, Xavier; Duke, Krika; Bautista, Edgar; Tan, Lawrence

    2004-02-01

    Lung volume reduction surgery has been shown to be an effective treatment for selected patients with advanced emphysema. Nevertheless, prolonged air leaks are a significant complication that limits the utility of this procedure. This study evaluated the safety and effectiveness of a novel surgical system designed to minimize this complication. In 14 dogs, severe upper lobe emphysema was produced by repeated bronchial instillations of papain administered over an approximate 6-month interval. Pulmonary function testing that included lung volumes and flows was performed at baseline, after emphysema, and at 1 month and 6 months after resection in the surgical group, while at comparable intervals in the nonsurgical group. Seven animals were randomly assigned to a surgical group to test a vacuum-assisted surgical system (VALR Surgical System; Spiration; Redmond, WA) that deploys a compression silicone sleeve over portions of the diseased tissue. The other seven dogs comprised the nonsurgical group. In both groups, emphysema increased total lung capacity (TLC) approximately 125% as compared to baseline. In the surgical group, no air leaks were observed after resection, and TLC significantly decreased at the 1-month and 6-month periods as compared with postemphysema measurements. At necropsy, histologic examination revealed fibrosis of the compressed lung contained within the sleeve and fibrotic encapsulation of the device. Two animals had evidence of localized infection. We successfully created a model of predominantly upper lobe emphysema. The vacuum-assisted surgical system provided safe and effective lung reduction without air leak complications and with sustained improvement in pulmonary function over 6 months.

  15. ADVANCEDMONITORING SYSTEMS FOR LANDSLIDE RISK REDUCTION IN THE'SIQ' OF PETRA (JORDAN

    Directory of Open Access Journals (Sweden)

    G. Delmonaco

    2017-08-01

    Full Text Available The UNESCO World Heritage Site of Petra is characterized by a spectacular geo-archaeological landscape that lead to its inscription as World Heritage Site in 1985. Petra is also a fragile site facing a wide diversity of risks, ranging from those posed by environmental factors as well as those attributed to tourism. In recent years, hazardous natural phenomena were registered as increasingly impacting the site, and most specifically the 'Siq', a 1.2 km naturally formed gorge serving as the only tourist entrance to the archaeological park, posing a major threat to cultural heritage and visitors. These recent events have prompted UNESCO Amman Office, in cooperation with the national authorities, to develop a strategy towards prevention and mitigation of instability phenomena at the 'Siq' and, thus, further contribute to the management and conservation of the site through the implementation of the multi-year Italian funded "Siq Stability" project Actions have been primarily focusing on the analysis of the stability conditions of the 'Siq' slopes, the installation of an integrated monitoring system and the definition and implementation of mitigation measures against rock instability. This paper reports a detailed description of the integrated monitoring system installed paying particular attention on the wireless monitoring devices and the EASA applications, which proved to be some of the most successful systems implemented in the framework of the project. Some preliminary results regarding the data retrieved, policies applied and actions taken to ensure long-term sustainability and capacity development of the national authorities are also reported.

  16. Concurrent System Engineering and Risk Reduction for Dual-Band (RF/optical) Spacecraft Communications

    Science.gov (United States)

    Fielhauer, Karl, B.; Boone, Bradley, G.; Raible, Daniel, E.

    2012-01-01

    This paper describes a system engineering approach to examining the potential for combining elements of a deep-space RF and optical communications payload, for the purpose of reducing the size, weight and power burden on the spacecraft and the mission. Figures of merit and analytical methodologies are discussed to conduct trade studies, and several potential technology integration strategies are presented. Finally, the NASA Integrated Radio and Optical Communications (iROC) project is described, which directly addresses the combined RF and optical approach.

  17. A discrete-time approach to stochastic model reduction for spatiotemporally chaotic systems

    Science.gov (United States)

    Lin, K. K.; Lu, F.; Chorin, A. J.

    2016-12-01

    In computational modeling of complex dynamical phenomena, itis often useful to be able to construct simpler reducedmodels that nevertheless capture key dynamical features ofinterest. One well-studied strategy is to fit parametricfamilies of stochastic models to data. Recently, Chorin andLu proposed a novel discrete-time approach that has certainappealing features. Here we investigate an application ofthis discrete-time approach to the Kuramoto-Sivashinskypartial differential equation, a prototypical model ofspatiotemporal chaos. We show that the resulting reducedmodels reproduce both short-time dynamics as well aslong-term statistics of the full system. We discuss someimplementation issues that arise and how they can beovercome.

  18. Alliance system and policy change: necessary ingredients for improvement in diabetes care and reduction of disparities.

    Science.gov (United States)

    Clark, Noreen M; Quinn, Martha; Dodge, Julia A; Nelson, Belinda W

    2014-11-01

    Reducing diabetes inequities requires system and policy changes based on real-life experiences of vulnerable individuals living with the condition. While introducing innovative interventions for African American, Native American, and Latino low-income people, the five community-based sites of the Alliance to Reduce Disparities in Diabetes recognized that policy changes were essential to sustain their efforts. Data regarding change efforts were collected from site leaders and examined against documents provided routinely to the National Program Office at the University of Michigan. A policy expert refined the original lists to include only confirmed policy changes, scope of change (organizational to national), and stage of accomplishment (1, beginning; 2, adoption; 3, implementation; and 4, full maintenance). Changes were again verified through site visits and telephone interviews. In 3 years, Alliance teams achieved 53 system and policy change accomplishments. Efforts were implemented at the organizational (33), citywide (13), state (5), and national (2) levels, and forces helping and hindering success were identified. Three types of changes were deemed especially significant for diabetes control: data sharing across care-providing organizations, embedding community health workers into the clinical care team, and linking clinic services with community assets and resources in support of self-management. © 2014 Society for Public Health Education.

  19. Electron contamination modeling and reduction in a 1 T open bore inline MRI-linac system.

    Science.gov (United States)

    Oborn, B M; Kolling, S; Metcalfe, P E; Crozier, S; Litzenberg, D W; Keall, P J

    2014-05-01

    A potential side effect of inline MRI-linac systems is electron contamination focusing causing a high skin dose. In this work, the authors reexamine this prediction for an open bore 1 T MRI system being constructed for the Australian MRI-Linac Program. The efficiency of an electron contamination deflector (ECD) in purging electron contamination from the linac head is modeled, as well as the impact of a helium gas region between the deflector and phantom surface for lowering the amount of air-generated contamination. Magnetic modeling of the 1 T MRI was used to generate 3D magnetic field maps both with and without the presence of an ECD located immediately below the MLC's. Forty-seven different ECD designs were modeled and for each the magnetic field map was imported into Geant4 Monte Carlo simulations including the linac head, ECD, and a 30 × 30 × 30 cm(3) water phantom located at isocenter. For the first generation system, the x-ray source to isocenter distance (SID) will be 160 cm, resulting in an 81.2 cm long air gap from the base of the ECD to the phantom surface. The first 71.2 cm was modeled as air or helium gas, with the latter encased between two windows of 50 μm thick high density polyethlyene. 2D skin doses (at 70 μm depth) were calculated across the phantom surface at 1 × 1 mm(2) resolution for 6 MV beams of field size of 5 × 5, 10 × 10, and 20 × 20 cm(2). The skin dose was predicted to be of similar magnitude as the generic systems modeled in previous work, 230% to 1400% of D(max) for 5 × 5 to 20 × 20 cm(2), respectively. Inclusion of the ECD introduced a nonuniformity to the MRI imaging field that ranged from ∼20 to ∼140 ppm while the net force acting on the ECD ranged from ∼151 N to ∼1773 N. Various ECD designs were 100% efficient at purging the electron contamination into the ECD magnet banks; however, a small percentage were scattered back into the beam and continued to the phantom surface. Replacing a large portion of the extended

  20. Effect of Multi-DG Installation to Loss Reduction in Distribution System

    Directory of Open Access Journals (Sweden)

    Nur Zahirah Mohd Ali

    2016-03-01

    Full Text Available Since last decade, Artificial Intelligence (AI methods have been used to solve complex DG problems because in most cases, they can provide global or near global solution. The major advantage of the AI methods is that they are relatively versatile for handling various qualitative constraints. AI methods mainly include Artificial Neural Network (ANN, Expert System (ES, Genetic Algorithm (GA, Evolutionary Programming (EP, Ant Colony Optimization (ACO and Particle Swarm Optimization (PSO. The purpose of this paper is to present a new technique, namely Adaptive Embedded Clonal Evolutionary Programming (AECEP. The objective of the study is to employ AECEP optimization techniques for loss minimization. This technique was developed to optimally determine the location and sizing of DG. The IEEE 41- Bus RTS was implemented for testing several cases in terms of loading conditions.

  1. A technique for reduction of spurious signals in a DRFM system

    Science.gov (United States)

    Barnes, Walter N.; Horn, John N.

    This paper presents the results of an investigation of the use of a random voltage to reduce or eliminate the nonlinear characteristics of a one-bit analog-to-digital (A/D) converter for radar and radar electronic countermeasure (ECM) applications. Specifically, it was shown that the addition of a random voltage with a uniform probability density function prior to the A/D converter eliminates the nonlinear effect, but results in a random interference. An implementation of an interference suppression technique that reduces the resulting random interference level is also described. Theoretically derived expressions for the signal-to-interference level at the output of a matched filter radar for the uniform random voltage technique and the interference suppression techniques are presented. Simulation results that verify the theoretical expressions are also presented in the context of a digital radio frequency memory (DRFM) ECM system. Signal spectrums for a conventional one-bit A/D converter are included for comparison.

  2. Pathogen Reduction and Hazard Analysis and Critical Control Point (HACCP) systems for meat and poultry. USDA.

    Science.gov (United States)

    Hogue, A T; White, P L; Heminover, J A

    1998-03-01

    The United States Department of Agriculture (USDA) Food Safety Inspection Service (FSIS) adopted Hazard Analysis and Critical Control Point Systems and established finished product standards for Salmonella in slaughter plants to improve food safety for meat and poultry. In order to make significant improvements in food safety, measures must be taken at all points in the farm-to-table chain including production, transportation, slaughter, processing, storage, retail, and food preparation. Since pathogens can be introduced or multiplied anywhere along the continuum, success depends on consideration and comparison of intervention measures throughout the continuum. Food animal and public health veterinarians can create the necessary preventative environment that mitigates risks for food borne pathogen contamination.

  3. Establishment of culture systems for Genotypes 3 and 4 hepatitis E virus (HEV) obtained from human blood and application of HEV inactivation using a pathogen reduction technology system.

    Science.gov (United States)

    Owada, Takashi; Kaneko, Moe; Matsumoto, Chieko; Sobata, Rieko; Igarashi, Masashi; Suzuki, Ko; Matsubayashi, Keiji; Mio, Kazuhiro; Uchida, Shigeharu; Satake, Masahiro; Tadokoro, Kenji

    2014-11-01

    It has been demonstrated that the hepatitis E virus (HEV) can be transmitted via blood transfusion, and the risk of HEV transmission via transfusion has become a major global concern. An HEV culture system for blood-derived HEV has been sought to obtain valuable knowledge of the virus and the risk of HEV infection through blood products. We endeavored to establish an HEV culture system using RNA-positive blood specimens for Genotypes (G) 3 and 4 and applied this system to evaluate tissue culture infectious dose (TCID). We applied this method to investigate the potential of the Mirasol pathogen reduction technology (PRT) system (Terumo BCT) to inactivate live HEV in contaminated platelet samples (PLTs). PLTs were spiked with cultured HEV G3 or G4 and then treated with the Mirasol PRT system. PLTs were examined before and after the treatment for HEV load using TCID titration. We successfully established two strains for HEV production: the JRC-HE3 strain for G3 and the UA1 strain for G4. The Mirasol PRT system expressed more than 3 log inactivation for JRC-HE3 and more than 2 log inactivation for UA1. The Mirasol PRT system inactivated greater than 2 to 3 logs of live HEV in PLTs and can potentially be used to lower the possibility of blood-borne HEV transmission. The G3 and G4 HEV inocula identified in this study and the hepatoma cell culture system provide a new means to assess HEV infectious titer and to evaluate other pathogen reduction strategies. © 2014 AABB.

  4. Subspace-based additive fuzzy systems for classification and dimension reduction

    Science.gov (United States)

    Jauch, Thomas W.

    1997-10-01

    In classification tasks the appearance of high dimensional feature vectors and small datasets is a common problem. It is well known that these two characteristics usually result in an oversized model with poor generalization power. In this contribution a new way to cope with such tasks is presented which is based on the assumption that in high dimensional problems almost all data points are located in a low dimensional subspace. A way is proposed to design a fuzzy system on a unified framework, and to use it to develop a new model for classification tasks. It is shown that the new model can be understood as an additive fuzzy system with parameter based basis functions. Different parts of the models are only defined in a subspace of the whole feature space. The subspaces are not defined a priori but are subject to an optimization procedure as all other parameters of the model. The new model has the capability to cope with high feature dimensions. The model has similarities to projection pursuit and to the mixture of experts architecture. The model is trained in a supervised manner via conjugate gradients and logistic regression, or backfitting and conjugate gradients to handle classification tasks. An efficient initialization procedure is also presented. In addition a technique based on oblique projections is presented which enlarges the capabilities of the model to use data with missing features. It is possible to use data with missing features in the training and in the classification phase. Based on the design of the model, it is possible to prune certain basis functions with an OLS (orthogonal least squares) based technique in order to reduce the model size. Results are presented on an artificial and an application example.

  5. On-road measurement of regulated pollutants from diesel and CNG buses with urea selective catalytic reduction systems

    Science.gov (United States)

    Guo, Jiadong; Ge, Yunshan; Hao, Lijun; Tan, Jianwei; Li, Jiaqiang; Feng, Xiangyu

    2014-12-01

    In this study, emissions from 13 buses operated in Beijing, including two Euro-III diesel buses, four Euro-IV diesel buses, three Euro-V diesel buses and four Euro-V CNG buses, were characterized in real world conditions. All of the buses tested were fitted with selective catalytic reduction (SCR) systems except for the Euro-III diesel buses. A SEMTECH-DS was used for testing the gaseous pollutants, and an electric low pressure impactor (ELPI) was used for measuring of particle numbers and size distributions. A comparison was made based on emission performance of these buses by employing the VSP approach and fuel- based emissions factors. Diesel buses emitted less CO and THC but more NOx and PM pollutants than CNG buses. The NOx reduction efficiencies of the SCR systems for CNG buses were higher because of the high exhaust temperature and high NO2/NOx ratio, whereas the efficiencies for diesel buses were lower. This resulted in extremely low NOx emissions from CNG buses, but the high NO2/NOx ratio needs further study. Failures of urea injection in the SCR systems were detected in this research, which resulted in very high NOx emissions. The CNG buses also emitted smaller numbers of particles and less particle mass with the presence of oxidation catalysts. Diesel buses satisfying the Euro-V standard performed better than Euro-IV and Euro-III diesel buses in terms of emission performance, except for more nuclei mode particles. Most of time, the Euro-IV diesel buses show no advantages in CO and NOx emissions compared with the Euro-III diesel buses.

  6. Laboratory for Engineering Man/Machine Systems (LEMS): System identification, model reduction and deconvolution filtering using Fourier based modulating signals and high order statistics

    Science.gov (United States)

    Pan, Jianqiang

    1992-01-01

    Several important problems in the fields of signal processing and model identification, such as system structure identification, frequency response determination, high order model reduction, high resolution frequency analysis, deconvolution filtering, and etc. Each of these topics involves a wide range of applications and has received considerable attention. Using the Fourier based sinusoidal modulating signals, it is shown that a discrete autoregressive model can be constructed for the least squares identification of continuous systems. Some identification algorithms are presented for both SISO and MIMO systems frequency response determination using only transient data. Also, several new schemes for model reduction were developed. Based upon the complex sinusoidal modulating signals, a parametric least squares algorithm for high resolution frequency estimation is proposed. Numerical examples show that the proposed algorithm gives better performance than the usual. Also, the problem was studied of deconvolution and parameter identification of a general noncausal nonminimum phase ARMA system driven by non-Gaussian stationary random processes. Algorithms are introduced for inverse cumulant estimation, both in the frequency domain via the FFT algorithms and in the domain via the least squares algorithm.

  7. Model Reduction Using Proper Orthogonal Decomposition and Predictive Control of Distributed Reactor System

    Directory of Open Access Journals (Sweden)

    Alejandro Marquez

    2013-01-01

    Full Text Available This paper studies the application of proper orthogonal decomposition (POD to reduce the order of distributed reactor models with axial and radial diffusion and the implementation of model predictive control (MPC based on discrete-time linear time invariant (LTI reduced-order models. In this paper, the control objective is to keep the operation of the reactor at a desired operating condition in spite of the disturbances in the feed flow. This operating condition is determined by means of an optimization algorithm that provides the optimal temperature and concentration profiles for the system. Around these optimal profiles, the nonlinear partial differential equations (PDEs, that model the reactor are linearized, and afterwards the linear PDEs are discretized in space giving as a result a high-order linear model. POD and Galerkin projection are used to derive the low-order linear model that captures the dominant dynamics of the PDEs, which are subsequently used for controller design. An MPC formulation is constructed on the basis of the low-order linear model. The proposed approach is tested through simulation, and it is shown that the results are good with regard to keep the operation of the reactor.

  8. Greenhouse Gas Emission Reduction Due to Improvement of Biodegradable Waste Management System

    Science.gov (United States)

    Bendere, R.; Teibe, I.; Arina, D.; Lapsa, J.

    2014-12-01

    To reduce emissions of greenhouse gas (GHG) from landfills, the European Union (EU) Landfill Directive 1999/31/EC requires that there be a progressive decrease in the municipal biodegradable waste disposal. The main problem of waste management (WM) in Latvia is its heavy dependence on the waste disposal at landfills. The poorly developed system for the sorted municipal waste collection and the promotion of landfilling as a major treatment option led to the disposal of 84% of the total collected municipal waste in 2012, with a high biodegradable fraction. In Latvia, the volume of emissions due to activities of the WM branch was 5.23% (632.6 CO2 eq.) of the total GHG emissions produced in the National economy in 2010 (12 097 Gg CO2 eq., except the land use, land-use change and forestry). Having revised the current situation in the management of biodegradable waste in Latvia, the authors propose improvements in this area. In the work, analysis of environmental impact was carried out using Waste Management Planning System (WAMPS) software in the WM modelling scenarios. The software computes the emissions, energy and turnover of waste streams for the processes within the WM system such as waste collection and transportation, composting, anaerobic digestion, and the final disposal (landfilling or incineration). The results of WAMPS modelling are presented in four categories associated with the environmental impact: acidification, global warming, eutrophication and photo-oxidant formation, each characterised by a particular emission. These categories cover an integrated WM system, starting with the point when products turn to waste which is then thrown into the bin for waste at its generation source, and ending with the point where the waste transforms either into useful material (recycled material, biogas or compost) or contributes to emissions into environment after the final disposal at a landfill or an incineration plant Rakstā veikts pašvaldības bioloģiski no

  9. Electromagnet weight reduction in a magnetic levitation system for contactless delivery applications.

    Science.gov (United States)

    Hong, Do-Kwan; Woo, Byung-Chul; Koo, Dae-Hyun; Lee, Ki-Chang

    2010-01-01

    This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper's procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results.

  10. The effect of spatial heterogeneity on nitrate reduction in soil systems

    DEFF Research Database (Denmark)

    Pedersen, Lasse Lu

    Nitrogen is not only an abundant element on earth, making up roughly 80%of the earth's atmosphere, it is also essential for life, and a functional nitrogen cycle is of great importance to human activities and our ecosystems. The nitrogen cycle ultimately returns reactive nitrogen, which was chemi......Nitrogen is not only an abundant element on earth, making up roughly 80%of the earth's atmosphere, it is also essential for life, and a functional nitrogen cycle is of great importance to human activities and our ecosystems. The nitrogen cycle ultimately returns reactive nitrogen, which...... of reactive nitrogen from the system. On top of that nitrous oxide is an important air pollutant and greenhouse gas, with a global warming potential per unit mass 300 times higher than carbon dioxide. DNRA, on the other hand, converts nitrate to ammonium, which is more easily retained in soils than nitrate...... a fascinating scientific activity, it may very well be central to gaining insights to influence fundamental soil processes such as nitrogen metabolism, promising advancement of agricultural and pollution prevention and remediation techniques.A number of conceptual and quantitative frameworks have been developed...

  11. Electromagnet Weight Reduction in a Magnetic Levitation System for Contactless Delivery Applications

    Science.gov (United States)

    Hong, Do-Kwan; Woo, Byung-Chul; Koo, Dae-Hyun; Lee, Ki-Chang

    2010-01-01

    This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper’s procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results. PMID:22163572

  12. Electromagnet Weight Reduction in a Magnetic Levitation System for Contactless Delivery Applications

    Directory of Open Access Journals (Sweden)

    Ki-Chang Lee

    2010-07-01

    Full Text Available This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG algorithm is adopted in the kriging model. This paper’s procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results.

  13. Evaluation of HDL-modulating interventions for cardiovascular risk reduction using a systems pharmacology approach.

    Science.gov (United States)

    Gadkar, Kapil; Lu, James; Sahasranaman, Srikumar; Davis, John; Mazer, Norman A; Ramanujan, Saroja

    2016-01-01

    The recent failures of cholesteryl ester transport protein inhibitor drugs to decrease CVD risk, despite raising HDL cholesterol (HDL-C) levels, suggest that pharmacologic increases in HDL-C may not always reflect elevations in reverse cholesterol transport (RCT), the process by which HDL is believed to exert its beneficial effects. HDL-modulating therapies can affect HDL properties beyond total HDL-C, including particle numbers, size, and composition, and may contribute differently to RCT and CVD risk. The lack of validated easily measurable pharmacodynamic markers to link drug effects to RCT, and ultimately to CVD risk, complicates target and compound selection and evaluation. In this work, we use a systems pharmacology model to contextualize the roles of different HDL targets in cholesterol metabolism and provide quantitative links between HDL-related measurements and the associated changes in RCT rate to support target and compound evaluation in drug development. By quantifying the amount of cholesterol removed from the periphery over the short-term, our simulations show the potential for infused HDL to treat acute CVD. For the primary prevention of CVD, our analysis suggests that the induction of ApoA-I synthesis may be a more viable approach, due to the long-term increase in RCT rate. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

  14. Water withdrawal and consumption reduction analysis for electrical energy generation system

    Science.gov (United States)

    Nouri, Narjes

    There is an increasing concern over shrinking water resources. Water use in the energy sector primarily occurs in electricity generation. Anticipating scarcer supplies, the value of water is undoubtedly on the rise and design, implementation, and utilization of water saving mechanisms in energy generation systems are becoming inevitable. Most power plants generate power by boiling water to produce steam to spin electricity-generating turbines. Large quantities of water are often used to cool the steam in these plants. As a consequence, most fossil-based power plants in addition to consuming water, impact the water resources by raising the temperature of water withdrawn for cooling. A comprehensive study is conducted in this thesis to analyze and quantify water withdrawals and consumption of various electricity generation sources such as coal, natural gas, renewable sources, etc. Electricity generation for the state of California is studied and presented as California is facing a serious drought problem affecting more than 30 million people. Integrated planning for the interleaved energy and water sectors is essential for both water and energy savings. A linear model is developed to minimize the water consumption while considering several limitations and restrictions. California has planned to shut down some of its hydro and nuclear plants due to environmental concerns. Studies have been performed for various electricity generation and water saving scenarios including no-hydro and no-nuclear plant and the results are presented. Modifications to proposed different scenarios have been applied and discussed to meet the practical and reliability constraints.

  15. Bioproducts for Sludge Reduction in Activated Sludge Systems Treating Oil Refinery Wastewater

    Directory of Open Access Journals (Sweden)

    Alexandre V.M.F.

    2016-03-01

    Full Text Available The use of bioproducts that change the cellular metabolism and reduce microbial growth without affecting the organic matter removal is very promising for reducing the amount of sludge in wastewater treatment systems. In this study, two bioproducts were evaluated and compared with a well-known chemical (2,4-DiNitroPhenol – DNP in activated sludge treating petroleum refinery wastewater. In batch experiments, 10 mg/L of DNP, 0.8 mg/L of a bioproduct based on Folic Acid (FA and 10 mg/L of a bioproduct based on Stress Proteins (SP led to 30.6%, 43.2% and 29.8% lower disposal of total solids, respectively. Operating on a continuous regimen, the addition of 10 mg/L of the bioproduct based on SP led to 45.7% lower disposal for 50 days. In all cases, no loss of efficiency in the Chemical Oxygen Demand (COD removal was observed.

  16. Temperature Control and Noise Reduction in our Compact ADR System for TES Microcalorimeter Operation

    Science.gov (United States)

    Hishi, U.; Fujimoto, R.; Kamiya, K.; Kotake, M.; Ito, H.; Kaido, T.; Tanaka, K.; Hattori, K.

    2016-08-01

    We have been developing a compact adiabatic demagnetization refrigerator, keeping ground application and future missions in mind. A salt pill fabricated in-house, a superconducting magnet with a passive magnetic shield around it, and a mechanical heat switch are mounted in a dedicated helium cryostat. The detector stage temperature is regulated by PID control of the magnet current, with a dI/dt term added to compensate the temperature rise due to parasitic heat. The temperature fluctuation of the detector stage is 1-2 \\upmu Krms, and the hold time was extended by about 15 % thanks to the dI/dt term. Bundle shields of the harnesses between the cryostat and the analog electronics boxes were connected to the chassis at both ends, and the analog electronics boxes were grounded to the cryostat through the bundle shields. This reduced the readout noise to 16 pA/√{Hz} in the 10-60 kHz range. Using this system, an energy resolution of 3.8 ± 0.2 eV (FWHM) was achieved at 5.9 keV.

  17. Effectiveness of selective catalytic reduction systems on reducing gaseous emissions from an engine using diesel and biodiesel blends.

    Science.gov (United States)

    Borillo, Guilherme C; Tadano, Yara S; Godoi, Ana F L; Santana, Simone S M; Weronka, Fernando M; Penteado Neto, Renato A; Rempel, Dennis; Yamamoto, Carlos I; Potgieter-Vermaak, Sanja; Potgieter, Johannes H; Godoi, Ricardo H M

    2015-03-03

    The aim of this investigation was to quantify organic and inorganic gas emissions from a four-cylinder diesel engine equipped with a urea selective catalytic reduction (SCR) system. Using a bench dynamometer, the emissions from the following mixtures were evaluated using a Fourier transform infrared (FTIR) spectrometer: low-sulfur diesel (LSD), ultralow-sulfur diesel (ULSD), and a blend of 20% soybean biodiesel and 80% ULSD (B20). For all studied fuels, the use of the SCR system yielded statistically significant (p < 0.05) lower NOx emissions. In the case of the LSD and ULSD fuels, the SCR system also significantly reduced emissions of compounds with high photochemical ozone creation potential, such as formaldehyde. However, for all tested fuels, the SCR system produced significantly (p < 0.05) higher emissions of N2O. In the case of LSD, the NH3 emissions were elevated, and in the case of ULSD and B20 fuels, the non-methane hydrocarbon (NMHC) and total hydrocarbon of diesel (HCD) emissions were significantly higher.

  18. Electric heating systems - Measures and options for the reduction of electricity consumption; Elektroheizungen Massnahmen und Vorgehensoptionen zur Reduktion des Stromverbrauchs

    Energy Technology Data Exchange (ETDEWEB)

    Nipkow, J.; Togni, G.

    2009-10-15

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at how electricity consumption for electrical heating systems can be reduced. The authors state that electric space heating consumes roughly 6% to 12% of Swiss electricity consumption, depending on the source of data. Important reduction potentials obtainable through the implementation of efficiency measures and substitution are well known. The results of two surveys on hardware installations and heating users' and utility companies' preferences are presented and discussed. The user survey yielded more than 900 evaluable answers. The main focus was on conditions considered necessary for changing a heating system. The utilities' survey was carried out by means of letters posted to 62 utilities, half of whom sent back evaluable answers. The main focus was on the number of dwellings supplied with electric space heating, current and past tariffs and utility activities to motivate customers to change their heating systems. The results showed that high investments necessary for a new heating system and additional thermal insulation of the building are the main obstacles for making changes. On the basis of the project's findings, a catalogue of measures was developed, whereby financial aspects and general conditions were taken into account.

  19. The Glasgow Parallel Reduction Machine: Programming Shared-memory Many-core Systems using Parallel Task Composition

    Directory of Open Access Journals (Sweden)

    Ashkan Tousimojarad

    2013-12-01

    Full Text Available We present the Glasgow Parallel Reduction Machine (GPRM, a novel, flexible framework for parallel task-composition based many-core programming. We allow the programmer to structure programs into task code, written as C++ classes, and communication code, written in a restricted subset of C++ with functional semantics and parallel evaluation. In this paper we discuss the GPRM, the virtual machine framework that enables the parallel task composition approach. We focus the discussion on GPIR, the functional language used as the intermediate representation of the bytecode running on the GPRM. Using examples in this language we show the flexibility and power of our task composition framework. We demonstrate the potential using an implementation of a merge sort algorithm on a 64-core Tilera processor, as well as on a conventional Intel quad-core processor and an AMD 48-core processor system. We also compare our framework with OpenMP tasks in a parallel pointer chasing algorithm running on the Tilera processor. Our results show that the GPRM programs outperform the corresponding OpenMP codes on all test platforms, and can greatly facilitate writing of parallel programs, in particular non-data parallel algorithms such as reductions.

  20. Non-linear model reduction and control of molten carbonate fuel cell systems with internal reforming

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Min

    2007-10-12

    Currently, the process design of fuel cells and the development of control strategies is mainly based on heuristic methods. Fuel cell models are often too complex for control purposes, or they are developed for a specific type of fuel cell and valid only in a small range of operation conditions. The application of fuel cell models to controller design is still limited. Furthermore, suitable and simple-to-implement design strategies for fuel cell control remain an open area. There is thus a motivation for simplifying dynamic models for process control applications and for designing suitable control strategies for fuel cells. This is the main objective of this work. As an application example, the 250 kW industrial molten carbonate fuel cell (MCFC) system HotModule by MTU CFC Solutions, Germany is considered. A detailed dynamic two-dimensional spatially distributed cross-flow model of a MCFC from literature is taken as a starting point for the investigation. In Chapter 2, two simplified model versions are derived by incorporating additional physical assumptions. One of the simplified models is extended to a three-dimensional stack model to deal with physical and chemical phenomena in the stack. Simulations of the stack model are performed in Chapter 3 in order to calculate the mass and temperature distributions in the direction perpendicular to the electrode area. The other simplified model forms the basis for a low order reduced model that is derived in Chapter 4. The reduced-order model is constructed by application of the Karhunen-Loeve Galerkin method. The spatial temperature, concentration and potential profiles are approximated by a set of orthogonal time independent spatial basis functions. Problem specific basis functions are generated numerically from simulation data of the detailed reference model. The advantage of this approach is that a small number of basis functions suffices in order to approximate the solution of the detailed model very well. The

  1. Volume reduction outweighs biogeochemical processes in controlling phosphorus treatment in aged detention systems

    Science.gov (United States)

    Shukla, Asmita; Shukla, Sanjay; Annable, Michael D.; Hodges, Alan W.

    2017-08-01

    Stormwater detention areas (SDAs) play an important role in treating end-of-the-farm runoff in phosphorous (P) limited agroecosystems. Phosphorus transport from the SDAs, including those through subsurface pathways, are not well understood. The prevailing understanding of these systems assumes that biogeochemical processes play the primary treatment role and that subsurface losses can be neglected. Water and P fluxes from a SDA located in a row-crop farm were measured for two years (2009-2011) to assess the SDA's role in reducing downstream P loads. The SDA treated 55% (497 kg) and 95% (205 kg) of the incoming load during Year 1 (Y1, 09-10) and Year 2 (Y2, 10-11), respectively. These treatment efficiencies were similar to surface water volumetric retention (49% in Y1 and 84% in Y2) and varied primarily with rainfall. Similar water volume and P retentions indicate that volume retention is the main process controlling P loads. A limited role of biogeochemical processes was supported by low to no remaining soil P adsorption capacity due to long-term drainage P input. The fact that outflow P concentrations (Y1 = 368.3 μg L- 1, Y2 = 230.4 μg L- 1) could be approximated by using a simple mixing of rainfall and drainage P input further confirmed the near inert biogeochemical processes. Subsurface P losses through groundwater were 304 kg (27% of inflow P) indicating that they are an important source for downstream P. Including subsurface P losses reduces the treatment efficiency to 35% (from 61%). The aboveground biomass in the SDA contained 42% (240 kg) of the average incoming P load suggesting that biomass harvesting could be a cost-effective alternative for reviving the role of biogeochemical processes to enhance P treatment in aged, P-saturated SDAs. The 20-year present economic value of P removal through harvesting was estimated to be 341,000, which if covered through a cost share or a payment for P treatment services program could be a positive outcome for both

  2. Photovoltaic Impact Assessment of Smart Inverter Volt-VAR Control on Distribution System Conservation Voltage Reduction and Power Quality

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Fei [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nagarajan, Adarsh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Baggu, Murali [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nguyen, Andu [SolarCity, San Mateo, CA (United States); Walinga, Sarah [SolarCity, San Mateo, CA (United States); McCarty, Michael [SolarCity, San Mateo, CA (United States); Bell, Frances [SolarCity, San Mateo, CA (United States)

    2016-12-01

    This report presents an impact assessment study of distributed photovoltaic (PV) with smart inverter Volt-VAR control on conservation voltage reduction (CVR) energy savings and distribution system power quality. CVR is a methodology of flattening and lowering a distribution system voltage profile in order to conserve energy. Traditional CVR relies on operating utility voltage regulators and switched capacitors. However, with the increased penetration of distributed PV systems, smart inverters provide the new opportunity to control local voltage and power factor by regulating the reactive power output, leading to a potential increase in CVR energy savings. This report proposes a methodology to implement CVR scheme by operating voltage regulators, capacitors, and autonomous smart inverter Volt-VAR control in order to achieve increased CVR benefit. Power quality is an important consideration when operating a distribution system, especially when implementing CVR. It is easy to measure the individual components that make up power quality, but a comprehensive method to incorporate all of these values into a single score has yet to be undertaken. As a result, this report proposes a power quality scoring mechanism to measure the relative power quality of distribution systems using a single number, which is aptly named the 'power quality score' (PQS). Both the CVR and PQS methodologies were applied to two distribution system models, one obtained from the Hawaiian Electric Company (HECO) and another obtained from Pacific Gas and Electric (PG&E). These two models were converted to the OpenDSS platform using previous model conversion tools that were developed by NREL. Multiple scenarios including various PV penetration levels and smart inverter densities were simulated to analyze the impact of smart inverter Volt-VAR support on CVR energy savings and feeder power quality. In order to analyze the CVR benefit and PQS, an annual simulation was conducted for each

  3. Network analysis of biochemical logic for noise reduction and stability: a system of three coupled enzymatic and gates.

    Science.gov (United States)

    Privman, Vladimir; Arugula, Mary A; Halámek, Jan; Pita, Marcos; Katz, Evgeny

    2009-04-16

    We develop an approach aimed at optimizing the parameters of a network of biochemical logic gates for reduction of the "analog" noise buildup. Experiments for three coupled enzymatic AND gates are reported, illustrating our procedure. Specifically, starch, one of the controlled network inputs, is converted to maltose by beta-amylase. With the use of phosphate (another controlled input), maltose phosphorylase then produces glucose. Finally, nicotinamide adenine dinucleotide (NAD(+)), the third controlled input, is reduced under the action of glucose dehydrogenase to yield the optically detected signal. Network functioning is analyzed by varying selective inputs and fitting standardized few-parameters "response-surface" functions assumed for each gate. This allows a certain probe of the individual gate quality, but primarily yields information on the relative contribution of the gates to noise amplification. The derived information is then used to modify our experimental system to put it in a regime of a less noisy operation.

  4. Large thermal conductivity reduction induced by La/O vacancies in the thermoelectric LaCoO3 system.

    Science.gov (United States)

    Wang, Yang; Li, Fang; Xu, Luxiang; Sui, Yu; Wang, Xianjie; Su, Wenhui; Liu, Xiaoyang

    2011-05-16

    A series of compact La/O-vacant La(1-x)CoO(3-y) compounds were prepared by a cold high-pressure procedure, and their thermoelectric (TE) properties were investigated. Compared with the ion-substituted hole-type LaCoO(3) systems (e.g., La(1-x)Sr(x)CoO(3)), the thermal conduction of La(1-x)CoO(3-y) is noticeably reduced by the La/O vacancies, whereas the electric transport is less influenced, which results in an efficient ZT enhancement. We demonstrate that the large thermal conductivity reduction originates from the strong point-defect scattering, and La(1-x)CoO(3-y) can be rationalized as a partially filled solid solution: La(1-x)◻(x)CoO(3-y)◻(y), where ◻ denotes a vacancy. Such intrinsic thermal conductivity suppression provides an effective pathway for the design of better TE materials.

  5. System and method for controlling ammonia levels in a selective catalytic reduction catalyst using a nitrogen oxide sensor

    Science.gov (United States)

    None

    2017-07-25

    A system according to the principles of the present disclosure includes an air/fuel ratio determination module and an emission level determination module. The air/fuel ratio determination module determines an air/fuel ratio based on input from an air/fuel ratio sensor positioned downstream from a three-way catalyst that is positioned upstream from a selective catalytic reduction (SCR) catalyst. The emission level determination module selects one of a predetermined value and an input based on the air/fuel ratio. The input is received from a nitrogen oxide sensor positioned downstream from the three-way catalyst. The emission level determination module determines an ammonia level based on the one of the predetermined value and the input received from the nitrogen oxide sensor.

  6. Treatment of buffy coat platelets in platelet additive solution with the mirasol(®) pathogen reduction technology system.

    Science.gov (United States)

    Castrillo, Azucena; Cardoso, Marcia; Rouse, Lindsay

    2013-02-01

    The Mirasol pathogen reduction technology (PRT) system uses riboflavin and ultraviolet light and is currently approved and used in Europe for the treatment of platelets and plasma. Mirasol treatment is intended to reduce the infectious pathogen load and to inactivate leukocytes in blood products. Our objective was to evaluate buffy coat platelet concentrates (BCPCs) prepared with platelet additive solution (PAS) and treated with the Mirasol system and to examine the effects on platelet cell quality during storage. 26 BCPCs were prepared and split, creating 13 paired control and test units. The test units were treated with the Mirasol system and the platelet quality was assessed in all units over 7 days of storage. All products met the incoming specifications for Mirasol treatment, and the pH of all Mirasol-treated BCPCs in PAS met the requirements of the Council of Europe guidelines throughout storage. Analysis of lactate production and glucose consumption rates, CD62p expression and cytokines indicates enhanced cellular metabolism in treated platelets, but the levels were within previously published ranges. While Mirasol-treated BCPCs in PAS had increased metabolism and activation compared to controls, the results indicate that these units can be stored for 7 days with acceptable cell quality.

  7. Biofouling potential reductions using a membrane hybrid system as a pre-treatment to seawater reverse osmosis.

    Science.gov (United States)

    Jeong, Sanghyun; Kim, Lan Hee; Kim, Sung-Jo; Nguyen, Tien Vinh; Vigneswaran, Saravanamuthu; Kim, In S

    2012-07-01

    Biofouling on reverse osmosis (RO) membranes is the most serious problem which affects desalination process efficiency and increases operation cost. The biofouling cannot be effectively removed by the conventional pre-treatment traditionally used in desalination plants. Hybrid membrane systems coupling the adsorption and/or coagulation with low-pressure membranes can be a sustainable pre-treatment in reducing membrane fouling and at the same time improving the feed water quality to the seawater reverse osmosis. The addition of powder activated carbon (PAC) of 1.5 g/L into submerged membrane system could help to remove significant amount of both hydrophobic compounds (81.4%) and hydrophilic compounds (73.3%). When this submerged membrane adsorption hybrid system (SMAHS) was combined with FeCl(3) coagulation of 0.5 mg of Fe(3+)/L, dissolved organic carbon removal efficiency was excellent even with lower dose of PAC (0.5 g/L). Detailed microbial studies conducted with the SMAHS and the submerged membrane coagulation-adsorption hybrid system (SMCAHS) showed that these hybrid systems can significantly remove the total bacteria which contain also live cells. As a result, microbial adenosine triphosphate (ATP) as well as total ATP concentrations in treated seawater and foulants was considerably decreased. The bacteria number in feed water prior to RO reduced from 5.10E(+06) cells/mL to 3.10E(+03) cells/mL and 9.30E(+03) cells/mL after SMAHS and SMCAHS were applied as pre-treatment, respectively. These led to a significant reduction of assimilable organic carbon (AOC) by 10.1 μg/L acetate-C when SMCAHS was used as a pre-treatment after 45-h RO operation. In this study, AOC method was modified to measure the growth of bacteria in seawater by using the Pseudomonas P.60 strain.

  8. Reduction of soil erosion and mercury losses in agroforestry systems compared to forests and cultivated fields in the Brazilian Amazon.

    Science.gov (United States)

    Béliveau, Annie; Lucotte, Marc; Davidson, Robert; Paquet, Serge; Mertens, Frédéric; Passos, Carlos J; Romana, Christine A

    2017-12-01

    In addition to causing physical degradation and nutrient depletion, erosion of cultivated soils in the Amazon affects aquatic ecosystems through the release of natural soil mercury (Hg) towards lakes and rivers. While traditional agriculture is generally cited as being among the main causes of soil erosion, agroforestry practices are increasingly appreciated for soil conservation. This study was carried out in family farms of the rural Tapajós region (Brazil) and aimed at evaluating soil erosion and associated Hg release for three land uses. Soils, runoff water and eroded sediments were collected at three sites representing a land cover gradient: a recently burnt short-cycle cropping system (SCC), a 2-year-old agroforestry system (AFS) and a mature forest (F). At each site, two PVC soil erosion plots (each composed of three 2 × 5 m isolated subplots) were implemented on steep and moderate slopes respectively. Sampling was done after each of the 20 rain events that occurred during a 1-month study period, in the peak of the 2011 rain season. Runoff volume and rate, as well as eroded soil particles with their Hg and cation concentrations were determined. Total Hg and cation losses were then calculated for each subplot. Erosion processes were dominated by land use type over rainfall or soil slope. Eroded soil particles, as well as the amount of Hg and cations (CaMgK) mobilized at the AFS site were similar to those at the F site, but significantly lower than those at the SCC site (p Erosion reduction at the AFS site was mainly attributed to the ground cover plants characterizing the recently established system. Moreover, edaphic change throughout AFS and F soil profiles differed from the SCC site. At the latter site, losses of fine particles and Hg were enhanced towards soil surface, while they were less pronounced at the other sites. This study shows that agroforestry systems, even in their early stages of implementation, are characterized by low erosion levels

  9. Residential, Commercial, and Utility-Scale Photovoltaic (PV) System Prices in the United States: Current Drivers and Cost-Reduction Opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Goodrich, A.; James, T.; Woodhouse, M.

    2012-02-01

    The price of photovoltaic (PV) systems in the United States (i.e., the cost to the system owner) has dropped precipitously in recent years, led by substantial reductions in global PV module prices. However, system cost reductions are not necessarily realized or realized in a timely manner by many customers. Many reasons exist for the apparent disconnects between installation costs, component prices, and system prices; most notable is the impact of fair market value considerations on system prices. To guide policy and research and development strategy decisions, it is necessary to develop a granular perspective on the factors that underlie PV system prices and to eliminate subjective pricing parameters. This report's analysis of the overnight capital costs (cash purchase) paid for PV systems attempts to establish an objective methodology that most closely approximates the book value of PV system assets.

  10. Cost reduction performance enhancements of multiple site cooling water systems, enabled by remote system monitoring/control and multifaceted data management

    Energy Technology Data Exchange (ETDEWEB)

    Cook, B. [BetzDearborn Water Management Group, Horsham, PA (United States); Young, D. [BetzDearborn Water Management Group, Mississauga, Ontario (Canada); Tari, K. [Praxair, Inc., Tonawanda, New York, NY (United States)

    1998-12-31

    An outsourced cooling water treatment automated control and data acquisition package, has been designed, installed, and commissioned in over 70 sites in North America and offshore. The standard package consists of a controller, sensors, human-machine interface software, data acquisition and management software, communications, and reporting. Significant challenges to applying this standard package in multiple sites arose from variations in cooling system design and makeup water quality as well as operations, environmental considerations, metrics, and language. A standard approach has met these challenges and overcome effects of downsizing through significant reduction in non-value-added, manual activities. Overall system reliability has been improved by migration to best practice throughout the organizations involved and immediate proactive response to out-of-specification conditions. This paper documents the evolution of a standard cooling water automation and data management package from its inception to current practice.

  11. SU-E-T-516: Investigation of a Novel Radiochromic Radiation Reporting System Utilizing the Reduction of Ferric Ion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H; Alqathami, M; Wang, J; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States); Blencowe, A [The University of South Australia, South Australia, SA (Australia)

    2015-06-15

    Purpose To introduce and characterize a new “reverse-Fricke” radiation reporting system utilizing the reduction of ferric ions (Fe{sup 3+}) to ferrous ions (Fe{sup 2+}). Methods Two formulations of the radiochromic reporting system, referred to as A and B, were prepared for investigation. Formulation-A consisted of 14 mM 1,10-phenanthroline, 42 mM ethanol, and 57 mM ammonium ferric oxalate in water. Formulation-B consisted of 27 mM 1,10-phenanthroline, 42 mM ethanol, and 28 mM ammonium ferric oxalate in water. Solutions were prepared immediately prior to irradiation with a Cobalt-60 unit with radiation doses of 0, 1, 5, 10, 15, 20, and 25 Gy. The change in optical density over the visible range of 450–650 nm was measured using a spectrophotometer immediately after irradiation. The effective atomic numbers of the formulations were calculated using Mayneord’s formula. Results Ionizing radiation energy absorbed in the solutions causes the reduction of ferric ions (Fe{sup 3+}) into ferrous ions (Fe{sup 2+}), which then forms a 1:3 red colored complex with 1,10-phenanthroline ([(C{sub 1} {sub 2}H{sub 8}N{sup 2}){sub 3}Fe]{sup 2+}) that can be measured spectrophotometrically. The absorbance spectra of the resulting complex displayed a peak maximum at 512 nm with a greater change in absorbance for Formulation-B after receiving comparable radiation doses. The change in absorbance relative to dose exhibited a linear response up to 25 Gy for both Formulation-A (R{sup 2} = 0.98) and Formulation-B (R{sup 2} = 0.97). The novel formulations were also nearly water equivalent (Zeff = 7.42) with effective atomic numbers of 7.65 and 7.52 and mass densities within 0.2% of water. Conclusion Both formulations displayed visible Fe{sup 2+} complex formation with 1,10-phenanthroline after irradiation using a Cobalt-60 source. The higher sensitivity measured for Formulation-B is attributed to the increase in 1,10-phenanthroline concentration and the increase in the 1

  12. Model predictive control of a lean-burn gasoline engine coupled with a passive selective catalytic reduction system

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Pingen [Tennessee Technological University (TTU); Lin, Qinghua [Tennessee Technological University (TTU); Prikhodko, Vitaly Y. [ORNL

    2017-10-01

    Lean-burn gasoline engines have demonstrated 10–20% engine efficiency gain over stoichiometric engines and are widely considered as a promising technology for meeting the 54.5 miles-per-gallon (mpg) Corporate Average Fuel Economy standard by 2025. Nevertheless, NOx emissions control for lean-burn gasoline for meeting the stringent EPA Tier 3 emission standards has been one of the main challenges towards the commercialization of highly-efficient lean-burn gasoline engines in the United States. Passive selective catalytic reduction (SCR) systems, which consist of a three-way catalyst and SCR, have demonstrated great potentials of effectively reducing NOx emissions for lean gasoline engines but may cause significant fuel penalty due to ammonia generation via rich engine combustion. The purpose of this study is to develop a model-predictive control (MPC) scheme for a lean-burn gasoline engine coupled with a passive SCR system to minimize the fuel penalty associated with passive SCR operation while satisfying stringent NOx and NH3 emissions requirements. Simulation results demonstrate that the MPC-based control can reduce the fuel penalty by 47.7% in a simulated US06 cycle and 32.0% in a simulated UDDS cycle, compared to the baseline control, while achieving over 96% deNOx efficiency and less than 15 ppm tailpipe ammonia slip. The proposed MPC control can potentially enable high engine efficiency gain for highly-efficient lean-burn gasoline engine while meeting the stringent EPA Tier 3 emission standards.

  13. Biogas slurry – An alternative growth media for algae cultivation in algiculture systems with simultaneous reduction algal predation

    Directory of Open Access Journals (Sweden)

    Abitha R

    2015-04-01

    Full Text Available Biogas slurry provides a complete and high growth rate producing algal cultivation medium thus offsetting the high cultivation costs of raising algal cultures in synthetic growth media. Robust mixed algal consortia can also be cultivated in non-traditional media such as wastewater or biogas slurry along with flooded agricultural crops such as paddy (Algiculture. This greatly enhances the Nsustainability of the algae cultivation. However, since the biogas slurry contains its own set of predators of algal biomass (grazers, it is now important to study the productivities attainable by using slurry in the conventional open ponds and Algiculture setup and understand its impact on grazer population dynamics. In this study we have used diluted biogas slurry (1:10 as growth media and compared algal growth and grazing /predation characteristics for algae cultivated under four treatments namely, Bold’s basal media (M, biogas slurry (S, Algiculture (ALGI, Algiculture with biogas slurry as growth stimulant (ALGI-S. The algal biomass cultivated in slurry based systems gave rise to a productivity of 6.8 g/m2/d as harvestable biomass with simultaneous reduction in the algal mass sacrificed to grazers. We thus attempt to show that biogas slurry may be used as a potential growth media especially in Algiculture system which tends to be vulnerable to grazer attack and loss of algal population.

  14. Determining the storage, availability and reactivity of NH3 within Cu-Chabazite-based Ammonia Selective Catalytic Reduction systems.

    Science.gov (United States)

    Lezcano-Gonzalez, I; Deka, U; Arstad, B; Van Yperen-De Deyne, A; Hemelsoet, K; Waroquier, M; Van Speybroeck, V; Weckhuysen, B M; Beale, A M

    2014-01-28

    Three different types of NH3 species can be simultaneously present on Cu(2+)-exchanged CHA-type zeolites, commonly used in Ammonia Selective Catalytic Reduction (NH3-SCR) systems. These include ammonium ions (NH4(+)), formed on the Brønsted acid sites, [Cu(NH3)4](2+) complexes, resulting from NH3 coordination with the Cu(2+) Lewis sites, and NH3 adsorbed on extra-framework Al (EFAl) species, in contrast to the only two reacting NH3 species recently reported on Cu-SSZ-13 zeolite. The NH4(+) ions react very slowly in comparison to NH3 coordinated to Cu(2+) ions and are likely to contribute little to the standard NH3-SCR process, with the Brønsted groups acting primarily as NH3 storage sites. The availability/reactivity of NH4(+) ions can be however, notably improved by submitting the zeolite to repeated exchanges with Cu(2+), accompanied by a remarkable enhancement in the low temperature activity. Moreover, the presence of EFAl species could also have a positive influence on the reaction rate of the available NH4(+) ions. These results have important implications for NH3 storage and availability in Cu-Chabazite-based NH3-SCR systems.

  15. The Efficiency of Variance Reduction in Manufacturing and Service Systems: The Comparison of the Control Variates and Stratified Sampling

    Directory of Open Access Journals (Sweden)

    Ergün Eraslan

    2009-01-01

    Full Text Available There has been a great interest in the use of variance reduction techniques (VRTs in simulation output analysis for the purpose of improving accuracy when the performance measurements of complex production and service systems are estimated. Therefore, a simulation output analysis to improve the accuracy and reliability of the output is required. The performance measurements are required to have a narrow and strong confidence interval. For a given confidence level, a smaller confidence interval is supposed to be better than the larger one. The wide of confidence interval, determined by the half length, will depend on the variance. Generally, increased replication of the simulation model appears to have been the easiest way to reduce variance but this increases the simulation costs in complex-structured and large-sized manufacturing and service systems. Thus, VRTs are used in experiments to avoid computational cost of decision-making processes for more precise results. In this study, the effect of Control Variates (CVs and Stratified Sampling (SS techniques in reducing variance of the performance measurements of M/M/1 and GI/G/1 queue models is investigated considering four probability distributions utilizing randomly generated parameters for arrival and service processes.

  16. Interference-Aware PAPR Reduction Scheme to Increase the Energy Efficiency of Large-Scale MIMO-OFDM Systems

    Directory of Open Access Journals (Sweden)

    Byung Moo Lee

    2017-08-01

    Full Text Available Large-scale (LS multi-user (MU multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM is considered to be a desirable signal transmission scheme because it can significantly improve the energy efficiency (EE and spectral efficiency (SE of the system. However, there are many difficulties in realizing an LS-MU-MIMO-OFDM system, and one of these is its high peak-to-average power ratio (PAPR, which results in serious nonlinear signal distortion and power inefficiency of the power amplifier (PA. LS-MIMO-OFDM systems require a lot of PAs, which are necessary to be connected to each antenna. To compensate for the PA nonlinearity and increase the efficiency, a digital pre-distorter (DPD is very popular and has been successfully implemented in current base stations (BSs. However, a DPD is very difficult to use in an LS-MU-MIMO-OFDM system because it is expensive, but should be applied to each antenna. Therefore, a considerate scheme of signal processing is necessary to cope with the PA nonliearity issue of the LS-MU-MIMO-OFDM system. In this paper, we propose an interference-aware iterative clipping and filtering peak-to-average power ratio (PAPR reduction scheme for LS-MU-MIMO-OFDM systems. In the proposed scheme, the clipping level in the clipping process is adaptively adjusted based on any kind of interference level that exists in the general communication environment. In particular, when matched filtering (MF precoding is used for the LS-MU-MIMO-OFDM, the inter-user interference (IUI always exists with a practical number of transmitter (TX antennas, and this inevitable IUI level can be a decision point for the clipping ratio (CR. Choosing a proper CR to make the clipping noise lower than IUI has a very high benefit for the EE improvement of the system. The results of numerical analysis show that the proposed scheme can induce a very effective peak-to-average power ratio (PAPR performance with little SE loss.

  17. Reduction or annihilation of aberrations of an optical system by balancing ghost-imaging technique and optimal imaging of a pure weak phase object

    NARCIS (Netherlands)

    Wang, Fei; Cai, Yangjian; Hoenders, Bernhard J.

    2014-01-01

    It is shown, using ghost-imaging techniques, that it is possible to reduce or even to annihilate the influence of aberrations connected with an arbitrary optical system. To this end, we consider a ghost-imaging setup, which consists of two arms, each containing an optical system. The reduction

  18. Development of the online data reduction system and feasibility studies of 6-layer tracking for the Belle II pixel detector

    Energy Technology Data Exchange (ETDEWEB)

    Muenchow, David

    2015-04-24

    reduction factor. Feasibility Studies of 6-Layer Tracking at Belle II In this part I investigated the limitations of the currently planned system with ROI selection and cluster rescue. Furthermore I investigated if it would be possible to increase the quality of data selection by adding a 6-layer tracking, a concept which would use all unreduced data from PXD and SVD to perform a tracking. The recent system does not include the PXD data in their tracking. In my studies I focused on two cases which could cause problems at the reconstruction of events: secondary vertex and low momentum charged particles. As an example for secondary vertex events I chose events including a K{sup 0}{sub S}. I investigated that a 6-layer tracking can increase the number of reconstructable pions from K{sup 0}{sub S} about 0.75% compared to the recently system. For transversal momenta of about p{sub t}∼200 MeV this increase can reach even ∼ 2%. For an example of low momentum particles I chose a decay channel of Z{sub c}(3900){sup -} via D{sup *-} which decays in anti D{sup 0} and π{sup -}. This pion has a very small momentum and may not reach enough SVD layer for a tracking without PXD. Here my result is, that the pions with such a low transversal momentum will be below the minimum ionizing momentum region. Therefore the cluster rescue covers those pions already. The increase of a 6-layer tracking will be only 0.12%.

  19. Attribute Reduction and Information Granularity

    Directory of Open Access Journals (Sweden)

    Li-hong Wang

    2003-02-01

    Full Text Available In the view of granularity, this paper analyzes the influence of three attribute reducts on an information system, finding that the possible reduct and m - decision reduct will make the granule view coarser, while discernible reduct will not change the granule view. In addition, we investigate the combination of reducts from two partial information systems in parallel or in incremental data mining and urge that the union of partial possible reducts can be regarded as a possible reduct for union of partial information systems.

  20. Development of Optimal Catalyst Designs and Operating Strategies for Lean NOx Reduction in Coupled LNT-SCR Systems

    Energy Technology Data Exchange (ETDEWEB)

    Harold, Michael [Univ. of Houston, TX (United States); Crocker, Mark [Univ. of Kentucky, Lexington, KY (United States); Balakotaiah, Vemuri [Univ. of Houston, TX (United States); Luss, Dan [Univ. of Houston, TX (United States); Choi, Jae-Soon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dearth, Mark [Ford Motor Company, Dearborn, MI (United States); McCabe, Bob [Ford Motor Company, Dearborn, MI (United States); Theis, Joe [Ford Motor Company, Dearborn, MI (United States)

    2013-09-30

    Oxides of nitrogen in the form of nitric oxide (NO) and nitrogen dioxide (NO2) commonly referred to as NOx, is one of the two chemical precursors that lead to ground-level ozone, a ubiquitous air pollutant in urban areas. A major source of NOx} is generated by equipment and vehicles powered by diesel engines, which have a combustion exhaust that contains NOx in the presence of excess O2. Catalytic abatement measures that are effective for gasoline-fueled engines such as the precious metal containing three-way catalytic converter (TWC) cannot be used to treat O2-laden exhaust containing NOx. Two catalytic technologies that have emerged as effective for NOx abatement are NOx storage and reduction (NSR) and selective catalytic reduction (SCR). NSR is similar to TWC but requires much larger quantities of expensive precious metals and sophisticated periodic switching operation, while SCR requires an on-board source of ammonia which serves as the chemical reductant of the NOx. The fact that NSR produces ammonia as a byproduct while SCR requires ammonia to work has led to interest in combining the two together to avoid the need for the cumbersome ammonia generation system. In this project a comprehensive study was carried out of the fundamental aspects and application feasibility of combined NSR/SCR. The project team, which included university, industry, and national lab researchers, investigated the kinetics and mechanistic features of the underlying chemistry in the lean NOx trap (LNT) wherein NSR was carried out, with particular focus on identifying the operating conditions such as temperature and catalytic properties which lead to the production of ammonia in the LNT. The performance features of SCR on both model and commercial catalysts focused on the synergy between the LNT and SCR converters in terms of utilizing the upstream-generated ammonia and

  1. Investigation of a Cu/Pd Bimetallic System Electrodeposited on Boron-Doped Diamond Films for Application in Electrocatalytic Reduction of Nitrate

    Directory of Open Access Journals (Sweden)

    Jorge T. Matsushima

    2012-01-01

    Full Text Available The Cu/Pd bimetallic system electrodeposited on boron-doped diamond (BDD films for application, as electrode material in the electrochemical reduction of nitrate was studied. The electrochemical behavior of Cu, Pd, and Cu/Pd bimetallic system was evaluated by cyclic voltammetry. From these results, the formation of the Cu/Pd composite was verified. In addition, Cu with different phases and a Cu/Pd phase in the composite were obtained. Morphological analysis by scanning electron microscopy (SEM revealed a homogeneous distribution of Cu/Pd bimetallic particles with intermediary dimensions compared to those observed in Cu or Pd electrodeposits separately. These composites were tested as electrocatalysts for nitrate reduction in Britton-Robinson buffer solution (pH 9. Electrochemical measurements showed that composites with higher Cu content displayed the best electrocatalytic activity for nitrate reduction, and the Cu/Pd phase in the bimetallic system served to improve the Cu adherence on BDD electrode.

  2. Reduction of Carbon Dioxide in Filtering Facepiece Respirators with an Active-Venting System: A Computational Study.

    Directory of Open Access Journals (Sweden)

    Erik Birgersson

    Full Text Available During expiration, the carbon dioxide (CO2 levels inside the dead space of a filtering facepiece respirator (FFR increase significantly above the ambient concentration. To reduce the CO2 concentration inside the dead space, we attach an active lightweight venting system (AVS comprising a one-way valve, a blower and a battery in a housing to a FFR. The achieved reduction is quantified with a computational-fluid-dynamics model that considers conservation of mass, momentum and the dilute species, CO2, inside the FFR with and without the AVS. The results suggest that the AVS can reduce the CO2 levels inside the dead space at the end of expiration to around 0.4% as compared to a standard FFR, for which the CO2 levels during expiration reach the same concentration as that of the expired alveolar air at around 5%. In particular, during inspiration, the average CO2 volume fraction drops to near-to ambient levels of around 0.08% with the AVS. Overall, the time-averaged CO2 volume fractions inside the dead space for the standard FFR and the one with AVS are around 3% and 0.3% respectively. Further, the ability of the AVS to vent the dead-space air in the form of a jet into the ambient - similar to the jets arising from natural expiration without a FFR - ensures that the expired air is removed and diluted more efficiently than a standard FFR.

  3. How changing root system architecture can help tackle a reduction in soil phosphate (P) levels for better plant P acquisition

    KAUST Repository

    HEPPELL, J.

    2014-06-24

    © 2014 John Wiley & Sons Ltd. The readily available global rock phosphate (P) reserves may run out within the next 50-130 years, causing soils to have a reduced P concentration which will affect plant P uptake. Using a combination of mathematical modelling and experimental data, we investigated potential plant-based options for optimizing crop P uptake in reduced soil P environments. By varying the P concentration within a well-mixed agricultural soil, for high and low P (35.5-12.5mgL-1 respectively using Olsen\\'s P index), we investigated branching distributions within a wheat root system that maximize P uptake. Changing the root branching distribution from linear (evenly spaced branches) to strongly exponential (a greater number of branches at the top of the soil) improves P uptake by 142% for low-P soils when root mass is kept constant between simulations. This causes the roots to emerge earlier and mimics topsoil foraging. Manipulating root branching patterns, to maximize P uptake, is not enough on its own to overcome the drop in soil P from high to low P. Further mechanisms have to be considered to fully understand the impact of P reduction on plant development.

  4. On model reduction

    Science.gov (United States)

    Al-Saggaf, Ubaid M.; Franklin, Gene F.

    1986-01-01

    Three model reduction methods are described. These are the discrete balanced realizations of Mullis and Roberts (1976) where a characterization of the reduction error is given and a previously unknown L(infinity) norm bound on the reduction error, is obtained. Another method is a new model reduction technique for discrete time systems which has the advantage that the reduced order model is balanced and has an L(infinity) norm bound on the reduction error. The last method derived is a frequency weighting technique for continuous and discrete systems where it is possible to specify the approximation accuracy with frequency and also, for this method, an L(infinity) norm on the weighted reduction error is obtained.

  5. Opioid Dose Reduction in a VA Health Care System--Implementation of a Primary Care Population-Level Initiative.

    Science.gov (United States)

    Westanmo, Anders; Marshall, Peter; Jones, Elzie; Burns, Kevin; Krebs, Erin E

    2015-05-01

    To describe processes and outcomes of a health system quality improvement initiative designed to reduce opioid-related harms. The initiative was a primary care population-level intervention to reduce high-dose opioid prescribing, which was locally defined as >200 morphine-equivalent mg (MED) daily. We describe the implementation process and report prescribing rates and primary care provider (PCP) attitudes and beliefs before and after implementation. A VA health care system comprising one large, urban teaching hospital and 11 outpatient clinics in surrounding suburban and rural locations. All patients who received any prescription from the outpatient pharmacy (unique pharmacy patients) were included in the population. PCPs at the main hospital were surveyed. Prescribing outcomes were determined from merged VA databases by examining rates of opioid dispensing within 90-day time windows before and after implementation. PCP beliefs and attitudes were evaluated with preimplementation and postimplementation surveys. Following implementation, the number of patients prescribed >200 MED daily decreased from 342 (0.65% of unique pharmacy patients) to 65 (0.12%). Overall, the number of unique pharmacy patients who received at least one opioid prescription within 90 days decreased from 6,942 (13.7%) on April 1, 2011 to 5,981 (11.0%) on October 1, 2014 (13.8% decrease). Most PCPs agreed it was reasonable for the medical center to set a 200 MED limit (76% at baseline and 87% at follow up). Opioid Safety Initiative implementation was associated with a substantial reduction in high-dose opioid prescribing. Factors that contributed to initiative success included leadership support and active clinical pharmacy engagement. Wiley Periodicals, Inc.

  6. Weight reduction, energy loss and gaseous emissions for different collection systems for food waste from households; Viktreducering, energifoerlust och gasemissioner vid olika insamlingssystem av matavfall fraan hushaall

    Energy Technology Data Exchange (ETDEWEB)

    Ternald, Olle (and others)

    2010-09-15

    This project investigates the weight reduction of biodegradable household waste for different types of collections systems. The report is based on empirical experiments simulating the path taken by biodegradable waste through the different systems, from kitchen to final treatment. Data from the empirical experiments have been coordinated with existing data covering the quantities of bio waste collection received by final treatment facilities. This project has resulted in updated data, which reflects the quantities of the biodegradable waste generated at household level. Through this data, it has been possible to calculate the effectiveness of the different systems for collecting biodegradable waste, including their effectiveness as a source for biogas and soil conditioner. The results regarding waste weight reduction show that systems that use paper bags give a substantial weight reduction in both the kitchen (12%) as well as in the garbage disposal container, resulting in an average total weight reduction of 27%. For the bio-plastic bag, there is a small, measurable weight reduction of 7% in the kitchen. One-family household containers also show a reduction but for multiple households contains (typically used for apartment blocks) the reduction was much smaller. The average total weight reduction for bio-plastic systems was 10%. The corresponding value for total weight reduction for plastic bags in an optical system was 2%-4%, with an average of 2%. The largest share of the reduction consists of water, but some carbon is also emitted. Another conclusion of the report it that a larger share of the biodegradable waste generated by the Swedish households is collected than previously assumed. The data for generated (collected) biodegradable waste material shows higher levels and larger differences between the different collection systems than the data for the received (weighted) material at the treatment facilities. The data shows the effectiveness of each system and

  7. Electronic nicotine delivery systems and/or electronic non-nicotine delivery systems for tobacco smoking cessation or reduction: a systematic review and meta-analysis.

    Science.gov (United States)

    El Dib, Regina; Suzumura, Erica A; Akl, Elie A; Gomaa, Huda; Agarwal, Arnav; Chang, Yaping; Prasad, Manya; Ashoorion, Vahid; Heels-Ansdell, Diane; Maziak, Wasim; Guyatt, Gordon

    2017-02-23

    A systematic review and meta-analysis to investigate the impact of electronic nicotine delivery systems (ENDS) and/or electronic non-nicotine delivery systems (ENNDS) versus no smoking cessation aid, or alternative smoking cessation aids, in cigarette smokers on long-term tobacco use. Searches of MEDLINE, EMBASE, PsycInfo, CINAHL, CENTRAL and Web of Science up to December 2015. Randomised controlled trials (RCTs) and prospective cohort studies. Three pairs of reviewers independently screened potentially eligible articles, extracted data from included studies on populations, interventions and outcomes and assessed their risk of bias. We used the Grading of Recommendations Assessment, Development and Evaluation approach to rate overall certainty of the evidence by outcome. Three randomised trials including 1007 participants and nine cohorts including 13 115 participants proved eligible. Results provided by only two RCTs suggest a possible increase in tobacco smoking cessation with ENDS in comparison with ENNDS (RR 2.03, 95% CI 0.94 to 4.38; p=0.07; I2=0%, risk difference (RD) 64/1000 over 6 to 12 months, low-certainty evidence). Results from cohort studies suggested a possible reduction in quit rates with use of ENDS compared with no use of ENDS (OR 0.74, 95% CI 0.55 to 1.00; p=0.051; I2=56%, very low certainty). There is very limited evidence regarding the impact of ENDS or ENNDS on tobacco smoking cessation, reduction or adverse effects: data from RCTs are of low certainty and observational studies of very low certainty. The limitations of the cohort studies led us to a rating of very low-certainty evidence from which no credible inferences can be drawn. Lack of usefulness with regard to address the question of e-cigarettes' efficacy on smoking reduction and cessation was largely due to poor reporting. This review underlines the need to conduct well-designed trials measuring biochemically validated outcomes and adverse effects. Published by the BMJ Publishing

  8. Transformation impacts of dissolved and solid phase Fe(II) on trichloroethylene (TCE) reduction in an iron-reducing bacteria (IRB) mixed column system: a mathematical model.

    Science.gov (United States)

    Bae, Yeunook; Kim, Dooil; Cho, Hyun-Hee; Singhal, Naresh; Park, Jae-Woo

    2012-12-01

    In this research, we conducted trichloroethylene (TCE) reduction in a column filled with iron and iron-reducing bacteria (IRB) and developed a mathematical model to investigate the critical reactions between active species in iron/IRB/contaminant systems. The formation of ferrous iron (Fe(II)) in this system with IRB and zero-valent iron (ZVI, Fe(0)) coated with a ferric iron (Fe(III)) crust significantly affected TCE reduction and IRB respiration in various ways. This study presents a new framework for transformation property and reducing ability of both dissolved (Fe(II)(dissolved)) and solid form ferrous iron (Fe(II)(solid)). Results showed that TCE reduction was strongly depressed by Fe(II)(solid) rather than by other inhibitors (e.g., Fe(III) and lactate), suggesting that Fe(II)(solid) might reduce IRB activation due to attachment to IRB cells. Newly exposed Fe(0) from the released Fe(II)(dissolved) was a strong contributor to TCE reduction compared to Fe(II)(solid). In addition, our research confirmed that less Fe(II)(solid) production strongly supported long-term TCE reduction because it may create an easier TCE approach to Fe(0) or increase IRB growth. Our findings will aid the understanding of the contributions of iron media (e.g., Fe(II)(solid), Fe(II)(dissolved), Fe(III), and Fe(0)) to IRB for decontamination in natural groundwater systems. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Resolution Improvement and Pattern Generator Development for theMaskless Micro-Ion-Beam Reduction Lithography System

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Ximan [Univ. of California, Berkeley, CA (United States)

    2006-05-18

    The shrinking of IC devices has followed the Moore's Law for over three decades, which states that the density of transistors on integrated circuits will double about every two years. This great achievement is obtained via continuous advance in lithography technology. With the adoption of complicated resolution enhancement technologies, such as the phase shifting mask (PSM), the optical proximity correction (OPC), optical lithography with wavelength of 193 nm has enabled 45 nm printing by immersion method. However, this achievement comes together with the skyrocketing cost of masks, which makes the production of low volume application-specific IC (ASIC) impractical. In order to provide an economical lithography approach for low to medium volume advanced IC fabrication, a maskless ion beam lithography method, called Maskless Micro-ion-beam Reduction Lithography (MMRL), has been developed in the Lawrence Berkeley National Laboratory. The development of the prototype MMRL system has been described by Dr. Vinh Van Ngo in his Ph.D. thesis. But the resolution realized on the prototype MMRL system was far from the design expectation. In order to improve the resolution of the MMRL system, the ion optical system has been investigated. By integrating a field-free limiting aperture into the optical column, reducing the electromagnetic interference and cleaning the RF plasma, the resolution has been improved to around 50 nm. Computational analysis indicates that the MMRL system can be operated with an exposure field size of 0.25 mm and a beam half angle of 1.0 mrad on the wafer plane. Ion-ion interactions have been studied with a two-particle physics model. The results are in excellent agreement with those published by the other research groups. The charge-interaction analysis of MMRL shows that the ion-ion interactions must be reduced in order to obtain a throughput higher than 10 wafers per hour on 300-mm wafers. In addition, two different maskless lithography

  10. Radiation dose reduction using a CdZnTe-based computed tomography system: comparison to flat-panel detectors.

    Science.gov (United States)

    Le Huy, Q; Ducote, Justin L; Molloi, Sabee

    2010-03-01

    Although x-ray projection mammography has been very effective in early detection of breast cancer, its utility is reduced in the detection of small lesions that are occult or in dense breasts. One drawback is that the inherent superposition of parenchymal structures makes visualization of small lesions difficult. Breast computed tomography using flat-panel detectors has been developed to address this limitation by producing three-dimensional data while at the same time providing more comfort to the patients by eliminating breast compression. Flat panels are charge integrating detectors and therefore lack energy resolution capability. Recent advances in solid state semiconductor x-ray detector materials and associated electronics allow the investigation of x-ray imaging systems that use a photon counting and energy discriminating detector, which is the subject of this article. A small field-of-view computed tomography (CT) system that uses CdZnTe (CZT) photon counting detector was compared to one that uses a flat-panel detector for different imaging tasks in breast imaging. The benefits afforded by the CZT detector in the energy weighting modes were investigated. Two types of energy weighting methods were studied: Projection based and image based. Simulation and phantom studies were performed with a 2.5 cm polymethyl methacrylate (PMMA) cylinder filled with iodine and calcium contrast objects. Simulation was also performed on a 10 cm breast specimen. The contrast-to-noise ratio improvements as compared to flat-panel detectors were 1.30 and 1.28 (projection based) and 1.35 and 1.25 (image based) for iodine over PMMA and hydroxylapatite over PMMA, respectively. Corresponding simulation values were 1.81 and 1.48 (projection based) and 1.85 and 1.48 (image based). Dose reductions using the CZT detector were 52.05% and 49.45% for iodine and hydroxyapatite imaging, respectively. Image-based weighting was also found to have the least beam hardening effect. The results

  11. Synthesis and Non-isothermal Carbothermic Reduction of FeTiO3-Fe2O3 Solid Solution Systems

    Science.gov (United States)

    Liu, Yiran; Zhang, Jianliang; Xing, Xiangdong; Liu, Zhengjian; Liu, Xingle; Li, Naiyao; Shen, Yansong

    2017-10-01

    To investigate the carbothermic reduction behaviors of xFeTiO3·(1 - x)Fe2O3 solid solutions, the solid solutions with different x values were synthesized and used in the corresponding reactions. With an increase in x, the temperature pertaining to the onset of carbothermic reduction increased, while the rate of reduction of the solid solutions, α, decreased. The lattice parameters calculated from XRD patterns indicated that the solid solution with a higher x led to a larger lattice distortion. The non-isothermal kinetics were calculated, and an average activation energy E value of 3.0 × 102 kJ/mol was obtained.

  12. A novel generalized oppositional biogeography-based optimization algorithm: application to peak to average power ratio reduction in OFDM systems

    Directory of Open Access Journals (Sweden)

    Goudos Sotirios K.

    2016-01-01

    Full Text Available A major drawback of orthogonal frequency division multiplexing (OFDM signals is the high value of peak to average power ratio (PAPR. Partial transmit sequences (PTS is a popular PAPR reduction method with good PAPR reduction performance, but its search complexity is high. In this paper, in order to reduce PTS search complexity we propose a new technique based on biogeography-based optimization (BBO. More specifically, we present a new Generalized Oppositional Biogeography Based Optimization (GOBBO algorithm which is enhanced with Oppositional Based Learning (OBL techniques. We apply both the original BBO and the new Generalized Oppositional BBO (GOBBO to the PTS problem. The GOBBO-PTS method is compared with other PTS schemes for PAPR reduction found in the literature. The simulation results show that GOBBO and BBO are in general highly efficient in producing significant PAPR reduction and reducing the PTS search complexity.

  13. Forecast-based Integrated Flood Detection System for Emergency Response and Disaster Risk Reduction (Flood-FINDER)

    Science.gov (United States)

    Arcorace, Mauro; Silvestro, Francesco; Rudari, Roberto; Boni, Giorgio; Dell'Oro, Luca; Bjorgo, Einar

    2016-04-01

    Most flood prone areas in the globe are mainly located in developing countries where making communities more flood resilient is a priority. Despite different flood forecasting initiatives are now available from academia and research centers, what is often missing is the connection between the timely hazard detection and the community response to warnings. In order to bridge the gap between science and decision makers, UN agencies play a key role on the dissemination of information in the field and on capacity-building to local governments. In this context, having a reliable global early warning system in the UN would concretely improve existing in house capacities for Humanitarian Response and the Disaster Risk Reduction. For those reasons, UNITAR-UNOSAT has developed together with USGS and CIMA Foundation a Global Flood EWS called "Flood-FINDER". The Flood-FINDER system is a modelling chain which includes meteorological, hydrological and hydraulic models that are accurately linked to enable the production of warnings and forecast inundation scenarios up to three weeks in advance. The system is forced with global satellite derived precipitation products and Numerical Weather Prediction outputs. The modelling chain is based on the "Continuum" hydrological model and risk assessments produced for GAR2015. In combination with existing hydraulically reconditioned SRTM data and 1D hydraulic models, flood scenarios are derived at multiple scales and resolutions. Climate and flood data are shared through a Web GIS integrated platform. First validation of the modelling chain has been conducted through a flood hindcasting test case, over the Chao Phraya river basin in Thailand, using multi temporal satellite-based analysis derived for the exceptional flood event of 2011. In terms of humanitarian relief operations, the EO-based services of flood mapping in rush mode generally suffer from delays caused by the time required for their activation, programming, acquisitions and

  14. Self-phase modulation induced transmission penalty reduction in a 5 Gbit/s FM/AM conversion system experiment over 205 km of standard fiber

    DEFF Research Database (Denmark)

    Jørgensen, Bo Foged; Pedersen, Rune Johan Skullerud; Jørgensen, Carsten Gudmann

    1994-01-01

    The transmission penalty of a standard non-dispersion shifted fiber is experimentally demonstrated to be reduced by self-phase modulation due to the optical Kerr effect. A 2 dB reduction of transmission penalty is achieved in a 5 Gbit/s FM/AM conversion system experiment over 205 km of fiber...

  15. Analysis of load reduction possibilities using a hydraulic soft yaw system for a 5-MW turbine and its sensitivity to yaw-bearing friction

    DEFF Research Database (Denmark)

    Stubkier, S.; Pedersen, H. C.; Jonkman, J. M.

    2014-01-01

    With the increasing size of wind turbines and with increasing lifetime demands, new methods for load reduction in the turbines need to be examined. One method is to make the yaw system of the turbine flexible, thereby dampening the loads to the system. This paper presents a hydraulic soft yaw...... concept and investigates the effect this has on critical loads in the turbine. To analyze the system, a novel friction model is developed and implemented for the yaw system using the NREL 5-MW turbine in the aerodynamic code FAST. Based on this model, the influence of friction is investigated...

  16. Posterior realignment of irreducible atlantoaxial dislocation with C1-C2 screw and rod system: a technique of direct reduction and fixation.

    Science.gov (United States)

    Yin, Yi-Heng; Qiao, Guang-Yu; Yu, Xin-Guang; Tong, Huai-Yu; Zhang, Yuan-Zheng

    2013-12-01

    Treatment of chronic and irreducible atlantoaxial dislocation (AAD) with ventral compression is challenging for surgeons. The main procedures are occipitocervical/C1-C2 fusion after transoral odontoidectomy or release of the periodontoid tissues. These surgical procedures, which are performed simultaneously or intermittently, have many disadvantages that may discount their effectiveness. Therefore, a more effective way to achieve surgical reduction and to keep solid stability with only a single procedure is needed. We describe a technique to reduce chronic and irreducible AAD with C1 lateral mass and C2 pedicle screw and rod system. This was a retrospective case series. Our sample comprised 26 patients (9 men and 17 women) with irreducible AAD who ranged in age from 15 to 54 years (mean, 35 years). Patients' neurologic status was evaluated with the Japanese Orthopedic Association (JOA) scale. Twenty-six symptomatic patients underwent posterior realignment and reduction through the C1 lateral mass and C2 pedicle screw and rod system. The proposed mechanism of reduction is that the implanted screws and rods between C1 and C2 acting as a lever system drew C1 backward and pushed C2 downward and forward after removing circumambient obstruction and scars and thoroughly releasing the facet joints. The preoperative and postoperative JOA score, the extent of reduction, and the conditions of C1-C2 bony fusion were examined. No neurovascular injury occurred during surgery. Follow-up ranged from 6 to 40 months (mean 20.7 months). Radiographic evaluation showed that solid bony fusion was achieved in all patients, and that complete reduction was attained in 18 patients and partial reduction (>60% reduction) in 8 patients. The mean postoperative JOA score at last follow-up was 15.7, compared with the preoperative score of 12.1 (p<.01). This C1-C2 screw and rod system provides reliable stability and sufficient reduction of the anatomic malalignment at the craniovertebral junction

  17. Reduction and temporary stabilization of Tile C pelvic ring injuries using a posteriorly based external fixation system.

    Science.gov (United States)

    Martin, Murphy P; Rojas, David; Mauffrey, Cyril

    2017-12-05

    Tile C pelvic ring injuries are challenging to manage even in the most experienced hands. The majority of such injuries can be managed using percutaneous reduction techniques, and the posterior ring can be stabilized using percutaneous transiliac-transsacral screw fixation. However, a subgroup of patients present with inadequate bony corridors, significant sacral zone 2 comminution or significant lateral/vertical displacement of the hemipelvis through a complete sacral fracture. Percutaneous strategies in such circumstances can be dangerous. Those patients may benefit from prone positioning and open reduction of the sacral fracture with fixation through tension band plating or lumbo-pelvic fixation. Soft tissue handling is critical, and direct reduction techniques around the sacrum can be difficult due to the complex anatomy and the fragile nature of the sacrum making clamp placement and tightening a challenge. In this paper, we propose a mini-invasive technique of indirect reduction and temporary stabilization, which is soft tissue friendly and permits maintenance of reduction during definitive fixation surgical.

  18. Confluence reduction for Markov automata

    NARCIS (Netherlands)

    Timmer, Mark; Katoen, Joost P.; van de Pol, Jaco; Stoelinga, Mariëlle Ida Antoinette

    2016-01-01

    Markov automata are a novel formalism for specifying systems exhibiting nondeterminism, probabilistic choices and Markovian rates. As expected, the state space explosion threatens the analysability of these models. We therefore introduce confluence reduction for Markov automata, a powerful reduction

  19. Material and system for catalytic reduction of nitrogen oxide in an exhaust stream of a combustion process

    Science.gov (United States)

    Gardner, Timothy J.; Lott, Stephen E.; Lockwood, Steven J.; McLaughlin, Linda I.

    1998-01-01

    A catalytic material of activated hydrous metal oxide doped with platinum, palladium, or a combination of these, and optionally containing an alkali or alkaline earth metal, that is effective for NO.sub.X reduction in an oxidizing exhaust stream from a combustion process is disclosed. A device for reduction of nitrogen oxides in an exhaust stream, particularly an automotive exhaust stream, the device having a substrate coated with the activated noble-metal doped hydrous metal oxide of the invention is also provided.

  20. Carbon-Neutral Energy Supply and Energy Demand-Reduction Technology Needed for Continued Economic Growth Without Dangerous Interference in the Climate System

    Science.gov (United States)

    Hoffert, M. I.; Caldeira, K.

    2007-12-01

    Stabilization of atmospheric CO2 at levels likely to avoid unacceptable climate risk will require a major transformation in the ways we produce and use energy. Most of our energy will need to come from sources that do not emit carbon dioxide to the atmosphere and that energy will need to be used efficiently. The required reduction of carbon dioxide emissions as global energy consumption and GDP grow imposes quantitative requirements on some combination of carbon-neutral primary power and energy demand reduction. (Emission reductions are expressed relative to an implicit or explicit baseline; explicit being better for policy-making. Energy demand reduction involves both efficiency improvements and lifestyle changes.) These requirements can be expressed as CO2 emission reductions needed, or as carbon-neutral primary power production needed combined with power not used by virtue of increased energy end use efficiency or lifestyle changes ("negawatts"), always subject to some reasonably well-characterized uncertainty limits. Climatic changes thus far have been closer to the more extreme zone of the climatic uncertainty envelope of global warming indicating the potential for disastrous impacts by mid-century and beyond for business-as-usual. Emission reductions needed to avoid "dangerous interference in the climate system" imply a revolutionary change in the global energy system beginning now; particularly ominous are massive conventional coal-fired electric power energy infrastructures under construction by the US, China & India. Strong arguments, based on physical science considerations, exist for prompt measures such as (1) an immediate moratorium on coal-fired plants that don't sequester CO2, (2) a gradually increasing price on carbon emissions and (3) regulatory standards, for example, that would encourage utilities and car manufacturers to improve efficiency, and (4) Apollo-scale R & D projects beginning now to develop sustainable carbon-neutral power that can be

  1. Uranium(VI) reduction by nanoscale zero-valent iron in anoxic batch systems: The role of Fe(II) and Fe(III)

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Sen; Chen, Yongheng; Xiang, Wu; Bao, Zhengyu; Liu, Chongxuan; Deng, Baolin

    2014-12-01

    The role of Fe(II) and Fe(III) on U(VI) reduction by nanoscale zerovalent iron (nanoFe0) was investigated using two iron chelators 1,10-phenanthroline and triethanolamine (TEA) under a CO2-free anoxic condition. The results showed U(VI) reduction was strongly inhibited by 1,10-phenanthroline and TEA in a pH range from 6.92 to 9.03. For instance, at pH 6.92 the observed U(VI) reduction rates decreased by 80.7% and 82.3% in the presence of 1,10-phenanthroline and TEA, respectively. The inhibition was attributed to the formation of stable complexes between 1,10-phenanthroline and Fe(II) or TEA and Fe(III). In the absence of iron chelators, U(VI) reduction can be enhanced by surface-bound Fe(II) on nanoFe0. Our results suggested that Fe(III) and Fe(II) probably acted as an electron shuttle to mediate the transfer of electrons from nanoFe0 to U(VI), therefore a combined system with Fe(II), Fe(III) and nanoFe0 can facilitate the U(VI) reductive immobilization in the contaminated groundwater.

  2. Electrochemical Reduction of Oxygen in Aprotic Ionic Liquids Containing Metal Cations: A Case Study on the Na-O2 system.

    Science.gov (United States)

    Azaceta, Eneko; Lutz, Lukas; Grimaud, Alexis; Vicent-Luna, Jose Manuel; Hamad, Said; Yate, Luis; Cabañero, German; Grande, Hans-Jurgen; Anta, Juan A; Tarascon, Jean-Marie; Tena-Zaera, Ramon

    2017-04-10

    Metal-air batteries are intensively studied because of their high theoretical energy-storage capability. However, the fundamental science of electrodes, electrolytes, and reaction products still needs to be better understood. In this work, the ionic liquid N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) was chosen to study the influence of a wide range of metal cations (M(n+) ) on the electrochemical behavior of oxygen. The relevance of the theory of Lewis hard and soft acids and bases to predict satisfactorily the reduction potential of oxygen in electrolytes containing metal cations is demonstrated. Systems with soft and intermediate M(n+) acidity are shown to facilitate oxygen reduction and metal oxide formation, whereas oxygen reduction is hampered by hard acid cations such as sodium and lithium. Furthermore, DFT calculations on the energy of formation of the resulting metal oxides rationalize the effect of M(n+) on oxygen reduction. A case study on the Na-O2 system is described in detail. Among other things, the Na(+) concentration of the electrolyte is shown to control the electrochemical pathway (solution precipitation vs. surface deposition) by which the discharge product grows. All in all, fundamental insights for the design of advanced electrolytes for metal-air batteries, and Na-air batteries in particular, are provided. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Comparison of PCA and ICA based clutter reduction in GPR systems for anti-personal landmine detection

    DEFF Research Database (Denmark)

    Karlsen, Brian; Larsen, Jan; Sørensen, Helge Bjarup Dissing

    2001-01-01

    This paper presents statistical signal processing approaches for clutter reduction in stepped-frequency ground penetrating radar (SF-GPR) data. In particular, we suggest clutter/signal separation techniques based on principal and independent component analysis (PCA/ICA). The approaches are succes......This paper presents statistical signal processing approaches for clutter reduction in stepped-frequency ground penetrating radar (SF-GPR) data. In particular, we suggest clutter/signal separation techniques based on principal and independent component analysis (PCA/ICA). The approaches...... are successfully evaluated and compared on a real SF-GPR time-series. Field-test data are acquired using a monostatic S-band rectangular waveguide antenna....

  4. In-line localized monitoring of catalyst activity in selective catalytic NO.sub.x reduction systems

    Science.gov (United States)

    Muzio, Lawrence J [Laguna Niguel, CA; Smith, Randall A [Huntington Beach, CA

    2009-12-22

    Localized catalyst activity in an SCR unit for controlling emissions from a boiler, power plant, or any facility that generates NO.sub.x-containing flue gases is monitored by one or more modules that operate on-line without disrupting the normal operation of the facility. Each module is positioned over a designated lateral area of one of the catalyst beds in the SCR unit, and supplies ammonia, urea, or other suitable reductant to the catalyst in the designated area at a rate that produces an excess of the reductant over NO.sub.x on a molar basis through the designated area. Sampling probes upstream and downstream of the designated area draw samples of the gas stream for NO.sub.x analysis, and the catalyst activity is determined from the difference in NO.sub.x levels between the two probes.

  5. Offering smoking treatment to primary care patients in two Wisconsin healthcare systems: Who chooses smoking reduction versus cessation?

    Science.gov (United States)

    Petersen, Angela; Mermelstein, Robin; Berg, Kristin M; Baker, Timothy B; Smith, Stevens S; Jorenby, Doug; Piper, Megan E; Schlam, Tanya R; Cook, Jessica W

    2017-12-01

    Smokers unwilling to make a quit attempt can still benefit from smoking intervention. However, it is unclear what proportion of smokers will enter such a Motivation phase intervention, and whether such an intervention attracts different types of smokers than does abstinence oriented treatment. We conducted a study from June 2010 to October 2013 based on a chronic care model of tobacco treatment among study eligible primary care patients (N=1579; 58% women, 89% White) presenting for regular health care visits in southern Wisconsin, U.S. Medical assistants, prompted via the electronic health record (EHR), invited smokers (n=10,242) to learn more about treatment options to help them either reduce their smoking or quit. Of those invited to learn more who were then reached by study staff, 10.2% (n=1046) reported interest in reduction treatment and 24% (n=2465) reported interest in cessation treatment. Patients who selected and ultimately entered reduction (n=492) versus cessation (n=1087) were more likely to report: older age; a history of anxiety; lower motivation to quit; lower primary dependence motives; more close friends or family who smoke; and a greater interval since their last quit attempt. Results suggest that Motivation phase treatment aimed at smoking reduction may increase the proportion and range of smokers inducted into tobacco treatment. Published by Elsevier Inc.

  6. Abstract models of transfinite reductions

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2010-01-01

    We investigate transfinite reductions in abstract reduction systems. To this end, we study two abstract models for transfinite reductions: a metric model generalising the usual metric approach to infinitary term rewriting and a novel partial order model. For both models we distinguish between a w...

  7. PAPR Reduction in OFDM-based Visible Light Communication Systems Using a Combination of Novel Peak-value Feedback Algorithm and Genetic Algorithm

    Science.gov (United States)

    Deng, Honggui; Liu, Yan; Ren, Shuang; He, Hailang; Tang, Chengying

    2017-10-01

    We propose an enhanced partial transmit sequence technique based on novel peak-value feedback algorithm and genetic algorithm (GAPFA-PTS) to reduce peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals in visible light communication (VLC) systems(VLC-OFDM). To demonstrate the advantages of our proposed algorithm, we analyze the flow of proposed technique and compare the performances with other techniques through MATLAB simulation. The results show that GAPFA-PTS technique achieves a significant improvement in PAPR reduction while maintaining low bit error rate (BER) and low complexity in VLC-OFDM systems.

  8. Nitrate reduction

    Science.gov (United States)

    Dziewinski, Jacek J.; Marczak, Stanislaw

    2000-01-01

    Nitrates are reduced to nitrogen gas by contacting the nitrates with a metal to reduce the nitrates to nitrites which are then contacted with an amide to produce nitrogen and carbon dioxide or acid anions which can be released to the atmosphere. Minor amounts of metal catalysts can be useful in the reduction of the nitrates to nitrites. Metal salts which are formed can be treated electrochemically to recover the metals.

  9. Generation IV Nuclear Energy Systems Construction Cost Reductions through the use of Virtual Environments: Task 1 Completion Report

    Energy Technology Data Exchange (ETDEWEB)

    Whisker, V.E.; Baratta, A.J.; Shaw, T.S.; Winters, J.W.; Trikouros, N.; Hess, C.

    2002-11-26

    OAK B204 The objective of this project is to demonstrate the feasibility and effectiveness of using full-scale virtual reality simulation in the design, construction, and maintenance of future nuclear power plants. Specifically, this project will test the suitability of Immersive Projection Display (IPD) technology to aid engineers in the design of the next generation nuclear power plant and to evaluate potential cost reductions that can be realized by optimization of installation and construction sequences. The intent is to see if this type of information technology can be used in capacities similar to those currently filled by full-scale physical mockups.

  10. Reduction of Mn-oxides by ferrous iron in a flow system: column experiment and reactive transport modeling

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Appelo, C. A. J.

    2000-01-01

    of the experiment. A model containing surface complexation coupled to varying concentrations of birnessite and ferrihydrite and a constant charge exchanger in addition to mineral equilibria provided a satisfactory description of the distribution of all solutes in time and space. However, the observed concentration......The reduction of Mn-oxide by Fe21 was studied in column experiments, using a column filled with natural Mn-oxide coated sand. Analysis of the Mn-oxide indicated the presence of both Mn(III) and Mn(IV) in the Mn-oxide. The initial exchange capacity of the column was determined by displacement...... Science Ltd...

  11. Commercial Refrigeration: Heat Transfer Optimization and Energy Reduction, Measurement and Verification of a Liquid Refrigerant Pump System Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gaul, Chris [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sheppy, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-22

    This study describes the test results of a Refrigerant Pump System integrated into a commercial supermarket direct expansion (DX) vapor compression refrigeration system. The Liquid Refrigerant Pump System retrofit (patent-pending; application number 13/964,198) was introduced to NREL in August 2014 by CTA Architects Engineers.

  12. Performance of a combined system of microbial fuel cell and membrane bioreactor: wastewater treatment, sludge reduction, energy recovery and membrane fouling.

    Science.gov (United States)

    Su, Xinying; Tian, Yu; Sun, Zhicai; Lu, Yaobin; Li, Zhipeng

    2013-11-15

    A novel combined system of sludge microbial fuel cell (S-MFC) stack and membrane bioreactor (MBR) was proposed in this study. The non-consumed sludge in the MBR sludge-fed S-MFC was recycled to the MBR. In the combined system, the COD and ammonia treatment efficiencies were more than 90% and the sludge reduction was 5.1% higher than that of the conventional MBR. It's worth noting that the energy recovery and fouling mitigation were observed in the combined system. In the single S-MFC, about 75 mg L(-1) COD could be translated to electricity during one cycle. The average voltage and maximum power production of the single S-MFC were 430 mV and 51 mWm(-2), respectively. Additionally, the combined system was able to mitigate membrane fouling by the sludge modification. Except for the content decrease (22%), S-MFC destroyed simple aromatic proteins and tryptophan protein-like substances in loosely bound extracellular polymeric substances (LB-EPS). These results indicated that effective wastewater treatment, sludge reduction, energy recovery and membrane fouling mitigation could be obtained in the combined system. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Exposure reduction in general dental practice using digital x-ray imaging system for intraoral radiography with additional x-ray beam filter

    Energy Technology Data Exchange (ETDEWEB)

    Shibuya, Hitoshi; Mori, Toshimichi; Hayakawa, Yoshihiko; Kuroyanagi, Kinya [Tokyo Dental Coll., Chiba (Japan); Ota, Yoshiko

    1997-12-01

    To measure exposure reduction in general dental practice using digital x-ray imaging systems for intraoral radiography with additional x-ray beam filter. Two digital x-ray imaging systems, Pana Digital (Pana-Heraus Dental) and CDR (Schick Technologies), were applied for intraoral radiography in general dental practice. Due to the high sensitivity to x-rays, additional x-ray beam filters for output reduction were used for examination. An Orex W II (Osada Electric Industry) x-ray generator was operated at 60 kVp, 7 mA. X-ray output (air-kerma; Gy) necessary for obtaining clinically acceptable images was measured at 0 to 20 cm in 5 cm steps from the cone tip using an ionizing chamber type 660 (Nuclear Associates) and compared with those for Ektaspeed Plus film (Eastman Kodak). The Pana Digital system was used with the optional filter supplied by Pana-Heraus Dental which reduced the output to 38%. The exposure necessary to obtain clinically acceptable images was only 40% of that for the film. The CDR system was used with the Dental X-ray Beam Filter Kit (Eastman Kodak) which reduced the x-ray output to 30%. The exposure necessary to obtain clinically acceptable images was only 20% of that for the film. The two digital x-ray imaging systems, Pana Digital and CDR, provided large dose savings (60-80%) compared with Ektaspeed Plus film when applied for intraoral radiography in general dental practice. (author)

  14. Intraoral radiology in general dental practices. A comparison of digital and film-based X-ray systems with regard to radiation protection and dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Anissi, H.D. [Ulm Univ. (Germany). Dentistry; Geibel, M.A. [Ulm Univ. (Germany). Dept. of Dentomaxillofacial Surgery

    2014-08-15

    Purpose: The purpose of this study was to gain insight into the distribution and application of digital intraoral radiographic techniques within general dental practices and to compare these with film-based systems in terms of patient dose reduction. Materials and Methods: 1100 questionnaires were handed out to general dental practitioners. Data was analyzed with respect to the type of system by using descriptive statistics and nonparametric tests, i.e. Kruskal-Wallis, Mann-Whitney and chi-square test (SPSS 20). Results: 64% of the questioned dentists still use film-based radiology, 23% utilize storage phosphor plate (SPP) systems and 13% use a charge-coupled device (CCD). A strong correlation between the number of dentists working in a practice and the use of digital dental imaging was observed. Almost 3/4 of the film users work with E- or F-speed film. 45% of them refuse to change to a digital system. The use of lead aprons was popular, while only a minority preferred thyroid shields and rectangular collimators. A fourfold reduction of exposure time from D-speed film to CCD systems was observed. Due to detector size and positioning errors, users of CCD systems take significantly more single-tooth radiographs in total. Considering the number of radiographs per patient, there is only a slight tendency towards more X-rays with CCD systems. Up to image generation, digital systems seem to be as or even more difficult to handle than film-based systems, while their handling was favored after radiographic exposure. Conclusion: Despite a slight increase of radiographs taken with CCD systems, there is a significant dosage reduction. Corresponding to the decrease in exposure time, the patient dose for SPP systems is reduced to one half compared to film. The main issues in CCD technology are positioning errors and the size of the X-ray detectors which are difficult to eliminate. The usage of radiation protection measures still needs to be improved. (orig.)

  15. Reduction of methane emission from landfills using bio-mitigation systems – from lab tests to full scale implementation

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Scheutz, Charlotte

    Landfills are significant sources of methane, which contributes to climate change. As an alternative to mitigation by gas utilization systems, bio-mitigation systems may be implemented. Such systems are based on microbial methane oxidation in full surface biological covers, so-called biocovers...... due to self-heating processes. Bio-mitigation can be used as a stand-alone technology or combined with active or passive gas collection. When implementing bio-mitigation systems focus should be on additional fugitive methane emissions or the presence of uncontrolled point releases. A protocol...... methane emissions when landfill gas utilization systems cannot be implemented or cease to perform as cost-efficient, sustainable solutions....

  16. Adhoco - a remote-control system that permits the reduction of energy consumption in housing; Adhoco - Systeme de domotique sans-fil autoadaptif permettant une reduction importante de la consommation energetique dans les habitations

    Energy Technology Data Exchange (ETDEWEB)

    Guillemin, A.; Schumann, T.

    2006-07-01

    This final report published by the Swiss Federal Office of Energy (SFOE) reports on a pilot project which tested an automatic control system for houses and apartments which was to make large energy savings possible by the use of an adaptive system. This system was installed in two apartments. The resulting savings of approximately 25% for heating energy and between 30% and 60% for artificial lighting are discussed. These figures are reported to be close to those obtained in a recent reference implementation (conducted in 2003 at the Swiss Federal Institute of Technology in Lausanne) which looked at the situation in offices. The electrical consumption necessary for the operation of the system is looked at and compared with amount of energy saved. Further advantages of the system, including increased comfort and safety, support for elderly people, and the provision of remote control functions, are examined and commented on.

  17. A simple Cr(VI)–S(IV)–O{sub 2} system for rapid and simultaneous reduction of Cr(VI) and oxidative degradation of organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Yanan; Yang, Shaojie [Department of Environmental Science, Hubei Key Lab of Biomass Resource Chemistry and Environmental Biotechnology, School of Resources and Environmental Science, Wuhan University, 430079 (China); Zhou, Danna, E-mail: zdncug@163.com [Faculty of Material Science and Chemistry, China University of Geosciences, Wuhan 430074 (China); Wu, Feng [Department of Environmental Science, Hubei Key Lab of Biomass Resource Chemistry and Environmental Biotechnology, School of Resources and Environmental Science, Wuhan University, 430079 (China)

    2016-04-15

    Highlights: • Rapid and simultaneous reduction of Cr(VI) and degradation of organic pollutants occur. • Oxysulfur radicals generated in Cr(VI)–S(IV)–O{sub 2} system oxidize the organic pollutants. • Acidic pH facilitates the reactions from both directions of reduction and oxidation. • Degradation potential of aromatic amines depends on the substituted groups. • Cr(VI)–S(IV)–O{sub 2} system is promising for “waste control by waste”. - Abstract: Hexavalent chromium (Cr(VI)), a heavy-metal contaminant, can be easily reduced to less toxic trivalent chromium (Cr(III)) by sulfite ions (S(IV)). However, S(IV) has not drawn as much attention as the ferrous ion has. We report herein a novel Cr(VI)–S(IV)–O{sub 2} system containing sulfite ions that rapidly and simultaneously reduces Cr(VI) and oxidize organic pollutants in the presence of oxygen in aqueous solutions. This Cr(VI)–S(IV)-O{sub 2} system contains the initiator Cr(VI), the reductant S(IV), and the oxidant O{sub 2}, which produce oxysulfur radicals (mainly SO{sub 4}·{sup −} and SO{sub 5}·{sup −}) and hydroxyl radicals (OH·). The Cr(VI)/S(IV) molar ratio, pH, and oxygen content play important roles in the entire reaction system. Acidic conditions (pH 3.0) facilitated degradation of organic compounds and reduction of Cr(VI) as well. In addition, experiments of rapid degradation of several kinds of organic pollutants such as azo dye (acid orange 7, AO7), aniline, phenol, bisphenol A etc were also conducted. Preliminary results show that the removal rates of the analogs of phenols or aromatic amines in this Cr(VI)–S(IV)–O{sub 2} system have a relationship with the electronic parameters (Hammett constant, σ) of the substituted groups. Thus, the Cr(VI)–S(IV)–O{sub 2} system, provides an excellent strategy of “waste control by waste” for removing multiple industrial contaminants.

  18. Dose reduction and image quality assessment in 64-detector row computed tomography of the coronary arteries using an automatic exposure control system.

    Science.gov (United States)

    Francone, Marco; Di Castro, Elisabetta; Napoli, Alessandro; Bolzan, Chiara; Carbone, Iacopo; Bertoletti, Linda; Iuliano, Luigi; Catalano, Carlo; Passariello, Roberto

    2008-01-01

    To evaluate dose reduction and image quality in coronary 64-slice multidetector computed tomography using an automatic exposure control system (AECs). A total of 101 patients were divided into 4 groups. Tube current was 600 and 800 mAs in groups A and B and adapted at 600 and 800 quality-reference mAs using an AECs in groups C and D. Effective dose and organ-equivalent dose were evaluated. Image noise was quantified as standard deviation of air-space attenuation. Two observers assessed technical adequacy and image quality using a 4-point scale. Effective dose ranged from 8.6 mSv (group C) to 15 mSv (group B) with significant dose reduction for examinations performed at 600 mAs (21.7%) and 800 mAs (29.4%). Contribution of organ-equivalent doses showed higher exposure for lungs (42%) and breast (22%). Noise was significantly higher in groups studied with AECs. Larger coronary segments resulted in higher image quality scores without differences between groups. Automatic exposure control systems provides images of diagnostic quality with substantial dose reduction.

  19. Photocatalytic reduction of Cr(VI) on the new hetero-system CuAl{sub 2}O{sub 4}/TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Gherbi, R. [Laboratory of Reaction Engineering, Faculty of Mechanic and Engineering Processes, USTHB, BP 32, 16111 Algiers (Algeria); Nasrallah, N. [Laboratory of Reaction Engineering, Faculty of Mechanic and Engineering Processes, USTHB, BP 32, 16111 Algiers (Algeria); Equipe chimie et Ingenierie des procedes, UMR CNRS 6226, E.N.S.C.R., Avenue du General Leclerc, CS 50837, 35708 Rennes Cedex 7 (France); Amrane, A. [Equipe chimie et Ingenierie des procedes, UMR CNRS 6226, E.N.S.C.R., Avenue du General Leclerc, CS 50837, 35708 Rennes Cedex 7 (France); Maachi, R. [Laboratory of Reaction Engineering, Faculty of Mechanic and Engineering Processes, USTHB, BP 32, 16111 Algiers (Algeria); Trari, M., E-mail: solarchemistry@gmail.com [Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry, USTHB, BP 32, 16111 Algiers (Algeria)

    2011-02-28

    Visible light driven HCrO{sub 4}{sup -} reduction was successfully achieved over the new hetero-system CuAl{sub 2}O{sub 4}/TiO{sub 2}. The spinel, elaborated by nitrate route, was characterized photo electrochemically. The optical gap was found to be 1.70 eV and the transition is directly allowed. The conduction band (-1.05 V{sub SCE}) is located below that of TiO{sub 2}, more negative than the HCrO{sub 4}{sup -}/Cr{sup 3+} level (+0.58 V{sub SCE}) yielding a thermodynamically feasible chromate reduction upon visible illumination. CuAl{sub 2}O{sub 4} is stable against photo corrosion by holes consumption reaction involving salicylic acid which favors the charges separation. There is a direct correlation between the dark adsorption and the photo activity. A reduction of more than 95% of chromate was achieved after 3 h irradiation at pH 2 with an optimal mass ratio (CuAl{sub 2}O{sub 4}/TiO{sub 2}) equal to 1/3. The reduction follows a first order kinetic with a half life of {approx}1 h and a quantum yield of 0.11% under polychromatic light. Prolonged illumination was accompanied by a deceleration of the Cr(VI) reduction thanks to the competitive water discharge. The hydrogen evolution, an issue of energetic concern, took place with a rate of 3.75 cm{sup 3} (g catalyst){sup -1} h{sup -1}.

  20. Studies on the reduction by hydrogen of nitrobenzene to aniline catalysed by the Pd(acac)/sub 2//pyridine (Py) system

    Energy Technology Data Exchange (ETDEWEB)

    Datta, M.C.; Saha, C.R.; Sen, D.

    1978-11-01

    Studies on the reduction by hydrogen of nitrobenzene to aniline catalysed by the Pd(acac)/sub 2//Pyridine (Py) system as a homogeneous catalyst indicated that the optimum reduction occurred at one atmosphere and room temperature in petroleum ether (bp 100/sup 0/-120/sup 0/C to yield 90 3< aniline; the optimum catalyst-substrate ratio was 0.0063:1. The preparation and isolation under similar conditions of a penta-coordinated palladium(II) complex, (Pd(II)(acac)H(C/sub 6/H/sub 5/NO/sub 2/)Py), (where acac is acetylacetonate), which is dimeric as a solid and monomeric in solution, suggests a mechanism involving the formation of a phenylnitrene metal complex as a hypothetical intermediate.

  1. Reduction of heat losses on the skid pipe system of a pusher type furnace; Verringerung der Waermeverluste am Tragrohrsystem eines Stossofens

    Energy Technology Data Exchange (ETDEWEB)

    Hoffelner, Mario; Winter, Franz [voestalpine Grobblech GmbH, Linz (Austria); Springer, Michael; Huegel, Frank [FBB Engineering GmbH, Moenchengladbach (Germany); Buhr, Andreas [Almatis GmbH, Frankfurt (Germany); Kockegey-Lorenz, Rainer [Almatis GmbH, Ludwigshafen (Germany)

    2013-06-15

    This paper discusses how energy consumption and energy loss can be reduced in reheating furnaces of hot rolling mills by new lightweight refractory materials and a new modular lining concept for the skid pipe insulation using pre-fabricated shells. The target is to optimise the hot rolling process from an energy point of view, and to reduce the operational cost of the furnaces. The new lightweight pre-fabricated shells based on the microporous castable and a thermotechnical optimised sandwich design can significantly reduce the heat losses compared to dense castable. Industrial application of the new system in a 110 t/h pusher type furnace at voestalpine Grobblech GmbH in Linz, Austria, resulted in reduction of heat loss about 30 %. The annualised energy saving gives a cost reduction of more than Euro 200,000 a year. Costs for the complete new lining about Euro 170,000 result in a payback period of less than one year. (orig.)

  2. Synthesis of FeNi-Ceramic composite by carbothermal reduction from Fe2O3-WO3-Ni system

    Directory of Open Access Journals (Sweden)

    Sutham Niyomwas

    2010-03-01

    Full Text Available FeNi-Ceramics (Fe3W3C, Fe6W6C composite powder was synthesized by carbothermal reduction of Fe2O3-WO3-Ni mixture under argon gas atmosphere at 1200oC temperature. The standard Gibbs energy minimization method was used to calculate the equilibrium composition of the reacting species. Effects of synthesis milling time of precursors on the FeNi-Ceramics conversion were investigated. The resulted product phases and morphologies were identified using XRD and SEM methods. The synthesized products showed composite of ceramic (Fe3W3C, Fe6W6C and iron-nickel alloy (FeNi phases.

  3. p-sd Shell Gap Reduction in Neutron-Rich Systems and Cross-ShellExcitations in 20O

    Energy Technology Data Exchange (ETDEWEB)

    Wiedeking, M.; Tabor, S.L.; Pavan, J.; Volya, A.; Aguilar, A.L.; Calderin, I.J.; Campbell, D.B.; Cluff, W.T.; Diffenderfer, E.; Fridmann,J.; Hoffman, C.R.; Kemper, K.W.; Lee, S.; Riley, M.A.; Roeder, B.T.; Teal, C.; Tripathi, V.; Wiedenhover, I.

    2005-04-07

    Excited states in {sup 20}O were populated in the reaction {sup 10}Be({sup 14}C,{alpha}) at Florida State University (FSU). Charged particles were detected with a particle telescope consisting of 4 annularly segmented Si surface barrier detectors and {gamma} radiation was detected with the FSU {gamma} detector array. Five new states were observed below 6 MeV from the {alpha}-{gamma} and {alpha}-{gamma}-{gamma} coincidence data. Shell model calculations suggest that most of the newly observed states are core-excited 1p-1h excitations across the N=Z=8 shell gap. Comparisons between experimental data and calculations for the neutron-rich O and F isotopes imply a steady reduction of the p-sd shell gap as neutrons are added.

  4. Measurement of ammonia emissions from three ammonia emission reduction systems for dairy cattle using a dynamic flux chamber

    NARCIS (Netherlands)

    Dooren, van H.J.C.; Mosquera, J.

    2010-01-01

    There is increasing interest among dairy farmers in The Netherlands for animal friendly housing systems that at the same moment reduce the ammonia emission compared to currently available systems. Therefore, there is a need for a relatively cheap and easy measuring method to investigate the

  5. Significant reduction of fluoroscopy repetition with lumbar localization system in minimally invasive spine surgery: A prospective study.

    Science.gov (United States)

    Fan, Guoxin; Zhang, Hailong; Gu, Xin; Wang, Chuanfeng; Guan, Xiaofei; Fan, Yunshan; He, Shisheng

    2017-05-01

    The conventional location methods for minimally invasive spinal surgery (MISS) were mainly based on repeated fluoroscopy in a trial-and-error manner preoperatively and intraoperatively. Localization system mainly consisted of preoperative applied radiopaque frame and intraoperative guiding device, which has the potential to minimize fluoroscopy repetition in MISS. The study aimed to evaluate the efficacy of a novel lumbar localization system in reducing radiation exposure to patients.Included patients underwent minimally invasive transforaminal lumbar interbody fusion (MISTLIF) or percutaneous transforaminal endoscopic discectomy (PTED). Patients treated with novel localization system were regarded as Group A, and patients treated without novel localization system were regarded as Group B.For PTED, The estimated effective dose was 0.41 ± 0.13 mSv in Group A and 0.57 ± 0.14 mSv in Group B (P minimizing radiation hazards.

  6. Reduction in phencyclidine induced sensorimotor gating deficits in the rat following increased system xc⁻ activity in the medial prefrontal cortex.

    Science.gov (United States)

    Lutgen, Victoria; Qualmann, Krista; Resch, Jon; Kong, Linghai; Choi, Sujean; Baker, David A

    2013-04-01

    Aspects of schizophrenia, including deficits in sensorimotor gating, have been linked to glutamate dysfunction and/or oxidative stress in the prefrontal cortex. System xc(-), a cystine-glutamate antiporter, is a poorly understood mechanism that contributes to both cellular antioxidant capacity and glutamate homeostasis. Our goal was to determine whether increased system xc(-) activity within the prefrontal cortex would normalize a rodent measure of sensorimotor gating. In situ hybridization was used to map messenger RNA (mRNA) expression of xCT, the active subunit of system xc(-), in the prefrontal cortex. Prepulse inhibition was used to measure sensorimotor gating; deficits in prepulse inhibition were produced using phencyclidine (0.3-3 mg/kg, sc). N-Acetylcysteine (10-100 μM) and the system xc(-) inhibitor (S)-4-carboxyphenylglycine (CPG, 0.5 μM) were used to increase and decrease system xc(-) activity, respectively. The uptake of (14)C-cystine into tissue punches obtained from the prefrontal cortex was used to assay system xc(-) activity. The expression of xCT mRNA in the prefrontal cortex was most prominent in a lateral band spanning primarily the prelimbic cortex. Although phencyclidine did not alter the uptake of (14)C-cystine in prefrontal cortical tissue punches, intraprefrontal cortical infusion of N-acetylcysteine (10-100 μM) significantly reduced phencyclidine- (1.5 mg/kg, sc) induced deficits in prepulse inhibition. N-Acetylcysteine was without effect when coinfused with CPG (0.5 μM), indicating an involvement of system xc(-). These results indicate that phencyclidine disrupts sensorimotor gating through system xc(-) independent mechanisms, but that increasing cystine-glutamate exchange in the prefrontal cortex is sufficient to reduce behavioral deficits produced by phencyclidine.

  7. Reduction in Phencyclidine Induced Sensorimotor Gating Deficits in the Rat Following Increased System xc− Activity in the Medial Prefrontal Cortex

    Science.gov (United States)

    Lutgen, Victoria; Qualmann, Krista; Resch, Jon; Kong, Linghai; Choi, SuJean; Baker, David A.

    2012-01-01

    Rationale Aspects of schizophrenia, including deficits in sensorimotor gating, have been linked to glutamate dysfunction and/or oxidative stress in the prefrontal cortex. System xc−, a cystine- glutamate antiporter, is a poorly understood mechanism that contributes to both cellular antioxidant capacity and glutamate homeostasis. Objectives Our goal was to determine whether increased system xc− activity within the prefrontal cortex would normalize a rodent measure of sensorimotor gating. Methods In situ hybridization was used to map mRNA expression of xCT, the active subunit of system xc−, in the prefrontal cortex. Prepulse inhibition was used to measure sensorimotor gating; deficits in prepulse inhibition were produced using phencyclidine (0.3–3 mg/kg, sc). N-acetylcysteine (10–100 μM) and the system xc− inhibitor (S)-4-carboxyphenylglycine (CPG, 0.5 μM) were used to increase and decrease system xc− activity, respectively. The uptake of 14C-cystine into tissue punches obtained from the prefrontal cortex was used to assay system xc− activity. Results The expression of xCT mRNA in the prefrontal cortex was most prominent in a lateral band spanning primarily the prelimbic cortex. Although phencyclidine did not alter the uptake of 14C-cystine in prefrontal cortical tissue punches, intra-prefrontal cortical infusion of N-acetylcysteine (10–100 μM) significantly reduced phencyclidine- (1.5 mg/kg, sc) induced deficits in prepulse inhibition. N-acetylcysteine was without effect when co-infused with CPG (0.5 μM), indicating an involvement of system xc−. Conclusions These results indicate that phencyclidine disrupts sensorimotor gating through system xc− independent mechanisms, but that increasing cystine-glutamate exchange in the prefrontal cortex is sufficient to reduce behavioral deficits produced by phencyclidine. PMID:23192314

  8. Data reduction in the ITMS system through a data acquisition model with self-adaptive sampling rate

    OpenAIRE

    Ruiz González, Mariano; López Navarro, Juan Manuel; Arcas Castro, Guillermo de; Barrera Lopez de Turiso, Eduardo; Melendez, R.; Vega, Jesús

    2008-01-01

    Long pulse or steady state operation of fusion experiments require data acquisition and processing systems that reduce the volume of data involved. The availability of self-adaptive sampling rate systems and the use of real-time lossless data compression techniques can help solve these problems. The former is important for continuous adaptation of sampling frequency for experimental requirements. The latter allows the maintenance of continuous digitization under limited memory conditions. Thi...

  9. Rich Reduction

    DEFF Research Database (Denmark)

    Niebuhr, Oliver

    2016-01-01

    Managing and, ideally, explaining phonetic variation has ever since been a key issue in the speech sciences. In this context, the major contribution of Lindblom's H&H theory was to replace the futile search for invariance by an explainable variance based on the tug-of-war metaphor. Recent empirical...... evidence on articulatory prosodies and the involvement of reduction in conveying communication functions both suggest the next steps along the line of argument opened up by Lindblom. Specifically, we need to supplement Lindblom's explanatory framework and revise the speaker-listener conflict that lies...... at the heart of the tug-of-war metaphor. The author's suggestion would be to "offshore" the tug-of-war metaphor and replace it by the ocean metaphor of Bolinger (1964), with the ups and downs at the surface of the ocean representing the speaker's variation along the hypo-hyper scale and wavelength...

  10. Graphene oxide nanoplatforms to enhance catalytic performance of iron phthalocyanine for oxygen reduction reaction in bioelectrochemical systems

    Science.gov (United States)

    Costa de Oliveira, Maida Aysla; Mecheri, Barbara; D'Epifanio, Alessandra; Placidi, Ernesto; Arciprete, Fabrizio; Valentini, Federica; Perandini, Alessando; Valentini, Veronica; Licoccia, Silvia

    2017-07-01

    We report the development of electrocatalysts based on iron phthalocyanine (FePc) supported on graphene oxide (GO), obtained by electrochemical oxidation of graphite in aqueous solution of LiCl, LiClO4, and NaClO4. Structure, surface chemistry, morphology, and thermal stability of the prepared materials were investigated by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, atomic force microscopy (AFM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The catalytic activity toward oxygen reduction reaction (ORR) at neutral pH was evaluated by cyclic voltammetry. The experimental results demonstrate that the oxidation degree of GO supports affects the overall catalytic activity of FePc/GO, due to a modulation effect of the interaction between FePc and the basal plane of GO. On the basis of electrochemical, spectroscopic, and morphological investigations, FePc/GO_LiCl was selected to be assembled at the cathode side of a microbial fuel cell prototype, demonstrating a good electrochemical performance in terms of voltage and power generation.

  11. Implications of feed concentrate reduction in organic grassland-based dairy systems: a long-term on-farm study.

    Science.gov (United States)

    Leiber, F; Schenk, I K; Maeschli, A; Ivemeyer, S; Zeitz, J O; Moakes, S; Klocke, P; Staehli, P; Notz, C; Walkenhorst, M

    2017-11-01

    In response to increasing efforts for reducing concentrate inputs to organic dairy production in grassland-rich areas of Europe, a long-term study was conducted, which assessed the impacts of concentrate reductions on cows' performance, health, fertility and average herd age. In total, 42 Swiss commercial organic dairy cattle farms were monitored over 6 years ('Y0', 2008/09 until 'Y5', 2013/14). In comparison with overall data of Swiss herdbooks (including conventional and organic farms), the herds involved in the project had lower milk yields, similar milk solids, shorter calving intervals and higher average lactation numbers. During the first 3 project years farmers reduced the concentrate proportion (i.e. cereals, oilseeds and grain legumes) in the dairy cows' diets to varying degrees. In Y0, farms fed between 0% and 6% (dietary dry matter proportion per year) of concentrates. During the course of the study they changed the quantity of concentrates to voluntarily chosen degrees. Retrospectively, farms were clustered into five farm groups: Group '0-conc' (n=6 farms) already fed zero concentrates in Y0 and stayed at this level. Group 'Dec-to0' (n=11) reduced concentrates to 0 during the project period. Groups 'Dec-strong' (n=8) and 'Dec-slight' (n=12) decreased concentrate amounts by >50% and organic dairy farms, affected neither milk composition, nor fertility and veterinary treatments. Milk yields tended to decline, but at a low rate per saved kilogram of concentrate.

  12. Introductory lecture: sunlight-driven water splitting and carbon dioxide reduction by heterogeneous semiconductor systems as key processes in artificial photosynthesis.

    Science.gov (United States)

    Hisatomi, Takashi; Domen, Kazunari

    2017-06-02

    Both solar water splitting and carbon dioxide reduction using semiconductor systems have been studied as important components of artificial photosynthesis. This paper describes the various photovoltaic-powered electrochemical, photoelectrochemical and photocatalytic processes. An overview of the state-of-the-art is presented along with a summary of recent research approaches. A concept developed by our own research group in which fixed particulate photocatalysts are applied to scalable solar water splitting is discussed. Finally, a description of a possible artificial photosynthesis plant is presented, along with a discussion of the economic aspects of operating such a plant and potential reactor designs.

  13. Early Training-Induced Reduction of Angiotensinogen in Autonomic Areas-The Main Effect of Exercise on Brain Renin-Angiotensin System in Hypertensive Rats.

    Directory of Open Access Journals (Sweden)

    Laiali Jurdi Chaar

    Full Text Available Exercise training (T blunts functional deficits and renin-angiotensin system (RAS hyperactivity in hypertensive individuals. There is no information on T-induced temporal changes of brain RAS. We evaluate now the simultaneous effects of T on functional responses and time course changes in the expression/activity of brain RAS components in autonomic cardiovascular-controlling areas.Spontaneously hypertensive rats (SHR and age-matched normotensive controls (WKY were trained for 0, 1, 2, 4, 8 and 12 weeks. Sedentary (S groups served as time-controls. After arterial pressure (AP and heart rate (HR recordings at rest, fresh and fixed brains were harvested for qPCR and immunofluorescence assays. SHR-S vs. WKY-S exhibited higher mean AP (MAP and HR, increased pressure variability and sympathetic activity, elevated AT1 receptor (AT1 expression in nucleus tractus solitarii (NTS and higher Mas receptor expression in the rostroventrolateral medulla (RVLM. In SHR, T promptly (T2 on reduced sympathetic variability to heart/vessels and largely decreased angiotensinogen expression in the paraventricular hypothalamic nucleus (PVN and NTS, with a late RVLM reduction (T4. AT1 expression was only reduced at T12 (PVN and NTS with transient, not maintained Mas receptor changes in PVN and RVLM. These responses were accompanied by baseline MAP and HR reduction in the SHR-T (from T4 on. In the SHR group, PVN angiotensinogen expression correlated positively with sympathetic activity, resting MAP and HR. In WKY-T, a precocious (T2-T12 RVLM AT1 decrease preceded the appearance of resting bradycardia (from T8 on.Early and maintained reduction of angiotensinogen content in autonomic areas of the SHR is the most prominent effect of training on brain RAS. Down-regulation of PVN RAS expression is an essential factor to drive cardiovascular benefits in SHR-T, while resting bradycardia in WKY-T is correlated to RVLM AT1 reduction.

  14. Early Training-Induced Reduction of Angiotensinogen in Autonomic Areas-The Main Effect of Exercise on Brain Renin-Angiotensin System in Hypertensive Rats.

    Science.gov (United States)

    Chaar, Laiali Jurdi; Alves, Tatiana Pereira; Batista Junior, Alvaro Martins; Michelini, Lisete Compagno

    2015-01-01

    Exercise training (T) blunts functional deficits and renin-angiotensin system (RAS) hyperactivity in hypertensive individuals. There is no information on T-induced temporal changes of brain RAS. We evaluate now the simultaneous effects of T on functional responses and time course changes in the expression/activity of brain RAS components in autonomic cardiovascular-controlling areas. Spontaneously hypertensive rats (SHR) and age-matched normotensive controls (WKY) were trained for 0, 1, 2, 4, 8 and 12 weeks. Sedentary (S) groups served as time-controls. After arterial pressure (AP) and heart rate (HR) recordings at rest, fresh and fixed brains were harvested for qPCR and immunofluorescence assays. SHR-S vs. WKY-S exhibited higher mean AP (MAP) and HR, increased pressure variability and sympathetic activity, elevated AT1 receptor (AT1) expression in nucleus tractus solitarii (NTS) and higher Mas receptor expression in the rostroventrolateral medulla (RVLM). In SHR, T promptly (T2 on) reduced sympathetic variability to heart/vessels and largely decreased angiotensinogen expression in the paraventricular hypothalamic nucleus (PVN) and NTS, with a late RVLM reduction (T4). AT1 expression was only reduced at T12 (PVN and NTS) with transient, not maintained Mas receptor changes in PVN and RVLM. These responses were accompanied by baseline MAP and HR reduction in the SHR-T (from T4 on). In the SHR group, PVN angiotensinogen expression correlated positively with sympathetic activity, resting MAP and HR. In WKY-T, a precocious (T2-T12) RVLM AT1 decrease preceded the appearance of resting bradycardia (from T8 on). Early and maintained reduction of angiotensinogen content in autonomic areas of the SHR is the most prominent effect of training on brain RAS. Down-regulation of PVN RAS expression is an essential factor to drive cardiovascular benefits in SHR-T, while resting bradycardia in WKY-T is correlated to RVLM AT1 reduction.

  15. Reduction in Radiation Dose in a Pediatric Cardiac Catheterization Lab Using the Philips AlluraClarity X-ray System.

    Science.gov (United States)

    Sullivan, Patrick M; Harrison, David; Badran, Sarah; Takao, Cheryl M; Ing, Frank F

    2017-08-02

    The objective of this study was to compare radiation doses and imaging quality using Philips AlluraClarity (Philips Healthcare, Best, The Netherlands) X-ray system and an older generation reference system. AlluraClarity is a new generation fluoroscopy system designed to reduce radiation without compromising image quality, but reports of its use in pediatric patients are limited. Dose area products (DAP, mGy cm(2)) and DAP/kg were compared in patients catheterized using Allura Xper and AlluraClarity systems over a year of use for each. Randomly selected studies from each system were assessed for image quality. The 430 patients imaged with Clarity were larger than the 332 imaged with Xper (median BSA: 0.74 vs. 0.64 m(2), p = 0.06), and median total fluoroscopic times (TFT) were similar (15.8 vs. 16.1 min, p = 0.37). Median DAPs were 8661 mGy cm(2) (IQR: 18,300 mGy cm(2)) and 4523 mGy cm(2) (IQR: 11,596 mGy cm(2)) with Xper and Clarity, respectively (p lab.

  16. Method I : Planar reduction

    NARCIS (Netherlands)

    Broer, H.; Hoveijn, I.; Lunter, G.; Vegter, G.

    2003-01-01

    We apply the planar reduction method to a general two degree of freedom system with optional symmetry, near equilibrium and close to resonance. As a leading example the spring-pendulum close to 1:2 resonance is used. The resulting planar model is computed explicitly, and the bifurcation curves

  17. Reduction of the visual impact of overhead transmission line systems through utilisation of line surge arresters as lightning protection

    DEFF Research Database (Denmark)

    Sørensen, Thomas Kjærsgaard; Holbøll, Joachim

    2008-01-01

    The main reason for the increasing public resistance to overhead transmission line systems in Denmark is the impact on the environment with emphasis on the visual aspect. Therefore the Danish Transmission System Operator Energinet.dk is currently carrying out a research project, in cooperation...... in line performance and lightning protection of the nearest substations requires thorough modelling of the new line including all electrical parameters necessary for performance evaluation under all conditions. In this paper, explicit use of line surge arresters as lightning protection on the line...

  18. Efficient anti-Prelog enantioselective reduction of acetyltrimethylsilane to (R-1-trimethylsilylethanol by immobilized Candida parapsilosis CCTCC M203011 cells in ionic liquid-based biphasic systems

    Directory of Open Access Journals (Sweden)

    Zhang Bo-Bo

    2012-08-01

    Full Text Available Abstract Background Biocatalytic asymmetric reductions with whole cells can offer high enantioselectivity, environmentally benign processes and energy-effective operations and thus are of great interest. The application of whole cell-mediated bioreduction is often restricted if substrate and product have low water solubility and/or high toxicity to the biocatalyst. Many studies have shown that a biphasic system is often useful in this instance. Hence, we developed efficient biphasic reaction systems with biocompatible water-immiscible ionic liquids (ILs, to improve the biocatalytic anti-Prelog enantioselective reduction of acetyltrimethylsilane (ATMS to (R-1-trimethylsilylethanol {(R-1-TMSE}, which is key synthon for a large number of silicon-containing drugs, using immobilized Candida parapsilosis CCTCC M203011 cells as the biocatalyst. Results It was found that the substrate ATMS and the product 1-TMSE exerted pronounced toxicity to immobilized Candida parapsilosis CCTCC M203011 cells. The biocompatible water-immiscible ILs can be applied as a substrate reservoir and in situ extractant for the product, thus greatly enhancing the efficiency of the biocatalytic process and the operational stability of the cells as compared to the IL-free aqueous system. Various ILs exerted significant but different effects on the bioreduction and the performances of biocatalysts were closely related to the kinds and combination of cation and anion of ILs. Among all the water-immiscible ILs investigated, the best results were observed in 1-butyl-3-methylimidazolium hexafluorophosphate (C4mim·PF6/buffer biphasic system. Furthermore, it was shown that the optimum substrate concentration, volume ratio of buffer to IL, buffer pH, reaction temperature and shaking rate for the bioreduction were 120 mM, 8/1 (v/v, 6.0, 30°C and 180 r/min, respectively. Under these optimized conditions, the initial reaction rate, the maximum yield and the product e.e. were 8.1

  19. Redução da instabilidade e melhoria de desempenho do sistema MRP MRP system: nervousness reduction and performance improvement

    Directory of Open Access Journals (Sweden)

    Moacir Godinho Filho

    2006-04-01

    Full Text Available O artigo propõe um método para melhorar o desempenho do sistema MRP em um estudo de caso, uma grande empresa que produz materiais para escrita. O método é conseqüência de um levantamento bibliográfico e de características particulares do estudo de caso. Este método parte do princípio de que a melhoria de desempenho dos sistemas MRP é viabilizada pela redução no grau de instabilidade de tais sistemas e esta por sua vez só pode ser conseguida por meio de dois fatores-chave: i uma correta parametrização do sistema e ii um planejamento e programação da produção integrados voltados para a elaboração de um Plano Mestre de Produção (MPS factível, respeitando as limitações de cálculo de capacidade do sistema. O método foi implementado e os resultados foram: uma redução drástica na instabilidade do sistema, com conseqüente redução nos custos dos estoques, melhoria no nível de serviço e aumento da satisfação e confiança das pessoas com relação ao sistema.The paper presents a method designed to get an improvement of the system performance in a case study, a large company that produces materials for writing. The method arises from a literature survey and from the particular characteristics of the case study. The method argues that the improvement on MRP performance is attained by system nervousness reduction which is supported by two main factors: i system parameters must be determined in a precise way; ii integrated production planning and scheduling focused on development of a realistic Master Production Schedule (MPS, which takes account the system capacity. The method was applied and the results were: reduction of system nervousness, reduction of inventory costs, improvement of service level, increase of the workers satisfaction and increase the reliance on the MRP system.

  20. The use of geographical information systems for disaster risk reduction strategies: a case study of Volcan de Colima, Mexico

    Science.gov (United States)

    Landeg, O.

    Contemporary disaster risk management requires the analysis of vulnerability and hazard exposure, which is imperative at Volcan de Colima (VdC), Mexico, due to the predicted, large-magnitude eruption forecast to occur before 2025. The methods used to gauge social vulnerability included the development and application of proxies to census records, the undertaking of a building vulnerability survey and the spatial mapping of civil and emergency infrastructure. Hazard exposure was assessed using primary modelling of laharic events and the digitalisation of secondary data sources detailing the modelled extent of pyroclastic flows and tephra deposition associated with a large-magnitude (VEI 5) eruption at VdC. The undertaking and analysis of a risk perception survey of the population enabled an understanding of the cognitive behaviour of residents towards the volcanic risk. In comparison to the published hazard map, the GIS analysis highlighted an underestimation of lahar hazard on the western flank of VdC and the regional tephra hazard. Vulnerability analysis identified three communities where social deprivation is relatively high, and those with significant elderly and transient populations near the volcano. Furthermore, recognition of the possibility of an eruption in the near future was found to be low across the study region. These results also contributed to the analysis of emergency management procedures and the preparedness of the regional authorities. This multidisciplinary research programme demonstrates the success of applying a GIS platform to varied integrative spatial and temporal analysis. Furthermore, ascertaining the impact of future activity at VdC upon its surrounding populations permits the evaluation of emergency preparedness and disaster risk reduction strategies.

  1. A robust semi-definite optimization based solution to the robust order reduction problem for parametric uncertain dissipative linear systems

    NARCIS (Netherlands)

    F.D. Barb

    2004-01-01

    textabstractIn this paper we address the problem of reducing the order of a linear system affected by uncertainties from the robust dissipative perspective introduced in Barb. Firstly, we show that all major balanced truncation techniques developed and reported in the literature of the last two

  2. Techno-stress: a prospective psychophysiological study of the impact of a controlled stress-reduction program in advanced telecommunication systems design work.

    Science.gov (United States)

    Arnetz, B B

    1996-01-01

    There is a void of studies concerning occupational health aspects from working with the most advanced forms of information technologies techniques such as are found in some of the world-renowned telecommunication systems development laboratories. However, many of these techniques will later be applied in the regular office environment. We wanted to identify some of the major stressors perceived by advanced telecommunication systems design employees and develop a valid and reliable instrument by which to monitor such stressors. We were also interested in assessing the impact of a controlled prospective stress-reduction program on perceived mental stress and specific psychophysiological parameters. A total of 116 employees were recruited. Sixty-one were offered to participate in one of three stress-reduction training programs (intervention group). The additional 50 functioned as a reference group. After a detailed baseline assessment, including a comprehensive questionnaire and psychophysiological measurements, new assessments were made at the end of the formal training program (+ 3 months) and after an additional 5-month period. Results reveal a significant improvement in the intervention group with regard to circulating levels of the stress-sensitive hormone prolactin as well as an attenuation in mental strain. Cardiovascular risk indicators were also improved. Circulating thrombocytes decreased in the intervention group. Type of stress-reduction programs chosen and intensity of participation did not significantly impact results. Coping style was not affected and no beneficial effects were observed with regard to the psychological characteristics of the work, eg intellectual discretion and control over work processes. The survey instrument is now being used in the continuous improvement of work processes and strategic leadership of occupational health issues. The results suggest that prior psychophysiological stress research, based on low- and medium-skill, rather

  3. An interactive diary for diet management (DAI): a new telemedicine system able to promote body weight reduction, nutritional education, and consumption of fresh local produce.

    Science.gov (United States)

    Rossi, Maria Chiara; Perozzi, Cinzia; Consorti, Carla; Almonti, Teresa; Foglini, Paolo; Giostra, Nena; Nanni, Paola; Talevi, Susanna; Bartolomei, Dante; Vespasiani, Giacomo

    2010-08-01

    The aim of this multicenter, longitudinal, single-arm, pre-post comparison was to test a telemedicine system able to promote body weight reduction, nutritional education, and consumption of fresh local produce. DAI (MeTeDa srl, San Benedetto del Tronto, Italy) is a software for mobile phones to support patients following a specific dietetic program. It facilitates the communication between the patient and dietician via short text messages. Overall, three specialized dieticians enrolled 140 consecutive patients with body mass index (BMI) >or=25 kg/m(2) who voluntered to follow a specific diet program to be managed with DAI. At baseline and after 20 weeks, data on body weight, waist circumference, BMI, fasting blood glucose, lipid profile, food habits, and physical activity were collected and compared by the Wilcoxon test or the McNemar test. Overall, 115 individuals (82.1%) completed the follow-up. The mean (95% confidence interval) reduction in body weight was -2.5 (-3.2; -1.8) kg, whereas the reduction in waist circumference was -3.7 (-4.6; -2.9) cm, and that in BMI was 1.0 (-0.7; -1.2) kg/m(2). The software was useful as an educational tool: participants achieving the Mediterranean diet targets increased from 14.4% to 69.8% after 20 weeks. On average, each patient recognized and chose fresh local vegetables eight times per week during the follow-up. Participants regularly communicated with dieticians through short text messages. This study allowed the documentation of the efficacy of a new telemedicine system in supporting people who need to lose body weight. The tool was also suitable for a more articulated initiative of "nutritional education" aiming to promote the healthy properties of the Mediterranean diet and the consumption of local produce.

  4. Reduction of CO2 emissions from road transport in cities impact of dynamic route guidance system on greenhouse gas emission

    CERN Document Server

    Markiewicz, Michal

    2017-01-01

    Michal Markiewicz presents the outcomes of his research regarding the influence of dynamic route guidance system on overall emission of carbon dioxide from road transport in rural areas. Sustainable transportation in smart cities is a big challenge of our time, but before electric vehicles replace vehicles that burn fossil fuels we have to think about traffic optimization methods that reduce the amount of greenhouse gas emissions. Contents Comparison of Travel Time Measurements Using Floating Car Data and Intelligent Infrastructure Integration of Cellular Automata Traffic Simulator with CO2 Emission Model Impact of Dynamic Route Guidance System on CO2 Emission Naxos Vehicular Traffic Simulator Target Groups Lecturers and students of computer science, transportation and logistics Traffic engineers The Author Dr. Michal Markiewicz defended his PhD thesis in computer science at the University of Bremen,TZI Technologie-Zentrum Informatik und Informationstechnik, Germany. Currently, he is working on commercializat...

  5. Complexity Reduction in Large Quantum Systems: Fragment Identification and Population Analysis via a Local Optimized Minimal Basis.

    Science.gov (United States)

    Mohr, Stephan; Masella, Michel; Ratcliff, Laura E; Genovese, Luigi

    2017-09-12

    We present, within Kohn-Sham density functional theory calculations, a quantitative method to identify and assess the partitioning of a large quantum-mechanical system into fragments. We then show how within this framework simple generalizations of other well-known population analyses can be used to extract, from first-principles, reliable electrostatic multipoles for the identified fragments. Our approach reduces arbitrariness in the fragmentation procedure and enables the possibility to assess quantitatively whether the corresponding fragment multipoles can be interpreted as observable quantities associated with a system moiety. By applying our formalism within the code BigDFT, we show that the use of a minimal set of in situ-optimized basis functions allows at the same time a proper fragment definition and an accurate description of the electronic structure.

  6. Synergetic Effect between Lighting Efficiency Enhancement and Building Energy Reduction Using Alternative Thermal Operating System of Indoor LED Lighting

    Directory of Open Access Journals (Sweden)

    Byung-Lip Ahn

    2015-08-01

    Full Text Available We investigated the synergetic effect between light-emitting diode (LED lighting efficiency and building energy savings in heating and cooling using an alternative thermal operating system (ATOS of indoor LED lighting integrated with the ventilation system of a building as an active cooling device. The heat generated from LED lighting and the indoor lighting illuminance were experimentally determined. The indoor heat gains in cooling and heating periods were determined using measurement data; the annual energy savings of an office building in heating and cooling were calculated through simulation. The LED lighting illuminance increased by approximately 40% and the lighting contribution for indoor heat gain was 7.8% in summer, while 69.8% in winter with the ATOS. Consequently, the annual total energy use of the office building could be reduced by 5.9%; the energy use in cooling and heating was reduced by 18.4% and 3.3%, respectively.

  7. IMAGES CONSTRUCTIONS TECHNIC, PLANNING AND RISK REDUCTION: THE IMPLANTATION OF THE ERP’S SYSTEM IN A PUBLIC EDUCATIONAL INSTITUTION

    Directory of Open Access Journals (Sweden)

    Henrique Cordeiro Martins

    2013-06-01

    Full Text Available This article describes the ERP planning and implementation process that includes identifying requirements,expectations, benefits, limitations and the ideational images built by the future users. The researchwas qualitative and quantitative descriptive based in the Instituto Federal Minas Gerais (IFMG case:the first Brazilian public federal institution of technological education to install the ERP’s system. The datawas collected based on free and semi-structured interviews. The images configuration technic use allowedidentifying the user’s images for the ERP software. The positive images represented the success factors andthe negative images were related to aversion system implementation. Generally, the results indicated thatthe IFM' ERP plans of implementation were propitious to build a unique identity. This paper aims also tocontribute with others studies related with ERP implementation in public organizations.

  8. Exceptional Reductions

    CERN Document Server

    Marrani, Alessio; Riccioni, Fabio

    2011-01-01

    Starting from basic identities of the group E8, we perform progressive reductions, namely decompositions with respect to the maximal and symmetric embeddings of E7xSU(2) and then of E6xU(1). This procedure provides a systematic approach to the basic identities involving invariant primitive tensor structures of various irreprs. of finite-dimensional exceptional Lie groups. We derive novel identities for E7 and E6, highlighting the E8 origin of some well known ones. In order to elucidate the connections of this formalism to four-dimensional Maxwell-Einstein supergravity theories based on symmetric scalar manifolds (and related to irreducible Euclidean Jordan algebras, the unique exception being the triality-symmetric N = 2 stu model), we then derive a fundamental identity involving the unique rank-4 symmetric invariant tensor of the 0-brane charge symplectic irrepr. of U-duality groups, with potential applications in the quantization of the charge orbits of supergravity theories, as well as in the study of mult...

  9. Developing the Philippines as a Global Hub for Disaster Risk Reduction - A Health Research Initiative as Presented at the 10th Philippine National Health Research System Week Celebration.

    Science.gov (United States)

    Banwell, Nicola; Montoya, Jaime; Opeña, Merlita; IJsselmuiden, Carel; Law, Ronald; Balboa, Gloria J; Rutherford, Shannon; Chu, Cordia; Murray, Virginia

    2016-10-25

    The recent Philippine National Health Research System (PNHRS) Week Celebration highlighted the growing commitment to Disaster Risk Reduction (DRR) in the Philippines. The event was lead by the Philippine Council for Health Research and Development of the Department of Science and Technology and the Department of Health, and saw the participation of national and international experts in DRR, and numerous research consortia from all over the Philippines. With a central focus on the Sendai Framework for Disaster Risk Reduction, the DRR related events recognised the significant disaster risks faced in the Philippines. They also illustrated the Philippine strengths and experience in DRR. Key innovations in science and technology showcased at the conference include the web-base hazard mapping applications 'Project NOAH' and 'FaultFinder'. Other notable innovations include 'Surveillance in Post Extreme Emergencies and Disasters' (SPEED) which monitors potential outbreaks through a syndromic reporting system. Three areas noted for further development in DRR science and technology included: integrated national hazard assessment, strengthened collaboration, and improved documentation. Finally, the event saw the proposal to develop the Philippines into a global hub for DRR. The combination of the risk profile of the Philippines, established national structures and experience in DRR, as well as scientific and technological innovation in this field are potential factors that could position the Philippines as a future global leader in DRR. The purpose of this article is to formally document the key messages of the DRR-related events of the PNHRS Week Celebration.

  10. Energy-Related Small Molecule Activation Reactions: Oxygen Reduction and Hydrogen and Oxygen Evolution Reactions Catalyzed by Porphyrin- and Corrole-Based Systems.

    Science.gov (United States)

    Zhang, Wei; Lai, Wenzhen; Cao, Rui

    2017-02-22

    Globally increasing energy demands and environmental concerns related to the use of fossil fuels have stimulated extensive research to identify new energy systems and economies that are sustainable, clean, low cost, and environmentally benign. Hydrogen generation from solar-driven water splitting is a promising strategy to store solar energy in chemical bonds. The subsequent combustion of hydrogen in fuel cells produces electric energy, and the only exhaust is water. These two reactions compose an ideal process to provide clean and sustainable energy. In such a process, a hydrogen evolution reaction (HER), an oxygen evolution reaction (OER) during water splitting, and an oxygen reduction reaction (ORR) as a fuel cell cathodic reaction are key steps that affect the efficiency of the overall energy conversion. Catalysts play key roles in this process by improving the kinetics of these reactions. Porphyrin-based and corrole-based systems are versatile and can efficiently catalyze the ORR, OER, and HER. Because of the significance of energy-related small molecule activation, this review covers recent progress in hydrogen evolution, oxygen evolution, and oxygen reduction reactions catalyzed by porphyrins and corroles.

  11. Data and Summaries for Catalytic Destruction of a Surrogate Organic Hazardous Air Pollutant as a Potential Co-benefit for Coal-Fired Selective Catalytic Reduction Systems

    Science.gov (United States)

    Table 1 summarizes and explanis the Operating Conditions of the SCR Reactor used in the Benzene-Destruction.Table 2 summarizes and explains the Experimental Design and Test Results.Table 3 summarizes and explains the Estimates for Individual Effects and Cross Effects Obtained from the Linear Regression Models for Destruction of C6H6 and Reduction of NO.Fig. 1 shows the Down-flow SCR reactor system in detail.Fig. 2 shows the graphical summary of the Effect of the inlet C6H6 concentration to the SCR reactor on the destruction of C6H6.Fig.3 shows the summary of Carbon mass balance for C6H6 destruction promoted by the V2O5-WO3/TiO2 catalyst.This dataset is associated with the following publication:Lee , C., Y. Zhao, S. Lu, and W.R. Stevens. Catalytic Destruction of a Surrogate Organic Hazardous Air Polutant as a Potential Co-benefit for Coal-fired Selective Catalyst Reduction Systems. AMERICAN CHEMICAL SOCIETY. American Chemical Society, Washington, DC, USA, 30(3): 2240-2247, (2016).

  12. Complexity Reduction in Large Quantum Systems: Reliable Electrostatic Embedding for Multiscale Approaches via Optimized Minimal Basis Functions

    OpenAIRE

    Mohr, Stephan; Masella, Michel; Ratcliff, Laura E.; Genovese, Luigi

    2017-01-01

    Given a partition of a large system into an active quantum mechanical (QM) region and its environment, we present a simple way of embedding the QM region into an effective electrostatic potential representing the environment. This potential is generated by partitioning the environment into well defined fragments, and assigning each one a set of electrostatic multipoles, which can then be used to build up the electrostatic potential. We show that, providing the fragments and the projection sch...

  13. Image support system in transarterial chemoembolization contributes to reduction of the quantity of radiation exposure and contrast media.

    Science.gov (United States)

    Tamai, Tsutomu; Taniyama, Oki; Oda, Kohei; Kasai, Ai; Ijyuin, Syo; Sakae, Haruka; Onishi, Hiroka; Tabu, Kazuaki; Kumagai, Kotaro; Mawatari, Seiichi; Moriuchi, Akihiro; Uto, Hirofumi; Ido, Akio

    2017-10-10

    We confirmed the clinical utility of a three-dimensional navigation system during transarterial chemoembolization. We evaluated 128 tumors in 91 patients enrolled between May 2015 and August 2016. We evaluated the accuracy of the three-dimensional navigation imaging system for all tumors. We compared the patients who were able to undergo route detection using three-dimensional navigation with previously treated patients who underwent transarterial chemoembolization without using three-dimensional navigation (n=21). For 38 patients who underwent super-selective microcatheter insertion after a feeding artery was identified by three-dimensional navigation, we confirmed the relationship between the tumors and contrasted liver parenchyma and divided the computed tomography hepatic arteriography findings into four grades. Grade 1: an overlap of >5 mm, Grade 2: an overlap between 0 mm and 5 mm, Grade 3: the borders of the tumor within the liver parenchyma but in contact with the edges, and Grade 4: a tumor outside the borders of the liver parenchyma. Using the three-dimensional navigation system, we identified a tumor-feeding artery in 125/128 tumors (97.6%). Furthermore, this system allowed us to significantly reduce the volume of contrast media and the radiation exposure dose in patients undergoing an evaluation. We identified 15 Grade 1 tumors (39.5%), 3 Grade 2 tumors (7.9%), 11 Grade 3 tumors (28.9%), and 9 Grade 4 tumors (23.7%) according to our definitions. The three-dimensional navigation is useful not only for patients, but also for surgeons who have relatively little experience. This article is protected by copyright. All rights reserved.

  14. Reduction in intraoperative bacterial contamination of peripheral intravenous tubing through the use of a passive catheter care system.

    Science.gov (United States)

    Loftus, Randy W; Brindeiro, Bryan S; Kispert, David P; Patel, Hetal M; Koff, Matthew D; Jensen, Jens T; Dodds, Thomas M; Yeager, Mark P; Ruoff, Kathryn L; Gallagher, John D; Beach, Michael L; Brown, Jeremiah R

    2012-12-01

    Bacterial contamination of intravascular devices has been associated with increased morbidity and mortality in various hospital settings, including the perioperative environment. Catheter hub disinfection has been shown in an ex vivo model to attenuate intraoperative injection of bacterial organisms originating from the anesthesia provider's hands, providing the impetus for improvement in intraoperative disinfection techniques and compliance. In the current study, we investigated the clinical effectiveness of a new, passive catheter care station in reducing the incidence of bacterial contamination of open lumen patient IV stopcock sets. The secondary aim was to evaluate the impact of this novel intervention on the combined incidence of 30-day postoperative infections and IV catheter-associated phlebitis. Five hundred ninety-four operating room environments were randomized by a computer-generated list to receive either a novel catheter care bundle (HubScrub and DOCit) or standard caps in conjunction with a sterile, conventional open lumen 3-way stopcock set (24 inch with 3-gang 4-way and T-Connector). Patients underwent general anesthesia according to usual practice and were followed prospectively for 30 postoperative days to identify the development of health care-associated infections (HCAIs) and/or phlebitis. The primary outcome was intraoperative bacterial contamination of the primary stopcock set used by the anesthesia provider(s). The secondary outcome was the combined incidence of 30-day postoperative infections and phlebitis. Five hundred seventy-two operating rooms were included in the final analysis. Study groups were comparable with no significant differences in patient, provider, anesthetic, or procedural characteristics. The catheter care station reduced the incidence of primary stopcock lumen contamination compared with standard caps (odds ratio [OR] 0.79, 95% confidence interval [CI] 0.63-0.98, P = 0.034) and was associated with a reduction in the

  15. RTS noise and dark current white defects reduction using selective averaging based on a multi-aperture system.

    Science.gov (United States)

    Zhang, Bo; Kagawa, Keiichiro; Takasawa, Taishi; Seo, Min Woong; Yasutomi, Keita; Kawahito, Shoji

    2014-01-16

    In extremely low-light conditions, random telegraph signal (RTS) noise and dark current white defects become visible. In this paper, a multi-aperture imaging system and selective averaging method which removes the RTS noise and the dark current white defects by minimizing the synthetic sensor noise at every pixel is proposed. In the multi-aperture imaging system, a very small synthetic F-number which is much smaller than 1.0 is achieved by increasing optical gain with multiple lenses. It is verified by simulation that the effective noise normalized by optical gain in the peak of noise histogram is reduced from 1.38e⁻ to 0.48 e⁻ in a 3 × 3-aperture system using low-noise CMOS image sensors based on folding-integration and cyclic column ADCs. In the experiment, a prototype 3 × 3-aperture camera, where each aperture has 200 × 200 pixels and an imaging lens with a focal length of 3.0 mm and F-number of 3.0, is developed. Under a low-light condition, in which the maximum average signal is 11e⁻ per aperture, the RTS and dark current white defects are removed and the peak signal-to-noise ratio (PSNR) of the image is increased by 6.3 dB.

  16. Reduction of the heat leak in superconducting system at half-wave-rectified current mode by peltier current lead

    CERN Document Server

    Yamaguchi, T; Nakamura, K; Yamaguchi, S; Hasegawa, Y

    2002-01-01

    Experiments of Peltier current lead (PCL) were performed by the way of half-wave-rectified current (HWRC) for an evaluation of the PCL system in the drive with the large-rippled current. The current ripple of the HWRC is large, and we discussed the cooling capability of the current ripple. The experimental results revealed that the temperature difference of the thermoelectric-element (TE) increased with the magnitude of the current in the PCL system, despite the large current ripple. Calorimetric measurements revealed that the PCL reduced the heat leak of 60% for the peak current 90A. We compared the PCL systems of the direct current (dc) mode and the HWRC mode. The results showed that the current dependence of the temperature difference in the HWRC mode did not match that of the dc mode, but those of the heat leak matched well. The performance of the Peltier cooling in the HWRC mode is reduced to be 2/pi time of the Seebeck coefficient for the dc mode by using the time-average method. (author)

  17. Experimental study of cross-phase modulation reduction in hybrid systems with co-propagating 100G PM-QPSK and 10G OOK.

    Science.gov (United States)

    Searcy, Steven; Tibuleac, Sorin

    2013-12-16

    We experimentally investigate various methods for reducing cross-phase modulation in hybrid networks with mixed 100G and 10G traffic. The experimental results over standard single-mode and non-zero dispersion-shifted fiber types demonstrate the effectiveness of several different XPM reduction techniques as well as the interplay between them. Nonlinear transmission performance is quantified using the Nonlinear Threshold metric as a function of key system features, including DCM type, dispersion map, spectral guard bands, and carrier phase estimation window size. Fiber Bragg grating-based DCMs are shown to offer a distinct advantage over fiber-based DCMs under certain conditions, particularly in dispersion-managed systems with very strong XPM. The average walk-off per span is introduced as a simple yet effective metric to compare different methods of XPM mitigation.

  18. Integrated testing of an electrochemical depolarized CO2 concentrator /EDC/ and a Bosch CO2 reduction subsystem /BRS/. [in spaceborne oxygen reclamation system

    Science.gov (United States)

    Schubert, F. H.; Clark, D. C.; Quattrone, P. D.

    1976-01-01

    An oxygen reclamation system (ORS) in a spacecraft has the task to revitalize the spacecraft atmosphere by recovering the elementary oxygen from metabolically produced carbon dioxide and water vapor. Life support subsystems which can form such an ORS are an electrochemical depolarized carbon dioxide concentrator (EDC), a Bosch carbon dioxide reduction subsystem (BRS), and an oxygen generation subsystem (OGS). A total recovery of the oxygen from metabolically generated carbon dioxide can be obtained with the aid of system composed of the considered three subsystems. Attention is given to the control concept which assures an integrated operation of the EDC, BRS, and OGS. A description is presented of the test results obtained during 86 days of testing.

  19. Energy-Efficiency Analysis of Per-Subcarrier Antenna Selection with Peak-Power Reduction in MIMO-OFDM Wireless Systems

    Directory of Open Access Journals (Sweden)

    Ngoc Phuc Le

    2014-01-01

    Full Text Available The use of per-subcarrier antenna subset selection in OFDM wireless systems offers higher system capacity and/or improved link reliability. However, the implementation of the conventional per-subcarrier selection scheme may result in significant fluctuations of the average power and peak power across antennas, which affects the potential benefits of the system. In this paper, power efficiency of high-power amplifiers and energy efficiency in per-subcarrier antenna selection MIMO-OFDM systems are investigated. To deliver the maximum overall power efficiency, we propose a two-step strategy for data-subcarrier allocation. This strategy consists of an equal allocation of data subcarriers based on linear optimization and peak-power reduction via cross-antenna permutations. For analysis, we derive the CCDF (complementary cumulative distribution function of the power efficiency as well as the analytical expressions of the average power efficiency. It is proved from the power-efficiency perspective that the proposed allocation scheme outperforms the conventional scheme. We also show that the improvement in the power efficiency translates into an improved capacity and, in turn, increases energy efficiency of the proposed system. Simulation results are provided to validate our analyses.

  20. Structure, Stability and Emissions of Lean Direct Injection Combustion, including a Novel Multi-Point LDI System for NOx Reduction

    Science.gov (United States)

    Villalva Gomez, Rodrigo

    Experimental research on Lean Direct Injection (LDI) combustors for gas turbine applications is presented. LDI combustion is an alternative to lean premixed combustion which has the potential of equivalent reduction of oxides of nitrogen (NOx) emissions and of peak combustor exit temperatures, but without some drawbacks of premixed combustors, such as flashback and autoignition. Simultaneous observations of the velocity field and reaction zone of an LDI swirl-stabilized combustor with a mixing tube at atmospheric conditions, with the goal of studying the flame stabilization mechanism, are shown. The flame was consistently anchored at the shear layer formed by the high-speed reactants exiting the mixing tube and the low speed recirculation region. Individual image analysis of the location of the tip of the recirculation zone and tip of the reaction region confirmed previously observed trends, but showed that calculation of the distance between these two points for corresponding image pairs yields results no different than when calculated from random image pairs. This most likely indicates a lag in the anchoring of the flame to changes in the recirculation zone, coupled with significant stochastic variation. An alternate LDI approach, multi-point LDI (MLDI), is also tested experimentally. A single large fuel nozzle is replaced by multiple small fuel nozzles to improve atomization and reduce the total volume of the high-temperature, low velocity recirculation zones, reducing NOx formation. The combustor researched employs a novel staged approach to allow good performance across a wide range of conditions by using a combination of nozzle types optimized to various power settings. The combustor has three independent fuel circuits referenced as pilot, intermediate, and outer. Emissions measurements, OH* chemiluminescence imaging, and thermoacoustic instability studies were run in a pressurized combustion facility at pressures from 2.0 to 5.3 bar. Combustor performance