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Sample records for distributedgeneration system solution

  1. Solution of Nonlinear Systems

    NASA Technical Reports Server (NTRS)

    Turner, L. R.

    1960-01-01

    The problem of solving systems of nonlinear equations has been relatively neglected in the mathematical literature, especially in the textbooks, in comparison to the corresponding linear problem. Moreover, treatments that have an appearance of generality fail to discuss the nature of the solutions and the possible pitfalls of the methods suggested. Probably it is unrealistic to expect that a unified and comprehensive treatment of the subject will evolve, owing to the great variety of situations possible, especially in the applied field where some requirement of human or mechanical efficiency is always present. Therefore we attempt here simply to pose the problem and to describe and partially appraise the methods of solution currently in favor.

  2. Analytical solutions of the Lorenz system

    NASA Astrophysics Data System (ADS)

    Kudryashov, Nikolay A.

    2015-03-01

    The Lorenz system is considered. The Painlevé test for the third-order equation corresponding to the Lorenz model at σ ≠ 0 is presented. The integrable cases of the Lorenz system and the first integrals for the Lorenz system are discussed. The main result of the work is the classification of the elliptic solutions expressed via the Weierstrass function. It is shown that most of the elliptic solutions are degenerated and expressed via the trigonometric functions. However, two solutions of the Lorenz system can be expressed via the elliptic functions.

  3. Soliton solutions of the Hirota's system

    NASA Astrophysics Data System (ADS)

    Yesmakhanova, Kuralay; Shaikhova, Gaukhar; Bekova, Guldana

    2016-08-01

    It is well known that nonlinear integrable systems have attracted a lot of attention among researchers. This fascinating subject of nonlinear science has branched out in almost all areas of technology and science. In nonlinear science soliton solutions play an important role. There are many ways to obtain soliton solutions of the nonlinear evolution equations, such as the Painleve analysis, the Hirota's bilinear method, Darboux transformation (DT) and so on. Among the various methods, the DT has been proved very successful in driving different kinds of solutions for many of the integrable equations from a trivial seed. In this work, we focus on the construction soliton solutions for the 2+1-dimensional Hirota's system, which is modified nonlinear Schrödinger equations. One-soliton solutions are obtained by means of the one-fold Darboux transformation for the 2+1-dimensional Hirota's system.

  4. Knee System Utilizing Personalized Solutions Instrumentation

    MedlinePlus

    ATTUNE® Knee System utilizing the TRUMATCH® Personalized Solutions Instrumentation Click Here to view the BroadcastMed, Inc. Privacy Policy and Legal Notice © 2016 BroadcastMed, Inc. All rights reserved.

  5. Flexible solution for interoperable cloud healthcare systems.

    PubMed

    Vida, Mihaela Marcella; Lupşe, Oana Sorina; Stoicu-Tivadar, Lăcrămioara; Bernad, Elena

    2012-01-01

    It is extremely important for the healthcare domain to have a standardized communication because will improve the quality of information and in the end the resulting benefits will improve the quality of patients' life. The standards proposed to be used are: HL7 CDA and CCD. For a better access to the medical data a solution based on cloud computing (CC) is investigated. CC is a technology that supports flexibility, seamless care, and reduced costs of the medical act. To ensure interoperability between healthcare information systems a solution creating a Web Custom Control is presented. The control shows the database tables and fields used to configure the two standards. This control will facilitate the work of the medical staff and hospital administrators, because they can configure the local system easily and prepare it for communication with other systems. The resulted information will have a higher quality and will provide knowledge that will support better patient management and diagnosis. PMID:22874196

  6. Automated iodine monitor system. [for aqueous solutions

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The feasibility of a direct spectrophotometric measurement of iodine in water was established. An iodine colorimeter, was built to demonstrate the practicality of this technique. The specificity of this method was verified when applied to an on-line system where a reference solution cannot be used, and a preliminary design is presented for an automated iodine measuring and controlling system meeting the desired specifications. An Automated iodine monitor/controller system based on this preliminary design was built, tested, and delivered to the Johnson Space Center.

  7. Microfluidic System for Solution Array Based Bioassays

    SciTech Connect

    Dougherty, G M; Tok, J B; Pannu, S S; Rose, K A

    2006-02-10

    The objective of this project is to demonstrate new enabling technology for multiplex biodetection systems that are flexible, miniaturizable, highly automated, low cost, and high performance. It builds on prior successes at LLNL with particle-based solution arrays, such as those used in the Autonomous Pathogen Detection System (APDS) successfully field deployed to multiple locations nationwide. We report the development of a multiplex solution array immunoassay based upon engineered metallic nanorod particles. Nanobarcodes{reg_sign} particles are fabricated by sequential electrodeposition of dissimilar metals within porous alumina templates, yielding optically encoded striping patterns that can be read using standard laboratory microscope optics and PC-based image processing software. The addition of self-assembled monolayer (SAM) coatings and target-specific antibodies allows each encoded class of nanorod particles to be directed against a different antigen target. A prototype assay panel directed against bacterial, viral, and soluble protein targets demonstrates simultaneous detection at sensitivities comparable to state of the art immunoassays, with minimal cross-reactivity. Studies have been performed to characterize the colloidal properties (zeta potential) of the suspended nanorod particles as a function of pH, the ionic strength of the suspending solution, and surface functionalization state. Additional studies have produced means for the non-contact manipulation of the particles, including the insertion of magnetic nickel stripes within the encoding pattern, and control via externally applied electromagnetic fields. Using the results of these studies, the novel Nanobarcodes{reg_sign} based assay was implemented in a prototype automated system with the sample processing functions and optical readout performed on a microfluidic card. The unique physical properties of the nanorod particles enable the development of integrated microfluidic systems for

  8. On the principal and strictly particular solutions to infinite systems

    NASA Astrophysics Data System (ADS)

    Ivanova, O. F.; Pavlov, N. N.; Fedorov, F. M.

    2016-03-01

    The concepts of the principal solution to infinite systems of linear algebraic equations and the reduction method are defined more precisely. The principal solution, if it exists, is a strictly particular solution to the infinite system. If the reduction method is convergent, then it necessarily converges to Kramer's determinant; however, Kramer's determinant is not always a solution to the infinite system. To confirm the obtained results, analytical and numerical solutions of specific infinite system are considered.

  9. Solutions and systems for recording interactive TV

    NASA Astrophysics Data System (ADS)

    Tan, Jingwei; Shi, Jun; Gan, Liang; Kell, Declan; Newton, Philip

    2005-09-01

    Digital TV is now being enhanced with interactivity based on such standards as Multimedia Home Platform (MHP) and Digital TV Application Software Environment (DASE). However, recording interactive DTV programme is not that straightforward as it seems. The user will expect the interactivity to still be accessible when a recorded programme is played back from storage. Due to the complexity of the iTV broadcasting, there are many problems for recording interactive TV programme. In this paper we analyze the MHP transport stream structure, describe the recording solution and storage format. Implementation system examples both for recording and playing back are depicted as well.

  10. A practical solution for KKT systems

    NASA Astrophysics Data System (ADS)

    Zheng, Hong; Li, Jianlin

    2007-10-01

    We consider KKT systems of linear equations with a 2???2 block indefinite matrix whose (2, 2) block is zero. Such systems arise in many applications. Treating such matrices would encounter some intricacies, especially when its (1, 1) block, i.e., the stiffness matrix in term of computational mechanics, is rank-deficient. It is the rank-deficiency of the stiffness matrix that leads to the so-called rigid-displacement issue. This is believed to be one of the main reasons that many programmers would unwillingly give up the Lagrange multiplier method but select the penalty method. Based on the Sherman?Morrison formula and the conventional LDLT decomposition for symmetric positive definite matrices, a robust direct solution is proposed, which is amenable to the conventional finite element codes, competent for both nonsingular and singular stiffness matrices, and particularly suitable to parallel computation. As a paradigm, the application to the element-free Galerkin method (EFGM) with the moving least squares interpolation is illustrated.

  11. Optimal parallel solution of sparse triangular systems

    NASA Technical Reports Server (NTRS)

    Alvarado, Fernando L.; Schreiber, Robert

    1990-01-01

    A method for the parallel solution of triangular sets of equations is described that is appropriate when there are many right-handed sides. By preprocessing, the method can reduce the number of parallel steps required to solve Lx = b compared to parallel forward or backsolve. Applications are to iterative solvers with triangular preconditioners, to structural analysis, or to power systems applications, where there may be many right-handed sides (not all available a priori). The inverse of L is represented as a product of sparse triangular factors. The problem is to find a factored representation of this inverse of L with the smallest number of factors (or partitions), subject to the requirement that no new nonzero elements be created in the formation of these inverse factors. A method from an earlier reference is shown to solve this problem. This method is improved upon by constructing a permutation of the rows and columns of L that preserves triangularity and allow for the best possible such partition. A number of practical examples and algorithmic details are presented. The parallelism attainable is illustrated by means of elimination trees and clique trees.

  12. The solution for RPR over MSTP system

    NASA Astrophysics Data System (ADS)

    Tao, Zhiyong; Yang, JiuMin; Liu, Guohui

    2004-04-01

    The rapid development of the data service has brought great challenge to the traditional telecommunication network. The integrated broadband MAN with large information capability, high subscriber density and multiple sorts of services, is becoming the hot point and competitive focus of the telecommunication field. Resilient packet ring (RPR) is a new metropolitan area network (MAN) technology supporting data transfer among stations interconnected in a dual-ring configuration. Key features of RPR include: Low-delay guaranteed rate, bounded delay committed rate, and best effort service classes; 50 millisecond service restoration following a single station or link failure; Ring capacity reuse downstream of unicast destination (spatial reuse); Weighted fair access to available ring capacity; Point-of-congestion aware flow control (allowing per destination queuing in client). But RPR is belong to layer 2 technology. SDH have already become the dominant optical transport network technology, and it is considered to be one of foundation for the physical layer of the broadband IP network. But SDH is taken as a voice-fit technology. This paper fully make use of RPR & SDH advantages to provide The integrated broadband MAN solution, this is the RPR over MSTP System. The architecture of RPR over MSTP and key technologies of realization of RPR over MSTP node is provided. The main technical specification of RPR over MSTP node is also provided.

  13. Compact spaceflight solution crystal-growth system

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.; Lal, Ravindra; Vikram, Chandra; Witherow, William

    1991-01-01

    A versatile, miniaturized, stand alone, crystal solution growth chamber design is presented which is based on fiber optics, diode lasers, and holographic optical elements in conjunction with knowledge gained from previous Spacelab work. Diagnostics instrumentation is based on a crystal growth monitor, a growth/dissolution monitor with feedback, solution diagnostics, multiple wavelength holography, and single wavelength or color Schlieren with video recording.

  14. Solution of linear systems by a singular perturbation technique

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.

    1976-01-01

    An approximate solution is obtained for a singularly perturbed system of initial valued, time invariant, linear differential equations with multiple boundary layers. Conditions are stated under which the approximate solution converges uniformly to the exact solution as the perturbation parameter tends to zero. The solution is obtained by the method of matched asymptotic expansions. Use of the results for obtaining approximate solutions of general linear systems is discussed. An example is considered to illustrate the method and it is shown that the formulas derived give a readily computed uniform approximation.

  15. Extensions to Dynamic System Simulation of Fissile Solution Systems

    SciTech Connect

    Klein, Steven Karl; Bernardin, John David; Kimpland, Robert Herbert; Spernjak, Dusan

    2015-08-24

    Previous reports have documented the results of applying dynamic system simulation (DSS) techniques to model a variety of fissile solution systems. The SUPO (Super Power) aqueous homogeneous reactor (AHR) was chosen as the benchmark for comparison of model results to experimental data for steadystate operation.1 Subsequently, DSS was applied to additional AHR to verify results obtained for SUPO and extend modeling to prompt critical excursions, ramp reactivity insertions of various magnitudes and rate, and boiling operations in SILENE and KEWB (Kinetic Experiment Water Boiler).2 Additional models for pressurized cores (HRE: Homogeneous Reactor Experiment), annular core geometries, and accelerator-driven subcritical systems (ADAHR) were developed and results reported.3 The focus of each of these models is core dynamics; neutron kinetics, thermal hydraulics, radiolytic gas generation and transport are coupled to examine the time-based evolution of these systems from start-up through transition to steady-state. A common characteristic of these models is the assumption that (a) core cooling system inlet temperature and flow and (b) plenum gas inlet pressure and flow are held constant; no external (to core) component operations that may result in dynamic change to these parameters are considered. This report discusses extension of models to include explicit reference to cooling structures and radiolytic gas handling. The accelerator-driven subcritical generic system model described in References 3 and 4 is used as a basis for this extension.

  16. National Institute for Rocket Propulsion Systems (NIRPS): Solutions Facilitator

    NASA Technical Reports Server (NTRS)

    Brown, Tom

    2011-01-01

    National Institute for Rocket Propulsion Systems (NIRPS) "Solutions" plans to enable our nation's future in rocket propulsion systems by leveraging existing skills and capabilities to support industry's future needs

  17. Microfluidic-Based Robotic Sampling System for Radioactive Solutions

    SciTech Connect

    Jack D. Law; Julia L. Tripp; Tara E. Smith; Veronica J. Rutledge; Troy G. Garn; John Svoboda; Larry Macaluso

    2014-02-01

    A novel microfluidic based robotic sampling system has been developed for sampling and analysis of liquid solutions in nuclear processes. This system couples the use of a microfluidic sample chip with a robotic system designed to allow remote, automated sampling of process solutions in-cell and facilitates direct coupling of the microfluidic sample chip with analytical instrumentation. This system provides the capability for near real time analysis, reduces analytical waste, and minimizes the potential for personnel exposure associated with traditional sampling methods. A prototype sampling system was designed, built and tested. System testing demonstrated operability of the microfluidic based sample system and identified system modifications to optimize performance.

  18. Regional satellite systems: Are they "the solution?"

    NASA Astrophysics Data System (ADS)

    Ospina, Sylvia

    Regional satellite systems are in operation in Europe and the Arab League countries. Several others are under consideration for developing countries in Africa, Asia and South America. Studies have concluded that technically, the regional satellite systems are feasible. However, their viability depends on more than the succesful launch of a satellite. This paper analyzes the existing systems, extrapolates a few "lessons" from their experience and examines how they may be applied to the proposed systems. It is suggested that future feasibility studies should give some attention to terrestrial concerns: the physical infrastructure as well as economic and legal issues which will affect any regional system's viability.

  19. Periodic solutions of a forced system with hysteresis.

    NASA Technical Reports Server (NTRS)

    Drew, J. H.

    1972-01-01

    Hysteresis damping arising in an oscillatory system due to the phenomenon of slip damping analyzed by Goodman and Klumpp (1956) is considered. An idealized physical model is proposed, and the existence of certain periodic motions is investigated in a system with small forcing which are near the largest periodic motion in a corresponding unforced system. Periodic solutions of the forced system are obtained.-

  20. Four positive periodic solutions for the first order differential system

    NASA Astrophysics Data System (ADS)

    Zhang, Zhengqiu; Tang, Hengsheng

    2007-08-01

    In this paper, we establish the existence of four positive periodic solutions for the first order differential system by using the continuation theorem of coincidence degree theory. When our result is applied to a competition Lotka-Volterra population model, we obtain the existence of four positive periodic solutions for this model.

  1. More Student Success: A Systemic Solution

    ERIC Educational Resources Information Center

    State Higher Education Executive Officers, 2007

    2007-01-01

    This book tells how to build a system leading to more student success beginning in elementary school and continuing through high school and postsecondary education. It identifies the key elements, describes effective practices, and shows how they come together to help students and educators succeed. "More Student Success" is an updated and…

  2. Crystallization in solid solution-aqueous solution systems: Thermodynamic and kinetic approaches

    SciTech Connect

    Shtukenberg, A. G. Punin, Yu. O.; Azimov, P. Ya.

    2010-03-15

    A new phenomenological approach is proposed to describe the crystallization kinetics in solid solution-aqueous solution binary systems. The phase diagrams, equilibria, and quasie-quilibria are considered within this approach. The crystallization kinetics near the true equilibrium and the crystallization features at large deviations from equilibrium are discussed on this basis. Special attention is paid to possible interactions in a solution with a seed crystal placed in it. In particular, the interactions leading to the seed's crystal growth or dissolution and to a possible exchange or metasomatic reactions are considered. In addition, the effect of the generated mismatch stress on the crystal growth rate and composition is analyzed.

  3. Finite-element solutions for geothermal systems

    NASA Technical Reports Server (NTRS)

    Chen, J. C.; Conel, J. E.

    1977-01-01

    Vector potential and scalar potential are used to formulate the governing equations for a single-component and single-phase geothermal system. By assuming an initial temperature field, the fluid velocity can be determined which, in turn, is used to calculate the convective heat transfer. The energy equation is then solved by considering convected heat as a distributed source. Using the resulting temperature to compute new source terms, the final results are obtained by iterations of the procedure. Finite-element methods are proposed for modeling of realistic geothermal systems; the advantages of such methods are discussed. The developed methodology is then applied to a sample problem. Favorable agreement is obtained by comparisons with a previous study.

  4. Iterative solution of high order compact systems

    SciTech Connect

    Spotz, W.F.; Carey, G.F.

    1996-12-31

    We have recently developed a class of finite difference methods which provide higher accuracy and greater stability than standard central or upwind difference methods, but still reside on a compact patch of grid cells. In the present study we investigate the performance of several gradient-type iterative methods for solving the associated sparse systems. Both serial and parallel performance studies have been made. Representative examples are taken from elliptic PDE`s for diffusion, convection-diffusion, and viscous flow applications.

  5. The Triple Value Model: A Systems Approach to Sustainable Solutions

    EPA Science Inventory

    The unintended environmental impacts of economic development threaten the continued availability of ecosystem services that are critical to human well being. An integrated systems approach is needed to characterize sustainability problems and evaluate potential solutions. The T...

  6. Solvent recovery system provides timely compliance solution

    SciTech Connect

    1996-11-01

    Hoechst Celanese Corp. (Coventry, Rhode Island) faced the challenge of meeting an Environmental Protection Agency (EPA) deadline for solvent recovery within one year. The company also had to ensure that a new solvent recovery system would satisfy Rhode Island state requirements. An initial search for the required technology was fruitless. Finally, MG Industries (Saint Charles, Missouri), an industrial gas supplier, was chosen for the job. Using CRYOSOLV, as the waste stream cools in the cryogenic condenser (heat exchanger), the solvents condense at temperatures below the dewpoint. The recovered solvent can be recycled into the process, while clean gas is vented to the atmosphere.

  7. Almost periodic solutions for Lotka-Volterra systems with delays

    NASA Astrophysics Data System (ADS)

    Liang, Yanlai; Li, Lijie; Chen, Lansun

    2009-09-01

    This paper studies a general class of delayed almost periodic Lotka-Volterra system with time-varying delays and distributed delays. By using the definition of almost periodic function, the sufficient conditions for the existence and uniqueness of globally exponentially stable almost periodic solution are obtained. The conditions can be easily reduced to special cases of cooperative systems and competitive systems.

  8. Implicit numerical integration for periodic solutions of autonomous nonlinear systems

    NASA Technical Reports Server (NTRS)

    Thurston, G. A.

    1982-01-01

    A change of variables that stabilizes numerical computations for periodic solutions of autonomous systems is derived. Computation of the period is decoupled from the rest of the problem for conservative systems of any order and for any second-order system. Numerical results are included for a second-order conservative system under a suddenly applied constant load. Near the critical load for the system, a small increment in load amplitude results in a large increase in amplitude of the response.

  9. Parallel preconditioning for the solution of nonsymmetric banded linear systems

    SciTech Connect

    Amodio, P.; Mazzia, F.

    1994-12-31

    Many computational techniques require the solution of banded linear systems. Common examples derive from the solution of partial differential equations and of boundary value problems. In particular the authors are interested in the parallel solution of block Hessemberg linear systems Gx = f, arising from the solution of ordinary differential equations by means of boundary value methods (BVMs), even if the considered preconditioning may be applied to any block banded linear system. BVMs have been extensively investigated in the last few years and their stability properties give promising results. A new class of BVMs called Reverse Adams, which are BV-A-stable for orders up to 6, and BV-A{sub 0}-stable for orders up to 9, have been studied.

  10. Temperature Profile of the Solution Vessel of an Accelerator-Driven Subcritical Fissile Solution System

    SciTech Connect

    Klein, Steven Karl; Determan, John C.

    2015-09-14

    Dynamic System Simulation (DSS) models of fissile solution systems have been developed and verified against a variety of historical configurations. DSS techniques have been applied specifically to subcritical accelerator-driven systems using fissile solution fuels of uranium. Initial DSS models were developed in DESIRE, a specialized simulation scripting language. In order to tailor the DSS models to specifically meet needs of system designers they were converted to a Visual Studio implementation, and one of these subsequently to National Instrument’s LabVIEW for human factors engineering and operator training. Specific operational characteristics of subcritical accelerator-driven systems have been examined using a DSS model tailored to this particular class using fissile fuel.

  11. Integrated Learning Systems: The Problems with the Solution.

    ERIC Educational Resources Information Center

    Bentley, Edward

    1991-01-01

    Discusses problems with integrated learning systems (ILSs) in the schools, noting they are still an unproven solution to problems in education plagued by many serious limitations. The article recommends dealing with the fundamental problems of the educational system before investing time and money in ILS. (SM)

  12. Solution of a system of dual integral equations.

    NASA Technical Reports Server (NTRS)

    Buell, J.; Kagiwada, H.; Kalaba, R.; Ruspini, E.; Zagustin, E.

    1972-01-01

    The solution of a presented system of differential equations with initial values is shown to satisfy a system of dual integral equations of a type appearing in the study of axisymmetric problems of potential theory. Of practical interest are possible applications in biomechanics, particularly, for the case of trauma due to impact.

  13. Positive periodic solutions of delayed periodic Lotka-Volterra systems

    NASA Astrophysics Data System (ADS)

    Lin, Wei; Chen, Tianping

    2005-01-01

    In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases.

  14. Merged Real Time GNSS Solutions for the READI System

    NASA Astrophysics Data System (ADS)

    Santillan, V. M.; Geng, J.

    2014-12-01

    Real-time measurements from increasingly dense Global Navigational Satellite Systems (GNSS) networks located throughout the western US offer a substantial, albeit largely untapped, contribution towards the mitigation of seismic and other natural hazards. Analyzed continuously in real-time, currently over 600 instruments blanket the San Andreas and Cascadia fault systems of the North American plate boundary and can provide on-the-fly characterization of transient ground displacements highly complementary to traditional seismic strong-motion monitoring. However, the utility of GNSS systems depends on their resolution, and merged solutions of two or more independent estimation strategies have been shown to offer lower scatter and higher resolution. Towards this end, independent real time GNSS solutions produced by Scripps Inst. of Oceanography and Central Washington University (PANGA) are now being formally combined in pursuit of NASA's Real-Time Earthquake Analysis for Disaster Mitigation (READI) positioning goals. CWU produces precise point positioning (PPP) solutions while SIO produces ambiguity resolved PPP solutions (PPP-AR). The PPP-AR solutions have a ~5 mm RMS scatter in the horizontal and ~10mm in the vertical, however PPP-AR solutions can take tens of minutes to re-converge in case of data gaps. The PPP solutions produced by CWU use pre-cleaned data in which biases are estimated as non-integer ambiguities prior to formal positioning with GIPSY 6.2 using a real time stream editor developed at CWU. These solutions show ~20mm RMS scatter in the horizontal and ~50mm RMS scatter in the vertical but re-converge within 2 min. or less following cycle-slips or data outages. We have implemented the formal combination of the CWU and SCRIPPS ENU displacements using the independent solutions as input measurements to a simple 3-element state Kalman filter plus white noise. We are now merging solutions from 90 stations, including 30 in Cascadia, 39 in the Bay Area, and 21

  15. On the Atkinson-Johnson Homogeneous Solution for Infinite Systems

    NASA Astrophysics Data System (ADS)

    Laraudogoitia, Jon Pérez

    2015-05-01

    This paper shows that the general homogeneous solution to equations of evolution for some infinite systems of particles subject to mutual binary collisions does not depend on a single arbitrary constant but on a potentially infinite number of such constants. This is because, as I demonstrate, a single self-excitation of a system of particles can depend on a potentially infinite number of parameters. The recent homogeneous solution obtained by Atkinson and Johnson, which depends on a single arbitrary constant, is only a particular case.

  16. Solute trapping and diffusionless solidification in a binary system

    NASA Astrophysics Data System (ADS)

    Galenko, Peter

    2007-09-01

    Numerous experimental data on the rapid solidification of binary systems exhibit the formation of metastable solid phases with initial (nominal) chemical composition. This fact is explained by complete solute trapping leading to diffusionless (chemically partitionless) solidification at a finite growth velocity of crystals. Special attention is paid to developing a model of rapid solidification which describes a transition from chemically partitioned to diffusionless growth of crystals. Analytical treatments lead to the condition for complete solute trapping which directly follows from the analysis of the solute diffusion around the solid-liquid interface and atomic attachment and detachment at the interface. The resulting equations for the flux balance at the interface take into account two kinetic parameters: diffusion speed VDI on the interface and diffusion speed VD in bulk phases. The model describes experimental data on nonequilibrium solute partitioning in solidification of Si-As alloys for the whole range of solidification velocity investigated.

  17. Preprocessing Inconsistent Linear System for a Meaningful Least Squares Solution

    NASA Technical Reports Server (NTRS)

    Sen, Syamal K.; Shaykhian, Gholam Ali

    2011-01-01

    Mathematical models of many physical/statistical problems are systems of linear equations. Due to measurement and possible human errors/mistakes in modeling/data, as well as due to certain assumptions to reduce complexity, inconsistency (contradiction) is injected into the model, viz. the linear system. While any inconsistent system irrespective of the degree of inconsistency has always a least-squares solution, one needs to check whether an equation is too much inconsistent or, equivalently too much contradictory. Such an equation will affect/distort the least-squares solution to such an extent that renders it unacceptable/unfit to be used in a real-world application. We propose an algorithm which (i) prunes numerically redundant linear equations from the system as these do not add any new information to the model, (ii) detects contradictory linear equations along with their degree of contradiction (inconsistency index), (iii) removes those equations presumed to be too contradictory, and then (iv) obtain the minimum norm least-squares solution of the acceptably inconsistent reduced linear system. The algorithm presented in Matlab reduces the computational and storage complexities and also improves the accuracy of the solution. It also provides the necessary warning about the existence of too much contradiction in the model. In addition, we suggest a thorough relook into the mathematical modeling to determine the reason why unacceptable contradiction has occurred thus prompting us to make necessary corrections/modifications to the models - both mathematical and, if necessary, physical.

  18. Ethernet transmisson solution for SONET/SDH system

    NASA Astrophysics Data System (ADS)

    Liu, Hui

    2004-04-01

    This paper reviews the recent progress and standardization activities on Ethernet over SONET/SDH technologies, focusing on the needs of the young metropolitan-area network. Furthermore, this paper reports the latest technologies such as LCAS, LAPS/GFP, and MPLS that meet the requests of MAN. Finally a solution for SDH system is given.

  19. Radial reactive solute transport in an aquifer-aquitard system

    NASA Astrophysics Data System (ADS)

    Wang, Quanrong; Zhan, Hongbin

    2013-11-01

    Radial reactive transport is investigated in an aquifer-aquitard system considering the important processes such as advection, radial and vertical dispersions for the aquifer, vertical advection and dispersion for the aquitards, and first-order biodegradation or radioactive decay. We solved the coupled governing equations of transport in the aquifer and the aquitards by honoring the continuity of concentration and mass flux across the aquifer-aquitard interfaces and recognizing the concentration variation along the aquifer thickness. This effort improved the averaged-approximation (AA) model, which dealt with radial dispersion in an aquifer-aquitard system by excluding the aquitard advection. To compare with our new solution, we expanded the AA model by including the aquitard advection. The expanded AA model considerably overestimated the mass in the upper aquitard when an upward advection existed there. The rates of mass change in the upper aquitard from the new solution and the AA model solution increased with time following sub-linear fashions. The times corresponding to the peak values of the residence time distributions for the AA model, the expanded AA model, and the new model were almost the same. The residence time distributions seemed to follow the Maxwell-Boltzmann distribution closely when plotting the time in logarithmic scale. In addition, we developed a finite-element COMSOL Multiphysics simulation of the problem, and found that the COMSOL solution agreed with the new solution well.

  20. Coherent pulsed excitation of degenerate multistate systems: Exact analytic solutions

    SciTech Connect

    Kyoseva, E. S.; Vitanov, N. V.

    2006-02-15

    We show that the solution of a multistate system composed of N degenerate lower (ground) states and one upper (excited) state can be reduced by using the Morris-Shore transformation to the solution of a two-state system involving only the excited state and a (bright) superposition of ground states. In addition, there are N-1 dark states composed of ground states. We use this decomposition to derive analytical solutions for degenerate extensions of the most popular exactly soluble models: the resonance solution, the Rabi, Landau-Zener, Rosen-Zener, Allen-Eberly, and Demkov-Kunike models. We suggest various applications of the multistate solutions, for example, as tools for creating multistate coherent superpositions by generalized resonant {pi} pulses. We show that such generalized {pi} pulses can occur even when the upper state is far off resonance, at specific detunings, which makes it possible to operate in the degenerate ground-state manifold without populating the (possibly lossy) upper state, even transiently.

  1. Similarity solutions for systems arising from an Aedes aegypti model

    NASA Astrophysics Data System (ADS)

    Freire, Igor Leite; Torrisi, Mariano

    2014-04-01

    In a recent paper a new model for the Aedes aegypti mosquito dispersal dynamics was proposed and its Lie point symmetries were investigated. According to the carried group classification, the maximal symmetry Lie algebra of the nonlinear cases is reached whenever the advection term vanishes. In this work we analyze the family of systems obtained when the wind effects on the proposed model are neglected. Wide new classes of solutions to the systems under consideration are obtained.

  2. Systemic solutions for multi-benefit water and environmental management.

    PubMed

    Everard, Mark; McInnes, Robert

    2013-09-01

    The environmental and financial costs of inputs to, and unintended consequences arising from narrow consideration of outputs from, water and environmental management technologies highlight the need for low-input solutions that optimise outcomes across multiple ecosystem services. Case studies examining the inputs and outputs associated with several ecosystem-based water and environmental management technologies reveal a range from those that differ little from conventional electro-mechanical engineering techniques through methods, such as integrated constructed wetlands (ICWs), designed explicitly as low-input systems optimising ecosystem service outcomes. All techniques present opportunities for further optimisation of outputs, and hence for greater cumulative public value. We define 'systemic solutions' as "…low-input technologies using natural processes to optimise benefits across the spectrum of ecosystem services and their beneficiaries". They contribute to sustainable development by averting unintended negative impacts and optimising benefits to all ecosystem service beneficiaries, increasing net economic value. Legacy legislation addressing issues in a fragmented way, associated 'ring-fenced' budgets and established management assumptions represent obstacles to implementing 'systemic solutions'. However, flexible implementation of legacy regulations recognising their primary purpose, rather than slavish adherence to detailed sub-clauses, may achieve greater overall public benefit through optimisation of outcomes across ecosystem services. Systemic solutions are not a panacea if applied merely as 'downstream' fixes, but are part of, and a means to accelerate, broader culture change towards more sustainable practice. This necessarily entails connecting a wider network of interests in the formulation and design of mutually-beneficial systemic solutions, including for example spatial planners, engineers, regulators, managers, farming and other businesses, and

  3. Balanced-Viscosity solutions for multi-rate systems

    NASA Astrophysics Data System (ADS)

    Mielke, Alexander; Rossi, Riccarda; Savaré, Giuseppe

    2016-06-01

    Several mechanical systems are modeled by the static momentum balance for the displacement u coupled with a rate-independent flow rule for some internal variable z. We consider a class of abstract systems of ODEs which have the same structure, albeit in a finite-dimensional setting, and regularize both the static equation and the rate-independent flow rule by adding viscous dissipation terms with coefficients εα and ε, where 0 < ε « 1 and α > 0 is a fixed parameter. Therefore for α ≠ 1 u and z have different relaxation rates. We address the vanishing-viscosity analysis as ε ↓ 0 of the viscous system. We prove that, up to a subsequence, (reparameterized) viscous solutions converge to a parameterized curve yielding a Balanced Viscosity solution to the original rate-independent system, and providing an accurate description of the system behavior at jumps. We also give a reformulation of the notion of Balanced Viscosity solution in terms of a system of subdifferential inclusions, showing that the viscosity in u and the one in z are involved in the jump dynamics in different ways, according to whether α > 1, α =1, and α є (0,1).

  4. A new two-component integrable system with peakon solutions

    PubMed Central

    Xia, Baoqiang; Qiao, Zhijun

    2015-01-01

    A new two-component system with cubic nonlinearity and linear dispersion: mt=bux+12[m(uv−uxvx)]x−12m(uvx−uxv),nt=bvx+12[n(uv−uxvx)]x+12n(uvx−uxv),m=u−uxx,n=v−vxx,where b is an arbitrary real constant, is proposed in this paper. This system is shown integrable with its Lax pair, bi-Hamiltonian structure and infinitely many conservation laws. Geometrically, this system describes a non-trivial one-parameter family of pseudo-spherical surfaces. In the case b=0, the peaked soliton (peakon) and multi-peakon solutions to this two-component system are derived. In particular, the two-peakon dynamical system is explicitly solved and their interactions are investigated in details. Moreover, a new integrable cubic nonlinear equation with linear dispersion mt=bux+12[m(|u|2−|ux|2)]x−12m(uux∗−uxu∗),m=u−uxx,is obtained by imposing the complex conjugate reduction v=u* to the two-component system. The complex-valued N-peakon solution and kink wave solution to this complex equation are also derived. PMID:25792956

  5. Parallel, iterative solution of sparse linear systems: Models and architectures

    NASA Technical Reports Server (NTRS)

    Reed, D. A.; Patrick, M. L.

    1984-01-01

    A model of a general class of asynchronous, iterative solution methods for linear systems is developed. In the model, the system is solved by creating several cooperating tasks that each compute a portion of the solution vector. A data transfer model predicting both the probability that data must be transferred between two tasks and the amount of data to be transferred is presented. This model is used to derive an execution time model for predicting parallel execution time and an optimal number of tasks given the dimension and sparsity of the coefficient matrix and the costs of computation, synchronization, and communication. The suitability of different parallel architectures for solving randomly sparse linear systems is discussed. Based on the complexity of task scheduling, one parallel architecture, based on a broadcast bus, is presented and analyzed.

  6. Self limiting features of accidental criticality in a solution system

    SciTech Connect

    Malenfant, R.E.

    1988-01-01

    Experience with the SHEBA solution critical assembly during validation testing of accidental criticality alarm detectors provided several insights into the character of potential accidental excursions. Two observations were of particular interest. First, it is nearly impossible to maintain a solution system, particularly one employing low-enrichment material, in a constant state. If super-critical, the system will heat up, expand (or form bubbles), return to a sub-critical state, and shut down of its own accord without going into short period oscillations. Second, a very slow change in the system could produce a long ''pulse'' resulting in lengthy exposures, a high dose, but a low dose rate. The experiments dramatically contradicted the popular contention that accidental criticality is characterized by a blue flash, a clap of thunder, and violet expulsion of material. 5 refs., 3 figs., 4 tabs.

  7. On optimal system, exact solutions and conservation laws of the Broer-Kaup system

    NASA Astrophysics Data System (ADS)

    Zhao, Zhonglong; Han, Bo

    2015-11-01

    The Broer-Kaup system is an important physical model which is used to model the bi-directional propagation of long waves in shallow water. In this paper, Lie symmetry analysis is performed on the Broer-Kaup system. We get the Lie point symmetries and optimal system of one-dimensional subalgebras. Similarity reductions of the system are obtained based on optimal system of one-dimensional subalgebras. We present some exact solutions of the system, which include similarity solutions and travelling wave solutions. Furthermore, some conservation laws are generated via multipliers. The conservation laws associated with symmetries of this equation are constructed by utilizing the new conservation theorem.

  8. Middle infrared optoelectronic absorption systems for monitoring physiological glucose solutions

    NASA Astrophysics Data System (ADS)

    Martin, W. Blake

    Tight monitoring of the glucose levels for diabetic individuals is essential to control long-term complications. A definitive diabetes management system has yet to be developed for the diabetic. This research investigates the application of middle infrared absorption frequencies for monitoring glucose levels in biological solutions. Three frequencies were identified using a Fourier transform infrared spectrometer and correlated to changes in glucose concentrations. The 1035 +/- 1 cm-1 frequency was determined to be the best representative frequency. Other biological molecules contributed no significant interference to monitoring glucose absorption. A second frequency at 1193 cm-1 was suggested as a representative background absorption frequency, which could be used for more accurate glucose absorption values. Next, a quantum cascade laser optoelectronic absorption system was designed and developed to monitor glucose. After careful alignment and design, the system was used to monitor physiological glucose concentrations. Correlation at 1036 cm-1 with glucose changes was comparable to the previous results. The use of the background absorption frequency was verified. This frequency essentially acts as a calibrating frequency to adjust in real-time to any changes in the background absorption that may alter the accuracy of the predicted glucose value. An evanescent wave cavity ring-down spectroscopy technique was explored to monitor molecules in a biological solution. Visible light at 425 nm was used to monitor hemoglobin in control urine samples. An adsorption isotherm for hemoglobin was detectable to limit of 5.8 nM. Evanescent wave cavity ring-down spectroscopy would be useful for a glucose solution. Given an equivalent system designed for the middle infrared, the molar extinction coefficient of glucose allows for a detectable limit of 45 mg/dl for a free-floating glucose solution, which is below normal physiological concentrations. The future use of a hydrophobic

  9. Rapid solution of large-scale systems of equations

    NASA Technical Reports Server (NTRS)

    Storaasli, Olaf O.

    1994-01-01

    The analysis and design of complex aerospace structures requires the rapid solution of large systems of linear and nonlinear equations, eigenvalue extraction for buckling, vibration and flutter modes, structural optimization and design sensitivity calculation. Computers with multiple processors and vector capabilities can offer substantial computational advantages over traditional scalar computer for these analyses. These computers fall into two categories: shared memory computers and distributed memory computers. This presentation covers general-purpose, highly efficient algorithms for generation/assembly or element matrices, solution of systems of linear and nonlinear equations, eigenvalue and design sensitivity analysis and optimization. All algorithms are coded in FORTRAN for shared memory computers and many are adapted to distributed memory computers. The capability and numerical performance of these algorithms will be addressed.

  10. Solution rheology of polyelectrolytes and polyelectrolyte-surfactant systems

    NASA Astrophysics Data System (ADS)

    Plucktaveesak, Nopparat

    The fundamental understanding of polyelectrolytes in aqueous solutions is an important branch of polymer research. In this work, the rheological properties of polyelectrolytes and polyelectrolyte/surfactant systems are studied. Various synthetic poly electrolytes are chosen with varied hydrophobicity. We discuss the effects of adding various surfactants to aqueous solutions of poly(ethylene oxide)-b-poly(propylene oxide)- b-polyethylene oxide)-g-poly(acrylic acid) (PEO-PPO-PAA) in the first chapter. Thermogelation in aqueous solutions of PEO-PPO-PAA is due to micellization caused by aggregation of poly(propylene oxide) (PPO) blocks resulting from temperature-induced dehydration of PPO. When nonionic surfactants with hydrophilic-lipophilic balance (HLB) parameter exceeding 11 or Cn alkylsulfates; n-octyl (C8), n-decyl (C 10) and n-dodecyl (C12) sulfates are added, the gelation threshold temperature (Tgel) of 1.0wt% PEO-PPO-PAA in aqueous solutions increases. In contrast, when nonionic surfactants with HLB below 11 are added, the gelation temperature decreases. On the other hand, alkylsulfates with n = 16 or 18 and poly(ethylene oxide) (PEO) do not affect the Tgel. The results imply that both hydrophobicity and tail length of the added surfactant play important roles in the interaction of PEO-PPO-PAA micelles and the surfactant. In the second chapter, the solution behavior of alternating copolymers of maleic acid and hydrophobic monomer is studied. The alternating structure of monomers with two-carboxylic groups and hydrophobic monomers make these copolymers unique. Under appropriate conditions, these carboxylic groups dissociate leaving charges on the chain. The potentiometric titrations of copolymer solutions with added CaCl2 reveal two distinct dissociation processes corresponding to the dissociation of the two adjacent carboxylic acids. The viscosity data as a function of polymer concentration of poly(isobutylene-alt-sodium maleate), poly

  11. Reaction paths and equilibrium end-points in solid-solution aqueous-solution systems

    SciTech Connect

    Glynn, P.D.; Plummer, L.N.; Busenberg, E. ); Reardon, E.J. )

    1990-02-01

    Equations are presented describing equilibrium in binary solid-solution aqueous-solution (SSAS) systems after a dissolution, precipitation, or recrystallization process, as a function of the composition and relative proportion of the initial phases. Equilibrium phase diagrams incorporating the concept of stoichiometric saturation are used to interpret possible reaction paths and to demonstrate relations between stoichiometric saturation, primary saturation, and thermodynamic equilibrium states. The concept of stoichiometric saturation is found useful in interpreting and putting limits on dissolution pathways, but there currently is no basis for possible application of this concept to the prediction and/or understanding of precipitation processes. Previously published dissolution experiments for (Ba, Sr)SO{sub 4} and (Sr, Ca)CO{sub 3orth.} solids are interpreted using equilibrium phase diagrams. These studies show that stoichiometric saturation can control, or at least influence, initial congruent dissolution pathways. The results for (Sr, Ca)CO{sub 3orth.} solids reveal that stoichiometric saturation can also control the initial stages of incongruent dissolution, despite the intrinsic instability of some of the initial solids. In contrast, recrystallization experiments in the highly soluble KCl-KBr-H{sub 2}O system demonstrate equilibrium. The phase diagram reveals an alyotropic maximum located at {chi}{sub KBr} = 0.676 and at a total solubility product, {Sigma}II = (K{sup +})((Cl{sup {minus}}) + (Br{sup {minus}})) = 15.35.

  12. ODE methods for the solution of differential/algebraic systems

    SciTech Connect

    Gear, C.W.; Petzold, L.R.

    1982-09-01

    In this paper we study the numerical solution of the differential/algebraic systems F(t, y, y') = 0. Many of these systems can be solved conveniently and economically using a range of ODE methods. Others can be solved only by a small subset of ODE methods, and still others present insurmountable difficulty for all current ODE methods. We examine the first two groups of problems and indicate which methods we believe to be best for them. Then we explore the properties of the third group which cause the methods to fail. We describe a reduction technique which allows systems to be reduced to ones that can be solved. It also provides a tool for the analytical study of the structure of systems.

  13. The Solution Space Organization: Linking Information Systems Architecture and Reuse

    NASA Astrophysics Data System (ADS)

    Dakhli, Salem Ben Dhaou

    Nowadays, improvement of software development productivity is among the main strategies proposed by academics and practitioners to deal with the chronic software crisis. As stressed by many authors during the last two decades, reuse of software artifacts provides efficient instruments to implement this strategy. Nevertheless, despite organizations high investments in defining software reuse plans, implementation of such plans has often failed. We think that the identification and description of the relationships between the areas of information systems architecture and software reuse are required to define a successful reuse approach which takes into account all the dimensions of information systems. In this chapter, we propose a structural and architecture-oriented description of the solution space associated with information systems development. We use such a description to build a reuse approach compliant with all the dimensions of information systems including the organizational, economic, and human dimensions.

  14. Simulator for an Accelerator-Driven Subcritical Fissile Solution System

    SciTech Connect

    Klein, Steven Karl; Day, Christy M.; Determan, John C.

    2015-09-14

    LANL has developed a process to generate a progressive family of system models for a fissile solution system. This family includes a dynamic system simulation comprised of coupled nonlinear differential equations describing the time evolution of the system. Neutron kinetics, radiolytic gas generation and transport, and core thermal hydraulics are included in the DSS. Extensions to explicit operation of cooling loops and radiolytic gas handling are embedded in these systems as is a stability model. The DSS may then be converted to an implementation in Visual Studio to provide a design team the ability to rapidly estimate system performance impacts from a variety of design decisions. This provides a method to assist in optimization of the system design. Once design has been generated in some detail the C++ version of the system model may then be implemented in a LabVIEW user interface to evaluate operator controls and instrumentation and operator recognition and response to off-normal events. Taken as a set of system models the DSS, Visual Studio, and LabVIEW progression provides a comprehensive set of design support tools.

  15. Spontaneously stochastic solutions in one-dimensional inviscid systems

    NASA Astrophysics Data System (ADS)

    Mailybaev, Alexei A.

    2016-08-01

    In this paper, we study the inviscid limit of the Sabra shell model of turbulence, which is considered as a particular case of a viscous conservation law in one space dimension with a nonlocal quadratic flux function. We present a theoretical argument (with a detailed numerical confirmation) showing that a classical deterministic solution before a finite-time blowup, t  <  t b , must be continued as a stochastic process after the blowup, t  >  t b , representing a unique physically relevant description in the inviscid limit. This theory is based on the dynamical system formulation written for the logarithmic time τ =log ≤ft(t-{{t}b}\\right) , which features a stable traveling wave solution for the inviscid Burgers equation, but a stochastic traveling wave for the Sabra model. The latter describes a universal onset of stochasticity immediately after the blowup.

  16. Integrating LPR with CCTV systems: problems and solutions

    NASA Astrophysics Data System (ADS)

    Bissessar, David; Gorodnichy, Dmitry O.

    2011-06-01

    A new generation of high-resolution surveillance cameras makes it possible to apply video processing and recognition techniques on live video feeds for the purpose of automatically detecting and identifying objects and events of interest. This paper addresses a particular application of detecting and identifying vehicles passing through a checkpoint. This application is of interest to border services agencies and is also related to many other applications. With many commercial automated License Plate Recognition (LPR) systems available on the market, some of which are available as a plug-in for surveillance systems, this application still poses many unresolved technological challenges, the main two of which are: i) multiple and often noisy license plate readings generated for the same vehicle, and ii) failure to detect a vehicle or license plate altogether when the license plate is occluded or not visible. This paper presents a solution to both of these problems. A data fusion technique based on the Levenshtein distance is used to resolve the first problem. An integration of a commercial LPR system with the in-house built Video Analytic Platform is used to solve the latter. The developed solution has been tested in field environments and has been shown to yield a substantial improvement over standard off-the-shelf LPR systems.

  17. Scalable Library for the Parallel Solution of Sparse Linear Systems

    Energy Science and Technology Software Center (ESTSC)

    1993-07-14

    BlockSolve is a scalable parallel software library for the solution of large sparse, symmetric systems of linear equations. It runs on a variety of parallel architectures and can easily be ported to others. BlockSovle is primarily intended for the solution of sparse linear systems that arise from physical problems having multiple degrees of freedom at each node point. For example, when the finite element method is used to solve practical problems in structural engineering, eachmore » node will typically have anywhere from 3-6 degrees of freedom associated with it. BlockSolve is written to take advantage of problems of this nature; however, it is still reasonably efficient for problems that have only one degree of freedom associated with each node, such as the three-dimensional Poisson problem. It does not require that the matrices have any particular structure other than being sparse and symmetric. BlockSolve is intended to be used within real application codes. It is designed to work best in the context of our experience which indicated that most application codes solve the same linear systems with several different right-hand sides and/or linear systems with the same structure, but different matrix values multiple times.« less

  18. Application of the Thermodynamic Solution Model of Dilute Binary Systems

    NASA Astrophysics Data System (ADS)

    Luáek, J.

    1997-12-01

    The thermodynamic solution model by Tanaka et al. for liquid binary systems was extended to solid binary systems. On the basis of this extension the activity coefficients of solute elements in the solid phase in infinite dilution for transition metals were calculated in Part I of this paper. The determination of the activity coefficients in both solid and liquid phases can enable one to predict the equilibrium segregation coefficient of the solute elements in transition metal base alloys without the knowledge of equilibrium binary phase diagrams. The model was applied on Ti, Zr and Hf-base dilute alloys at their melting points. The calculated values of equilibrium segregation coefficients are compared with values derived by other methods. The effect of the model parameters on the value of equilibrium segregation coefficients was discussed. Das thermodynamische Modell für flüssige binäre Systeme nach Tanaka wurde auf feste binäre Systeme ausgedehnt. Auf dieser Grundlage wurden die Aktivitätskoeffizienten der gelösten Elemente in der Solidusphase für die Übergangsmetalle in Teil I dieser Arbeit berechnet. Die Bestimmung der Aktivitätskoeffizienten in der Solidus- und Liquidusphase ermöglicht die Vorhersage des Gleichgewichtsverteilungskoeffizienten der gelösten Elemente in den Legierungen der Übergangsmetalle ohne Kenntnis ihrer Zustandsdiagramme. Das Modell wurde auf Ti, Zr und Hf-Legierungen im Bereich der Schmelztemperatur der Hauptkomponente angewandt. Die berechneten Werte der Gleichgewichtsverteilungskoeffizienten wurden mit den Werten anderer Methoden verglichen. Der Einfluss der Eingangsparameter in unserem Modell auf die Werte der Gleichgewichtsverteilungskoeffizienten wurde diskutiert.

  19. Analytical solution of two-dimensional solute transport in an aquifer-aquitard system.

    PubMed

    Zhan, Hongbin; Wen, Zhang; Huang, Guanhua; Sun, Dongmin

    2009-07-21

    This study deals with two-dimensional solute transport in an aquifer-aquitard system by maintaining rigorous mass conservation at the aquifer-aquitard interface. Advection, longitudinal dispersion, and transverse vertical dispersion are considered in the aquifer. Vertical advection and diffusion are considered in the aquitards. The first-type and the third-type boundary conditions are considered in the aquifer. This study differs from the commonly used averaged approximation (AA) method that treats the mass flux between the aquifer and aquitard as an averaged volumetric source/sink term in the governing equation of transport in the aquifer. Analytical solutions of concentrations in the aquitards and aquifer and mass transported between the aquifer and upper or lower aquitard are obtained in the Laplace domain, and are subsequently inverted numerically to yield results in the real time domain (the Zhan method). The breakthrough curves (BTCs) and distribution profiles in the aquifer obtained in this study are drastically different from those obtained using the AA method. Comparison of the numerical simulation using the model MT3DMS and the Zhan method indicates that the numerical result differs from that of the Zhan method for an asymmetric case when aquitard advections are at the same direction. The AA method overestimates the mass transported into the upper aquitard when an upward advection exists in the upper aquitard. The mass transported between the aquifer and the aquitard is sensitive to the aquitard Peclet number, but less sensitive to the aquitard diffusion coefficient. PMID:19477033

  20. Reaction paths and equilibrium end-points in solid-solution aqueous-solution systems

    USGS Publications Warehouse

    Glynn, P.D.; Reardon, E.J.; Plummer, L.N.; Busenberg, E.

    1990-01-01

    Equations are presented describing equilibrium in binary solid-solution aqueous-solution (SSAS) systems after a dissolution, precipitation, or recrystallization process, as a function of the composition and relative proportion of the initial phases. Equilibrium phase diagrams incorporating the concept of stoichiometric saturation are used to interpret possible reaction paths and to demonstrate relations between stoichiometric saturation, primary saturation, and thermodynamic equilibrium states. The concept of stoichiometric saturation is found useful in interpreting and putting limits on dissolution pathways, but there currently is no basis for possible application of this concept to the prediction and/ or understanding of precipitation processes. Previously published dissolution experiments for (Ba, Sr)SO4 and (Sr, Ca)C??O3orth. solids are interpreted using equilibrium phase diagrams. These studies show that stoichiometric saturation can control, or at least influence, initial congruent dissolution pathways. The results for (Sr, Ca)CO3orth. solids reveal that stoichiometric saturation can also control the initial stages of incongruent dissolution, despite the intrinsic instability of some of the initial solids. In contrast, recrystallisation experiments in the highly soluble KCl-KBr-H2O system demonstrate equilibrium. The excess free energy of mixing calculated for K(Cl, Br) solids is closely modeled by the relation GE = ??KBr??KClRT[a0 + a1(2??KBr-1)], where a0 is 1.40 ?? 0.02, a1, is -0.08 ?? 0.03 at 25??C, and ??KBr and ??KCl are the mole fractions of KBr and KCl in the solids. The phase diagram constructed using this fit reveals an alyotropic maximum located at ??KBr = 0.676 and at a total solubility product, ???? = [K+]([Cl-] + [Br-]) = 15.35. ?? 1990.

  1. JOVIAN STRATOSPHERE AS A CHEMICAL TRANSPORT SYSTEM: BENCHMARK ANALYTICAL SOLUTIONS

    SciTech Connect

    Zhang Xi; Shia Runlie; Yung, Yuk L.

    2013-04-20

    We systematically investigated the solvable analytical benchmark cases in both one- and two-dimensional (1D and 2D) chemical-advective-diffusive systems. We use the stratosphere of Jupiter as an example but the results can be applied to other planetary atmospheres and exoplanetary atmospheres. In the 1D system, we show that CH{sub 4} and C{sub 2}H{sub 6} are mainly in diffusive equilibrium, and the C{sub 2}H{sub 2} profile can be approximated by modified Bessel functions. In the 2D system in the meridional plane, analytical solutions for two typical circulation patterns are derived. Simple tracer transport modeling demonstrates that the distribution of a short-lived species (such as C{sub 2}H{sub 2}) is dominated by the local chemical sources and sinks, while that of a long-lived species (such as C{sub 2}H{sub 6}) is significantly influenced by the circulation pattern. We find that an equator-to-pole circulation could qualitatively explain the Cassini observations, but a pure diffusive transport process could not. For slowly rotating planets like the close-in extrasolar planets, the interaction between the advection by the zonal wind and chemistry might cause a phase lag between the final tracer distribution and the original source distribution. The numerical simulation results from the 2D Caltech/JPL chemistry-transport model agree well with the analytical solutions for various cases.

  2. Analytical solutions for one-, two-, and three-dimensional solute transport in ground-water systems with uniform flow

    USGS Publications Warehouse

    Wexler, Eliezer J.

    1989-01-01

    Analytical solutions to the advective-dispersive solute transport equation are useful in predicting the fate of solutes in groundwater. Analytical solutions compiled from available literature or derived by the author are presented in this report for a variety of boundary condition types and solute-source configuration in one-, two-, and three-dimensional systems with uniform groundwater flow. A set of user-oriented computer programs was created to evaluate these solutions and to display the results in tabular and computer-graphics format. These programs incorporate many features that enhance their accuracy, ease of use, and versatility. Documentation for the programs describes their operation and required input data, and presents the results of sample problems. Derivations of select solutions, source codes for the computer programs, and samples of program input and output also are described. (USGS)

  3. Analytical solutions for one-, two-, and three-dimensional solute transport in ground-water systems with uniform flow

    USGS Publications Warehouse

    Wexler, Eliezer J.

    1992-01-01

    Analytical solutions to the advective-dispersive solute-transport equation are useful in predicting the fate of solutes in ground water. Analytical solutions compiled from available literature or derived by the author are presented for a variety of boundary condition types and solute-source configurations in one-, two-, and three-dimensional systems having uniform ground-water flow. A set of user-oriented computer programs was created to evaluate these solutions and to display the results in tabular and computer-graphics format. These programs incorporate many features that enhance their accuracy, ease of use, and versatility. Documentation for the programs describes their operation and required input data, and presents the results of sample problems. Derivations of selected solutions, source codes for the computer programs, and samples of program input and output also are included.

  4. SNS INJECTION AND EXTRACTION SYSTEMS ? ISSUES AND SOLUTIONS

    SciTech Connect

    Plum, Michael A

    2008-01-01

    Beam loss is higher than expected in the Ring injection section and in the injection dump beam line. The primary causes are fairly well understood, and we have made some equipment modifications to reduce the loss. In the ring extraction beam line the beam distribution exhibits cross-plane coupling (tilt), and the cause has been traced to a large skew-quadrupole component in the extraction Lambertson septum magnet. In this paper we will discuss the issues surrounding the ring injection and extraction systems, the solutions we have implemented to date, and our plans for future improvements.

  5. Sucrose and KF quenching system for solution phase parallel synthesis.

    PubMed

    Chavan, Sunil; Watpade, Rahul; Toche, Raghunath

    2016-01-01

    The KF, sucrose (table sugar) exploited as quenching system in solution phase parallel synthesis. Excess of electrophiles were covalently trapped with hydroxyl functionality of sucrose and due to polar nature of sucrose derivative was solubilize in water. Potassium fluoride used to convert various excess electrophilic reagents such as acid chlorides, sulfonyl chlorides, isocyanates to corresponding fluorides, which are less susceptible for hydrolysis and subsequently sucrose traps these fluorides and dissolves them in water thus removing them from reaction mixture. Various excess electrophilic reagents such as acid chlorides, sulfonyl chlorides, and isocyanates were quenched successfully to give pure products in excellent yields. PMID:27462506

  6. Thermal expansion of solid solutions in apatite binary systems

    SciTech Connect

    Knyazev, Alexander V.; Bulanov, Evgeny N. Korokin, Vitaly Zh.

    2015-01-15

    Graphical abstract: Thermal dependencies of volume thermal expansion parameter for with thermal expansion diagrams for Pb{sub 5}(PO{sub 4}){sub 3}F{sub x}Cl{sub 1−x}. - Highlights: • Solid solutions in three apatitic binary systems were investigated via HT-XRD. • Thermal expansion coefficients of solid solutions in the systems were calculated. • Features of the thermal deformation of the apatites were described. • Termoroentgenography is a sensitive method for the investigation of isomorphism. - Abstract: High-temperature insitu X-ray diffraction was used to investigate isomorphism and the thermal expansion of apatite-structured compounds in three binary systems in the entire temperature range of the existence of its hexagonal modifications. Most of the studied compounds are highly expandable (α{sub l} > 8 × 10{sup 6} (K{sup −1})). In Pb{sub 5}(PO{sub 4}){sub 3}F–Pb{sub 5}(PO{sub 4}){sub 3}Cl system, volume thermal expansion coefficient is independence from the composition at 573 K. In Pb{sub 5}(PO{sub 4}){sub 3}Cl–Pb{sub 5}(VO{sub 4}){sub 3}Cl, the compound with equimolar ratio of substituted atoms has constant volume thermal expansion coefficient in temperature range 298–973 K. Ca{sub 5}(PO{sub 4}){sub 3}Cl–Pb{sub 5}(PO{sub 4}){sub 3}Cl system is characterized by the most thermal sensitive composition, in which there is an equal ratio of isomorphic substituted atoms.

  7. The efficient parallel iterative solution of large sparse linear systems

    SciTech Connect

    Jones, M.T.; Plassmann, P.E.

    1992-06-01

    The development of efficient, general-purpose software for the iterative solution of sparse linear systems on a parallel MIMD computer requires an interesting combination of expertise. Parallel graph heuristics, convergence analysis, and basic linear algebra implementation issues must all be considered. In this paper, we discuss how we have incorporated recent results in these areas into a general-purpose iterative solver. First, we consider two recently developed parallel graph coloring heuristics. We show how the method proposed by Luby, based on determining maximal independent sets, can be modified to run in an asynchronous manner and give aa expected running time bound for this modified heuristic. In addition, a number of graph reduction heuristics are described that are used in our implementation to improve the individual processor performance. The effect of these various graph reductions on the solution of sparse triangular systems is categorized. Finally, we discuss the performance of this solver from the perspective of two large-scale applications: a piezoelectric crystal finite-element modeling problem, and a nonlinear optimization problem to determine the minimum energy configuration of a three-dimensional, layered superconductor model.

  8. Darboux transformation of the Drinfeld–Sokolov–Satsuma–Hirota system and exact solutions

    SciTech Connect

    Geng, Xianguo; Li, Ruomeng

    2015-10-15

    A Darboux transformation for the Drinfeld–Sokolov–Satsuma–Hirota system of coupled equations is constructed with the aid of gauge transformations between the Lax pairs. As an application, several types of solutions of the Drinfeld–Sokolov–Satsuma–Hirota system are obtained, including soliton solutions, periodic solutions, rational solutions and others.

  9. VLT instruments: industrial solutions for non-scientific detector systems

    NASA Astrophysics Data System (ADS)

    Duhoux, P.; Knudstrup, J.; Lilley, P.; Di Marcantonio, P.; Cirami, R.; Mannetta, M.

    2014-07-01

    . ESPRESSO is a fiber-fed, cross-dispersed echelle spectrograph that will be located in the Combined-Coudé Laboratory of the VLT in the Paranal Observatory in Chile. It will be able to operate either using the light of any of the UT's or using the incoherently combined light of up to four UT's. The stabilization of the incoming beam is achieved by dedicated piezo systems controlled via active loops closed on 4 + 4 dedicated TCCD's for the stabilization of the pupil image and of the field with a frequency goal of 3 Hz on a 2nd to 3rd magnitude star. An additional 9th TCCD system shall be used as an exposure-meter. In this paper we will present the technical CCD solution for future VLT instruments.

  10. Multiple solutions for a singular quasilinear elliptic system.

    PubMed

    Chen, Lin; Chen, Caisheng; Xiu, Zonghu

    2013-01-01

    We consider the multiplicity of nontrivial solutions of the following quasilinear elliptic system -div(|x|(-ap)|∇u|(p-2)∇u) + f₁(x)|u|(p-2) u = (α/(α + β))g(x)|u| (α-2) u|v| (β) + λh₁(x)|u| (γ-2) u + l₁(x), -div(|x|(-ap) |∇v| (p-2)∇v) + f₂(x)|v| (p-2) v = (β/(α + β))g(x)|v|(β-2) v|u|(α) + μh 2(x)|v|(γ-2)v + l 2(x), u(x) > 0, v(x) > 0, x ∈ ℝ(N), where λ, μ > 0, 1 < p < N, 1 < γ < p < α + β < p* = Np/(N-pd), 0 ≤ a < (N - p)/p, a ≤ b < a + 1, d = a + 1 - b > 0. The functions f₁(x), f₂(x), g(x), h₁(x), h₂(x), l₁(x), and l₂(x) satisfy some suitable conditions. We will prove that the problem has at least two nontrivial solutions by using Mountain Pass Theorem and Ekeland's variational principle. PMID:24282377

  11. A numerical solution for the diffusion equation in hydrogeologic systems

    USGS Publications Warehouse

    Ishii, A.L.; Healy, R.W.; Striegl, R.G.

    1989-01-01

    The documentation of a computer code for the numerical solution of the linear diffusion equation in one or two dimensions in Cartesian or cylindrical coordinates is presented. Applications of the program include molecular diffusion, heat conduction, and fluid flow in confined systems. The flow media may be anisotropic and heterogeneous. The model is formulated by replacing the continuous linear diffusion equation by discrete finite-difference approximations at each node in a block-centered grid. The resulting matrix equation is solved by the method of preconditioned conjugate gradients. The conjugate gradient method does not require the estimation of iteration parameters and is guaranteed convergent in the absence of rounding error. The matrixes are preconditioned to decrease the steps to convergence. The model allows the specification of any number of boundary conditions for any number of stress periods, and the output of a summary table for selected nodes showing flux and the concentration of the flux quantity for each time step. The model is written in a modular format for ease of modification. The model was verified by comparison of numerical and analytical solutions for cases of molecular diffusion, two-dimensional heat transfer, and axisymmetric radial saturated fluid flow. Application of the model to a hypothetical two-dimensional field situation of gas diffusion in the unsaturated zone is demonstrated. The input and output files are included as a check on program installation. The definition of variables, input requirements, flow chart, and program listing are included in the attachments. (USGS)

  12. Is the system really the solution? Operating costs in hospital systems.

    PubMed

    Burns, Lawton Robert; McCullough, Jeffrey S; Wholey, Douglas R; Kruse, Gregory; Kralovec, Peter; Muller, Ralph

    2015-06-01

    Hospital system formation has recently accelerated. Executives emphasize scale economies that lower operating costs, a claim unsupported in academic research. Do systems achieve lower costs than freestanding facilities, and, if so, which system types? We test hypotheses about the relationship of cost with membership in systems, larger systems, and centralized and local hub-and-spoke systems. We also test whether these relationships have changed over time. Examining 4,000 U.S. hospitals during 1998 to 2010, we find no evidence that system members exhibit lower costs. However, members of smaller systems are lower cost than larger systems, and hospitals in centralized systems are lower cost than everyone else. There is no evidence that the system's spatial configuration is associated with cost, although national system hospitals exhibit higher costs. Finally, these results hold over time. We conclude that while systems in general may not be the solution to lower costs, some types of systems are. PMID:25904540

  13. Picture archiving and communications systems for integrated healthcare information solutions

    NASA Astrophysics Data System (ADS)

    Goldburgh, Mitchell M.; Glicksman, Robert A.; Wilson, Dennis L.

    1997-05-01

    The rapid and dramatic shifts within the US healthcare industry have created unprecedented needs to implement changes in the delivery systems. These changes must not only address the access to healthcare, but the costs of delivery, and outcomes reporting. The resulting vision to address these needs has been called the Integrated Healthcare Solution whose core is the Electronic Patient Record. The integration of information by itself is not the issue, nor will it address the challenges in front of the healthcare providers. The process and business of healthcare delivery must adopt, apply and expand its use of technology which can assist in re-engineering the tools for healthcare. Imaging is becoming a larger part of the practice of healthcare both as a recorder of health status and as a defensive record for gatekeepers of healthcare. It is thus imperative that imaging specialists adopt technology which competitively integrates them into the process, reduces the risk, and positively effects the outcome.

  14. Robotic design for an automated uranium solution enrichment system

    SciTech Connect

    Horley, E.C.; Beugelsdijk, T.; Biddle, R.S.; Bronisz, L.E.; Hansen, W.J.; Li, T.K.; Sampson, T.E.; Walton, G.

    1990-01-01

    A method to automate solution enrichment analysis by gamma-ray spectroscopy is being developed at Los Alamos National Laboratory. Both passive and x-ray fluorescence (XRF) analyses will be remotely performed to determine the amounts of {sup 235}U and total uranium in sample containers. A commercial laboratory robot will be used to process up to 40 batch and 8 priority samples in an unattended mode. Samples will be read by a bar-code reader to determine measurement requirements, then assayed by either or both of the gamma-ray and XRF instruments. The robot will be responsible for moving the sample containers and operating all shield doors and shutters. In addition to reducing hardware complexity, this feature will also allow manual operation of the instruments if the robot fails. This automated system will reduce personnel radiation exposure and increase the reliability and repeatability of the measurements.

  15. Periodic solution and almost periodic solution for a nonautonomous Lotka-Volterra dispersal system with infinite delay

    NASA Astrophysics Data System (ADS)

    Meng, Xinzhu; Chen, Lansun

    2008-03-01

    This paper studies a nonautonomous Lotka-Volterra dispersal systems with infinite time delay which models the diffusion of a single species into n patches by discrete dispersal. Our results show that the system is uniformly persistent under an appropriate condition. The sufficient condition for the global asymptotical stability of the system is also given. By using Mawhin continuation theorem of coincidence degree, we prove that the periodic system has at least one positive periodic solution, further, obtain the uniqueness and globally asymptotical stability for periodic system. By using functional hull theory and directly analyzing the right functional of almost periodic system, we show that the almost periodic system has a unique globally asymptotical stable positive almost periodic solution. We also show that the delays have very important effects on the dynamic behaviors of the system.

  16. On axisymmetric and stationary solutions of the self-gravitating Vlasov system

    NASA Astrophysics Data System (ADS)

    Ames, Ellery; Andréasson, Håkan; Logg, Anders

    2016-08-01

    Axisymmetric and stationary solutions are constructed to the Einstein–Vlasov and Vlasov–Poisson systems. These solutions are constructed numerically, using finite element methods and a fixed-point iteration in which the total mass is fixed at each step. A variety of axisymmetric stationary solutions are exhibited, including solutions with toroidal, disk-like, spindle-like, and composite spatial density configurations, as are solutions with non-vanishing net angular momentum. In the case of toroidal solutions, we show for the first time, solutions of the Einstein–Vlasov system which contain ergoregions.

  17. Systems solutions by lactic acid bacteria: from paradigms to practice

    PubMed Central

    2011-01-01

    Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which serve as scientific paradigms. Moreover, functional and comparative metagenomic studies are taking off and provide a wealth of insight in the activity of lactic acid bacteria used in a variety of applications, ranging from starters in complex fermentations to their marketing as probiotics. In this new era of high throughput analysis, biology has become big science. Hence, there is a need to systematically store the generated information, apply this in an intelligent way, and provide modalities for constructing self-learning systems that can be used for future improvements. This review addresses these systems solutions with a state of the art overview of the present paradigms that relate to the use of lactic acid bacteria in industrial applications. Moreover, an outlook is presented of the future developments that include the transition into practice as well as the use of lactic acid bacteria in synthetic biology and other next generation applications. PMID:21995776

  18. Systems solutions by lactic acid bacteria: from paradigms to practice.

    PubMed

    de Vos, Willem M

    2011-08-30

    Lactic acid bacteria are among the powerhouses of the food industry, colonize the surfaces of plants and animals, and contribute to our health and well-being. The genomic characterization of LAB has rocketed and presently over 100 complete or nearly complete genomes are available, many of which serve as scientific paradigms. Moreover, functional and comparative metagenomic studies are taking off and provide a wealth of insight in the activity of lactic acid bacteria used in a variety of applications, ranging from starters in complex fermentations to their marketing as probiotics. In this new era of high throughput analysis, biology has become big science. Hence, there is a need to systematically store the generated information, apply this in an intelligent way, and provide modalities for constructing self-learning systems that can be used for future improvements. This review addresses these systems solutions with a state of the art overview of the present paradigms that relate to the use of lactic acid bacteria in industrial applications. Moreover, an outlook is presented of the future developments that include the transition into practice as well as the use of lactic acid bacteria in synthetic biology and other next generation applications. PMID:21995776

  19. Teleradiology mobile internet system with a new information security solution

    NASA Astrophysics Data System (ADS)

    Satoh, Hitoshi; Niki, Noboru; Eguchi, Kenji; Ohmatsu, Hironobu; Kusumoto, Masahiko; Kaneko, Masahiro; Moriyama, Noriyuki

    2014-03-01

    We have developed an external storage system by using secret sharing scheme and tokenization for regional medical cooperation, PHR service and information preservation. The use of mobile devices such as smart phones and tablets will be accelerated for a PHR service, and the confidential medical information is exposed to the risk of damage and intercept. We verified the transfer rate of the sending and receiving of data to and from the external storage system that connected it with PACS by the Internet this time. External storage systems are the data centers that exist in Okinawa, in Osaka, in Sapporo and in Tokyo by using secret sharing scheme. PACS continuously transmitted 382 CT images to the external data centers. Total capacity of the CT images is about 200MB. The total time that had been required to transmit was about 250 seconds. Because the preservation method to use secret sharing scheme is applied, security is strong. But, it also takes the information transfer time of this system too much. Therefore, DICOM data is masked to the header information part because it is made to anonymity in our method. The DICOM data made anonymous is preserved in the data base in the hospital. Header information including individual information is divided into two or more tallies by secret sharing scheme, and preserved at two or more external data centers. The token to relate the DICOM data anonymity made to header information preserved outside is strictly preserved in the token server. The capacity of header information that contains patient's individual information is only about 2% of the entire DICOM data. This total time that had been required to transmit was about 5 seconds. Other, common solutions that can protect computer communication networks from attacks are classified as cryptographic techniques or authentication techniques. Individual number IC card is connected with electronic certification authority of web medical image conference system. Individual number IC

  20. [Norfloxacin Solution Degradation Under Ultrasound, Potassium Persulfate Collaborative System].

    PubMed

    Wei, Hong; Shi, Jing-zhuan; Li, Jia-lin; Li, Ke-bin; Zhao, Lin; Han, Kai

    2015-11-01

    High oxidative sulfate radicals can be produced by potassium persulfate (K2S2O8). The integrated effect of ultrasonic and K2S2O8, on norfloxacin degradation was investigated. The experimental parameters such as K2S2O8 concentration, norfloxacin initial concentration, initial pH value, free radicals quenching agents such as methanol and tert-butyl on norfloxacin degradation were discussed. The results indicated that ultrasonic/K2S2O8, system had an obvious degradation and mineralization effect on norfloxacin. Norfloxacin removal efficiencies were 3.2 and 8.9 times in ultrasonic/K2S2O8 system than those in single K252O8 and ultrasonic oxidation system, respectively. And the reaction followed the first-order kinetics. Norfloxacin removal efficiency varied gently with K2S2O8 concentration. Solution initial pH had a significant effect on norfloxacin degradation, which was attributed to the different oxidizing species under different pH values. The radicals were sulfate radicals under acidic and neutral conditions, and was the combination of sulfate and hydroxyl radicals under alkaline conditions. TOC and agar diffusion test with E. coli showed that 49.12% norfloxacin was mineralized and antibacterial activity was completely removed, with the diameter of E. coli inhibition zone decreased from 45 mm to 14 mm (filter paper diameter). The result implied that ultrasound/K2S2O8 showed promising results as a possible application for treatment of norfloxacin antibiotics wastewater. PMID:26910998

  1. Least-squares solution of ill-conditioned systems. II

    NASA Astrophysics Data System (ADS)

    Branham, R. L., Jr.

    1980-11-01

    A singular-value analysis of normal equations from observations of minor planets 6 (Hebe), 7 (Iris), 8 (Flora), 9 (Metis), and 15 (Eunomia) is undertaken to determine corrections to a number of astronomical parameters, particularly the equinox correction for the FK4. In a previous investigation the test for small singular values was criticized because it resulted in discordant equinox determinations. Here it is shown that none of the tests employed by singular-value analysis leads to solutions superior to those given by classical least squares. It is concluded that singular-value analysis has legitimate uses in astronomy, but that it is misapplied when employed to estimate astronomical parameters in a well defined model. Also discussed is the question of whether it is preferable to reduce the equations of condition by orthogonal transformations rather than to form normal equations. Some suggestions are made regarding the desirability of planning observational programs in such a way that the observations do not lead to extremely ill-conditioned systems.

  2. Meso-/micro-optical system interface coupling solutions.

    SciTech Connect

    Armendariz, Marcelino G.; Kemme, Shanalyn A.; Boye, Robert R.

    2005-10-01

    Optoelectronic microsystems are more and more prevalent as researchers seek to increase transmission bandwidths, implement electrical isolation, enhance security, or take advantage of sensitive optical sensing methods. Board level photonic integration techniques continue to improve, but photonic microsystems and fiber interfaces remain problematic, especially upon size reduction. Optical fiber is unmatched as a transmission medium for distances ranging from tens of centimeters to kilometers. The difficulty with using optical fiber is the small size of the core (approximately 9 {micro}m for the core of single mode telecommunications fiber) and the tight requirement on spot size and input numerical aperture (NA). Coupling to devices such as vertical cavity emitting lasers (VCSELs) and photodetectors presents further difficulties since these elements work in a plane orthogonal to the electronics board and typically require additional optics. This leads to the need for a packaging solution that can incorporate dissimilar materials while maintaining the tight alignment tolerances required by the optics. Over the course of this LDRD project, we have examined the capabilities of components such as VCSELs and photodetectors for high-speed operation and investigated the alignment tolerances required by the optical system. A solder reflow process has been developed to help fulfill these packaging requirements and the results of that work are presented here.

  3. Exact Solutions for Confined Model Systems Using Kummer Functions

    NASA Astrophysics Data System (ADS)

    Burrows, B. L.; Cohen, M.

    We treat model systems where an electron is confined in a region of space. The particular models considered have solutions which may be expressed in terms of the Kummer functions. Both standard and non-standard Kummer functions are used in these models and a comprehensive summary of the usual and exceptional Kummer functions is given. The definition of confinement is widened to treat radial confinement in any spherical shell, including the asymptotic region and cases where the electron is confined to a lower dimension. Initially we consider the theory in K dimensional space and then give particular examples in 1, 2, and 3 dimensions. A commonly treated model is the radially confined hydrogen atom in 3 dimensions with an infinite barrier on a confining sphere so that the wavefunction is identically zero on this sphere. We have extended this model to treat a more general model of spherical confinement where the derivative of the charge density is zero on the confining sphere. It is shown that the analogous models for the radial harmonic oscillator and radial constant potentials may be treated using a generic technique.

  4. A numerical method for solving systems of linear ordinary differential equations with rapidly oscillating solutions

    NASA Technical Reports Server (NTRS)

    Bernstein, Ira B.; Brookshaw, Leigh; Fox, Peter A.

    1992-01-01

    The present numerical method for accurate and efficient solution of systems of linear equations proceeds by numerically developing a set of basis solutions characterized by slowly varying dependent variables. The solutions thus obtained are shown to have a computational overhead largely independent of the small size of the scale length which characterizes the solutions; in many cases, the technique obviates series solutions near singular points, and its known sources of error can be easily controlled without a substantial increase in computational time.

  5. Practical solutions to implementing "Born Semantic" data systems

    NASA Astrophysics Data System (ADS)

    Leadbetter, A.; Buck, J. J. H.; Stacey, P.

    2015-12-01

    The concept of data being "Born Semantic" has been proposed in recent years as a Semantic Web analogue to the idea of data being "born digital"[1], [2]. Within the "Born Semantic" concept, data are captured digitally and at a point close to the time of creation are annotated with markup terms from semantic web resources (controlled vocabularies, thesauri or ontologies). This allows heterogeneous data to be more easily ingested and amalgamated in near real-time due to the standards compliant annotation of the data. In taking the "Born Semantic" proposal from concept to operation, a number of difficulties have been encountered. For example, although there are recognised methods such as Header, Dictionary, Triples [3] for the compression, publication and dissemination of large volumes of triples these systems are not practical to deploy in the field on low-powered (both electrically and computationally) devices. Similarly, it is not practical for instruments to output fully formed semantically annotated data files if they are designed to be plugged into a modular system and the data to be centrally logged in the field as is the case on Argo floats and oceanographic gliders where internal bandwidth becomes an issue [2]. In light of these issues, this presentation will concentrate on pragmatic solutions being developed to the problem of generating Linked Data in near real-time systems. Specific examples from the European Commission SenseOCEAN project where Linked Data systems are being developed for autonomous underwater platforms, and from work being undertaken in the streaming of data from the Irish Galway Bay Cable Observatory initiative will be highlighted. Further, developments of a set of tools for the LogStash-ElasticSearch software ecosystem to allow the storing and retrieval of Linked Data will be introduced. References[1] A. Leadbetter & J. Fredericks, We have "born digital" - now what about "born semantic"?, European Geophysical Union General Assembly, 2014

  6. Perturbational Blowup Solutions to the Two-Component Dullin-Gottwald-Holm System

    PubMed Central

    2016-01-01

    We construct a family of nonradially symmetric exact solutions for the two-component DGH system by the perturbational method. Depending on the parameters, the class of solutions includes both blowup type and global existence type. PMID:27127801

  7. Solitary and periodic wave solutions of the Majda-Biello system

    NASA Astrophysics Data System (ADS)

    Adem, Abdullahi Rashid

    2016-05-01

    In this paper, we present the exact solutions of the Majda-Biello system. This system describes the nonlinear interaction of long-wavelength equatorial Rossby waves and barotropic Rossby waves with a substantial midlatitude projection, in the presence of suitable horizontally and vertically sheared zonal mean flows. The methods used to construct the exact solutions are the Kudryashov method and Jacobi elliptic function method. These two methods yield solitary wave solutions and periodic wave solutions.

  8. On certain new exact solutions of a diffusive predator-prey system

    NASA Astrophysics Data System (ADS)

    Kraenkel, R. A.; Manikandan, K.; Senthilvelan, M.

    2013-05-01

    We construct exact solutions for a system of two coupled nonlinear partial differential equations describing the spatio-temporal dynamics of a predator-prey system where the prey per capita growth rate is subject to the Allee effect. Using the {G'}/{G} expansion method, we derive exact solutions to this model for two different wave speeds. For each wave velocity we report three different forms of solutions. We also discuss the biological relevance of the solutions obtained.

  9. Security solution against denial of service attacks in BESIP system

    NASA Astrophysics Data System (ADS)

    Rezac, Filip; Voznak, Miroslav; Safarik, Jakub; Partila, Pavol; Tomala, Karel

    2013-05-01

    This article deals about embedded SIP communication server with an easy integration into the computer network based on open source solutions and its effective defense against the most frequent attack in the present - Denial of Service. The article contains brief introduction into the Bright Embedded Solution for IP Telephony - BESIP and describes the most common types of DoS attacks, which are applied on SIP elements of the VoIP infrastructure including the results of defensive mechanism that has been designed.

  10. Abundant soliton solutions for the coupled Schrödinger-Boussinesq system via an analytical method

    NASA Astrophysics Data System (ADS)

    Manafian, Jalil; Aghdaei, Mehdi Fazli

    2016-04-01

    In this paper, the improved tan(Φ(ξ)/2)-expansion method is proposed to find the exact soliton solutions of the coupled Schrödinger-Boussinesq (SB) system. The exact particular solutions are of five types: hyperbolic function solution (exact soliton wave solution), trigonometric function solution (exact periodic wave solution), rational exponential solution (exact singular kink-type wave solution), logarithmic solution and rational solution (exact singular cupson wave solution). We obtained the further solutions comparing with other methods. The results demonstrate that the new tan(Φ(ξ)/2)-expansion method is more efficient than the Ansatz method applied by Bilige et al. (2013). Recently this method was developed for searching the exact travelling-wave solutions of nonlinear partial differential equations. Abundant exact travelling-wave solutions including solitons, kink, periodic and rational solutions have been found. These solutions might play an important role in Laser and plasma. It is shown that this method, with the help of symbolic computation, provides a straightforward and powerful mathematical tool for solving the nonlinear problems.

  11. Analytical solutions of solute transport in a fracture-matrix system with different reaction rates for fracture and matrix

    NASA Astrophysics Data System (ADS)

    Zhu, Yonghui; Zhan, Hongbin; Jin, Menggui

    2016-08-01

    This study deals with the problem of reactive solute transport in a fracture-matrix system using both analytical and numerical modeling methods. The groundwater flow velocity in the fracture is assumed to be high enough (no less than 0.1 m/day) to ensure the advection-dominant transport in the fracture. The problem includes advection along the fracture, transverse diffusion in the matrix, with linear sorption as well as first-order reactions operative in both the fracture and the matrix. A constant-concentration boundary condition and a decay source boundary condition in the fracture are considered. With a constant-concentration source, we obtain closed-form analytical solutions that account for the transport without reaction as well as steady-state solutions with different first-order reactions in the two media. With a decay source, a semi-analytical solution is obtained. The analytical and semi-analytical solutions are in excellent agreement with the numerical simulation results obtained using COMSOL Multiphysics. Sensitivity analysis is conducted to assess the relative importance of matrix diffusion coefficient, fracture aperture, and matrix porosity. We conclude that the first-order reaction as well as the matrix diffusion in the fractured rock would decrease the solute peak concentration and shorten the penetration distance into the fracture. The solutions can be applied to assess the spatial-temporal distribution of concentrations in the fracture and the matrix as well as to assess the contaminant mass stored in the rock matrix. All of these are useful for designing remediation plans for contaminated fractured rocks or for risk assessment of contaminated fracture-matrix systems.

  12. Existence of spherically symmetric solutions for a reduced gravity two-and-a-half layer system

    NASA Astrophysics Data System (ADS)

    Yao, Lei; Li, Zilai; Wang, Wenjun

    2016-08-01

    In this paper, we consider the well-posedness of solutions to a reduced gravity two-and-a-half layer system in oceanic fluid dynamics. By constructing suitable approximate solutions and using the method of weak convergence, we obtain the global existence of weak solutions in two-dimensional exterior spatial domain, when the initial data are large and spherically symmetric.

  13. Discretization of Stationary Solutions of Stochastic Systems Driven by Fractional Brownian Motion

    SciTech Connect

    Garrido-Atienza, Maria J. Kloeden, Peter E. Neuenkirch, Andreas

    2009-10-15

    In this article we study the behavior of dissipative systems with additive fractional noise of any Hurst parameter. Under a one-sided dissipative Lipschitz condition on the drift the continuous stochastic system is shown to have a unique stationary solution, which pathwise attracts all other solutions. The same holds for the discretized stochastic system, if the drift-implicit Euler method is used for the discretization. Moreover, the unique stationary solution of the drift-implicit Euler scheme converges to the unique stationary solution of the original system as the stepsize of the discretization decreases.

  14. Impact of delayed neutron precursor mobility in fissile solution systems

    SciTech Connect

    Kiedrowski, B. C.

    2012-07-01

    A research version of the Monte Carlo software package MCNP6 is modified to incorporate advection and diffusion of delayed neutron precursors, resulting in the emission of delayed neutrons at locations different from the original fission sites. Results of two test problems, a pipe carrying flowing fissile solution and a sphere of fissile solution with precursor diffusion, show that the fission product mobility tends to perturb the fundamental mode, has a negative reactivity effect, and, perhaps most importantly, causes a decrease in the effective delayed neutron fraction. (authors)

  15. Systemic study on fluorescent switching systems composed of naphthopyran and benzimidazole in solution and film forms

    NASA Astrophysics Data System (ADS)

    He, Yi; Wang, Guang; Wang, Mingxin

    2016-07-01

    The fluorescent photo-switching systems were prepared based on fluorescent benzimidazole and photochromic naphthopyran. Naphthopyran in this systems displayed excellent photochromic performance in tetrahydrofuran solutions and in PMMA films. The fluorescent emission of benzimidazole was modulated between "on" and "off" via the photoisomerization of naphthopyran in high-contrast due to the photoinduced energy transfer from benzimidazole to the open-form naphthopyran. Both the fluorescent photoswitching and the photochromism of benzimidazole-naphthopyran dyads in solutions and films displayed excellent fatigue resistance. The spaces between benzimidazole and naphthopyran affect the absorbance and fluorescence spectra of benzimidazole-naphthopyran dyads. The non-destructive readout ability of synthesized dyads in doped PMMA film was achieved.

  16. On solutions of mixed boundary-value problems for the elasticity system in unbounded domains

    NASA Astrophysics Data System (ADS)

    Matevossian, H. A.

    2003-10-01

    We study the properties of generalized solutions of mixed boundary-value problems for the linear system of elasticity theory in the exterior of a compact set and in a half-space under the assumption that the energy integral with weight \\vert x\\vert^a is finite for such solutions. Depending on the value of the parameter a, a uniqueness criterion is established for these solutions, and exact formulae are obtained for the dimension of the space of solutions.

  17. Wormhole solution in coupled Yang-Mills--axion system

    SciTech Connect

    Das, A. Department of Astronomy, University of Rochester, Rochester, New York 14627 ); Maharana, J. )

    1990-01-15

    We show that wormhole solutions arise naturally in the effective action, resulting from a heterotic string theory, in which Einstein gravity is coupled to the antisymmetric tensor and an SU(2) Yang-Mills field. The Peccei-Quinn scale in this case gets related to the string tension which is natural in any string compactification.

  18. Existence of global solutions for a chemotaxis-fluid system with nonlinear diffusion

    NASA Astrophysics Data System (ADS)

    Chung, Yun-Sung; Kang, Kyungkeun

    2016-04-01

    We consider a coupled system consisting of the Navier-Stokes equations and a porous medium type of Keller-Segel system that model the motion of swimming bacteria living in fluid and consuming oxygen. We establish the global-in-time existence of weak solutions for the Cauchy problem of the system in dimension three. In addition, if the Stokes system, instead Navier-Stokes system, is considered for the fluid equation, we prove that bounded weak solutions exist globally in time.

  19. Solute effect on basal and prismatic slip systems of Mg.

    PubMed

    Moitra, Amitava; Kim, Seong-Gon; Horstemeyer, M F

    2014-11-01

    In an effort to design novel magnesium (Mg) alloys with high ductility, we present a first principles data based on the Density Functional Theory (DFT). The DFT was employed to calculate the generalized stacking fault energy curves, which can be used in the generalized Peierls-Nabarro (PN) model to study the energetics of basal slip and prismatic slip in Mg with and without solutes to calculate continuum scale dislocation core widths, stacking fault widths and Peierls stresses. The generalized stacking fault energy curves for pure Mg agreed well with other DFT calculations. Solute effects on these curves were calculated for nine alloying elements, namely Al, Ca, Ce, Gd, Li, Si, Sn, Zn and Zr, which allowed the strength and ductility to be qualitatively estimated based on the basal dislocation properties. Based on our multiscale methodology, a suggestion has been made to improve Mg formability. PMID:25273695

  20. Exact traveling wave solutions for system of nonlinear evolution equations.

    PubMed

    Khan, Kamruzzaman; Akbar, M Ali; Arnous, Ahmed H

    2016-01-01

    In this work, recently deduced generalized Kudryashov method is applied to the variant Boussinesq equations, and the (2 + 1)-dimensional breaking soliton equations. As a result a range of qualitative explicit exact traveling wave solutions are deduced for these equations, which motivates us to develop, in the near future, a new approach to obtain unsteady solutions of autonomous nonlinear evolution equations those arise in mathematical physics and engineering fields. It is uncomplicated to extend this method to higher-order nonlinear evolution equations in mathematical physics. And it should be possible to apply the same method to nonlinear evolution equations having more general forms of nonlinearities by utilizing the traveling wave hypothesis. PMID:27347461

  1. Lubrication of space systems: Challenges and potential solutions

    NASA Technical Reports Server (NTRS)

    Fusaro, Robert L.

    1992-01-01

    Future space missions will all require advanced mechanical moving components which will require wear protection and lubrication. The tribology practices used today are primarily based upon a technology base that is more than 20 years old. This paper will discuss NASA's future space missions and some of the mechanism tribology challenges that will be encountered. Potential solutions to these challenges using coatings technology will be assessed.

  2. Biogeochemistry of fluoride in a plant-solution system

    NASA Technical Reports Server (NTRS)

    Mackowiak, C. L.; Grossl, P. R.; Bugbee, B. G.

    2003-01-01

    Fluoride (F-) pollutants can harm plants and the animals feeding on them. However, it is largely unknown how complexing and chelating agents affect F bioavailability. Two studies were conducted that measured F- bioavailability and uptake by rice (Oryza sativa L.). In the first study, rice was grown in solution culture (pH 5.0) with 0, 2, or 4 mM F- as KF to compare the interaction of F- with humic acid (HA) and with a conventional chelating agent, N-hydroxyethylenthylenediaminetriacetic acid (HEDTA). In the second study, F was supplied at 0, 0.5, 1.0, and 2.0 mM KF with an additional 2 mM F- treatment containing solution Ca at 2x (2 mM Ca) the level used in the first study, to test the effect added Ca had on F- availability and uptake. Total biomass was greatest with HEDTA and F- < 1 mM. Leaf and stem F concentrations increased exponentially as solution F- increased linearly, with nearly no F partitioning into the seed. Results suggest that F was taken up as HF0 while F- uptake was likely restricted. Additionally, F- competed with HA for Ca, thus preventing the formation of Ca-HA flocculents. The addition of soluble Ca resulted in the precipitation of CaF2 solids on the root surface, as determined by tissue analysis and energy dispersive X-ray spectroscopy.

  3. A Solution-Oriented Approach to Conflict Resolution in a Work System.

    ERIC Educational Resources Information Center

    Webb, Susan B.

    1995-01-01

    Growing involvement of counselors in organizational development is addressed by describing the application of a solution-oriented family therapy approach to conflict resolution in a work system. Outlines the system's storying of the problem, development of new meanings and identification of solutions. Key concepts in this postmodern approach are…

  4. Solution to problems of bacterial impurity of heating systems

    NASA Astrophysics Data System (ADS)

    Sharapov, V. I.; Zamaleev, M. M.

    2015-09-01

    The article describes the problems of the operation of open and closed district heating systems related to the bacteriological contamination of heating-system water. It is noted that district heating systems are basically safe in sanitary epidemiological terms. Data on the dangers of sulfide contamination of heating systems are given. It is shown that the main causes of the development of sulfate-reducing and iron bacteria in heating systems are a significant biological contamination of source water to fuel heating systems, which is determined by water oxidizability, and a low velocity of the motion of heating-system water in the heating system elements. A case of sulfide contamination of a part of the outdoor heat-supply system of the city of Ulyanovsk is considered in detail. Measures for cleaning pipelines and heating system equipment from the waste products of sulfate-reducing bacteria and iron bacteria and for improving the quality of heating-system water by organizing the hydraulic and water-chemistry condition that makes it possible to avoid the bacteriological contamination of heating systems are proposed. The positive effect of sodium silicate on the prevention of sulfide contamination of heating systems is shown.

  5. Global Existence of Renormalized Solutions to Entropy-Dissipating Reaction-Diffusion Systems

    NASA Astrophysics Data System (ADS)

    Fischer, J.

    2015-10-01

    In the present work we introduce the notion of a renormalized solution for reaction-diffusion systems with entropy-dissipating reactions. We establish the global existence of renormalized solutions. In the case of integrable reaction terms our notion of a renormalized solution reduces to the usual notion of a weak solution. Our existence result in particular covers all reaction-diffusion systems involving a single reversible reaction with mass-action kinetics and (possibly species-dependent) Fick-law diffusion; more generally, it covers the case of systems of reversible reactions with mass-action kinetics which satisfy the detailed balance condition. For such equations the existence of any kind of solution in general was an open problem, thereby motivating the study of renormalized solutions.

  6. Solution thermodynamics for alkoxy phenols in alcohol and in water-alcohol systems

    SciTech Connect

    Beezer, A.E.; Hunter, W.H.; Lima, M.C.P.; Volpe, P.L.O.

    1986-04-01

    Solubilities have been measured for m-alkoxyphenols in water-alcohol mixtures. The alcohols ranged from the co-solvent methanol to the co-solute 1-octanol, and each alcohol was present at the saturating concentration of 1-octanol in water viz. 0.00316M. Plots of solubility vs. carbon number of the alcohols show discontinuities. Enthalpies of solution in these same solvent systems have also been measured. The enthalpies of solution and the derived enthalpies of transfer both support the observations on solubilities. The results are discussed on the basis of solvent-solute interactions and in terms of solute volumes.

  7. Localized modulated wave solutions in diffusive glucose-insulin systems

    NASA Astrophysics Data System (ADS)

    Mvogo, Alain; Tambue, Antoine; Ben-Bolie, Germain H.; Kofané, Timoléon C.

    2016-06-01

    We investigate intercellular insulin dynamics in an array of diffusively coupled pancreatic islet β-cells. The cells are connected via gap junction coupling, where nearest neighbor interactions are included. Through the multiple scale expansion in the semi-discrete approximation, we show that the insulin dynamics can be governed by the complex Ginzburg-Landau equation. The localized solutions of this equation are reported. The results suggest from the biophysical point of view that the insulin propagates in pancreatic islet β-cells using both temporal and spatial dimensions in the form of localized modulated waves.

  8. On the Solution of a Boltzmann System for Gas Mixtures

    NASA Astrophysics Data System (ADS)

    Sotirov, Alexander; Yu, Shih-Hsien

    2010-02-01

    We study the Boltzmann equation for a mixture of two gases in one space dimension with initial condition of one gas near vacuum and the other near a Maxwellian equilibrium state. A qualitative-quantitative mathematical analysis is developed to study this mass diffusion problem based on the Green’s function of the Boltzmann equation for the single species hard sphere collision model in Liu andYu (Commun Pure Appl Math 57:1543-1608, 2004). The cross-species resonance of the mass diffusion and the diffusion-sound wave is investigated. An exponentially sharp global solution is obtained.

  9. The nonlinear stability of the trivial solution to the Maxwell-Born-Infeld system

    NASA Astrophysics Data System (ADS)

    Speck, Jared

    2012-08-01

    In this article, we use an electromagnetic gauge-free framework to establish the existence of small-data global solutions to the Maxwell-Born-Infeld (MBI) system on the Minkowski spacetime background in 1+3 dimensions. Because the nonlinearities in the system have a special null structure, we are also able to show that these solutions decay at least as fast as solutions to the linear Maxwell-Maxwell system. In addition, we show that on any Lorentzian manifold, the MBI system is hyperbolic in the interior of the field-strength regime in which its Lagrangian is real-valued.

  10. The Fallacy of Univariate Solutions to Complex Systems Problems.

    PubMed

    Lessov-Schlaggar, Christina N; Rubin, Joshua B; Schlaggar, Bradley L

    2016-01-01

    Complex biological systems, by definition, are composed of multiple components that interact non-linearly. The human brain constitutes, arguably, the most complex biological system known. Yet most investigation of the brain and its function is carried out using assumptions appropriate for simple systems-univariate design and linear statistical approaches. This heuristic must change before we can hope to discover and test interventions to improve the lives of individuals with complex disorders of brain development and function. Indeed, a movement away from simplistic models of biological systems will benefit essentially all domains of biology and medicine. The present brief essay lays the foundation for this argument. PMID:27375425

  11. Practical solutions to turbine control system retrofit problems

    SciTech Connect

    Cavanagh, M.; Lovejoy, K.

    1996-10-01

    This paper addresses the use of microprocessors in retrofitting turbine control systems. The topics of the paper include modern control system architecture, human machine interface, steam flow linearization and automatic valve calibration, retrofit hydraulic interfacing, reliability considerations, and advanced valve positioning technique (quarter cycle damping).

  12. Spacecraft Power Systems Engineering: Solutions for NASA's Manned Space Program

    NASA Technical Reports Server (NTRS)

    Scott, John H.

    2007-01-01

    An overview of spacecraft power systems is presented, with a focus on applications in the manned space program. The topics include: 1) History; 2) State-of-the-art; 3) Development directions; 4) Focus on applications in the manned space program led from JSC; 5) Power Systems Engineering Trade Space; 6) Power Generation and Energy Storage; 7) Power Distribution and Control; and 8) Actuation

  13. Hydrothermal Dehydration of Aqueous Fructose Solutions in a Closed System

    SciTech Connect

    Yao, Chunhua; Shin, Yongsoon; Wang, Li Q.; Windisch, Charles F.; Samuels, William D.; Arey, Bruce W.; Wang, Chong M.; Risen Jr., William M.; Exarhos, Gregory J.

    2007-10-25

    The synthesis of materials with targeted size and shape has attracted much attention. Specifically, colloidal spheres with targeted and uniform sizes have opened the door for a variety of applications associated with drug delivery, and manipulation of light (photonic band-gap crystals). Surface modification is a key to realizing many of these applications owing to the inherent inert surface.The remarkable transformation of carbohydrate molecules including sugars to homogeneous carbon spheres is found to readily occur by a dehydration mechanism and subsequent sequestering in aqueous solutions that are heated at 160-180oC in a pressurized vessel. Under such conditions, these molecules actually dehydrate even though they are dissolved in water. Size-tunable metal and metal oxides with uniform shells have also been prepared by using carbon spheres as templates.

  14. Comparison of Integrated AOP Systems for BTEX Removal From Solution

    SciTech Connect

    Peters, Robert W.; Mohammad, Jan

    2004-03-31

    This paper investigates the removal of BTEX compounds (benzene, toluene, ethylbenzene and xylene) from water using different advanced oxidation processes (AOPs) used singly or in combination with one another. This research is an extension of our work performed under the Environmental Management Science Program (EMSP) which addressed treating chlorinated organic contaminated water using sonication, vapor stripping and combined sonication + vapor stripping. In our current study, various AOP processes were investigated for their ability to remove BTEX compounds from solution, including the following. ? Ultraviolet (UV) light alone ? UV light + hydrogen peroxide (H2O2) ? Sonication alone ? Air sparging alone ? Air sparging + sonication ? Air sparging + UV light ? Sonication + UV light ? Sonication + H2O2 ? Sonication + air sparging + UV light ? Sonication + air sparging + H2O2 ? Sonication + air sparging + H2O2 + UV light ? Sonication + air sparging with O3 ? Sonication + O3 + H2O2 ? Sonication + O3 + H2O2 + UV light

  15. Purification of uranothorite solid solutions from polyphase systems

    NASA Astrophysics Data System (ADS)

    Clavier, Nicolas; Szenknect, Stéphanie; Costin, Dan Tiberiu; Mesbah, Adel; Ravaux, Johann; Poinssot, Christophe; Dacheux, Nicolas

    2013-10-01

    The mineral coffinite, nominally USiO4, and associated Th1-xUxSiO4 uranothorite solid solutions are of great interest from a geochemical point of view and in the case of the direct storage of spent nuclear fuels. Nevertheless, they clearly exhibit a lack in the evaluation of their thermodynamic data, mainly because of the difficulties linked with their preparation as pure phases. This paper thus presents physical and chemical methods aiming to separate uranothorite solid solutions from oxide additional phases such as amorphous SiO2 and nanometric crystallized Th1-yUyO2. The repetition of centrifugation steps envisaged in first place was rapidly dropped due to poor recovery yields, to the benefit of successive washings in acid then basic media. Under both static and dynamic flow rates (i.e. low or high rate of leachate renewal), ICP-AES (Inductively Coupled Plasma - Atomic Emission Spectroscopy) analyses revealed the systematic elimination of Th1-yUyO2 in acid media and of SiO2 in basic media. Nevertheless, two successive steps were always needed to reach pure samples. On this basis, a first cycle performed in static conditions was chosen to eliminate the major part of the accessory phases while a second one, in dynamic conditions, allowed the elimination of the residual impurities. The complete purification of the samples was finally evidenced through the characterization of the samples by the means of PXRD (Powder X-Ray Diffraction), SEM (Scanning Electron Microscopy) observations and X-EDS (X-Ray Energy Dispersive Spectroscopy) analyses.

  16. Periodic Solutions for Nonlinear Integro-Differential Systems with Piecewise Constant Argument

    PubMed Central

    2014-01-01

    We investigate the existence of the periodic solutions of a nonlinear integro-differential system with piecewise alternately advanced and retarded argument of generalized type, in short DEPCAG; that is, the argument is a general step function. We consider the critical case, when associated linear homogeneous system admits nontrivial periodic solutions. Criteria of existence of periodic solutions of such equations are obtained. In the process we use Green's function for periodic solutions and convert the given DEPCAG into an equivalent integral equation. Then we construct appropriate mappings and employ Krasnoselskii's fixed point theorem to show the existence of a periodic solution of this type of nonlinear differential equations. We also use the contraction mapping principle to show the existence of a unique periodic solution. Appropriate examples are given to show the feasibility of our results. PMID:24574895

  17. Periodic solutions for nonlinear integro-differential systems with piecewise constant argument.

    PubMed

    Chiu, Kuo-Shou

    2014-01-01

    We investigate the existence of the periodic solutions of a nonlinear integro-differential system with piecewise alternately advanced and retarded argument of generalized type, in short DEPCAG; that is, the argument is a general step function. We consider the critical case, when associated linear homogeneous system admits nontrivial periodic solutions. Criteria of existence of periodic solutions of such equations are obtained. In the process we use Green's function for periodic solutions and convert the given DEPCAG into an equivalent integral equation. Then we construct appropriate mappings and employ Krasnoselskii's fixed point theorem to show the existence of a periodic solution of this type of nonlinear differential equations. We also use the contraction mapping principle to show the existence of a unique periodic solution. Appropriate examples are given to show the feasibility of our results. PMID:24574895

  18. The Fallacy of Univariate Solutions to Complex Systems Problems

    PubMed Central

    Lessov-Schlaggar, Christina N.; Rubin, Joshua B.; Schlaggar, Bradley L.

    2016-01-01

    Complex biological systems, by definition, are composed of multiple components that interact non-linearly. The human brain constitutes, arguably, the most complex biological system known. Yet most investigation of the brain and its function is carried out using assumptions appropriate for simple systems—univariate design and linear statistical approaches. This heuristic must change before we can hope to discover and test interventions to improve the lives of individuals with complex disorders of brain development and function. Indeed, a movement away from simplistic models of biological systems will benefit essentially all domains of biology and medicine. The present brief essay lays the foundation for this argument. PMID:27375425

  19. Some exact solutions of a system of nonlinear Schroedinger equations in three-dimensional space

    SciTech Connect

    Moskalyuk, S.S.

    1988-02-01

    Interactions that break the symmetry of systems of nonrelativistic Schroedinger equations but preserve their symmetry with respect to one-parameter subgroups of the Schroedinger group are described. Ansatzes for invariant solutions and the corresponding systems of reduced equations in invariant variables for Galileo-invariant Schroedinger equations are found. Exact solutions for the system of nonlinear Schroedinger equations in three-dimensional space for the generalized Hubbard model are obtained.

  20. Exact solution of a problem of the oscillations of a system with random parametric excitation

    NASA Astrophysics Data System (ADS)

    Dimentberg, M. F.

    1980-12-01

    A second-order system with external and parametric random excitations of white-noise type is considered. An exact analytical solution of the stationary Fokker-Planck-Kolmogorov equation is obtained for a special relationship between coordinate modulation intensity and velocity for this system; this equation describes the power dependence for the combined probability density of the coordinate and velocity. This solution can be used to verify various approximate methods for the analysis of the dynamics of systems with randomly varying parameters.

  1. Technology Solutions Case Study: Hydronic Systems: Designing for Setback Operation

    SciTech Connect

    2014-05-01

    For years, conventional wisdom surrounding space heating has specified two points: size the mechanical systems to the heating loads, and setting the thermostat back at night will result in energy savings. The problem is these two recommendations oppose each other. A system that is properly sized to the heating load will not have the extra capacity necessary to recover from a thermostat setback, especially at design conditions. Properly designing a hydronic system for setback operation can be accomplished but depends on several factors. Determining the appropriateness of setback for a particular project is the first step. This is followed by proper sizing of the boiler and baseboard to ensure the needed capacity can be met. Finally, control settings must be chosen that result in the most efficient and responsive performance. This guide provides step-by-step instructions for heating contractors and hydronic designers for selecting the proper control settings to maximize system performance and improve response time when using a thermostat setback.

  2. Existence of solutions for a Schrödinger system with linear and nonlinear couplings

    NASA Astrophysics Data System (ADS)

    Li, Kui; Zhang, Zhitao

    2016-08-01

    We study an important system of Schrödinger equations with linear and nonlinear couplings arising from Bose-Einstein condensates. We use the Nehari manifold to prove the existence of a ground state solution; moreover, we give the sign of the solutions depending on linear coupling; by using index theory and Nehari manifold, we prove that there exist infinitely many positive bound state solutions.

  3. A real time monitoring system of ringer's solution residual amount for automatic nursing in hopsitals

    NASA Astrophysics Data System (ADS)

    Kwon, Jong-Won; Ha, Kwan-Yong; Nam, Chul; Ayurzana, Odgelral; Kim, Hie-Sik

    2005-12-01

    A real-time embedded system was developed for remote monitoring and checking the residual quantity and changing of Ringer's solution. It is monitored nurses' room. A Load Cell was applied as a sensor to check the residual quantity of Ringer's solution. This Load Cell detects the physical changes of Ringer's solution and transfers electronic signal to the amplifier. Amplified analog signal is converted into digital signal by A/D converter. Developed Embedded system, which computes these data with microprocess (8052) then makes it possible to monitor the residual quantity of Ringer's solution real-time on a server computer. A Checking system on Residual Quantity of Ringer's Solution Using Load cell cut costs using a simple design for a circuit.

  4. A fast solution switching system with temperature control for single cell measurements

    PubMed Central

    Koh, Duk-Su; Chen, Liangyi; Ufret-Vincenty, Carmen A.; Jung, Seung-Ryoung

    2011-01-01

    This article describes a perfusion system for biophysical single cell experiments at the physiological temperature. Our system regulates temperature of test solutions using a small heat exchanger that includes several capillaries. Water circulating inside the heat exchanger warms or cools test solutions flowing inside the capillaries. Temperature-controlled solutions are delivered directly to a single cell(s) through a multibarreled manifold that switches solutions bathing a cell in less than 1 s. This solution exchange is optimal for patch clamp, single-cell microamperometry, and microfluorometry experiments. Using this system, we demonstrate that exocytosis from pancreatic β cells and activation of TRPV1 channels are temperature sensitive. We also discuss how to measure local temperature near a single cell under investigation. PMID:21536068

  5. Teleradiology network system using the web medical image conference system with a new information security solution

    NASA Astrophysics Data System (ADS)

    Satoh, Hitoshi; Niki, Noboru; Eguchi, Kenji; Ohmatsu, Hironobu; Kusumoto, Masahiro; Kaneko, Masahiro; Kakinuma, Ryutaru; Moriyama, Noriyuki

    2012-02-01

    We have developed the teleradiology network system with a new information security solution that provided with web medical image conference system. In the teleradiology network system, the security of information network is very important subjects. We are studying the secret sharing scheme and the tokenization as a method safely to store or to transmit the confidential medical information used with the teleradiology network system. The confidential medical information is exposed to the risk of the damage and intercept. Secret sharing scheme is a method of dividing the confidential medical information into two or more tallies. Individual medical information cannot be decoded by using one tally at all. Our method has the function of automatic backup. With automatic backup technology, if there is a failure in a single tally, there is redundant data already copied to other tally. Confidential information is preserved at an individual Data Center connected through internet because individual medical information cannot be decoded by using one tally at all. Therefore, even if one of the Data Centers is struck and information is damaged due to the large area disaster like the great earthquake of Japan, the confidential medical information can be decoded by using the tallies preserved at the data center to which it escapes damage. Moreover, by using tokenization, the history information of dividing the confidential medical information into two or more tallies is prevented from lying scattered by replacing the history information with another character string (Make it to powerlessness). As a result, information is available only to those who have rightful access it and the sender of a message and the message itself are verified at the receiving point. We propose a new information transmission method and a new information storage method with a new information security solution.

  6. Global small solutions of 2-D incompressible MHD system

    NASA Astrophysics Data System (ADS)

    Lin, Fanghua; Xu, Li; Zhang, Ping

    2015-11-01

    In this paper, we consider the global wellposedness of 2-D incompressible magneto-hydrodynamical system with smooth initial data which is close to some non-trivial steady state. It is a coupled system between the Navier-Stokes equations and a free transport equation with a universal nonlinear coupling structure. The main difficulty of the proof lies in exploring the dissipative mechanism of the system. To achieve this and to avoid the difficulty of propagating anisotropic regularity for the free transport equation, we first reformulate our system (1.1) in the Lagrangian coordinates (2.19). Then we employ anisotropic Littlewood-Paley analysis to establish the key a prioriL1 (R+ ; Lip (R2)) estimate for the Lagrangian velocity field Yt. With this estimate, we can prove the global wellposedness of (2.19) with smooth and small initial data by using the energy method. We emphasize that the algebraic structure of (2.19) is crucial for the proofs to work. The global wellposedness of the original system (1.1) then follows by a suitable change of variables.

  7. INEEL HEPA Filter Leach System: A Mixed Waste Solution

    SciTech Connect

    K. Archibald; K. Brewer; K. Kline; K. Pierson; K. Shackelford; M. Argyle; R. Demmer

    1999-02-01

    Calciner operations and the fuel dissolution process at the Idaho National Engineering and Environmental Laboratory have generated many mixed waste high-efficiency particulate air (HEPA)filters. The HEPA Filter Leach System located at the Idaho Nuclear Technology and Engineering Center lowers radiation contamination levels and reduces cadmium, chromium, and mercury concentrations on spent HEPA filter media to below disposal limits set by the Resource Conservation and Recovery Act (RCRA). The treated HEPA filters are disposed as low-level radioactive waste. The technical basis for the existing system was established and optimized in initial studies using simulants in 1992. The treatment concept was validated for EPA approval in 1994 by leaching six New Waste Calcining Facility spent HEPA filters. Post-leach filter media sampling results for all six filters showed that both hazardous and radiological constituent levels were reduced so the filters could be disposed of as low-level radioactive waste. Since the validation tests the HEPA Filter Leach System has processed 78 filters in 1997 and 1998. The Idaho National Engineering and Environmental Laboratory HEPA Filter Leach System is the only mixed waste HEPA treatment system in the DOE complex. This process is of interest to many of the other DOE facilities and commercial companies that have generated mixed waste HEPA filters but currently do not have a treatment option available.

  8. INEEL HEPA Filter Leach System: A Mixed Waste Solution

    SciTech Connect

    Argyle, Mark Don; Demmer, Ricky Lynn; Archibald, Kip Ernest; Brewer, Ken Neal; Pierson, Kenneth Alan; Shackelford, Kimberlee Rene; Kline, Kelli Suzanne

    1999-03-01

    Calciner operations and the fuel dissolution process at the Idaho National Engineering and Environmental Laboratory have generated many mixed waste high-efficiency particulate air (HEPA) filters. The HEPA Filter Leach System located at the Idaho Nuclear Technology and Engineering Center lowers radiation contamination levels and reduces cadmium, chromium, and mercury concentrations on spent HEPA filter media to below disposal limits set by the Resource Conservation and Recovery Act (RCRA). The treated HEPA filters are disposed as low-level radioactive waste. The technical basis for the existing system was established and optimized in initial studies using simulants in 1992. The treatment concept was validated for EPA approval in 1994 by leaching six New Waste Calcining Facility spent HEPA filters. Post-leach filter media sampling results for all six filters showed that both hazardous and radiological constituent levels were reduced so the filters could be disposed of as low-level radioactive waste. Since the validation tests the HEPA Filter Leach System has processed 78 filters in 1997 and 1998. The Idaho National Engineering and Environmental Laboratory HEPA Filter Leach System is the only mixed waste HEPA treatment system in the DOE complex. This process is of interest to many of the other DOE facilities and commercial companies that have generated mixed waste HEPA filters but currently do not have a treatment option available.

  9. Reprocessing system with nuclide separation based on chromatography in hydrochloric acid solution

    SciTech Connect

    Suzuki, Tatsuya; Tachibana, Yu; Koyama, Shi-ichi

    2013-07-01

    We have proposed the reprocessing system with nuclide separation processes based on the chromatographic technique in the hydrochloric acid solution system. Our proposed system consists of the dissolution process, the reprocessing process, the minor actinide separation process, and nuclide separation processes. In the reprocessing and separation processes, the pyridine resin is used as a main separation media. It was confirmed that the dissolution in the hydrochloric acid solution is easily achieved by the plasma voloxidation and by the addition of oxygen peroxide into the hydrochloric acid solution.

  10. Linear stability of stationary solutions of the Vlasov-Poisson system in three dimensions

    SciTech Connect

    Batt, J.; Rein, G. . Mathematisches Inst.); Morrison, P.J. )

    1993-03-01

    Rigorous results on the stability of stationary solutions of the Vlasov-Poisson system are obtained in both the plasma physics and stellar dynamics contexts. It is proven that stationary solutions in the plasma physics (stellar dynamics) case are linearly stable if they are decreasing (increasing) functions of the local, i.e. particle, energy. The main tool in the analysis is the free energy of the system, a conserved quantity. In addition, an appropriate global existence result is proven for the linearized Vlasov-Poisson system and the existence of stationary solutions that satisfy the above stability condition is established.

  11. A performability solution method for degradable nonrepairable systems

    NASA Technical Reports Server (NTRS)

    Furchtgott, D. G.; Meyer, J. F.

    1984-01-01

    The present performability model-solving algorithm identifies performance with 'reward', representing the state behavior of a system S by a finite-state stochastic process and determining reward by means of reward rates that are associated with the states of the base model. A general method is obtained for determining the probability distribution function of the performance (reward) variable, and therefore the performability, of the corresponding system. This is done for bounded utilization periods, and the result is an integral expression which is either analytically or numerically solvable.

  12. Solutions on high-resolution multiple configuration system sensors

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Ding, Quanxin; Guo, Chunjie; Zhou, Liwei

    2014-11-01

    For aim to achieve an improved resolution in modern image domain, a method of continuous zoom multiple configuration, with a core optics is attempt to establish model by novel principle on energy transfer and high accuracy localization, by which the system resolution can be improved with a level in nano meters. A comparative study on traditional vs modern methods can demonstrate that the dialectical relationship and their balance is important, among Merit function, Optimization algorithms and Model parameterization. The effect of system evaluated criterion that MTF, REA, RMS etc. can support our arguments qualitatively.

  13. Particular transcendent solution of the Ernst system generalized on n fields

    SciTech Connect

    Leaute, B.; Marcilhacy, G.

    1986-03-01

    A particular solution, a function of a particular form of the fifth Painleve transcendent, of the Ernst system generalized to n fields is determined, which characterizes both the stationary axially symmetric fields, the solution of the Einstein (n-1) Maxwell equations, and one class of axially symmetric static self-dual SU(n+1) Yang--Mills fields.

  14. Expanding the Space of Plausible Solutions in a Medical Tutoring System for Problem-Based Learning

    ERIC Educational Resources Information Center

    Kazi, Hameedullah; Haddawy, Peter; Suebnukarn, Siriwan

    2009-01-01

    In well-defined domains such as Physics, Mathematics, and Chemistry, solutions to a posed problem can objectively be classified as correct or incorrect. In ill-defined domains such as medicine, the classification of solutions to a patient problem as correct or incorrect is much more complex. Typical tutoring systems accept only a small set of…

  15. New solutions of the Zakharov's equation system for quantum plasmas in form of nonlinear bursts lattice

    SciTech Connect

    Dubinov, Alexander E.; Kitayev, Ilya N.

    2014-02-15

    New multiplicative solutions of the Zakharov's quantum system of equations using the separation of variables method are found. The found solutions are interpreted as spatial-periodical lattices of non-linear plasma bursts. It is shown that the bursts could be both symmetrical and asymmetrical by an electric field.

  16. The Singular Set of Solutions to Non-Differentiable Elliptic Systems

    NASA Astrophysics Data System (ADS)

    Mingione, Giuseppe

    We estimate the Hausdorff dimension of the singular set of solutions to elliptic systems of the type If the vector fields a and b are Hölder continuous with respect to the variable x with exponent α, then the Hausdorff dimension of the singular set of any weak solution is at most n-2α.

  17. Periodic solutions of a spring-pendulum system.

    NASA Technical Reports Server (NTRS)

    Broucke, R.; Baxa, P. A.

    1973-01-01

    A study has been made of a dynamical system composed of a pendulum and a harmonic oscillator, in order to show the remarkable resemblance with many classical celestial mechanics problems, in particular, the restricted three-body problem. It is shown that the well-known investigations of periodic orbits can be applied to the present dynamics problem.

  18. Distributed Cooperation Solution Method of Complex System Based on MAS

    NASA Astrophysics Data System (ADS)

    Weijin, Jiang; Yuhui, Xu

    To adapt the model in reconfiguring fault diagnosing to dynamic environment and the needs of solving the tasks of complex system fully, the paper introduced multi-Agent and related technology to the complicated fault diagnosis, an integrated intelligent control system is studied in this paper. Based on the thought of the structure of diagnostic decision and hierarchy in modeling, based on multi-layer decomposition strategy of diagnosis task, a multi-agent synchronous diagnosis federation integrated different knowledge expression modes and inference mechanisms are presented, the functions of management agent, diagnosis agent and decision agent are analyzed, the organization and evolution of agents in the system are proposed, and the corresponding conflict resolution algorithm in given, Layered structure of abstract agent with public attributes is build. System architecture is realized based on MAS distributed layered blackboard. The real world application shows that the proposed control structure successfully solves the fault diagnose problem of the complex plant, and the special advantage in the distributed domain.

  19. Exploiting special problem structure when reliably investigating the solution of systems of IVPs and DDEs

    NASA Astrophysics Data System (ADS)

    Enright, W. H.

    2016-06-01

    In recent years we have developed a class of reliable order p methods for the approximate solution of general systems of initial value problems (IVPs) and delay differential equations (DDEs). In the theoretical analysis of these methods we have identified several trade-offs that do arise and have to be addressed when applying these methods to problems that exhibit special structure. Similar trade-offs also arise when one is concerned with investigating other important properties of the solutions. We will give examples of such trade-offs that arise when investigating the sensitivities of the solutions, and when very accurate approximate solutions are required.

  20. Diffractive Elements in the Optical System: Successes, Challenges, and Solutions

    NASA Astrophysics Data System (ADS)

    Greisukh, G. I.; Ezhov, E. G.; Levin, I. A.; Kazin, S. V.; Stepanov, S. A.

    2015-01-01

    Correction of aberrations is regarded as one of the most successful applications of diffractive optical elements in the optical system. The ways of overcoming these negative properties of the diffractive elements as spherochromatism and power spectral selectivity are presented. Using the technique given in this paper, a compact plastic-lens refractive-diffractive objective, which can operate in a wide spectral range including the visible and near-infrared radiation, has been designed.

  1. Evaluation of powertrain solutions for future tactical truck vehicle systems

    NASA Astrophysics Data System (ADS)

    Pisu, Pierluigi; Cantemir, Codrin-Gruie; Dembski, Nicholas; Rizzoni, Giorgio; Serrao, Lorenzo; Josephson, John R.; Russell, James

    2006-05-01

    The article presents the results of a large scale design space exploration for the hybridization of two off-road vehicles, part of the Future Tactical Truck System (FTTS) family: Maneuver Sustainment Vehicle (MSV) and Utility Vehicle (UV). Series hybrid architectures are examined. The objective of the paper is to illustrate a novel design methodology that allows for the choice of the optimal values of several vehicle parameters. The methodology consists in an extensive design space exploration, which involves running a large number of computer simulations with systematically varied vehicle design parameters, where each variant is paced through several different mission profiles, and multiple attributes of performance are measured. The resulting designs are filtered to choose the design tradeoffs that better satisfy the performance and fuel economy requirements. At the end, few promising vehicle configuration designs will be selected that will need additional detailed investigation including neglected metrics like ride and drivability. Several powertrain architectures have been simulated. The design parameters include the number of axles in the vehicle (2 or 3), the number of electric motors per axle (1 or 2), the type of internal combustion engine, the type and quantity of energy storage system devices (batteries, electrochemical capacitors or both together). An energy management control strategy has also been developed to provide efficiency and performance. The control parameters are tunable and have been included into the design space exploration. The results show that the internal combustion engine and the energy storage system devices are extremely important for the vehicle performance.

  2. An effective system to produce smoke solutions from dried plant tissue for seed germination studies1

    PubMed Central

    Coons, Janice; Coutant, Nancy; Lawrence, Barbara; Finn, Daniel; Finn, Stephanie

    2014-01-01

    • Premise of the study: An efficient and inexpensive system was developed to produce smoke solutions from plant material to research the influence of water-soluble compounds from smoke on seed germination. • Methods and Results: Smoke solutions (300 mL per batch) were produced by burning small quantities (100–200 g) of dried plant material from a range of species in a bee smoker attached by a heater hose to a side-arm flask. The flask was attached to a vacuum water aspirator, to pull the smoke through the water. The entire apparatus was operated in a laboratory fume hood. • Conclusions: Compared with other smoke solution preparation systems, the system described is easy to assemble and operate, inexpensive to build, and effective at producing smoke solutions from desired species in a small indoor space. Quantitative measurements can be made when using this system, allowing for replication of the process. PMID:25202613

  3. Continuous countercurrent membrane column for the separation of solute/solvent and solvent/solvent systems

    DOEpatents

    Nerad, Bruce A.; Krantz, William B.

    1988-01-01

    A reverse osmosis membrane process or hybrid membrane - complementary separator process for producing enriched product or waste streams from concentrated and dilute feed streams for both solvent/solvent and solute/solvent systems is described.

  4. Positive periodic solutions for a neutral Lotka-Volterra system with state dependent delays

    NASA Astrophysics Data System (ADS)

    Li, Yongkun; Zhao, Lili

    2009-04-01

    By using a fixed point theorem of strict-set-contraction, some new criteria are established for the existence of positive periodic solutions of the following periodic neutral Lotka-Volterra system with state dependent delays

  5. Satellite and Ground System Solutions at Your Fingertips

    NASA Technical Reports Server (NTRS)

    2005-01-01

    In the summer of 1998, the blockbuster action movie Armageddon captivated audiences with a thrilling doomsday plot about a meteor the size of Texas that was racing towards the Earth. Though the premise of the movie was purely fictional, the unfortunate reality is that near-Earth asteroids such as the one portrayed in the film do exist. On December 23, 2004, NASA announced that an asteroid it anticipated to pass near the Earth on April 13, 2029, had been assigned the highest score to date on the universally used Torino Impact Hazard Scale. At first, the flyby distance for the asteroid, dubbed MN4, was uncertain and an Earth impact could not be ruled out. The odds of impact were initially believed to be 1 in 300, high enough to merit special monitoring by astronomers around the world, but were then escalated to 1 in 37 on December 27. NASA officials noted, however, that these odds should not be of public concern, since they were likely to change on a day-to-day basis as new data were received. The officials were correct in their assertion, as any chances of an impact with Earth in 2029 were completely ruled out later that same day. Integral Systems, Inc., a leading provider of satellite ground systems and the first company to offer an integrated suite of commercial-off-the-shelf software products for satellite command and control, is helping NASA keep a careful watch for any close-encountering asteroids with its tracking technology. The company supported the first NASA Discovery mission, the Near Earth Asteroid Rendezvous (NEAR) program, back in 1996, and has expanded its business by building more ground systems for a greater variety of satellites than any other company in the world. (NASA has since launched seven more Discovery missions, with the eighth lifting off earlier this year.) The experience gained from the company s participation in developing satellite command and control ground systems for the NEAR program has bolstered its flagship product line, the

  6. Closed-form solutions of performability. [modeling of a degradable buffer/multiprocessor system

    NASA Technical Reports Server (NTRS)

    Meyer, J. F.

    1981-01-01

    Methods which yield closed form performability solutions for continuous valued variables are developed. The models are similar to those employed in performance modeling (i.e., Markovian queueing models) but are extended so as to account for variations in structure due to faults. In particular, the modeling of a degradable buffer/multiprocessor system is considered whose performance Y is the (normalized) average throughput rate realized during a bounded interval of time. To avoid known difficulties associated with exact transient solutions, an approximate decomposition of the model is employed permitting certain submodels to be solved in equilibrium. These solutions are then incorporated in a model with fewer transient states and by solving the latter, a closed form solution of the system's performability is obtained. In conclusion, some applications of this solution are discussed and illustrated, including an example of design optimization.

  7. Liquid solution delivery through the pulled nanopipette combined with QTF-AFM system

    NASA Astrophysics Data System (ADS)

    An, Sangmin; Stambaugh, Corey; Kim, Gunn; Lee, Manhee; Kim, Yonghee; Lee, Kunyoung; Jhe, Wonho

    2012-02-01

    Nanopipette is a versatile fluidic tool for biochemical analysis, controlled liquid delivery in bio-nanotechnology. However, most of the researches have been performed in solution based system, thus it is challenge to study nanofluidic properties of the liquid solution delivery through the nanopipette in ambient conditions. In this work, we demonstrated the liquid ejection, dispersion, and subsequent deposition of the nanoparticles via a 30 nm aperture pipette based on the quartz tuning fork -- atomic force microscope (QTF-AFM) combined nanopipette system.

  8. Travelling wave solutions of a coupled Korteweg-de Vries-Burgers system

    NASA Astrophysics Data System (ADS)

    Motsepa, Tanki; Khalique, Chaudry Masood

    2016-02-01

    In this paper we study a coupled Korteweg-de Vries-Burgers system which arises in mathematical physics and has a wide range of scientific applications. We obtain new travelling wave solutions of this system by employing the (G'/G)-expansion method. The solutions that will be obtained are going to be expressed in two different forms, viz., hyperbolic functions and trigonometric functions.

  9. Unbounded sets of solutions of non-cooperative elliptic systems on spheres

    NASA Astrophysics Data System (ADS)

    Rybicki, Sławomir; Stefaniak, Piotr

    2015-10-01

    The aim of this paper is to show that any continuum of nontrivial solutions of a non-cooperative system of elliptic equations on the sphere S n - 1, bifurcating from the set of trivial solutions, is unbounded. Moreover, we characterize bifurcation points of this system at which the global symmetry-breaking phenomenon occurs. As the main tool we use the degree for SO (2)-invariant strongly indefinite functionals defined in [13].

  10. Non-Existence of Global Solutions For a Quasilinear Benney System

    NASA Astrophysics Data System (ADS)

    Antontsev, S.; Dias, J. P.; Figueira, M.; Oliveira, F.

    2011-06-01

    Benney introduced in 1977 (cf. Stud Appl Math 56:81-94, 1977) a general strategy for deriving systems of nonlinear PDEs describing the interaction between long and short waves. In Dias et al. (CR Acad Sci Paris I 344:493-496, 2007) we have studied the local existence and unicity of solutions to a quasilinear version of these systems. In the present paper we prove that in some important cases global strong solutions do not exist.

  11. Interoperability of a mobile health care solution with electronic healthcare record systems.

    PubMed

    De Toledo, P; Lalinde, W; Del Pozo, F; Thurber, D; Jimenez-Fernandez, S

    2006-01-01

    Mobile health care solutions involving patient monitoring are an increasingly accepted element in chronic disease management strategies. When used in healthcare systems with different providers, it is essential that the information gathered from the patient is available at each of these providers information repositories. This paper describes the design of a connectivity interface based on the HL7 standard that allows the MOTOHEALTH mobile health care solution to communicate with external electronic healthcare record systems supporting HL7. PMID:17946289

  12. Existence of almost periodic solutions for forced perturbed systems with piecewise constant argument

    NASA Astrophysics Data System (ADS)

    Xia, Yonghui; Huang, Zhenkun; Han, Maoan

    2007-09-01

    Certain almost periodic forced perturbed systems with piecewise argument are considered in this paper. By using the contraction mapping principle and some new analysis technique, some sufficient conditions are obtained for the existence and uniqueness of almost periodic solution of these systems. Furthermore, we study the harmonic and subharmonic solutions of these systems. The obtained results generalize the previous known results such as [A.M. Fink, Almost Periodic Differential Equation, Lecture Notes in Math., volE 377, Springer-Verlag, Berlin, 1974; C.Y. He, Almost Periodic Differential Equations, Higher Education Press, Beijing, 1992 (in Chinese); Z.S. Lin, The existence of almost periodic solution of linear system, Acta Math. Sinica 22 (5) (1979) 515-528 (in Chinese); C.Y. He, Existence of almost periodic solutions of perturbation systems, Ann. Differential Equations 9 (2) (1992) 173-181; Y.H. Xia, M. Lin, J. Cao, The existence of almost periodic solutions of certain perturbation system, J. Math. Anal. Appl. 310 (1) (2005) 81-96]. Finally, a tangible example and its numeric simulations show the feasibility of our results, the comparison between non-perturbed system and perturbed system, the relation between systems with and without piecewise argument.

  13. Technology Solutions Case Study: Selecting Ventilation Systems for Existing Homes

    SciTech Connect

    2014-12-01

    In multifamily buildings, particularly in the Northeast, exhaust ventilation strategies are the norm as a means of meeting both local exhaust and whole-unit mechanical ventilation rates. The issue of where the "fresh" air is coming from is gaining significance as air-tightness standards for enclosures become more stringent, and the normal leakage paths through the building envelope disappear. Researchers from the Consortium for Advanced Residential Buildings (CARB) found that the majority of high performance, new construction, multifamily housing in the Northeast use one of four general strategies for ventilation: continuous exhaust only with no designated supply or make-up air source, continuous exhaust with ducted make-up air to apartments, continuous exhaust with supply through a make-up air device integral to the unit HVAC, and continuous exhaust with supply through a passive inlet device, such as a trickle vent. Insufficient information is available to designers on how these various systems are best applied. In this project, the CARB team evaluated the four different strategies for providing make-up air to multifamily residential buildings and developed guidelines to help contractors and building owners choose the best ventilation systems.

  14. Closed form analytical inverse solutions for Risley-prism-based beam steering systems in different configurations.

    PubMed

    Li, Yajun

    2011-08-01

    Nonparaxial ray tracing through Risley prisms of four different configurations is performed to give the exact solution of the inverse problem arisen from applications of Risley prisms to free space communications. Predictions of the exact solution and the third-order theory [Appl. Opt. 50, 679 (2011)] are compared and results are shown by curves for systems using prisms of different materials. The exact solution for the problem of precision pointing is generalized to investigate the synthesis of the scan pattern, i.e., to create a desirable scan pattern on some plane perpendicular to the optical axis of the system by controlling the circular motion of the two prisms. PMID:21833103

  15. A Uniqueness Criterion for Unbounded Solutions to the Vlasov-Poisson System

    NASA Astrophysics Data System (ADS)

    Miot, Evelyne

    2016-07-01

    We prove uniqueness for the Vlasov-Poisson system in two and three dimensions under the condition that the L p norms of the macroscopic density grow at most linearly with respect to p. This allows for solutions with logarithmic singularities. We provide explicit examples of initial data that fulfill the uniqueness condition and that exhibit a logarithmic blow-up. In the gravitational two-dimensional case, such states are intimately related to radially symmetric steady solutions of the system. Our method relies on the Lagrangian formulation for the solutions, exploiting the second-order structure of the corresponding ODE.

  16. Solutions to a degenerate system of parabolic equations from marine biology.

    PubMed

    Wörz-Busekros, A

    1976-11-25

    A system of parabolic and ordinary differential equations ut = a2 uxx + F(u,v,w), vt = a2 vxx + G(u,v,w), wx = -k(u) w is studied which has been proposed by Radach and Maier-Reimer for the dynamics of phytoplankton and nutrient in dependence of light intensity. It is shown that there is a unique solution to this system satisfying given initial and boundary conditions. The solution depends continuously on the data. For specific nonlinearities F, G, and k bounds for the solutions are given. PMID:1022838

  17. Winding solutions for the two-particle system in ? gravity

    NASA Astrophysics Data System (ADS)

    Welling, M.

    1998-03-01

    We use a computer to follow the evolution of two gravitating particles in a (2 + 1)-dimensional closed universe. In a closed universe there is enough energy to produce a Gott-pair, i.e. a pair of particles with tachyonic centre of mass, from regular initial data. We study such a pair and find that they can wind around each other with ever increasing momentum. As was shown by 't Hooft, the universe must crunch before any closed timelike curve can be traversed. We study the two-particle system and quantize it, long before this crunch happens, in the high-momentum limit. We find that both the relevant configuration variable and its conjugate momentum become discretized.

  18. A Functional-Phylogenetic Classification System for Transmembrane Solute Transporters

    PubMed Central

    Saier, Milton H.

    2000-01-01

    A comprehensive classification system for transmembrane molecular transporters has been developed and recently approved by the transport panel of the nomenclature committee of the International Union of Biochemistry and Molecular Biology. This system is based on (i) transporter class and subclass (mode of transport and energy coupling mechanism), (ii) protein phylogenetic family and subfamily, and (iii) substrate specificity. Almost all of the more than 250 identified families of transporters include members that function exclusively in transport. Channels (115 families), secondary active transporters (uniporters, symporters, and antiporters) (78 families), primary active transporters (23 families), group translocators (6 families), and transport proteins of ill-defined function or of unknown mechanism (51 families) constitute distinct categories. Transport mode and energy coupling prove to be relatively immutable characteristics and therefore provide primary bases for classification. Phylogenetic grouping reflects structure, function, mechanism, and often substrate specificity and therefore provides a reliable secondary basis for classification. Substrate specificity and polarity of transport prove to be more readily altered during evolutionary history and therefore provide a tertiary basis for classification. With very few exceptions, a phylogenetic family of transporters includes members that function by a single transport mode and energy coupling mechanism, although a variety of substrates may be transported, sometimes with either inwardly or outwardly directed polarity. In this review, I provide cross-referencing of well-characterized constituent transporters according to (i) transport mode, (ii) energy coupling mechanism, (iii) phylogenetic grouping, and (iv) substrates transported. The structural features and distribution of recognized family members throughout the living world are also evaluated. The tabulations should facilitate familial and functional

  19. Segregated and Synchronized Vector Solutions for Nonlinear Schrödinger Systems

    NASA Astrophysics Data System (ADS)

    Peng, Shuangjie; Wang, Zhi-qiang

    2013-04-01

    We consider the following nonlinear Schrödinger system in {{R}^3} \\{begin{array}{ll}-Δ u + P(|x|)u = μ u2u + β v^2u,quad x in {R}^3,\\Δ v + Q(|x|)v = ν v2v + β u^2v,quad x in {R}^3,. where P( r) and Q( r) are positive radial potentials, {μ > 0, ν > 0} and {β in {R}} is a coupling constant. This type of system arises, in particular, in models in Bose-Einstein condensates theory. We examine the effect of nonlinear coupling on the solution structure. In the repulsive case, we construct an unbounded sequence of non-radial positive vector solutions of segregated type, and in the attractive case we construct an unbounded sequence of non-radial positive vector solutions of synchronized type. Depending upon the system being repulsive or attractive, our results exhibit distinct characteristic features of vector solutions.

  20. Applications of isotopes to tracing sources of solutes and water in shallow systems

    USGS Publications Warehouse

    Kendall, Carol; Krabbenhoft, David P.

    1995-01-01

    New awareness of the potential danger to water supplies posed by the use of agricultural chemicals has focused attention on the nature of groundwater recharge and the mobility of various solutes, especially nitrate and pesticides, in shallow systems. A better understanding of hydrologic flowpaths and solute sources is required to determine the potential impact of sources of contamination on water supplies, to develop management practices for preserving water quality, and to develop remediation plans for sites that are already contaminated. In many cases, environmental isotopes can be employed as 'surgical tools' for answering very specific questions about water and solute sources. Isotopic data can often provide more accurate information about the system than hydrologic measurements or complicated hydrologic models. This note focuses on practical and cost-effective examples of how naturally-occurring isotopes can be used to track water and solutes as they move through shallow systems.

  1. Iterative solutions to the steady-state density matrix for optomechanical systems.

    PubMed

    Nation, P D; Johansson, J R; Blencowe, M P; Rimberg, A J

    2015-01-01

    We present a sparse matrix permutation from graph theory that gives stable incomplete lower-upper preconditioners necessary for iterative solutions to the steady-state density matrix for quantum optomechanical systems. This reordering is efficient, adding little overhead to the computation, and results in a marked reduction in both memory and runtime requirements compared to other solution methods, with performance gains increasing with system size. Either of these benchmarks can be tuned via the preconditioner accuracy and solution tolerance. This reordering optimizes the condition number of the approximate inverse and is the only method found to be stable at large Hilbert space dimensions. This allows for steady-state solutions to otherwise intractable quantum optomechanical systems. PMID:25679739

  2. Regularity and Existence of Global Solutions to the Ericksen-Leslie System in

    NASA Astrophysics Data System (ADS)

    Huang, Jinrui; Lin, Fanghua; Wang, Changyou

    2014-10-01

    In this paper, we first establish the regularity theorem for suitable weak solutions to the Ericksen-Leslie system in . Building on such a regularity, we then establish the existence of a global weak solution to the Ericksen-Leslie system in for any initial data in the energy space, under the physical constraints on the Leslie coefficients ensuring the dissipation of energy of the system, which is smooth away from at most finitely many times. This extends earlier works by Lin et al. (Arch Ration Mech Anal 197:297-336, 2010) on a simplified nematic liquid crystal flow to the general Ericksen-Leslie system.

  3. A similarity solution for reaction front propagation in a fracture-matrix system.

    PubMed

    Rajaram, Harihar; Arshadi, Masoud

    2016-10-13

    We propose a new composite similarity variable, based on which a similarity solution is derived for reaction front propagation in fracture-matrix systems. The similarity solution neglects diffusion/dispersion within the fracture and assumes the existence of a sharp reaction front in the rock matrix. The reaction front location in the rock matrix is shown to follow a linear decrease with distance along the fracture. The reaction front propagation along the fracture is shown to scale like diffusion (i.e. as the square root of time). The similarity solution using the composite similarity variable appears to be applicable to a broad class of reactive transport problems involving mineral reactions in fracture-matrix systems. It also reproduces the solutions for non-reactive solute and heat transport when diffusion/dispersion/conduction are neglected in the fracture. We compared our similarity solution against numerical simulations for nonlinear reactive transport of an aqueous species with a mineral in the rock matrix. The similarity solutions agree very well with the numerical solutions, especially at later times when diffusion limitations are more pronounced.This article is part of the themed issue 'Energy and the subsurface'. PMID:27597793

  4. Consumer empowerment as a solution to health system financing.

    PubMed

    Prewo, W

    2000-01-01

    The health system of the welfare state has basic design flaws. First, it treats citizens as recipients of entitlements that are bestowed on them rather than as sovereign customers who otherwise can choose among an array of goods and services; with uniform health plans, there are no incentives to economise. Second, benefits are provided by government through monopoly schemes; their performance has been dismal when compared with other sectors of the economy that, under competition, have yielded continuous efficiency improvements. Ceaselessly rising costs for healthcare are the consequence. Applying the principles of the market economy to healthcare--and to social security in general--would unleash a vast potential of efficiency gains. The issue in such a reform is equity. Healthcare must be affordable for all. In reconciling efficiency and equity, the cornerstones of this proposal are financial empowerment and individual responsibility; to hand the individual the money required to purchase the current level of benefits--nobody loses--and to leave it to the individual, within bounds, whether to do so. While guaranteeing that everybody can buy the current benefits, the savings from restraint will be the individual's to keep. The reform steps would be as follows: (i) empowerment, (ii) fairness and finance, (iii) safeguard and choice, and (iv) savings to keep. This is a 'consumer model' of healthcare. Efficiency is achieved by privatisation, individual responsibility and freedom of choice on the demand side and by competition on the supply side. Equity is guaranteed by financial empowerment of the individual and a no-loss rule; mandatory minimum insurance would preserve the safety net. PMID:11151313

  5. Dixon resultant's solution of systems of geodetic polynomial equations

    NASA Astrophysics Data System (ADS)

    Paláncz, Béla; Zaletnyik, Piroska; Awange, Joseph L.; Grafarend, Erik W.

    2008-08-01

    The Dixon resultant is proposed as an alternative to Gröbner basis or multipolynomial resultant approaches for solving systems of polynomial equations inherent in geodesy. Its smallness in size, high density (ratio on the number of nonzero elements to the number of all elements), speed, and robustness (insensitive to combinatorial sequence and monomial order, e.g., Gröbner basis) makes it extremely attractive compared to its competitors. Using 3D-intersection and conformal C 7 datum transformation problems, we compare its performance to those of the Sturmfels’s resultant and Gröbner basis. For the 3D-intersection problem, Sturmfels’s resultant needed 0.578 s to solve a 6 × 6 resultant matrix whose density was 0.639, the Dixon resultant on the other hand took 0.266 s to solve a 4 × 4 resultant matrix whose density was 0.870. For the conformal C 7 datum transformation problem, the Dixon resultant took 2.25 s to compute a quartic polynomial in scale parameter whereas the computaton of the Gröbner basis fails. Using relative coordinates to compute the quartic polynomial in scale parameter, the Gröbner basis needed 0.484 s, while the Dixon resultant took 0.016 s. This highlights the robustness of the Dixon resultant (i.e., the capability to use both absolute and relative coordinates with any order of variables) as opposed to Gröbner basis, which only worked well with relative coordinates, and was sensitive to the combinatorial sequence and order of variables. Geodetic users uncomfortable with lengthy expressions of Gröbner basis or multipolynomial resultants, and who aspire to optimize on the attractive features of Dixon resultant, may find it useful.

  6. Measurement and prediction of aromatic solute distribution coefficients for aqueous-organic solvent systems. Final report

    SciTech Connect

    Campbell, J.R.; Luthy, R.G.

    1984-06-01

    Experimental and modeling activities were performed to assess techniques for measurement and prediction of distribution coefficients for aromatic solutes between water and immiscible organic solvents. Experiments were performed to measure distribution coefficients in both clean water and wastewater systems, and to assess treatment of a wastewater by solvent extraction. The theoretical portions of this investigation were directed towards development of techniques for prediction of solute-solvent/water distribution coefficients. Experiments were performed to assess treatment of a phenolic-laden coal conversion wastewater by solvent extraction. The results showed that solvent extraction for recovery of phenolic material offered several wastewater processing advantages. Distribution coefficients were measured in clean water and wastewater systems for aromatic solutes of varying functionality with different solvent types. It was found that distribution coefficients for these compounds in clean water systems were not statistically different from distribution coefficients determined in a complex coal conversion process wastewater. These and other aromatic solute distribution coefficient data were employed for evaluation of modeling techniques for prediction of solute-solvent/water distribution coefficients. Eight solvents were selected in order to represent various chemical classes: toluene and benzene (aromatics), hexane and heptane (alkanes), n-octanol (alcohols), n-butyl acetate (esters), diisopropyl ether (ethers), and methylisobutyl ketone (ketones). The aromatic solutes included: nonpolar compounds such as benzene, toluene and naphthalene, phenolic compounds such as phenol, cresol and catechol, nitrogenous aromatics such as aniline, pyridine and aminonaphthalene, and other aromatic solutes such as naphthol, quinolinol and halogenated compounds. 100 references, 20 figures, 34 tables.

  7. Asymptotic stability of Riemann solutions in BGK approximations to certain multidimensional systems of conservation laws

    NASA Astrophysics Data System (ADS)

    Frid, Hermano; Rendón, Leonardo

    We prove the asymptotic stability of nonplanar two-states Riemann solutions in BGK approximations of a class of multidimensional systems of conservation laws. The latter consists of systems whose flux-functions in different directions share a common complete system of Riemann invariants, the level surfaces of which are hyperplanes. The asymptotic stability to which the main result refers is in the sense of the convergence as t→∞ in Lloc1 of the space of directions ζ=x/t. That is, the solution z(t,x,ξ) of the perturbed Cauchy problem for the corresponding BGK system satisfies ∫z(t,tζ,ξ) dμ(ξ)→R(ζ) as t→∞, in Lloc1(R), where R(ζ) is the self-similar entropy solution of the two-states nonplanar Riemann problem for the system of conservation laws.

  8. A General Solution for Groundwater Flow in Estuarine Leaky Aquifer System with Considering Aquifer Anisotropy

    NASA Astrophysics Data System (ADS)

    Chen, Po-Chia; Chuang, Mo-Hsiung; Tan, Yih-Chi

    2014-05-01

    In recent years the urban and industrial developments near the coastal area are rapid and therefore the associated population grows dramatically. More and more water demand for human activities, agriculture irrigation, and aquaculture relies on heavy pumping in coastal area. The decline of groundwater table may result in the problems of seawater intrusion and/or land subsidence. Since the 1950s, numerous studies focused on the effect of tidal fluctuation on the groundwater flow in the coastal area. Many studies concentrated on the developments of one-dimensional (1D) and two-dimensional (2D) analytical solutions describing the tide-induced head fluctuations. For example, Jacob (1950) derived an analytical solution of 1D groundwater flow in a confined aquifer with a boundary condition subject to sinusoidal oscillation. Jiao and Tang (1999) derived a 1D analytical solution of a leaky confined aquifer by considered a constant groundwater head in the overlying unconfined aquifer. Jeng et al. (2002) studied the tidal propagation in a coupled unconfined and confined costal aquifer system. Sun (1997) presented a 2D solution for groundwater response to tidal loading in an estuary. Tang and Jiao (2001) derived a 2D analytical solution in a leaky confined aquifer system near open tidal water. This study aims at developing a general analytical solution describing the head fluctuations in a 2D estuarine aquifer system consisted of an unconfined aquifer, a confined aquifer, and an aquitard between them. Both the confined and unconfined aquifers are considered to be anisotropic. The predicted head fluctuations from this solution will compare with the simulation results from the MODFLOW program. In addition, the solutions mentioned above will be shown to be special cases of the present solution. Some hypothetical cases regarding the head fluctuation in costal aquifers will be made to investigate the dynamic effects of water table fluctuation, hydrogeological conditions, and

  9. A GPU-accelerated toolbox for the solutions of systems of linear equations

    NASA Astrophysics Data System (ADS)

    Humphrey, John R., Jr.; Paolini, Aaron L.; Price, Daniel K.; Kelmelis, Eric J.

    2009-05-01

    The modern graphics processing unit (GPU) found in many off-the shelf personal computers is a very high performance computing engine that often goes unutilized. The tremendous computing power coupled with reasonable pricing has made the GPU a topic of interest in recent research. An application for such power would be the solution to large systems of linear equations. Two popular solution domains are direct solution, via the LU decomposition, and iterative solution, via a solver such as the Generalized Method of Residuals (GMRES). Our research focuses on the acceleration of such processes, utilizing the latest in GPU technologies. We show performance that exceeds that of a standard computer by an order of magnitude, thus significantly reducing the run time of the numerous applications that depend on the solution of a set of linear equations.

  10. Multiple solutions to dense systems in radar scattering using a preconditioned block GMRES solver

    SciTech Connect

    Boyse, W.E.

    1996-12-31

    Multiple right-hand sides occur in radar scattering calculations in the computation of the simulated radar return from a body at a large number of angles. Each desired angle requires a right-hand side vector to be computed and the solution generated. These right-hand sides are naturally smooth functions of the angle parameters and this property is utilized in a novel way to compute solutions an order of magnitude faster than LINPACK The modeling technique addressed is the Method of Moments (MOM), i.e. a boundary element method for time harmonic Maxwell`s equations. Discretization by this method produces general complex dense systems of rank 100`s to 100,000`s. The usual way to produce the required multiple solutions is via LU factorization and solution routines such as found in LINPACK. Our method uses the block GMRES iterative method to directly iterate a subset of the desired solutions to convergence.

  11. System for creating at a site, remote from a sterile environment, a parenteral solution

    NASA Technical Reports Server (NTRS)

    Scharf, Mike (Inventor); Finley, Mike (Inventor); Veillon, Joe (Inventor); Kipp, Jim (Inventor); Dudar, Tom (Inventor); Owens, Jim (Inventor); Ogle, Jim (Inventor)

    1996-01-01

    The present invention relates to a container, system, and method for creating parenteral solutions at a site, remote from sterile environments. The system includes a flexible container that is empty except for a prepackaged amount of a solute that is housed in the interior of the container. The container includes at least one port and a sterilizing filter in communication with an interior of the port. The container is so constructed and arranged that a fluid flow path is created from the port through the filter and into the interior of the container. A sterile water source including means for establishing fluid flow from the sterile water source into the port is provided. Accordingly, sterile water can flow from the sterile water source through the filter into the container where it is mixed with the solute to create a parenteral solution that can then be infused into a patient. A method and container are also provided.

  12. Systems and methods for laser assisted sample transfer to solution for chemical analysis

    SciTech Connect

    Van Berkel, Gary J.; Kertesz, Vilmos; Ovchinnikova, Olga S.

    2014-06-03

    Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

  13. Systems and methods for laser assisted sample transfer to solution for chemical analysis

    SciTech Connect

    Van Berkel, Gary J.; Kertesz, Vilmos; Ovchinnikova, Olga S.

    2015-09-29

    Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

  14. Systems and methods for laser assisted sample transfer to solution for chemical analysis

    DOEpatents

    Van Berkel, Gary J; Kertesz, Vilmos; Ovchinnikova, Olga S

    2013-08-27

    Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

  15. Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

    NASA Astrophysics Data System (ADS)

    Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.; Suarez, D. L.

    2014-12-01

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems modeling framework that accounts for reduced plant water uptake due to root zone salinity. Two explicit, closed-form analytical solutions for the root zone solute concentration profile are obtained, corresponding to two alternative functional forms of the uptake reduction function. The solutions express a general relationship between irrigation water salinity, irrigation rate, crop salt tolerance, crop transpiration, and (using standard approximations) crop yield. Example applications are illustrated, including the calculation of irrigation requirements for obtaining targeted submaximal yields, and the generation of crop-water production functions for varying irrigation waters, irrigation rates, and crops. Model predictions are shown to be mostly consistent with existing models and available experimental data. Yet the new solutions possess advantages over available alternatives, including: (i) the solutions were derived from a complete physical-mathematical description of the system, rather than based on an ad hoc formulation; (ii) the analytical solutions are explicit and can be evaluated without iterative techniques; (iii) the solutions permit consideration of two common functional forms of salinity induced reductions in crop water uptake, rather than being tied to one particular representation; and (iv) the utilized modeling framework is compatible with leading transient-state numerical models.

  16. Development of Three-Layer Simulation Model for Freezing Process of Food Solution Systems

    NASA Astrophysics Data System (ADS)

    Kaminishi, Koji; Araki, Tetsuya; Shirakashi, Ryo; Ueno, Shigeaki; Sagara, Yasuyuki

    A numerical model has been developed for simulating freezing phenomena of food solution systems. The cell model was simplified to apply to food solution systems, incorporating with the existence of 3 parts such as unfrozen, frozen and moving boundary layers. Moreover, the moving rate of freezing front model was also introduced and calculated by using the variable space network method proposed by Murray and Landis (1957). To demonstrate the validity of the model, it was applied to the freezing processes of coffee solutions. Since the model required the phase diagram of the material to be frozen, the initial freezing temperatures of 1-55 % coffee solutions were measured by the DSC method. The effective thermal conductivity for coffee solutions was determined as a function of temperature and solute concentration by using the Maxwell - Eucken model. One-dimensional freezing process of 10 % coffee solution was simulated based on its phase diagram and thermo-physical properties. The results were good agreement with the experimental data and then showed that the model could accurately describe the change in the location of the freezing front and the distributions of temperature as well as ice fraction during a freezing process.

  17. Regularity of solutions to the liquid crystals systems in {{R}}^2 and {R}^3

    NASA Astrophysics Data System (ADS)

    Dai, Mimi; Qing, Jie; Schonbek, Maria

    2012-02-01

    In this paper, we establish regularity and uniqueness for solutions to density dependent nematic liquid crystals systems. The results presented extend the regularity and uniqueness for constant density liquid crystals systems, obtained by Lin and Liu (1995 Commun. Pure Appl. Math. XLVIII 501-37).

  18. Existence of travelling wave solutions for a Fisher-Kolmogorov system with biomedical applications

    NASA Astrophysics Data System (ADS)

    Belmonte-Beitia, Juan

    2016-07-01

    We consider a Fisher-Kolmogorov system with applications in oncology Pérez-García et al. (2015). Of interest is the question of the existence of travelling front solutions of the system. When the speed of the travelling wave is sufficiently large, existence of such fronts is shown using singular geometric perturbation theory.

  19. A priori [Formula: see text] estimates for solutions of a class of reaction-diffusion systems.

    PubMed

    Du, Zengji; Peng, Rui

    2016-05-01

    In this short paper, we establish a priori [Formula: see text]-norm estimates for solutions of a class of reaction-diffusion systems which can be used to model the spread of infectious disease. The developed technique may find applications in other reaction-diffusion systems. PMID:26141826

  20. Positive minimizers of the best constants and solutions to coupled critical quasilinear systems

    NASA Astrophysics Data System (ADS)

    Kang, Dongsheng

    2016-01-01

    In this paper, systems of quasilinear elliptic equations are investigated, which involve critical homogeneous nonlinearities and deferent Hardy-type terms. By variational methods and careful analysis, positive minimizers of the related best Sobolev constants are found and the existence of positive solutions to the systems is verified. The results are new even in the case p = 2.

  1. Stability of Transition Front Solutions in Multidimensional Cahn-Hilliard Systems

    NASA Astrophysics Data System (ADS)

    Howard, Peter

    2016-06-01

    We consider nonlinear stability for planar transition front solutions bar{u} (x_1) arising in multidimensional (i.e., xin R^n) Cahn-Hilliard systems. In previous work, the author has established conditions under which such waves are spectrally and linearly stable, and in this analysis, it is shown that spectral stability implies nonlinear stability for such systems.

  2. Solution of large linear systems of equations on the massively parallel processor

    NASA Technical Reports Server (NTRS)

    Ida, Nathan; Udawatta, Kapila

    1987-01-01

    The Massively Parallel Processor (MPP) was designed as a special machine for specific applications in image processing. As a parallel machine, with a large number of processors that can be reconfigured in different combinations it is also applicable to other problems that require a large number of processors. The solution of linear systems of equations on the MPP is investigated. The solution times achieved are compared to those obtained with a serial machine and the performance of the MPP is discussed.

  3. Numerical solutions of the reaction diffusion system by using exponential cubic B-spline collocation algorithms

    NASA Astrophysics Data System (ADS)

    Ersoy, Ozlem; Dag, Idris

    2015-12-01

    The solutions of the reaction-diffusion system are given by method of collocation based on the exponential B-splines. Thus the reaction-diffusion systemturns into an iterative banded algebraic matrix equation. Solution of the matrix equation is carried out byway of Thomas algorithm. The present methods test on both linear and nonlinear problems. The results are documented to compare with some earlier studies by use of L∞ and relative error norm for problems respectively.

  4. Global existence of weak solution to the heat and moisture transport system in fibrous porous media

    NASA Astrophysics Data System (ADS)

    Li, Buyang; Sun, Weiwei; Wang, Yi

    This paper is concerned with theoretical analysis of a heat and moisture transfer model arising from textile industries, which is described by a degenerate and strongly coupled parabolic system. We prove the global (in time) existence of weak solution by constructing an approximate solution with some standard smoothing. The proof is based on the physical nature of gas convection, in which the heat (energy) flux in convection is determined by the mass (vapor) flux in convection.

  5. Solutions of the Strominger System via Stable Bundles on Calabi-Yau Threefolds

    NASA Astrophysics Data System (ADS)

    Andreas, Björn; Garcia-Fernandez, Mario

    2012-10-01

    We prove that a given Calabi-Yau threefold with a stable holomorphic vector bundle can be perturbed to a solution of the Strominger system provided that the second Chern class of the vector bundle is equal to the second Chern class of the tangent bundle. If the Calabi-Yau threefold has strict SU(3) holonomy then the equations of motion derived from the heterotic string effective action are also satisfied by the solutions we obtain.

  6. Development of a Decision Support System for Analysis and Solutions of Prolonged Standing in the Workplace

    PubMed Central

    Halim, Isa; Arep, Hambali; Kamat, Seri Rahayu; Abdullah, Rohana; Omar, Abdul Rahman; Ismail, Ahmad Rasdan

    2014-01-01

    Background Prolonged standing has been hypothesized as a vital contributor to discomfort and muscle fatigue in the workplace. The objective of this study was to develop a decision support system that could provide systematic analysis and solutions to minimize the discomfort and muscle fatigue associated with prolonged standing. Methods The integration of object-oriented programming and a Model Oriented Simultaneous Engineering System were used to design the architecture of the decision support system. Results Validation of the decision support system was carried out in two manufacturing companies. The validation process showed that the decision support system produced reliable results. Conclusion The decision support system is a reliable advisory tool for providing analysis and solutions to problems related to the discomfort and muscle fatigue associated with prolonged standing. Further testing of the decision support system is suggested before it is used commercially. PMID:25180141

  7. A System for Managing Replenishment of a Nutrient Solution Using an Electrical Conductivity Controller

    NASA Technical Reports Server (NTRS)

    Davis, D.; Dogan, N.; Aglan, H.; Mortley, D.; Loretan, P.

    1998-01-01

    Control of nutrient solution parameters is very important for the growth and development of plants grown hydroponically. Protocols involving different nutrient solution replenishment times (e.g. one-week, two-week, or two-day replenishment) provide manual periodic control of the nutrient solution's electrical conductivity (EC). Since plants take-up nutrients as they grow, manual control has a drawback in that EC is not held constant between replenishments. In an effort to correct this problem the Center for Food and Environmental Systems for Human Exploration of Space at Tuskegee University has developed a system for managing and controlling levels of EC over a plant's entire growing cycle. A prototype system is being tested on sweetpotato production using the nutrient film technique (NFT), and it is being compared to a system in which sweetpotatoes are grown using NFT with manual control. NASA has played an important role in the development of environmental control systems. They have become a forerunner in growing plants hydroponically with some control systems through the use of networked data acquisition and control using environmental growth chambers. Data acquisition systems which involve the use of real-time, calibration, set points, user panel, and graphical representation programming provide a good method of controlling nutrient solution parameters such as EC and pH [Bledsoe, 19931]. In NASA's Biomass Production Chamber (BPC) at Kennedy Space Center, control is provided by a programmable logic controller (PLC). This is an industrial controller which combines ladder computer logic which has the ability to handle various levels of electrical power. The controller controls temperature, light and other parameters that affect the plant's environment, in the BPC, the Nutrient Delivery System (NIX), a sub-system of the PLC, controls nutrient solution parameters such as EC, pH, and solution levels. When the nutrient EC measurement goes outside a preset range (120

  8. Automated pH Control of Nutrient Solution in a Hydroponic Plant Growth System

    NASA Technical Reports Server (NTRS)

    Smith, B.; Dogan, N.; Aglan, H.; Mortley, D.; Loretan, P.

    1998-01-01

    Over, the years, NASA has played an important role in providing to and the development of automated nutrient delivery and monitoring, systems for growing crops hydroponically for long term space missions. One example are the systems used in the Biomass Production Chamber (BPC) at Kennedy Space Center (KSC). The current KSC monitoring system is based on an engineering workstation using standard analog/digital input/output hardware and custom written software. The monitoring system uses completely separate sensors to provide a check of control sensor accuracy and has the ability to graphically display and store data form past experiment so that they are available for data analysis [Fortson, 1992]. In many cases, growing systems have not been fitted with the kind of automated control systems as used at KSC. The Center for Food and Environmental Systems for Human Exploration of Space (CFESH) located on the campus of Tuskegee University, has effectively grown sweetpotatoes and peanuts hydroponically for the past five years. However they have adjusted the pH electrical conductivity and volume of the hydroponic nutrient solution only manually at times when the solution was to be replenished or changed out according to its protocol (e.g. one-week, two-week, or two-day cycle). But the pH of the nutrient solution flowing through the channel is neither known nor controlled between the update, change out, or replenishment period. Thus, the pH of the nutrient solution is not held at an optimum level over the span of the plant's growth cycle. To solve this dilemma, an automated system for the control and data logging of pH data relative to sweetpotato production using the nutrient film technique (NFT) has been developed, This paper discusses a microprocessor-based system, which was designed to monitor, control, and record the pH of a nutrient solution used for growing sweetpotatoes using NFT.

  9. Analytical solutions of tidal groundwater flow in coastal two-aquifer system

    NASA Astrophysics Data System (ADS)

    Li, Hailong; Jiao, Jiu Jimmy

    This paper presents a complete analytical solution to describe tidal groundwater level fluctuations in a coastal subsurface system. The system consists of two aquifers and a leaky layer between them. Previous solutions of Jacob [Flow of groundwater, in: H. Rouse (Ed.), Engineering Hydraulics, Wiley, New York, 1950, pp. 321-386], Jiao and Tang [Water Resour. Res. 35 (3) (1999) 747], Li and Jiao [Adv. Water Resour. 24 (5) (2001a) 565], Li et al. [Water Resour. Res. 37 (2001) 1095] and Jeng et al. [Adv. Water Resour. (in press)] are special cases of the new solution. The present solution differs from previous work in that both the effects of the leaky layer's elastic storage and the tidal wave interference between the two aquifers are considered. If the upper and lower aquifers have the same storativities and transimissivities, the system can be simplified into an equivalent double-layered, aquifer-aquitard system bounded by impermeable layers from up and down. It is found that the leaky layer's elastic storage behaves as a buffer to the tidal wave interference between the two aquifers. The buffer capacity increases with the leaky layer's thickness, specific storage, and decreases with the leaky layer's vertical permeability. Great buffer capacity can result in negligible tidal wave interference between the upper and lower aquifers so that the Li and Jiao (loc. cit.) solution applies.

  10. Viscosity Solutions of Systems of PDEs with Interconnected Obstacles and Switching Problem

    SciTech Connect

    Hamadene, S. Morlais, M. A.

    2013-04-15

    This paper deals with existence and uniqueness of a solution in viscosity sense, for a system of m variational partial differential inequalities with inter-connected obstacles. A particular case is the Hamilton-Jacobi-Bellmann system of the Markovian stochastic optimal m-states switching problem. The switching cost functions depend on (t,x). The main tool is the notion of systems of reflected backward stochastic differential equations with oblique reflection.

  11. Three-dimensional analytical solution for transient guided wave propagation in liquid-filled pipe systems.

    PubMed

    Tang, Liguo; Wu, Zhaojun; Liu, Shengxing; Yang, Wuyi

    2012-08-01

    The objective of this study is to investigate the three-dimensional (3-D) analytical solution for transient guided wave propagation in liquid-filled pipe systems using the eigenfunction expansion method (EEM). The eigenfunctions corresponding to finite liquid-filled pipe systems with a traction-free lateral boundary and rigid smooth end boundaries are obtained. Additionally, the orthogonality of the eigenfunctions is proved in detail. Subsequently, the exact 3-D analytical transient response of finite liquid-filled pipe systems to external body forces is constructed using the EEM, based on which, the approximate 3-D analytical transient response of the systems to external surface forces is derived. Furthermore, the analytical solution for transient guided wave propagation in finite liquid-filled pipe systems is extended explicitly and concisely to infinite liquid-filled pipe systems. Several numerical examples are given to illustrate the analysis of the spatial and frequency distributions of the radial and axial displacement amplitudes of various guided wave modes; the numerical examples also simulate the transient displacement of the pipe wall and the transient pressure of the internal liquid from the present solution. The present solution can provide some theoretical guidelines for the guided wave nondestructive evaluation of liquid-filled pipes and the guided wave technique for downhole data transfer. PMID:22899122

  12. Analysis of cloud-based solutions on EHRs systems in different scenarios.

    PubMed

    Fernández-Cardeñosa, Gonzalo; de la Torre-Díez, Isabel; López-Coronado, Miguel; Rodrigues, Joel J P C

    2012-12-01

    Nowadays with the growing of the wireless connections people can access all the resources hosted in the Cloud almost everywhere. In this context, organisms can take advantage of this fact, in terms of e-Health, deploying Cloud-based solutions on e-Health services. In this paper two Cloud-based solutions for different scenarios of Electronic Health Records (EHRs) management system are proposed. We have researched articles published between the years 2005 and 2011 about the implementation of e-Health services based on the Cloud in Medline. In order to analyze the best scenario for the deployment of Cloud Computing two solutions for a large Hospital and a network of Primary Care Health centers have been studied. Economic estimation of the cost of the implementation for both scenarios has been done via the Amazon calculator tool. As a result of this analysis two solutions are suggested depending on the scenario: To deploy a Cloud solution for a large Hospital a typical Cloud solution in which are hired just the needed services has been assumed. On the other hand to work with several Primary Care Centers it's suggested the implementation of a network, which interconnects these centers with just one Cloud environment. Finally it's considered the fact of deploying a hybrid solution: in which EHRs with images will be hosted in the Hospital or Primary Care Centers and the rest of them will be migrated to the Cloud. PMID:22492177

  13. The existence of traveling wave solutions for a bistable three-component lattice dynamical system

    NASA Astrophysics Data System (ADS)

    Guo, Jong-Shenq; Wu, Chin-Chin

    2016-01-01

    We study the traveling wave solutions for a three-component lattice dynamical system. This problem arises in the modeling of three species competing two food resources in an environment with migration in which the habitat is one-dimensional and is divided into countable niches. We are concerned with the case when two species have different preferences of food and the third species has both preferences of food. To understand which species win the competition under the bistable condition, the existence of a traveling wave solution for this lattice dynamical system is proven.

  14. Variational Solutions and Random Dynamical Systems to SPDEs Perturbed by Fractional Gaussian Noise

    PubMed Central

    Zeng, Caibin; Yang, Qigui; Cao, Junfei

    2014-01-01

    This paper deals with the following type of stochastic partial differential equations (SPDEs) perturbed by an infinite dimensional fractional Brownian motion with a suitable volatility coefficient Φ: dX(t) = A(X(t))dt+Φ(t)dBH(t), where A is a nonlinear operator satisfying some monotonicity conditions. Using the variational approach, we prove the existence and uniqueness of variational solutions to such system. Moreover, we prove that this variational solution generates a random dynamical system. The main results are applied to a general type of nonlinear SPDEs and the stochastic generalized p-Laplacian equation. PMID:24574903

  15. A frequency averaging framework for the solution of complex dynamic systems

    PubMed Central

    Lecomte, Christophe

    2014-01-01

    A frequency averaging framework is proposed for the solution of complex linear dynamic systems. It is remarkable that, while the mid-frequency region is usually very challenging, a smooth transition from low- through mid- and high-frequency ranges is possible and all ranges can now be considered in a single framework. An interpretation of the frequency averaging in the time domain is presented and it is explained that the average may be evaluated very efficiently in terms of system solutions. PMID:24910518

  16. A Two Stage Solution Procedure for Production Planning System with Advance Demand Information

    NASA Astrophysics Data System (ADS)

    Ueno, Nobuyuki; Kadomoto, Kiyotaka; Hasuike, Takashi; Okuhara, Koji

    We model for ‘Naiji System’ which is a unique corporation technique between a manufacturer and suppliers in Japan. We propose a two stage solution procedure for a production planning problem with advance demand information, which is called ‘Naiji’. Under demand uncertainty, this model is formulated as a nonlinear stochastic programming problem which minimizes the sum of production cost and inventory holding cost subject to a probabilistic constraint and some linear production constraints. By the convexity and the special structure of correlation matrix in the problem where inventory for different periods is not independent, we propose a solution procedure with two stages which are named Mass Customization Production Planning & Management System (MCPS) and Variable Mesh Neighborhood Search (VMNS) based on meta-heuristics. It is shown that the proposed solution procedure is available to get a near optimal solution efficiently and practical for making a good master production schedule in the suppliers.

  17. Big Data challenges and solutions in building the Global Earth Observation System of Systems (GEOSS)

    NASA Astrophysics Data System (ADS)

    Mazzetti, Paolo; Nativi, Stefano; Santoro, Mattia; Boldrini, Enrico

    2014-05-01

    . The current implementation of GEOSS already addresses several big data challenges. In particular, the brokered architecture adopted in the GEOSS Common Infrastructure with the deployment of the GEO DAB (Discovery and Access Broker) allows to connect more than 20 big EO infrastructures while keeping them autonomous as required by their own mandate and governance. They make more than 60 million of unique resources discoverable and accessible through the GEO Portal. Through the GEO DAB, users are able to seamlessly discover resources provided by different infrastructures, and access them in a harmonized way, collecting datasets from different sources on a Common Environment (same coordinate reference system, spatial subset, format, etc.). Through the GEONETCast system, GEOSS is also providing a solution related to the Velocity challenge, for delivering EO resources to developing countries with low bandwidth connections. Several researches addressing other Big data Vs challenges in GEOSS are on-going, including quality representation for Veracity (as in the FP7 GeoViQua project), brokering big data analytics platforms for Velocity, and support of other EO resources for Variety (such as modelling resources in the Model Web).

  18. Microbiological and physicochemical stability of fentanyl and sufentanil solutions for patient-controlled delivery systems.

    PubMed

    Chapalain-Pargade, Sophie; Laville, Isabelle; Paci, Angelo; Chachaty, Elisabeth; Mercier, Lionel; Bourget, Philippe

    2006-07-01

    The aim of this study was to assess the microbiological and physicochemical stability of opioid solutions containing fentanyl or sufentanil and thereby determine the feasibility of extending the expiration dates after mixing. Five systems containing fentanyl or sufentanil solutions at 50 microg/mL in portable patient-controlled analgesia (PCA) systems were filled and stored at room temperature for 14 days. They were sampled immediately after preparation, at day 3, and each day of the following weeks. Microbiological stability was assessed by performing sterility tests. The physicochemical study was performed by determining aspect, pH, and osmolality evolution. All samples were tested for appearance, change in color, and loss of concentration using an analytical method. There was no significant change in pH and osmolality values of any solutions. No precipitation or change in color was observed in any of the sample solutions. There was no significant loss of fentanyl or sufentanil over 14 days (4.3% and 4.1%, respectively). This study indicates that both drug solutions in the PCA systems are stable for a minimum of 14 days at room temperature. PMID:16824989

  19. Preprocessing in Matlab Inconsistent Linear System for a Meaningful Least Squares Solution

    NASA Technical Reports Server (NTRS)

    Sen, Symal K.; Shaykhian, Gholam Ali

    2011-01-01

    Mathematical models of many physical/statistical problems are systems of linear equations Due to measurement and possible human errors/mistakes in modeling/data, as well as due to certain assumptions to reduce complexity, inconsistency (contradiction) is injected into the model, viz. the linear system. While any inconsistent system irrespective of the degree of inconsistency has always a least-squares solution, one needs to check whether an equation is too much inconsistent or, equivalently too much contradictory. Such an equation will affect/distort the least-squares solution to such an extent that renders it unacceptable/unfit to be used in a real-world application. We propose an algorithm which (i) prunes numerically redundant linear equations from the system as these do not add any new information to the model, (ii) detects contradictory linear equations along with their degree of contradiction (inconsistency index), (iii) removes those equations presumed to be too contradictory, and then (iv) obtain the . minimum norm least-squares solution of the acceptably inconsistent reduced linear system. The algorithm presented in Matlab reduces the computational and storage complexities and also improves the accuracy of the solution. It also provides the necessary warning about the existence of too much contradiction in the model. In addition, we suggest a thorough relook into the mathematical modeling to determine the reason why unacceptable contradiction has occurred thus prompting us to make necessary corrections/modifications to the models - both mathematical and, if necessary, physical.

  20. Acceleration of multiple solution of a boundary value problem involving a linear algebraic system

    NASA Astrophysics Data System (ADS)

    Gazizov, Talgat R.; Kuksenko, Sergey P.; Surovtsev, Roman S.

    2016-06-01

    Multiple solution of a boundary value problem that involves a linear algebraic system is considered. New approach to acceleration of the solution is proposed. The approach uses the structure of the linear system matrix. Particularly, location of entries in the right columns and low rows of the matrix, which undergo variation due to the computing in the range of parameters, is used to apply block LU decomposition. Application of the approach is considered on the example of multiple computing of the capacitance matrix by method of moments used in numerical electromagnetics. Expressions for analytic estimation of the acceleration are presented. Results of the numerical experiments for solution of 100 linear systems with matrix orders of 1000, 2000, 3000 and different relations of variated and constant entries of the matrix show that block LU decomposition can be effective for multiple solution of linear systems. The speed up compared to pointwise LU factorization increases (up to 15) for larger number and order of considered systems with lower number of variated entries.

  1. Water Wave Solutions of the Coupled System Zakharov-Kuznetsov and Generalized Coupled KdV Equations

    PubMed Central

    Seadawy, A. R.; El-Rashidy, K.

    2014-01-01

    An analytic study was conducted on coupled partial differential equations. We formally derived new solitary wave solutions of generalized coupled system of Zakharov-Kuznetsov (ZK) and KdV equations by using modified extended tanh method. The traveling wave solutions for each generalized coupled system of ZK and KdV equations are shown in form of periodic, dark, and bright solitary wave solutions. The structures of the obtained solutions are distinct and stable. PMID:25374940

  2. Water wave solutions of the coupled system Zakharov-Kuznetsov and generalized coupled KdV equations.

    PubMed

    Seadawy, A R; El-Rashidy, K

    2014-01-01

    An analytic study was conducted on coupled partial differential equations. We formally derived new solitary wave solutions of generalized coupled system of Zakharov-Kuznetsov (ZK) and KdV equations by using modified extended tanh method. The traveling wave solutions for each generalized coupled system of ZK and KdV equations are shown in form of periodic, dark, and bright solitary wave solutions. The structures of the obtained solutions are distinct and stable. PMID:25374940

  3. Global solutions to the two-dimensional Riemann problem for a system of conservation laws

    NASA Astrophysics Data System (ADS)

    Pang, Yicheng; Cai, Shaohong; Zhao, Yuanying

    2016-06-01

    We study the global solutions to the two-dimensional Riemann problem for a system of conservation laws. The initial data are three constant states separated by three rays emanating from the origin. Under the assumption that each ray in the initial data outside of the origin projects exactly one planar contact discontinuity, this problem is classified into five cases. By the self-similar transformation, the reduced system changes type from being elliptic near the origin to being hyperbolic far away in self-similar plane. Then in hyperbolic region, applying the generalized characteristic analysis method, a Goursat problem is solved to describe the interactions of planar contact discontinuities. While, in elliptic region, a boundary value problem arises. It is proved that this boundary value problem admits a unique solution. Based on these preparations, five explicit solutions and their corresponding criteria can be obtained in self-similar plane.

  4. A first principle particle mesh method for solution SAXS of large bio-molecular systems

    NASA Astrophysics Data System (ADS)

    Marchi, Massimo

    2016-07-01

    This paper will show that the solution small angle X-ray scattering (SAXS) intensity of globular and membrane proteins can be efficiently and accurately computed from molecular dynamics trajectories using 3D fast Fourier transforms (FFTs). A suitable particle meshing interpolation, similar to the one used in smooth particle mesh Ewald for electrostatic energies and forces, was combined with a uniform solvent density FFT padding scheme to obtain a convenient SAXS spectral resolution. The CPU time scaling of the method, as a function of system size, is highly favorable and its application to large systems such as solutions of solvated membrane proteins is computationally undemanding. Differently from other approaches, all contributions from the simulation cell are included. This means that the subtraction of the buffer from the solution scattering intensity is straightforward and devoid of artifact due to ad hoc definitions of proximal and distal solvent intensity contributions.

  5. A first principle particle mesh method for solution SAXS of large bio-molecular systems.

    PubMed

    Marchi, Massimo

    2016-07-28

    This paper will show that the solution small angle X-ray scattering (SAXS) intensity of globular and membrane proteins can be efficiently and accurately computed from molecular dynamics trajectories using 3D fast Fourier transforms (FFTs). A suitable particle meshing interpolation, similar to the one used in smooth particle mesh Ewald for electrostatic energies and forces, was combined with a uniform solvent density FFT padding scheme to obtain a convenient SAXS spectral resolution. The CPU time scaling of the method, as a function of system size, is highly favorable and its application to large systems such as solutions of solvated membrane proteins is computationally undemanding. Differently from other approaches, all contributions from the simulation cell are included. This means that the subtraction of the buffer from the solution scattering intensity is straightforward and devoid of artifact due to ad hoc definitions of proximal and distal solvent intensity contributions. PMID:27475396

  6. Genera of conjoined bases of linear Hamiltonian systems and limit characterization of principal solutions at infinity

    NASA Astrophysics Data System (ADS)

    Šepitka, Peter; Šimon Hilscher, Roman

    2016-04-01

    In this paper we derive a general limit characterization of principal solutions at infinity of linear Hamiltonian systems under no controllability assumption. The main result is formulated in terms of a limit involving antiprincipal solutions at infinity of the system. The novelty lies in the fact that the principal and antiprincipal solutions at infinity may belong to two different genera of conjoined bases, i.e., the eventual image of their first components is not required to be the same as in the known literature. For this purpose we extend the theory of genera of conjoined bases, which was recently initiated by the authors. We show that the orthogonal projector representing each genus of conjoined bases satisfies a symmetric Riccati matrix differential equation. This result then leads to an exact description of the structure of the set of all genera, in particular it forms a complete lattice. We also provide several examples, which illustrate our new theory.

  7. Periodic solution of neutral Lotka-Volterra system with periodic delays

    NASA Astrophysics Data System (ADS)

    Liu, Zhijun; Chen, Lansun

    2006-12-01

    A nonautonomous n-species Lotka-Volterra system with neutral delays is investigated. A set of verifiable sufficient conditions is derived for the existence of at least one strictly positive periodic solution of this Lotka-Volterra system by applying an existence theorem and some analysis techniques, where the assumptions of the existence theorem are different from that of Gaines and Mawhin's continuation theorem [R.E. Gaines, J.L. Mawhin, Coincidence Degree and Nonlinear Differential Equations, Springer-Verlag, Berlin, 1977] and that of abstract continuation theory for k-set contraction [W. Petryshyn, Z. Yu, Existence theorem for periodic solutions of higher order nonlinear periodic boundary value problems, Nonlinear Anal. 6 (1982) 943-969]. Moreover, a problem proposed by Freedman and Wu [H.I. Freedman, J. Wu, Periodic solution of single species models with periodic delay, SIAM J. Math. Anal. 23 (1992) 689-701] is answered.

  8. Numerical solution of flow problems using body-fitted coordinate systems

    NASA Technical Reports Server (NTRS)

    Thompson, J. F.

    1980-01-01

    The paper deals with numerically generated boundary-fitted coordinate systems. This procedure eliminates the shape of the boundaries as a complicating factor and allows the flow about arbitrary boundaries to be treated essentially as easily as that about simple boundaries. The technique of boundary-fitted coordinate systems is based on a method of automatic numerical generation of a general curvilinear coordinate system having a coordinate line coincident with each boundary of a general multiconnected region involving any number of arbitrarily shaped boundaries. Once the curvilinear coordinate system is generated, any partial differential system of interest may be solved on the coordinate system by transforming the equations and solving the resulting system in finite-difference approximation on the rectangular transformed plane. Attention is given to the types of boundary-fitted coordinate systems, coordinate system control, operation of the coordinate codes, solution of partial differential equations, application to free-surface flow, and other applications of interest.

  9. Fock space, symbolic algebra, and analytical solutions for small stochastic systems

    NASA Astrophysics Data System (ADS)

    Santos, Fernando A. N.; Gadêlha, Hermes; Gaffney, Eamonn A.

    2015-12-01

    Randomness is ubiquitous in nature. From single-molecule biochemical reactions to macroscale biological systems, stochasticity permeates individual interactions and often regulates emergent properties of the system. While such systems are regularly studied from a modeling viewpoint using stochastic simulation algorithms, numerous potential analytical tools can be inherited from statistical and quantum physics, replacing randomness due to quantum fluctuations with low-copy-number stochasticity. Nevertheless, classical studies remained limited to the abstract level, demonstrating a more general applicability and equivalence between systems in physics and biology rather than exploiting the physics tools to study biological systems. Here the Fock space representation, used in quantum mechanics, is combined with the symbolic algebra of creation and annihilation operators to consider explicit solutions for the chemical master equations describing small, well-mixed, biochemical, or biological systems. This is illustrated with an exact solution for a Michaelis-Menten single enzyme interacting with limited substrate, including a consideration of very short time scales, which emphasizes when stiffness is present even for small copy numbers. Furthermore, we present a general matrix representation for Michaelis-Menten kinetics with an arbitrary number of enzymes and substrates that, following diagonalization, leads to the solution of this ubiquitous, nonlinear enzyme kinetics problem. For this, a flexible symbolic maple code is provided, demonstrating the prospective advantages of this framework compared to stochastic simulation algorithms. This further highlights the possibilities for analytically based studies of stochastic systems in biology and chemistry using tools from theoretical quantum physics.

  10. Fock space, symbolic algebra, and analytical solutions for small stochastic systems.

    PubMed

    Santos, Fernando A N; Gadêlha, Hermes; Gaffney, Eamonn A

    2015-12-01

    Randomness is ubiquitous in nature. From single-molecule biochemical reactions to macroscale biological systems, stochasticity permeates individual interactions and often regulates emergent properties of the system. While such systems are regularly studied from a modeling viewpoint using stochastic simulation algorithms, numerous potential analytical tools can be inherited from statistical and quantum physics, replacing randomness due to quantum fluctuations with low-copy-number stochasticity. Nevertheless, classical studies remained limited to the abstract level, demonstrating a more general applicability and equivalence between systems in physics and biology rather than exploiting the physics tools to study biological systems. Here the Fock space representation, used in quantum mechanics, is combined with the symbolic algebra of creation and annihilation operators to consider explicit solutions for the chemical master equations describing small, well-mixed, biochemical, or biological systems. This is illustrated with an exact solution for a Michaelis-Menten single enzyme interacting with limited substrate, including a consideration of very short time scales, which emphasizes when stiffness is present even for small copy numbers. Furthermore, we present a general matrix representation for Michaelis-Menten kinetics with an arbitrary number of enzymes and substrates that, following diagonalization, leads to the solution of this ubiquitous, nonlinear enzyme kinetics problem. For this, a flexible symbolic maple code is provided, demonstrating the prospective advantages of this framework compared to stochastic simulation algorithms. This further highlights the possibilities for analytically based studies of stochastic systems in biology and chemistry using tools from theoretical quantum physics. PMID:26764734

  11. Exact Solution of the Two-Level System and the Einstein Solid in the Microcanonical Formalism

    ERIC Educational Resources Information Center

    Bertoldi, Dalia S.; Bringa, Eduardo M.; Miranda, E. N.

    2011-01-01

    The two-level system and the Einstein model of a crystalline solid are taught in every course of statistical mechanics and they are solved in the microcanonical formalism because the number of accessible microstates can be easily evaluated. However, their solutions are usually presented using the Stirling approximation to deal with factorials. In…

  12. Lines of Eigenvectors and Solutions to Systems of Linear Differential Equations

    ERIC Educational Resources Information Center

    Rasmussen, Chris; Keynes, Michael

    2003-01-01

    The purpose of this paper is to describe an instructional sequence where students invent a method for locating lines of eigenvectors and corresponding solutions to systems of two first order linear ordinary differential equations with constant coefficients. The significance of this paper is two-fold. First, it represents an innovative alternative…

  13. Stability of the solitary wave solutions to a coupled BBM system

    NASA Astrophysics Data System (ADS)

    Chen, Hongqiu; Wang, Xiaojun

    2016-07-01

    In this work, we present a stability criteria for the solitary wave solutions to a BBM system that contains coupled nonlinear terms. Using the idea by Bona, Chen and Karakashian [5] and exploiting the accurate point spectrum information of the associated Schrödinger operator, we improve the stability results previously gotten by Pereira [15].

  14. Step-by-Step Solution Possibilities in Different Computer Algebra Systems.

    ERIC Educational Resources Information Center

    Tonisson, Eno

    This paper compares a number of different Computer Algebra Systems (CAS) in their solution of one-step and multi-step problems. The CAS programs considered include DERIVE, Maple, Mathematica, and MuPAD while the problems are taken from the final examinations of grades 9 and 12 in Estonian schools. The different outputs to one-step problems with…

  15. Mixed solvent systems for recovery of ethanol from dilute aqueous solution by liquid-liquid extraction

    SciTech Connect

    Mitchell, R.J.; Arrowsmith, A.; Ashton, N.

    1987-01-01

    Distribution coefficients and selectivities of a number of mixed solvent systems have been determined in order to assess their suitability in preferentially extracting ethanol from aqueous solution. The measured values of distribution coefficients and selectivities differ substantially from the values estimated by interpolating between the pure solvents. (Refs. 10).

  16. Invariant Solutions to the Strominger System on Complex Lie Groups and Their Quotients

    NASA Astrophysics Data System (ADS)

    Fei, Teng; Yau, Shing-Tung

    2015-09-01

    Using canonical 1-parameter family of Hermitian connections on the tangent bundle, we provide invariant solutions to the Strominger system on certain complex Lie groups and their quotients. Both flat and non-flat cases are discussed in detail. This paper answers a question proposed by Andreas and Garcia-Fernandez in Comm Math Phys 332(3):1381-1383, 2014.

  17. Closed-form solutions for linear regulator design of mechanical systems including optimal weighting matrix selection

    NASA Technical Reports Server (NTRS)

    Hanks, Brantley R.; Skelton, Robert E.

    1991-01-01

    Vibration in modern structural and mechanical systems can be reduced in amplitude by increasing stiffness, redistributing stiffness and mass, and/or adding damping if design techniques are available to do so. Linear Quadratic Regulator (LQR) theory in modern multivariable control design, attacks the general dissipative elastic system design problem in a global formulation. The optimal design, however, allows electronic connections and phase relations which are not physically practical or possible in passive structural-mechanical devices. The restriction of LQR solutions (to the Algebraic Riccati Equation) to design spaces which can be implemented as passive structural members and/or dampers is addressed. A general closed-form solution to the optimal free-decay control problem is presented which is tailored for structural-mechanical system. The solution includes, as subsets, special cases such as the Rayleigh Dissipation Function and total energy. Weighting matrix selection is a constrained choice among several parameters to obtain desired physical relationships. The closed-form solution is also applicable to active control design for systems where perfect, collocated actuator-sensor pairs exist.

  18. Global Existence of Strong Solutions to the Cucker-Smale-Stokes System

    NASA Astrophysics Data System (ADS)

    Bae, Hyeong-Ohk; Choi, Young-Pil; Ha, Seung-Yeal; Kang, Moon-Jin

    2016-06-01

    A coupled kinetic-fluid model describing the interactions between Cucker-Smale flocking particles and a Stokes fluid is presented. We demonstrate the global existence and uniqueness of strong solutions to this coupled system in a three-dimensional spatially periodic domain for initial data that are sufficiently regular, but not necessarily small.

  19. 76 FR 59167 - Siemens Medical Solutions USA, Inc., Oncology Care Systems Division, Concord, CA; Siemens Medical...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-23

    ... Register on April 23, 2010 (75 FR 21355). The Department's Notice was amended on July 29, 2011 to include... the Federal Register on August 12, 2011 (76 FR 50269). The workers are engaged in employment related... Employment and Training Administration Siemens Medical Solutions USA, Inc., Oncology Care Systems...

  20. The Challenge of Multiple Perspectives: Multiple Solution Tasks for Students Incorporating Diverse Tools and Representation Systems

    ERIC Educational Resources Information Center

    Kordaki, Maria

    2015-01-01

    This study focuses on the role of multiple solution tasks (MST) incorporating multiple learning tools and representation systems (MTRS) in encouraging each student to develop multiple perspectives on the learning concepts under study and creativity of thought. Specifically, two types of MST were used, namely tasks that allowed and demanded…

  1. Implementation guide for MINPACK-1. [Package of Fortran subprograms for solution of systems of nonlinear equations

    SciTech Connect

    Garbow, B.S.; Hillstrom, K.E.; More, J.J.

    1980-07-01

    MINPACK-1 is a package of Fortran subprograms for the numerical solution of systems of nonlinear equations and nonlinear least-squares problems. This report describes how to implement the package from the tape on which it is transmitted. 3 tables.

  2. Stationary distribution and periodic solution for stochastic predator-prey systems with nonlinear predator harvesting

    NASA Astrophysics Data System (ADS)

    Zuo, Wenjie; Jiang, Daqing

    2016-07-01

    In this paper, we investigate the dynamics of the stochastic autonomous and non-autonomous predator-prey systems with nonlinear predator harvesting respectively. For the autonomous system, we first give the existence of the global positive solution. Then, in the case of persistence, we prove that there exists a unique stationary distribution and it has ergodicity by constructing a suitable Lyapunov function. The result shows that, the relatively weaker white noise will strengthen the stability of the system, but the stronger white noise will result in the extinction of one or two species. Particularly, for the non-autonomous periodic system, we show that there exists at least one nontrivial positive periodic solution according to the theory of Khasminskii. Finally, numerical simulations illustrate our theoretical results.

  3. Optoelectronic ally automated system for carbon nanotubes synthesis via arc-discharge in solution

    SciTech Connect

    Bera, Debasis; Brinley, Erik; Kuiry, Suresh C.; McCutchen, Matthew; Seal, Sudipta; Heinrich, Helge; Kabes, Bradley

    2005-03-01

    The method of arc discharge in the solution is unique and inexpensive route for synthesis of the carbon nanotubes (CNTs), carbon onions, and other carbon nanostructures. Such a method can be used for in situ synthesis of CNTs decorated with nanoparticles. Herein, we report a simple and inexpensive optoelectronically automated system for arc discharge in solution synthesis of CNTs. The optoelectronic system maintains a constant gap between the two electrodes allowing a continuous synthesis of the carbon nanostructures. The system operates in a feedback loop consisting of an electrode-gap detector and an analog electronic unit, as controller. This computerized feeding system of the anode was used for in situ nanoparticles incorporated CNTs. For example, we have successfully decorated CNTs with ceria, silica, and palladium nanoparticles. Characterizations of nanostructures are performed using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy dispersive spectroscopy, and scanning electron microscopy.

  4. Optoelectronically automated system for carbon nanotubes synthesis via arc-discharge in solution

    NASA Astrophysics Data System (ADS)

    Bera, Debasis; Brinley, Erik; Kuiry, Suresh C.; McCutchen, Matthew; Seal, Sudipta; Heinrich, Helge; Kabes, Bradley

    2005-03-01

    The method of arc discharge in the solution is unique and inexpensive route for synthesis of the carbon nanotubes (CNTs), carbon onions, and other carbon nanostructures. Such a method can be used for in situ synthesis of CNTs decorated with nanoparticles. Herein, we report a simple and inexpensive optoelectronically automated system for arc discharge in solution synthesis of CNTs. The optoelectronic system maintains a constant gap between the two electrodes allowing a continuous synthesis of the carbon nanostructures. The system operates in a feedback loop consisting of an electrode-gap detector and an analog electronic unit, as controller. This computerized feeding system of the anode was used for in situ nanoparticles incorporated CNTs. For example, we have successfully decorated CNTs with ceria, silica, and palladium nanoparticles. Characterizations of nanostructures are performed using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy dispersive spectroscopy, and scanning electron microscopy.

  5. System for creating on site, remote from a sterile environment, parenteral solutions

    NASA Technical Reports Server (NTRS)

    Finley, Mike (Inventor); Scharf, Mike (Inventor); Packard, Jeff (Inventor); Kipp, Jim (Inventor); Dudar, Tom (Inventor); Owens, Jim (Inventor); Bindokas, Al (Inventor)

    1996-01-01

    The present invention provides a system and method for creating on site, remote from a sterile environment, parenteral solutions in large volume parenteral containers for intravenous administration to a patient. In an embodiment, this system comprises an empty large volume container including at least one port for accessing an interior of the container. The port includes a sterilizing filter for sterilizing a fluid fed through the port into the container. A second container is provided including a solute and having means for coupling the second container to the large volume container and thereby providing fluid communication therebetween allowing the solute to be received within the interior of the container. A sterile water source is also provided including means for placing the sterile water source in fluid communication with the port and allowing water to flow from the sterile water source into the interior of the container. This allows the solute, and sterile water that has been fed through the filter, to create a parenteral solution in the large volume parenteral container.

  6. Solid Solution Effects on the MgAl2O4 System

    SciTech Connect

    O'Hara, Kelley; Smith, Jeffrey D; Hemrick, James Gordon

    2009-01-01

    Phase relations between the binaries MgAl2O4-ZnAl2O4 and MgAl2O4-MgGa2O4 were studied. Stoichiometric MgAl2O4 spinel can be formed in the laboratory through a coprecipitation method. Complete solid solution formation in the MgAl2O4-MgGa2O4 system was confirmed through X-ray diffraction (XRD) analysis. XRD analysis of the MgAl2O4-ZnAl2O4 system did not confirm solid solution due to the similar lattice parameters of the two end points, however, previous studies have shown that complete solid solution does form. Thermal conductivity data is pending and will be included in the presentation. Based on previous experimentation and open literature, it is suspected that thermal conductivity will be decreased with the addition of solid solution. With increased amounts of disruption to the lattice from solid solution it is also theorized that the temperature at which the mean free path still impacts thermal conductivity could be increased.

  7. On the existence of periodic solutions to nonlinear elasto-dynamic systems with symmetry

    NASA Astrophysics Data System (ADS)

    Whalen, Timothy Michael

    The nonlinear dynamics of periodic motion for elastic structures are investigated. By exploiting the underlying symmetry of the structure, the linearized dynamics problem is solved efficiently. Using these solutions as approximations, the existence of solution branches for the nonlinear dynamics is proved using bifurcation theorems and group theoretic ideas. The technique is illustrated for two discretized, rotating systems: a three bar truss with D(3) symmetry and a dish antenna with D(6) symmetry. Linear solutions are obtained by employing coordinate transformations motivated by the symmetry that block-diagonalise the governing equations. Although these equations are only C(n) symmetric (due to the gyroscopic effects), a theorem is proved that allows the use of D(n) group-theoretic information in the computation of the transformation. Using Liapunov-Schmidt reduction, conditions are checked that guarantee bifurcation of certain solutions. These conditions hold only when the natural frequencies are nonresonant. This is shown to occur generically for stiffening constitutive laws. The antenna problem is analyzed numerically, and the computational savings obtained by exploiting symmetry are shown. Problems involving vibration of elastic loops are examined. For a rotating loop, the symmetry group S0(2) is used to find families of linear solutions. One family is found to possess resonant natural frequencies, invalidating our method. Bifurcation is proved formally for the other families. For a pressurized loop, bifurcating travelling wave solutions are sought, and the existence of such motions is formally exhibited. The applicability of certain analysis results in our calculations is discussed. Resonance is investigated by studying the vibration of a pinned string. The linearization is shown to have resonance problems for all natural frequencies because of scale invariance. Solutions are found for this

  8. System for absolute measurement of electrolytic conductivity in aqueous solutions based on van der Pauw's theory

    NASA Astrophysics Data System (ADS)

    Zhang, Bing; Lin, Zhen; Zhang, Xiao; Yu, Xiang; Wei, Jiali; Wang, Xiaoping

    2014-05-01

    Based on an innovative application of van der Pauw's theory, a system was developed for the absolute measurement of electrolytic conductivity in aqueous solutions. An electrolytic conductivity meter was designed that uses a four-electrode system with an axial-radial two-dimensional adjustment structure coupled to an ac voltage excitation source and signal collecting circuit. The measurement accuracy, resolution and repeatability of the measurement system were examined through a series of experiments. Moreover, the measurement system and a high-precision electrolytic conductivity meter were compared using some actual water samples.

  9. PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM

    SciTech Connect

    W.L. Lundberg; G.A. Israelson; R.R. Moritz; S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann

    2000-02-01

    Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

  10. Solution of the inverse Langevin problem for open dissipative systems with anisotropic interparticle interaction

    SciTech Connect

    Lisin, E. A.; Lisina, I. I.; Vaulina, O. S.; Petrov, O. F.

    2015-03-15

    Solution of the inverse Langevin problem is presented for open dissipative systems with anisotropic interparticle interaction. Possibility of applying this solution for experimental determining the anisotropic interaction forces between dust particles in complex plasmas with ion flow is considered. For this purpose, we have tested the method on the results of numerical simulation of chain structures of particles with quasidipole-dipole interaction, similar to the one occurring due to effects of ion focusing in gas discharges. Influence of charge spatial inhomogeneity and fluctuations on the results of recovery is also discussed.

  11. Asymptotic Stability of Riemann Solutions for a Class of Multidimensional Systems of Conservation Laws with Viscosity

    NASA Astrophysics Data System (ADS)

    Frid, Hermano

    2006-07-01

    We prove the asymptotic stability of two-state nonplanar Riemann solutions for a class of multidimensional hyperbolic systems of conservation laws when the initial data are perturbed and viscosity is added. The class considered here is those systems whose flux functions in different directions share a common complete system of Riemann invariants, the level surfaces of which are hyperplanes. In particular, we obtain the uniqueness of the self-similar L ∞ entropy solution of the two-state nonplanar Riemann problem. The asymptotic stability to which the main result refers is in the sense of the convergence as t→∞ in L loc 1 of the space of directions ξ = x/t. That is, the solution u(t, x) of the perturbed problem satisfies u(t, t ξ)→R(ξ) as t→∞, in L loc 1(ℝ n ), where R(ξ) is the self-similar entropy solution of the corresponding two-state nonplanar Riemann problem.

  12. Stability and attractivity of periodic solutions of parabolic systems with time delays

    NASA Astrophysics Data System (ADS)

    Pao, C. V.

    2005-04-01

    This paper is concerned with the existence, stability, and global attractivity of time-periodic solutions for a class of coupled parabolic equations in a bounded domain. The problem under consideration includes coupled system of parabolic and ordinary differential equations, and time delays may appear in the nonlinear reaction functions. Our approach to the problem is by the method of upper and lower solutions and its associated monotone iterations. The existence of time-periodic solutions is for a class of locally Lipschitz continuous reaction functions without any quasimonotone requirement using Schauder fixed point theorem, while the stability and attractivity analysis is for quasimonotone nondecreasing and mixed quasimonotone reaction functions using the monotone iterative scheme. The results for the general system are applied to the standard parabolic equations without time delay and to the corresponding ordinary differential system. Applications are also given to three Lotka-Volterra reaction diffusion model problems, and in each problem a sufficient condition on the reaction rates is obtained to ensure the stability and global attractivity of positive periodic solutions.

  13. New developments in the numerical solution of differential/algebraic systems

    SciTech Connect

    Petzold, L.R.

    1987-04-01

    In this paper we survey some recent developments in the numerical solution of nonlinear differential/algebraic equation (DAE) systems of the form 0 = F(t,y,y'), where the initial values of y are known and par. deltaF/par. deltay' may be singular. These systems arise in the simulation of electrical networks, as well as in many other applications. DAE systems include standard form ODEs as a special case, but they also include problems which are in many ways quite different from ODEs. We examine the classification of DAE systems according to the degree of singularity of the system, and present some results on the analytical structure of these systems. We give convergence results for backward differentiation formulas applied to DAEs and examine some of the software issues involved in the numerical solution of DAEs. One-step methods are potentially advantageous for solving DAE systems with frequent discontinuities. However, recent results indicate that there is a reduction in the order of accuracy of many implicit Runge-Kutta methods even for simple DAE systems. We examine the current state of solving DAE systems by implicit Runge-Kutta methods. Finding a consistent set of initial conditions is often a problem for DAEs arising in applications. We explore some numerical methods for obtaining a consistent set of initial conditions. 21 refs.

  14. A Proposed Implementation of Tarjan's Algorithm for Scheduling the Solution Sequence of Systems of Federated Models

    SciTech Connect

    McNunn, Gabriel S; Bryden, Kenneth M

    2013-01-01

    Tarjan's algorithm schedules the solution of systems of equations by noting the coupling and grouping between the equations. Simulating complex systems, e.g., advanced power plants, aerodynamic systems, or the multi-scale design of components, requires the linkage of large groups of coupled models. Currently, this is handled manually in systems modeling packages. That is, the analyst explicitly defines both the method and solution sequence necessary to couple the models. In small systems of models and equations this works well. However, as additional detail is needed across systems and across scales, the number of models grows rapidly. This precludes the manual assembly of large systems of federated models, particularly in systems composed of high fidelity models. This paper examines extending Tarjan's algorithm from sets of equations to sets of models. The proposed implementation of the algorithm is demonstrated using a small one-dimensional system of federated models representing the heat transfer and thermal stress in a gas turbine blade with thermal barrier coating. Enabling the rapid assembly and substitution of different models permits the rapid turnaround needed to support the “what-if” kinds of questions that arise in engineering design.

  15. Semirational solutions and baseband modulational instability of the AB system in fluid mechanics

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Wang, Zi-Zhe; Jiang, Dong-Yang; Qi, Feng-Hua; Guo, Rui

    2015-10-01

    Under investigation in this paper is the AB system describing marginally unstable baroclinic wave packets in geophysical fluids. By means of the n -fold modified Darboux transformation, the semirational solutions in terms of the determinants of the AB system are derived. These solutions, which are a combination of rational and exponential functions, can be used to model the nonlinear superposition of the Akhmediev breathers (or the Kuznetsov-Ma breathers) and the rogue waves. The k -order rogue wave of the AB system is produced by the interaction between the l-order rogue wave with 1/2(k-l)(k+l+1) neighboring elements in the (k-l)-order breathers (0

  16. Trace Formula for Linear Hamiltonian Systems with its Applications to Elliptic Lagrangian Solutions

    NASA Astrophysics Data System (ADS)

    Hu, Xijun; Ou, Yuwei; Wang, Penghui

    2015-04-01

    In the present paper, we build up trace formulas for both the linear Hamiltonian systems and Sturm-Liouville systems. The formula connects the monodromy matrix of a symmetric periodic orbit with the infinite sum of eigenvalues of the Hessian of the action functional. A natural application is to study the non-degeneracy of linear Hamiltonian systems. Precisely, by the trace formula, we can give an estimation for the upper bound such that the non-degeneracy preserves. Moreover, we could estimate the relative Morse index by the trace formula. Consequently, a series of new stability criteria for the symmetric periodic orbits is given. As a concrete application, the trace formula is used to study the linear stability of elliptic Lagrangian solutions of the classical planar three-body problem, which depends on the mass parameter and the eccentricity . Based on the trace formula, we estimate the stable region and hyperbolic region of the elliptic Lagrangian solutions.

  17. The Vacuole System Is a Significant Intracellular Pathway for Longitudinal Solute Transport in Basidiomycete Fungi†

    PubMed Central

    Darrah, P. R.; Tlalka, M.; Ashford, A.; Watkinson, S. C.; Fricker, M. D.

    2006-01-01

    Mycelial fungi have a growth form which is unique among multicellular organisms. The data presented here suggest that they have developed a unique solution to internal solute translocation involving a complex, extended vacuole. In all filamentous fungi examined, this extended vacuole forms an interconnected network, dynamically linked by tubules, which has been hypothesized to act as an internal distribution system. We have tested this hypothesis directly by quantifying solute movement within the organelle by photobleaching a fluorescent vacuolar marker. Predictive simulation models were then used to determine the transport characteristics over extended length scales. This modeling showed that the vacuolar organelle forms a functionally important, bidirectional diffusive transport pathway over distances of millimeters to centimeters. Flux through the pathway is regulated by the dynamic tubular connections involving homotypic fusion and fission. There is also a strongly predicted interaction among vacuolar organization, predicted diffusion transport distances, and the architecture of the branching colony margin. PMID:16835455

  18. Closed-form analytical solutions incorporating pumping and tidal effects in various coastal aquifer systems

    NASA Astrophysics Data System (ADS)

    Wang, Chaoyue; Li, Hailong; Wan, Li; Wang, Xusheng; Jiang, Xiaowei

    2014-07-01

    Pumping wells are common in coastal aquifers affected by tides. Here we present analytical solutions of groundwater table or head variations during a constant rate pumping from a single, fully-penetrating well in coastal aquifer systems comprising an unconfined aquifer, a confined aquifer and semi-permeable layer between them. The unconfined aquifer terminates at the coastline (or river bank) and the other two layers extend under tidal water (sea or tidal river) for a certain distance L. Analytical solutions are derived for 11 reasonable combinations of different situations of the L-value (zero, finite, and infinite), of the middle layer's permeability (semi-permeable and impermeable), of the boundary condition at the aquifer's submarine terminal (Dirichlet describing direct connection with seawater and no-flow describing the existence of an impermeable capping), and of the tidal water body (sea and tidal river). Solutions are discussed with application examples in fitting field observations and parameter estimations.

  19. Solute trapping in rapid solidification of a binary dilute system: a phase-field study.

    PubMed

    Galenko, P K; Abramova, E V; Jou, D; Danilov, D A; Lebedev, V G; Herlach, D M

    2011-10-01

    The phase-field model of Echebarria, Folch, Karma, and Plapp [Phys. Rev. E 70, 061604 (2004)] is extended to the case of rapid solidification in which local nonequilibrium phenomena occur in the bulk phases and within the diffuse solid-liquid interface. Such an extension leads to the fully hyperbolic system of equations given by the atomic diffusion equation and the phase-field equation of motion. This model is applied to the problem of solute trapping, which is accompanied by the entrapment of solute atoms beyond chemical equilibrium by a rapidly moving interface. The model predicts the beginning of complete solute trapping and diffusionless solidification at a finite solidification velocity equal to the diffusion speed in bulk liquid. PMID:22181123

  20. HOW ECCENTRIC ORBITAL SOLUTIONS CAN HIDE PLANETARY SYSTEMS IN 2:1 RESONANT ORBITS

    SciTech Connect

    Anglada-Escude, Guillem; Chambers, John E.; Lopez-Morales, Mercedes E-mail: mercedes@dtm.ciw.ed

    2010-01-20

    The Doppler technique measures the reflex radial motion of a star induced by the presence of companions and is the most successful method to detect exoplanets. If several planets are present, their signals will appear combined in the radial motion of the star, leading to potential misinterpretations of the data. Specifically, two planets in 2:1 resonant orbits can mimic the signal of a single planet in an eccentric orbit. We quantify the implications of this statistical degeneracy for a representative sample of the reported single exoplanets with available data sets, finding that (1) around 35% of the published eccentric one-planet solutions are statistically indistinguishable from planetary systems in 2:1 orbital resonance, (2) another 40% cannot be statistically distinguished from a circular orbital solution, and (3) planets with masses comparable to Earth could be hidden in known orbital solutions of eccentric super-Earths and Neptune mass planets.

  1. Wash Solution Bath Life Extension for the Space Shuttle Rocket Motor Aqueous Cleaning System

    NASA Technical Reports Server (NTRS)

    Saunders, Chad; Evans, Kurt; Sagers, Neil

    1999-01-01

    A spray-in-air aqueous cleaning system, which replaced 1,1,1 trichloroethane (TCA) vapor degreasing, is used for critical cleaning of Space Shuttle Redesigned Solid Rocket Motor (RSRM) metal parts. Small-scale testing demonstrated that the alkaline-based wash solution possesses adequate soil loading and cleaning properties. However, full-scale testing exhibited unexpected depletion of some primary components of the wash solution. Specifically, there was a significant decrease in the concentration of sodium metasilicate which forced change-out of the wash solution after eight days. Extension of wash solution bath life was necessary to ease the burden of frequent change-out on manufacturing. A laboratory study supports a depletion mechanism that is initiated by the hydrolysis of sodium tripolyphosphate (STPP) lowering the pH of the solution. The decrease in pH causes polymerization and subsequent precipitation of sodium metasilicate (SM). Further investigation showed that maintaining the pH was the key to preventing the precipitation of the sodium metasilicate. Implementation to the full scale operation demonstrated that periodic additions of potassium hydroxide (KOH) extended the useful bath life to more than four months.

  2. An algorithm for constructing polynomial systems whose solution space characterizes quantum circuits

    NASA Astrophysics Data System (ADS)

    Gerdt, Vladimir P.; Severyanov, Vasily M.

    2006-05-01

    An algorithm and its first implementation in C# are presented for assembling arbitrary quantum circuits on the base of Hadamard and Toffoli gates and for constructing multivariate polynomial systems over the finite field Z II arising when applying the Feynman's sum-over-paths approach to quantum circuits. The matrix elements determined by a circuit can be computed by counting the number of common roots in Z II for the polynomial system associated with the circuit. To determine the number of solutions in Z II for the output polynomial system, one can use the Grobner bases method and the relevant algorithms for computing Grobner bases.

  3. Numerical solution of stiff systems of ordinary differential equations with applications to electronic circuits

    NASA Technical Reports Server (NTRS)

    Rosenbaum, J. S.

    1971-01-01

    Systems of ordinary differential equations in which the magnitudes of the eigenvalues (or time constants) vary greatly are commonly called stiff. Such systems of equations arise in nuclear reactor kinetics, the flow of chemically reacting gas, dynamics, control theory, circuit analysis and other fields. The research reported develops an A-stable numerical integration technique for solving stiff systems of ordinary differential equations. The method, which is called the generalized trapezoidal rule, is a modification of the trapezoidal rule. However, the method is computationally more efficient than the trapezoidal rule when the solution of the almost-discontinuous segments is being calculated.

  4. Various power quality challenges and solution techniques using FACTS technology for power system

    NASA Astrophysics Data System (ADS)

    Soni, J. Sandeep; Jangalwa, N. K.; Gupta, R.; Palwalia, D. K.

    2016-03-01

    This paper presents a comprehensive review on the various power quality problems and various solution techniques using FACTS in Power system. The term "Power Quality" is a broad concept and its meaning is taken different by different peoples. It is associated with electrical transmission, distribution and utilization systems those are having experience of any Voltage, current or frequency divergence from normal operation. Due to power quality problems industries have to invest large amount for mitigation of Voltage sags, distortions, harmonics and short term interruptions/disturbances etc. In paper authors tried to cover various possible sources and compensation methods of reactive power in power system.

  5. A Solution Space for a System of Null-State Partial Differential Equations: Part 3

    NASA Astrophysics Data System (ADS)

    Flores, Steven M.; Kleban, Peter

    2015-01-01

    This article is the third of four that completely and rigorously characterize a solution space for a homogeneous system of 2 N + 3 linear partial differential equations (PDEs) in 2 N variables that arises in conformal field theory (CFT) and multiple Schramm-Löwner evolution (SLE κ ). The system comprises 2 N null-state equations and three conformal Ward identities that govern CFT correlation functions of 2 N one-leg boundary operators. In the first two articles (Flores and Kleban, in Commun Math Phys, arXiv:1212.2301, 2012; Commun Math Phys, arXiv:1404.0035, 2014), we use methods of analysis and linear algebra to prove that dim , with C N the Nth Catalan number. Extending these results, we prove in this article that dim and entirely consists of (real-valued) solutions constructed with the CFT Coulomb gas (contour integral) formalism. In order to prove this claim, we show that a certain set of C N such solutions is linearly independent. Because the formulas for these solutions are complicated, we prove linear independence indirectly. We use the linear injective map of Lemma 15 in Flores and Kleban (Commun Math Phys, arXiv:1212.2301, 2012) to send each solution of the mentioned set to a vector in , whose components we find as inner products of elements in a Temperley-Lieb algebra. We gather these vectors together as columns of a symmetric matrix, with the form of a meander matrix. If the determinant of this matrix does not vanish, then the set of C N Coulomb gas solutions is linearly independent. And if this determinant does vanish, then we construct an alternative set of C N Coulomb gas solutions and follow a similar procedure to show that this set is linearly independent. The latter situation is closely related to CFT minimal models. We emphasize that, although the system of PDEs arises in CFT in away that is typically non-rigorous, our treatment of this system here and in Flores and Kleban (Commun Math Phys, arXiv:1212.2301, 2012; Commun Math Phys, arXiv:1404

  6. Community of Solution for the U.S. Health Care System: Lessons from the U.S. Educational System

    PubMed Central

    DeVoe, Jennifer E.; Gold, Rachel

    2016-01-01

    The Folsom Group asserts that radical changes are needed to fix the health care system in the United States. The U.S. education system is one potential model to emulate. Could a future health care system-level community of solution be modeled after the U.S. education system? Could community health care services be planned, organized, and delivered at the neighborhood level by district, similar to the structure for delivering public education? Could community health centers, governed by community boards, serve every neighborhood? This essay imagines how U.S. health care system reforms could be designed using our public school system as a roadmap. Our intention is to challenge readers to recognize the urgent need for radical reform in the U.S. health care system, to introduce one potential model for reform, and to encourage creative thinking about other system-level communities of solution that could lead to profound change and improvements in the U.S. health care system. PMID:23657701

  7. SUPPORT OF NEW COMPUTER HARDWARE AT LUCH'S MC&A SYSTEM: PROBLEMS AND A SOLUTION

    SciTech Connect

    Fedoseev, Victor; Shanin, Oleg

    2009-07-14

    Abstract Microsoft Windows NT 4.0 operating system is the only software product certified in Russia for using in MC&A systems. In the paper a solution for allowing the installation of this outdated operating system on new computers is discussed. The solution has been successfully tested and has been in use at Luch's network since March 2008. Furthermore, it is being recommended for other Russian enterprises for the same purpose. Introduction Typically, the software part of a nuclear material control and accounting (MC&A) system consists of an operating system (OS), database management systems (DBMS), accounting program itself and database of nuclear materials. Russian regulations require the operating system and database for MC&A be certified for information security, and the whole system must pass an accreditation. Historically, the only certified operating system for MC&A still continues to be Microsoft Windows NT 4.0 Server/Workstation. Attempts to certify newer versions of Windows failed. Luch, like most other Russian sites, uses Microsoft Windows NT 4.0 and SQL Server 6.5. Luch's specialists have developed an application (LuchMAS) for accounting purposes. Starting from about 2004, some problems appeared in Luch's accounting system. They were related to the complexity of installing Windows NT 4.0 on new computers. At first, it was possible to solve the problem choosing computer equipment that is compatible with Windows NT 4.0 or selecting certain operating system settings. Over time, the problem worsened and now it is almost impossible to install Windows NT 4.0 on new computers. The reason is the lack of hardware drivers in the outdated operating system. The problem was serious enough that it could have affected the long-term sustainability of Luch's MC&A system if adequate alternate measures were not developed.

  8. Stochastic coalescence in finite systems: an algorithm for the numerical solution of the multivariate master equation.

    NASA Astrophysics Data System (ADS)

    Alfonso, Lester; Zamora, Jose; Cruz, Pedro

    2015-04-01

    The stochastic approach to coagulation considers the coalescence process going in a system of a finite number of particles enclosed in a finite volume. Within this approach, the full description of the system can be obtained from the solution of the multivariate master equation, which models the evolution of the probability distribution of the state vector for the number of particles of a given mass. Unfortunately, due to its complexity, only limited results were obtained for certain type of kernels and monodisperse initial conditions. In this work, a novel numerical algorithm for the solution of the multivariate master equation for stochastic coalescence that works for any type of kernels and initial conditions is introduced. The performance of the method was checked by comparing the numerically calculated particle mass spectrum with analytical solutions obtained for the constant and sum kernels, with an excellent correspondence between the analytical and numerical solutions. In order to increase the speedup of the algorithm, software parallelization techniques with OpenMP standard were used, along with an implementation in order to take advantage of new accelerator technologies. Simulations results show an important speedup of the parallelized algorithms. This study was funded by a grant from Consejo Nacional de Ciencia y Tecnologia de Mexico SEP-CONACYT CB-131879. The authors also thanks LUFAC® Computacion SA de CV for CPU time and all the support provided.

  9. A solution method for the unsteady incompressible Navier-Stokes equations in generalized coordinate systems

    NASA Technical Reports Server (NTRS)

    Rosenfeld, Moshe; Kwak, Dochan; Vinokur, Marcel

    1988-01-01

    A solution method based on a fractional step approach is developed for obtaining time-dependent solutions of the three-dimensional, incompressible Navier-Stokes equations in generalized coordinate systems. The governing equations are discretized conservatively by finite volumes using a staggered mesh system. The primitive variable formulation uses the volume fluxes across the faces of each computational cell as dependent variables. This procedure, combined with accurate and consistent approximations of geometric parameters, is done to satisfy the discretized mass conservation equation to machine accuracy as well as to gain favorable convergence properties of the Poisson solver. The discretized equations are second-order-accurate in time and space and no smoothing terms are added. An approximate-factorization scheme is implemented in solving the momentum equations. A novel ZEBRA scheme with four-color ordering is devised for the efficient solution of the Poisson equation. Several two and three-dimensional solutions are compared with other numerical and experimental results to validate the present method.

  10. ARAS: an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes

    DOE PAGESBeta

    Dooraghi, Alex A.; Carroll, Lewis; Collins, Jeffrey; van Dam, R. Michael; Chatziioannou, Arion F.

    2016-03-09

    Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing a safe environment for radiation workers but also to ensure accuracy of dispensed radioactivity and an efficient workflow. For this purpose, we have designed ARAS, an automated radioactivity aliquoting system for dispensing solutions containing positron-emitting radioisotopes with particular focus on fluorine-18 (18F). The key to the system is the combination of a radiation detector measuring radioactivity concentration, in line with a peristaltic pump dispensing known volumes. Results show the combined system demonstrates volume variation to be within 5 % for dispensing volumes of 20 μLmore » or greater. When considering volumes of 20 μL or greater, the delivered radioactivity is in agreement with the requested amount as measured independently with a dose calibrator to within 2 % on average. In conclusion, the integration of the detector and pump in an in-line system leads to a flexible and compact approach that can accurately dispense solutions containing radioactivity concentrations ranging from the high values typical of [18F]fluoride directly produced from a cyclotron (~0.1-1 mCi μL-1) to the low values typical of batches of [18F]fluoride-labeled radiotracers intended for preclinical mouse scans (~1-10 μCi μL-1).« less

  11. Diagnostic Solution Assistant cornerstone for intelligent system monitoring, management, analysis and administration

    NASA Astrophysics Data System (ADS)

    Aaseng, Gordon; Holland, Courtney; Nelson, Bill

    2000-01-01

    The Diagnostic Solution Assistant (DSA) provides diagnostics for space hardware and subsystems. Advanced Honewell `smart' model-based technology performs the real-time fault detection, isolation and diagnostics. This model-based technology provides 24-hour access to the operational knowledge of the system experts. The complexity of the International Space Station (ISS) and other manned space vehicles requires that a full staff of ground based system diagnosis experts be trained and available at all times. Response to critical situations must be immediate no matter what time of the day or night. Installation of new systems plus normal staff turnover cause personnel to be in training constantly. Domain knowledge lost due to staff attrition may also never be regained. All of these factors lead to higher cost ground based flight system monitoring stations and sub-optimal efficiency. The Diagnostic Solution Assistant (DSA) provides a solution to these issues. The DSA can be deployed into the ISS Mission Control Center to enhance Flight Controller awareness and decision making. DSA can be utilized onboard the vehicle to enhance crew awareness and potentially offload the crew in time- or safety-critical situations. The DSA can be used to isolate and diagnose faults during flight preparation, thus reducing the overall vehicle turn-around time. In addition to having diagnostic capability, DSA is a tremendous requirements and operations knowledge capture tool that could streamline training for the flight controller and crew, and facilitate the rapid location of important information. .

  12. Global solution to a hyperbolic problem arising in the modeling of blood flow in circulatory systems

    NASA Astrophysics Data System (ADS)

    Ruan, Weihua; Clark, M. E.; Zhao, Meide; Curcio, Anthony

    2007-07-01

    This paper considers a system of first-order, hyperbolic, partial differential equations in the domain of a one-dimensional network. The system models the blood flow in human circulatory systems as an initial-boundary-value problem with boundary conditions of either algebraic or differential type. The differential equations are nonhomogeneous with frictional damping terms and the state variables are coupled at internal junctions. The existence and uniqueness of the local classical solution have been established in our earlier work [W. Ruan, M.E. Clark, M. Zhao, A. Curcio, A hyperbolic system of equations of blood flow in an arterial network, J. Appl. Math. 64 (2) (2003) 637-667; W. Ruan, M.E. Clark, M. Zhao, A. Curcio, Blood flow in a network, Nonlinear Anal. Real World Appl. 5 (2004) 463-485; W. Ruan, M.E. Clark, M. Zhao, A. Curcio, A quasilinear hyperbolic system that models blood flow in a network, in: Charles V. Benton (Ed.), Focus on Mathematical Physics Research, Nova Science Publishers, Inc., New York, 2004, pp. 203-230]. This paper continues the analysis and gives sufficient conditions for the global existence of the classical solution. We prove that the solution exists globally if the boundary data satisfy the dissipative condition (2.3) or (3.2), and the norms of the initial and forcing functions in a certain Sobolev space are sufficiently small. This is only the first step toward establishing the global existence of the solution to physiologically realistic models, because, in general, the chosen dissipative conditions (2.3) and (3.2) do not appear to hold for the originally proposed boundary conditions (1.3)-(1.12).

  13. Adsorption of sodium bis(2-ethylhexyl) sulfosuccinate and wettability in polytetrafluoroethylene solution air system

    NASA Astrophysics Data System (ADS)

    Harkot, Joanna; Jańczuk, Bronisław

    2007-06-01

    The role of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) adsorption at water-air and polytetrafluoroethylene-water (PTFE) interfaces in wetting of low energy PTFE was established from measurements of the contact angle of aqueous AOT solutions in PTFE-solution drop-air systems and the aqueous AOT solution surface tension measurements. For calculations of the adsorption at these interfaces the relationship between adhesion tension ( γLV cos θ) and surface tension ( γLV), and the Gibbs and Young equations were taken into account. On the basis of the measurements and calculations the slope of the γLV cos θ- γLV curve was found to be constant and equal -1 over the whole range of surfactant concentration in solution. It means that the amount of surfactant adsorbed at the PTFE-water interface, ΓSL, is essentially equal to its amount adsorbed at water-air interface, ΓLV. By extrapolating the linear dependence between γLV cos θ and γLV to cos θ = 1 the determined value of critical surface tension of PTFE surface wetting, γC, was obtained (23.6 mN/m), and it was higher than the surface tension of PTFE (20.24 mN/m). Using the value of PTFE surface tension and the measured surface tension of aqueous AOT solution in Young equation, the PTFE-solution interface tension, γSL, was also determined. The shape of the γSL-log C curve occurred to be similar to the isotherm of AOT adsorption at water-air interface, and a linear dependence existed between the PTFE-solution interfacial tension and polar component of aqueous AOT solution. The dependence was found to be established by the fact that the work of adhesion of AOT solution to the PTFE surface was practically constant amounting 46.31 mJ/m 2 which was close to the work of water adhesion to PTFE surface.

  14. Parallel domain decomposition and the solution of nonlinear systems of equations

    SciTech Connect

    Gropp, W.D. ); Keyes, D.E. . Dept. of Mechanical Engineering)

    1990-01-01

    Many linear systems arise as subproblems in the solution of nonlinear equations, either as part of a simple fixed-point of a Newton's method iteration. This paper considers the use of domain decomposition techniques for the solution of these linear problems in the context of solving a multicomponent system of nonlinear equations on two types of parallel processors. One of the computations is drawn from fluid dynamics and includes locally refined grids. Such problems require great computational resources, and domain, decomposition seems to offer a way to efficiently solve these problems on computers with significant parallelism. The domain decomposition approach used is as in Gropp and Keyes, modified to achieve better parallelism and to reduce the computational work. 13 refs., 2 figs., 5 tabs.

  15. System and method for laser assisted sample transfer to solution for chemical analysis

    SciTech Connect

    Van Berkel, Gary J; Kertesz, Vilmos

    2014-01-28

    A system and method for laser desorption of an analyte from a specimen and capturing of the analyte in a suspended solvent to form a testing solution are described. The method can include providing a specimen supported by a desorption region of a specimen stage and desorbing an analyte from a target site of the specimen with a laser beam centered at a radiation wavelength (.lamda.). The desorption region is transparent to the radiation wavelength (.lamda.) and the sampling probe and a laser source emitting the laser beam are on opposite sides of a primary surface of the specimen stage. The system can also be arranged where the laser source and the sampling probe are on the same side of a primary surface of the specimen stage. The testing solution can then be analyzed using an analytical instrument or undergo further processing.

  16. Cyclic electrowinning/precipitation (CEP) system for the removal of heavy metal mixtures from aqueous solutions

    PubMed Central

    Grimshaw, Pengpeng; Calo, Joseph M.; Hradil, George

    2011-01-01

    The description and operation of a novel cyclic electrowinning/precipitation (CEP) system for the simultaneous removal of mixtures of heavy metals from aqueous solutions are presented. CEP combines the advantages of electrowinning in a spouted particulate electrode (SPE) with that of chemical precipitation and redissolution, to remove heavy metals at low concentrations as solid metal deposits on particulate cathode particles without exporting toxic metal precipitate sludges from the process. The overall result is very large volume reduction of the heavy metal contaminants as a solid metal deposit on particles that can either be safely discarded as such, or further processed to recover particular metals. The performance of this system is demonstrated with data on the removal of mixtures of copper, nickel, and cadmium from aqueous solutions. PMID:22102792

  17. Cyclic electrowinning/precipitation (CEP) system for the removal of heavy metal mixtures from aqueous solutions.

    PubMed

    Grimshaw, Pengpeng; Calo, Joseph M; Hradil, George

    2011-11-15

    The description and operation of a novel cyclic electrowinning/precipitation (CEP) system for the simultaneous removal of mixtures of heavy metals from aqueous solutions are presented. CEP combines the advantages of electrowinning in a spouted particulate electrode (SPE) with that of chemical precipitation and redissolution, to remove heavy metals at low concentrations as solid metal deposits on particulate cathode particles without exporting toxic metal precipitate sludges from the process. The overall result is very large volume reduction of the heavy metal contaminants as a solid metal deposit on particles that can either be safely discarded as such, or further processed to recover particular metals. The performance of this system is demonstrated with data on the removal of mixtures of copper, nickel, and cadmium from aqueous solutions. PMID:22102792

  18. Solutions to the Inverse LQR Problem with Application to Biological Systems Analysis

    PubMed Central

    Priess, M Cody; Conway, Richard; Choi, Jongeun; Popovich, John M; Radcliffe, Clark

    2015-01-01

    In this paper, we present a set of techniques for finding a cost function to the time-invariant Linear Quadratic Regulator (LQR) problem in both continuous- and discrete-time cases. Our methodology is based on the solution to the inverse LQR problem, which can be stated as: does a given controller K describe the solution to a time-invariant LQR problem, and if so, what weights Q and R produce K as the optimal solution? Our motivation for investigating this problem is the analysis of motion goals in biological systems. We first describe an efficient Linear Matrix Inequality (LMI) method for determining a solution to the general case of this inverse LQR problem when both the weighting matrices Q and R are unknown. Our first LMI-based formulation provides a unique solution when it is feasible. Additionally, we propose a gradient-based, least-squares minimization method that can be applied to approximate a solution in cases when the LMIs are infeasible. This new method is very useful in practice since the estimated gain matrix K from the noisy experimental data could be perturbed by the estimation error, which may result in the infeasibility of the LMIs. We also provide an LMI minimization problem to find a good initial point for the minimization using the proposed gradient descent algorithm. We then provide a set of examples to illustrate how to apply our approaches to several different types of problems. An important result is the application of the technique to human subject posture control when seated on a moving robot. Results show that we can recover a cost function which may provide a useful insight on the human motor control goal. PMID:26640359

  19. Critical experiments on an enriched uranium solution system containing periodically distributed strong thermal neutron absorbers

    SciTech Connect

    Rothe, R.E.

    1996-09-30

    A series of 62 critical and critical approach experiments were performed to evaluate a possible novel means of storing large volumes of fissile solution in a critically safe configuration. This study is intended to increase safety and economy through use of such a system in commercial plants which handle fissionable materials in liquid form. The fissile solution`s concentration may equal or slightly exceed the minimum-critical-volume concentration; and experiments were performed for high-enriched uranium solution. Results should be generally applicable in a wide variety of plant situations. The method is called the `Poisoned Tube Tank` because strong neutron absorbers (neutron poisons) are placed inside periodically spaced stainless steel tubes which separate absorber material from solution, keeping the former free of contamination. Eight absorbers are investigated. Both square and triangular pitched lattice patterns are studied. Ancillary topics which closely model typical plant situations are also reported. They include the effect of removing small bundles of absorbers as might occur during inspections in a production plant. Not taking the tank out of service for these inspections would be an economic advantage. Another ancillary topic studies the effect of the presence of a significant volume of unpoisoned solution close to the Poisoned Tube Tank on the critical height. A summary of the experimental findings is that boron compounds were excellent absorbers, as expected. This was true for granular materials such as Gerstley Borate and Borax; but it was also true for the flexible solid composed of boron carbide and rubber, even though only thin sheets were used. Experiments with small bundles of absorbers intentionally removed reveal that quite reasonable tanks could be constructed that would allow a few tubes at a time to be removed from the tank for inspection without removing the tank from production service.

  20. Existing Whole-House Solutions Case Study: Multifamily Individual Heating and Ventilation Systems, Lawrence, Massachusetts

    SciTech Connect

    2013-11-01

    The conversion of an older Massachusetts building into condominiums illustrates a safe, durable, and cost-effective solution for heating and ventilation systems that can potentially benefit millions of multifamily buildings. In this project, Merrimack Valley Habitat for Humanity (MVHfH) partnered with U.S. Department of Energy Building America team Building Science Corporation (BSC) to provide high performance affordable housing for 10 families in the retrofit of an existing mass masonry building (a former convent).

  1. CRC Clinical Trials Management System (CTMS): An Integrated Information Management Solution for Collaborative Clinical Research

    PubMed Central

    Payne, Philip R.O.; Greaves, Andrew W.; Kipps, Thomas J.

    2003-01-01

    The Chronic Lymphocytic Leukemia (CLL) Research Consortium (CRC) consists of 9 geographically distributed sites conducting a program of research including both basic science and clinical components. To enable the CRC’s clinical research efforts, a system providing for real-time collaboration was required. CTMS provides such functionality, and demonstrates that the use of novel data modeling, web-application platforms, and management strategies provides for the deployment of an extensible, cost effective solution in such an environment. PMID:14728471

  2. An analytical solution for predicting the transient seepage from a subsurface drainage system

    NASA Astrophysics Data System (ADS)

    Xin, Pei; Dan, Han-Cheng; Zhou, Tingzhang; Lu, Chunhui; Kong, Jun; Li, Ling

    2016-05-01

    Subsurface drainage systems have been widely used to deal with soil salinization and waterlogging problems around the world. In this paper, a mathematical model was introduced to quantify the transient behavior of the groundwater table and the seepage from a subsurface drainage system. Based on the assumption of a hydrostatic pressure distribution, the model considered the pore-water flow in both the phreatic and vadose soil zones. An approximate analytical solution for the model was derived to quantify the drainage of soils which were initially water-saturated. The analytical solution was validated against laboratory experiments and a 2-D Richards equation-based model, and found to predict well the transient water seepage from the subsurface drainage system. A saturated flow-based model was also tested and found to over-predict the time required for drainage and the total water seepage by nearly one order of magnitude, in comparison with the experimental results and the present analytical solution. During drainage, a vadose zone with a significant water storage capacity developed above the phreatic surface. A considerable amount of water still remained in the vadose zone at the steady state with the water table situated at the drain bottom. Sensitivity analyses demonstrated that effects of the vadose zone were intensified with an increased thickness of capillary fringe, capillary rise and/or burying depth of drains, in terms of the required drainage time and total water seepage. The analytical solution provides guidance for assessing the capillary effects on the effectiveness and efficiency of subsurface drainage systems for combating soil salinization and waterlogging problems.

  3. Positive periodic solutions of periodic neutral Lotka-Volterra system with state dependent delays

    NASA Astrophysics Data System (ADS)

    Li, Yongkun

    2007-06-01

    By using a fixed point theorem of strict-set-contraction, some new criteria are established for the existence of positive periodic solutions of the following periodic neutral Lotka-Volterra system with state dependent delays where (i,j=1,2,...,n) are [omega]-periodic functions and (i=1,2,...,n) are [omega]-periodic functions with respect to their first arguments, respectively.

  4. Counties turn to GIS for NPDES solutions. [Geographic Information Systems, National Pollutant Discharge Elimination System

    SciTech Connect

    McCormick, T.C. . Water Resources Div.)

    1994-06-01

    This article examines the use of geographic information systems (GIS) as a cost effective approach to meeting the challenges presented by the EPA storm water permitting requirements. The topics of the article include the national pollutant discharge elimination system background, GIS applicability, NPDES/GIS framework, system inventory, and identifying and eliminating illicit discharges.

  5. The discussion of crucial techniques in the emergency solution of special equipment security systems

    NASA Astrophysics Data System (ADS)

    Li, Zhao; Liu, Renyi; Liu, Nan

    2007-06-01

    This paper analyzes the necessity and feasibility of the supervision of special equipment security. The emergency solution of special equipment security system aims to integrate the emergency response department, such as police security, fire control, first aid, and traffic police and so on, to conduct the disaster rescue jointly under the command of the government departments. China Special Equipment Inspection and Research Center launched a GIS based system that manages the special equipment security. It designs the database, software and hardware structure, and functional module of the emergency solution of special equipment security based on WebGIS and GPS techniques. This paper analyzes three key issues of this system is explosion model, security patrol vehicles and special vehicles GPS positioning and special equipment monitoring. This system uses the information sharing technology based on Web Service. Transplanting GIS to Internet, designs special equipment spatial data WebGIS web site. B/S architecture is used in the system, and the software SuperMap IS Java of SuperMap Company is used as the GIS server for the spatial data publishing. This system also contains a PDA platform that provide for fieldwork.

  6. Controls of carbonate mineralogy and solid-solution of Mg in calcite: evidence from spelean systems

    SciTech Connect

    Gonzalez, L.A.; Lohmann, K.C.

    1985-01-01

    Precipitation of carbonate minerals in spelean systems occurs under a wide range of fluid chemistry, Mg-Ca ratios, alkalinities, pH and temperatures; thus, spelean systems provide ideal settings to determine factors controlling the mineralogy of precipitated carbonates and solid-solution of Mg in calcite. Cave waters and actively-precipitating carbonate speleothems were collected from Carlsbad Caverns National Park, New Mexico and the Mammoth-Flint Cave System, Kentucky. Carbonate mineralogy of precipitated phases was determined by x-ray diffraction, and major and minor element composition of waters and accompanying minerals were determined by Atomic Absorption Spectrophotometry. Results demonstrate that at a constant CO3 concentration the precipitation threshold for calcite to aragonite is controlled dominantly by the Mg/Ca ratio of the ambient fluid. Aragonite precipitation is favored by high Mg/Ca ratios. Conversely, with increasing CO3 concentration at constant fluid Mg/Ca ratios, calcite is preferentially precipitated. Solid-solution of Mg in calcite is positively correlated with both increased Mg/Ca ratios and CO3 concentrations. These data suggest that Mg contents of calcite can not be defined solely in terms of a homogeneous distribution coefficient. Rather, Mg concentrations can be also be affected by the CO3 concentration and degree of calcite saturation, suggesting that the rate of crystal growth also plays and important role in Mg solid-solution in calcites.

  7. EXAFS Phase Retrieval Solution Tracking for Complex Multi-Component System: Synthesized Topological Inverse Computation

    NASA Astrophysics Data System (ADS)

    Lee, Jay Min; Yang, Dong-Seok; Bunker, Grant B.

    2013-04-01

    Using the FEFF kernel A(k,r), we describe the inverse computation from χ(k)-data to g(r)-solution in terms of a singularity regularization method based on complete Bayesian statistics process. In this work, we topologically decompose the system-matched invariant projection operators into two distinct types, (A+AA+A) and (AA+AA+), and achieved Synthesized Topological Inversion Computation (STIC), by employing a 12-operator-closed-loop emulator of the symplectic transformation. This leads to a numerically self-consistent solution as the optimal near-singular regularization parameters are sought, dramatically suppressing instability problems connected with finite precision arithmetic in ill-posed systems. By statistically correlating a pair of measured data, it was feasible to compute an optimal EXAFS phase retrieval solution expressed in terms of the complex-valued χ(k), and this approach was successfully used to determine the optimal g(r) for a complex multi-component system.

  8. Solutions for 3D self-reconfiguration in a modular robotic system: implementation and motion planning

    NASA Astrophysics Data System (ADS)

    Unsal, Cem; Khosla, Pradeep K.

    2000-10-01

    In this manuscript, we discuss new solutions for mechanical design and motion planning for a class of 3D modular self- reconfigurable robotic system, namely I-Cubes. This system is a bipartite collection of active links that provide motions for self-reconfiguration, and cubes acting as connection points. The links are three degree of freedom manipulators that can attach to and detach from the cube faces. The cubes can be positioned and oriented using the links. These capabilities enable the system to change its shape and perform locomotion tasks over difficult terrain. This paper describes the scaled down version of the system previously described in and details the new design and manufacturing approaches. Initially designed algorithms for motion planning of I-Cubes are improved to provide better results. Results of our tests are given and issues related to motion planning are discussed. The user interfaces designed for the control of the system and algorithm evaluation is also described.

  9. Global attractivity of positive periodic solution to periodic Lotka-Volterra competition systems with pure delay

    NASA Astrophysics Data System (ADS)

    Tang, Xianhua; Cao, Daomin; Zou, Xingfu

    We consider a periodic Lotka-Volterra competition system without instantaneous negative feedbacks (i.e., pure-delay systems) x(t)=x(t)[r(t)-∑j=1na(t)x(t-τ(t))], i=1,2,…,n. We establish some 3/2-type criteria for global attractivity of a positive periodic solution of the system, which generalize the well-known Wright's 3/2 criteria for the autonomous delay logistic equation, and thereby, address the open problem proposed by both Kuang [Y. Kuang, Global stability in delayed nonautonomous Lotka-Volterra type systems without saturated equilibria, Differential Integral Equations 9 (1996) 557-567] and Teng [Z. Teng, Nonautonomous Lotka-Volterra systems with delays, J. Differential Equations 179 (2002) 538-561].

  10. A Class of Dust-Like Self-Similar Solutions of the Massless Einstein-Vlasov System

    NASA Astrophysics Data System (ADS)

    Rendall, Alan D.; Velázquez, Juan J. L.

    2011-07-01

    In this paper the existence of a class of self-similar solutions of the Einstein-Vlasov system is proved. The initial data for these solutions are not smooth, with their particle density being supported in a submanifold of codimension one. They can be thought of as intermediate between smooth solutions of the Einstein-Vlasov system and dust. The motivation for studying them is to obtain insights into possible violation of weak cosmic censorship by solutions of the Einstein-Vlasov system. By assuming a suitable form of the unknowns it is shown that the existence question can be reduced to that of the existence of a certain type of solution of a four-dimensional system of ordinary differential equations depending on two parameters. This solution starts at a particular point $P_0$ and converges to a stationary solution $P_1$ as the independent variable tends to infinity. The existence proof is based on a shooting argument and involves relating the dynamics of solutions of the four-dimensional system to that of solutions of certain two- and three-dimensional systems obtained from it by limiting processes.

  11. Membrane contactor assisted water extraction system for separating hydrogen peroxide from a working solution, and method thereof

    SciTech Connect

    Snyder, Seth W.; Lin, Yupo J.; Hestekin' Jamie A.; Henry, Michael P.; Pujado, Peter; Oroskar, Anil; Kulprathipanja, Santi; Randhava, Sarabjit

    2010-09-21

    The present invention relates to a membrane contactor assisted extraction system and method for extracting a single phase species from multi-phase working solutions. More specifically one preferred embodiment of the invention relates to a method and system for membrane contactor assisted water (MCAWE) extraction of hydrogen peroxide (H.sub.2O.sub.2) from a working solution.

  12. The Effects of Predictive Solutions on Training Time and Post-Training Performance for Control Systems with Human Operators.

    ERIC Educational Resources Information Center

    Myers, David Lee

    The effect of predictive solutions on training time (speed) and subsequent performance in a complex manual control system was investigated. A control system with a slow and complex response to the input signals was formulated. Fifty control operators, 25 with the aid of predictive solutions and 25 without, were tested; the mean performances of the…

  13. 78 FR 48467 - Delphi Automotive Systems, LLC, Products and Service Solutions Division, Including On-Site Leased...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-08

    ... Department's notice of determination was published in the Federal Register on February 22, 2013 (Volume 78 FR... Employment and Training Administration Delphi Automotive Systems, LLC, Products and Service Solutions... workers of Delphi Automotive Systems, LLC, Product and Service Solutions Division, Original...

  14. Reversible Hydrogel–Solution System of Silk with High Beta-Sheet Content

    PubMed Central

    2015-01-01

    Silkworm silk has been widely used as a textile fiber, as biomaterials and in optically functional materials due to its extraordinary properties. The β-sheet-rich natural nanofiber units of about 10–50 nm in diameter are often considered the origin of these properties, yet it remains unclear how silk self-assembles into these hierarchical structures. A new system composed of β-sheet-rich silk nanofibers about 10–20 nm in diameter is reported here, where these nanofibers formed into “flowing hydrogels” at 0.5–2% solutions and could be transformed back into the solution state at lower concentrations, even with a high β-sheet content. This is in contrast with other silk processed materials, where significant β-sheet content negates reversibility between solution and solid states. These fibers are formed by regulating the self-assembly process of silk in aqueous solution, which changes the distribution of negative charges while still supporting β-sheet formation in the structures. Mechanistically, there appears to be a shift toward negative charges along the outside of the silk nanofibers in our present study, resulting in a higher zeta potential (above −50 mV) than previous silk materials which tend to be below −30 mV. The higher negative charge on silk nanofibers resulted in electrostatic repulsion strong enough to negate further assembly of the nanofibers. Changing silk concentration changed the balance between hydrophobic interactions and electrostatic repulsion of β-sheet-rich silk nanofibers, resulting in reversible hydrogel–solution transitions. Furthermore, the silk nanofibers could be disassembled into shorter fibers and even nanoparticles upon ultrasonic treatment following the transition from hydrogel to solution due to the increased dispersion of hydrophobic smaller particles, without the loss of β-sheet content, and with retention of the ability to transition between hydrogel and solution states through reversion to longer nanofibers

  15. Reversible hydrogel-solution system of silk with high beta-sheet content.

    PubMed

    Bai, Shumeng; Zhang, Xiuli; Lu, Qiang; Sheng, Weiqin; Liu, Lijie; Dong, Boju; Kaplan, David L; Zhu, Hesun

    2014-08-11

    Silkworm silk has been widely used as a textile fiber, as biomaterials and in optically functional materials due to its extraordinary properties. The β-sheet-rich natural nanofiber units of about 10-50 nm in diameter are often considered the origin of these properties, yet it remains unclear how silk self-assembles into these hierarchical structures. A new system composed of β-sheet-rich silk nanofibers about 10-20 nm in diameter is reported here, where these nanofibers formed into "flowing hydrogels" at 0.5-2% solutions and could be transformed back into the solution state at lower concentrations, even with a high β-sheet content. This is in contrast with other silk processed materials, where significant β-sheet content negates reversibility between solution and solid states. These fibers are formed by regulating the self-assembly process of silk in aqueous solution, which changes the distribution of negative charges while still supporting β-sheet formation in the structures. Mechanistically, there appears to be a shift toward negative charges along the outside of the silk nanofibers in our present study, resulting in a higher zeta potential (above -50 mV) than previous silk materials which tend to be below -30 mV. The higher negative charge on silk nanofibers resulted in electrostatic repulsion strong enough to negate further assembly of the nanofibers. Changing silk concentration changed the balance between hydrophobic interactions and electrostatic repulsion of β-sheet-rich silk nanofibers, resulting in reversible hydrogel-solution transitions. Furthermore, the silk nanofibers could be disassembled into shorter fibers and even nanoparticles upon ultrasonic treatment following the transition from hydrogel to solution due to the increased dispersion of hydrophobic smaller particles, without the loss of β-sheet content, and with retention of the ability to transition between hydrogel and solution states through reversion to longer nanofibers during self

  16. Iterative solutions of sparse linear systems on systolic arrays. Technical report

    SciTech Connect

    Melhem, R.

    1987-03-01

    The idea of grouping the non-zero elements of a sparse matrix into few strips that are almost parallel is applied to the design of a systolic accelerator for sparse matrix operations. This accelerator is, then, integrated into a complete systolic system for the solution of large sparse linear systems of equations. The design demonstrates that the application of systolic arrays is not limited to regular computations, and that computationally irregular problems may be solved on systolic networks if local storage is provided in each systolic cell for buffering the irregularity in the data movement and for absorbing the irregularity in the computation.

  17. UBV Photometry, Times of Minimum, and Light Curve Solutions for the Algol system, RU Eri

    NASA Astrophysics Data System (ADS)

    Shope, S.; Sowell, J.; Williamon, R.

    1999-12-01

    RU Eri is an Algol system with partial eclipses and a period of 15 hours. The components appear to be slightly evolved F and K stars. UBV photometry has been acquired over six seasons with the 36-inch telescope at the DeKalb County (GA) School System's Fernbank Science Center. Times of minimum have been determined per filter and season, and a literature search has provided additional values for examining the possibility of period changes. Preliminary light curve solutions using all of our data have been derived with the Wilson-Devinney binary star code.

  18. Iterative solution of large, sparse linear systems on a static data flow architecture - Performance studies

    NASA Technical Reports Server (NTRS)

    Reed, D. A.; Patrick, M. L.

    1985-01-01

    The applicability of static data flow architectures to the iterative solution of sparse linear systems of equations is investigated. An analytic performance model of a static data flow computation is developed. This model includes both spatial parallelism, concurrent execution in multiple PE's, and pipelining, the streaming of data from array memories through the PE's. The performance model is used to analyze a row partitioned iterative algorithm for solving sparse linear systems of algebraic equations. Based on this analysis, design parameters for the static data flow architecture as a function of matrix sparsity and dimension are proposed.

  19. Semi-analytical solution of groundwater flow in a leaky aquifer system subject to bending effect

    NASA Astrophysics Data System (ADS)

    Yu, Chia-Chi; Yang, Shaw-Yang; Yeh, Hund-Der

    2013-04-01

    SummaryThe bending of aquitard like a plate due to aquifer pumping and compression is often encountered in many practical problems of subsurface flow. This reaction will have large influence on the release of the volume of water from the aquifer, which is essential for the planning and management of groundwater resources in aquifers. However, the groundwater flow induced by pumping in a leaky aquifer system is often assumed that the total stress of aquifer maintains constant all the time and the mechanical behavior of the aquitard formation is negligible. Therefore, this paper devotes to the investigation of the effect of aquitard bending on the drawdown distribution in a leaky aquifer system, which is obviously of interest in groundwater hydrology. Based on the work of Wang et al. (2004) this study develops a mathematical model for investigating the impacts of aquitard bending and leakage rate on the drawdown of the confined aquifer due to a constant-rate pumping in the leaky aquifer system. This model contains three equations; two flow equations delineate the transient drawdown distributions in the aquitard and the confined aquifer, while the other describes the vertical displacement in response to the aquitard bending. For the case of no aquitard bending, this new solution can reduce to the Hantush Laplace-domain solution (Hantush, 1960). On the other hand, this solution without the leakage effect can reduce to the time domain solution of Wang et al. (2004). The results show that the aquifer drawdown is influenced by the bending effect at early time and by the leakage effect at late time. The results of sensitivity analysis indicate that the aquifer compaction is sensitive only at early time, causing less amount of water released from the pumped aquifer than that predicted by the traditional groundwater theory. The dimensionless drawdown is rather sensitive to aquitard's hydraulic conductivity at late time. Additionally, both the hydraulic conductivity and

  20. Troubleshooting complex systems--An expert system, interactive video, transportable PC solution

    SciTech Connect

    Broadaway, E.R.; Williams, L.C.; Mullens, J.A.; Zabriskie, W.L.; Roberts, A.G.

    1989-08-01

    Troubleshooting complex control systems presents special problems for the maintenance technician. Because problems occur infrequently, maintenance or repair work may be requested many months after the technician received training for a particular system. An expert system with an object-oriented programming environment for authoring was developed at Oak Ridge National Laboratory to address this problem. The need to transport the delivery system to a variety of locations necessitated the integration of a transportable, 386-based system with color display. Using Smalltalk/V286, this system combined an inference engine with a windowed environment for development of rules and tutorials and display of documentation. In addition, still-frame video with graphic overlays are used.

  1. Fluorescence behavior of a unique two-photon fluorescent probe in aggregate and solution states and highly sensitive detection of RNA in water solution and living systems.

    PubMed

    Liu, Yong; Meng, Fangfang; He, Longwei; Yu, Xiaoqiang; Lin, Weiying

    2016-07-01

    It is found that 2,7-substituted carbazole derivative possesses distinct luminescence features in both aggregate and solution states. In view of this, probe realizes highly sensitive detection of RNA in pure water systems by an aggregation-disaggregation method for the first time. PMID:27346863

  2. X-ray computed tomography system for laboratory small-object imaging: Enhanced tomography solutions.

    PubMed

    Kharfi, F; Yahiaoui, M L; Boussahoul, F

    2015-07-01

    A portable X-ray tomography system has been installed and actually being tested at our medical imaging laboratory. This tomography system employs a combination of scintillator screen and CCD camera as image detector. The limit of spatial resolution of 290 μm of this imaging system is determined by the establishment of its modulation transfer function (MTF). In this work, we present attempts to address some issues such as limited resolution and low contrast through the development of affordable post-acquisition solutions based on the application of super-resolution method (projection onto convex sets, POCS) to create new projections set enabling the reconstruction of an improved 3D image in terms of contrast, resolution and noise. In addition to small-object examination, this tomography system is used for hands-on training activities involving students and scientists. PMID:25817383

  3. Pointwise estimates of solutions for the multi-dimensional bipolar Euler-Poisson system

    NASA Astrophysics Data System (ADS)

    Wu, Zhigang; Li, Yeping

    2016-06-01

    In the paper, we consider a multi-dimensional bipolar hydrodynamic model from semiconductor devices and plasmas. This system takes the form of Euler-Poisson with electric field and frictional damping added to the momentum equations. By making a new analysis on Green's functions for the Euler system with damping and the Euler-Poisson system with damping, we obtain the pointwise estimates of the solution for the multi-dimensions bipolar Euler-Poisson system. As a by-product, we extend decay rates of the densities {ρ_i(i=1,2)} in the usual L 2-norm to the L p -norm with {p≥1} and the time-decay rates of the momentums m i ( i = 1,2) in the L 2-norm to the L p -norm with p > 1 and all of the decay rates here are optimal.

  4. The next generation in optical transport semiconductors: IC solutions at the system level

    NASA Astrophysics Data System (ADS)

    Gomatam, Badri N.

    2005-02-01

    In this tutorial overview, we survey some of the challenging problems facing Optical Transport and their solutions using new semiconductor-based technologies. Advances in 0.13um CMOS, SiGe/HBT and InP/HBT IC process technologies and mixed-signal design strategies are the fundamental breakthroughs that have made these solutions possible. In combination with innovative packaging and transponder/transceiver architectures IC approaches have clearly demonstrated enhanced optical link budgets with simultaneously lower (perhaps the lowest to date) cost and manufacturability tradeoffs. This paper will describe: *Electronic Dispersion Compensation broadly viewed as the overcoming of dispersion based limits to OC-192 links and extending link budgets, *Error Control/Coding also known as Forward Error Correction (FEC), *Adaptive Receivers for signal quality monitoring for real-time estimation of Q/OSNR, eye-pattern, signal BER and related temporal statistics (such as jitter). We will discuss the theoretical underpinnings of these receiver and transmitter architectures, provide examples of system performance and conclude with general market trends. These Physical layer IC solutions represent a fundamental new toolbox of options for equipment designers in addressing systems level problems. With unmatched cost and yield/performance tradeoffs, it is expected that IC approaches will provide significant flexibility in turn, for carriers and service providers who must ultimately manage the network and assure acceptable quality of service under stringent cost constraints.

  5. Transfer of control system interface solutions from other domains to the thermal power industry.

    PubMed

    Bligård, L-O; Andersson, J; Osvalder, A-L

    2012-01-01

    In a thermal power plant the operators' roles are to control and monitor the process to achieve efficient and safe production. To achieve this, the human-machine interfaces have a central part. The interfaces need to be updated and upgraded together with the technical functionality to maintain optimal operation. One way of achieving relevant updates is to study other domains and see how they have solved similar issues in their design solutions. The purpose of this paper is to present how interface design solution ideas can be transferred from domains with operator control to thermal power plants. In the study 15 domains were compared using a model for categorisation of human-machine systems. The result from the domain comparison showed that nuclear power, refinery and ship engine control were most similar to thermal power control. From the findings a basic interface structure and three specific display solutions were proposed for thermal power control: process parameter overview, plant overview, and feed water view. The systematic comparison of the properties of a human-machine system allowed interface designers to find suitable objects, structures and navigation logics in a range of domains that could be transferred to the thermal power domain. PMID:22317152

  6. A General Closed-Form Solution for the Lunar Reconnaissance Orbiter (LRO) Antenna Pointing System

    NASA Technical Reports Server (NTRS)

    Shah, Neerav; Chen, J. Roger; Hashmall, Joseph A.

    2010-01-01

    The National Aeronautics and Space Administration s (NASA) Lunar Reconnaissance Orbiter (LRO) launched on June 18, 2009 from the Cape Canaveral Air Force Station aboard an Atlas V launch vehicle into a direct insertion trajectory to the Moon LRO, designed, built, and operated by the NASA Goddard Space Flight Center in Greenbelt, MD, is gathering crucial data on the lunar environment that will help astronauts prepare for long-duration lunar expeditions. During the mission s nominal life of one year its six instruments and one technology demonstrator will find safe landing site, locate potential resources, characterize the radiation environment and test new technology. To date, LRO has been operating well within the bounds of its requirements and has been collecting excellent science data images taken from the LRO Camera Narrow Angle Camera (LROC NAC) of the Apollo landing sites have appeared on cable news networks. A significant amount of information on LRO s science instruments is provided at the LRO mission webpage. LRO s Attitude Control System (ACS), in addition to controlling the orientation of the spacecraft is also responsible for pointing the High Gain Antenna (HGA). A dual-axis (or double-gimbaled) antenna, deployed on a meter-long boom, is required to point at a selected Earth ground station. Due to signal loss over the distance from the Moon to Earth, pointing precision for the antenna system is very tight. Since the HGA has to be deployed in spaceflight, its exact geometry relative to the spacecraft body is uncertain. In addition, thermal distortions and mechanical errors/tolerances must be characterized and removed to realize the greatest gain from the antenna system. These reasons necessitate the need for an in-flight calibration. Once in orbit around the moon, a series of attitude maneuvers was conducted to provide data needed to determine optimal parameters to load onboard, which would account for the environmental and mechanical errors at any

  7. Effect of solutal Marangoni convection on motion, coarsening, and coalescence of droplets in a monotectic system

    NASA Astrophysics Data System (ADS)

    Wang, F.; Choudhury, A.; Selzer, M.; Mukherjee, R.; Nestler, B.

    2012-12-01

    In this paper, we study the effect of solutal Marangoni convection (SMC) on the microstructure evolution in a monotectic system, using the convective Cahn-Hilliard and Navier-Stokes equations with a capillary tensor contributed by the chemical concentration gradient. At first, we simulate the spontaneous motion of two distant droplets induced by SMC and compare our results with an analytical solution. We then compute the coalescence of two droplets in contact and coarsening of two distant droplets considering different sizes. We further study the influence of SMC on the evolution of phase separation processes inside the spinodal region for Fe-50 at %Sn and Fe-40 at %Sn alloys. In the former case, we rationalize our results using Fourier spectra and in the latter case, we compare the size distribution of droplets with the LSW theory.

  8. Effect of solutal Marangoni convection on motion, coarsening, and coalescence of droplets in a monotectic system.

    PubMed

    Wang, F; Choudhury, A; Selzer, M; Mukherjee, R; Nestler, B

    2012-12-01

    In this paper, we study the effect of solutal Marangoni convection (SMC) on the microstructure evolution in a monotectic system, using the convective Cahn-Hilliard and Navier-Stokes equations with a capillary tensor contributed by the chemical concentration gradient. At first, we simulate the spontaneous motion of two distant droplets induced by SMC and compare our results with an analytical solution. We then compute the coalescence of two droplets in contact and coarsening of two distant droplets considering different sizes. We further study the influence of SMC on the evolution of phase separation processes inside the spinodal region for Fe-50 at %Sn and Fe-40 at %Sn alloys. In the former case, we rationalize our results using Fourier spectra and in the latter case, we compare the size distribution of droplets with the LSW theory. PMID:23368049

  9. On the Shape of Meissner Solutions to a Limiting Form of Ginzburg-Landau Systems

    NASA Astrophysics Data System (ADS)

    Xiang, Xingfei

    2016-07-01

    In this paper we study a semilinear system involving the curl operator, which is a limiting form of the Ginzburg-Landau model for superconductors in R^3 for a large value of the Ginzburg-Landau parameter. We consider the locations of the maximum points of the magnitude of solutions, which are associated with the nucleation of instability of the Meissner state for superconductors when the applied magnetic field is increased in the transition between the Meissner state and the vortex state. For small penetration depth, we prove that the location is not only determined by the tangential component of the applied magnetic field, but also by the normal curvatures of the boundary in some directions. This improves the result obtained by Bates and Pan in Commun. Math. Phys. 276, 571-610 (2007). We also show that the solutions decay exponentially in the normal direction away from the boundary if the penetration depth is small.

  10. Refracting the k-function: Stavroudis's solution to the eikonal equation for multielement optical systems.

    PubMed

    Hoffnagle, John A; Shealy, David L

    2011-06-01

    The k-function of Stavroudis describes a solution of the eikonal equation in a region of constant refractive index. Given the k-function describing the optical field in one region of space, and given a prescribed refractive or reflective boundary, we construct the k-function for the refracted or reflected field. This procedure, which Stavroudis calls refracting the k-function, can be repeated any number of times, and therefore extends the usefulness of the k-function formalism to multielement optical systems. As examples, we present an analytic solution for the k-function, wavefronts, and caustics generated by a biconvex thick lens illuminated by a plane wave propagating parallel to the symmetry axis, and numerical results for off-axis plane-wave illumination of a two-mirror telescope. PMID:21643418

  11. Note on Solutions of the Strominger System from Unitary Representations of Cocompact Lattices of

    NASA Astrophysics Data System (ADS)

    Andreas, Bjorn; Garcia-Fernandez, Mario

    2014-12-01

    This note is motivated by a recently published paper (Biswas and Mukherjee in Commun Math Phys 322(2):373-384, 2013). We prove a no-go result for the existence of suitable solutions of the Strominger system in a compact complex parallelizable manifold . For this, we assume G to be non-abelian, the Hermitian metric to be induced from a right invariant metric on G, the Bianchi identity to be satisfied using the Chern connection and furthermore the gauge field to be flat. In Biswas and Mukherjee (Commun Math Phys 322(2):373-384, 2013) it is claimed that one such solution exists on . Our result contradicts the main result in Biswas and Mukherjee (Commun Math Phys 322(2):373-384, 2013).

  12. Hydrogen‐Bonded Macrocyclic Supramolecular Systems in Solution and on Surfaces

    PubMed Central

    Mayoral, María J.; Bilbao, Nerea

    2015-01-01

    Abstract Cyclization into closed assemblies is the most recurrent approach to realize the noncovalent synthesis of discrete, well‐defined nanostructures. This review article particularly focuses on the noncovalent synthesis of monocyclic hydrogen‐bonded systems that are self‐assembled from a single molecule with two binding‐sites. Taking advantage of intramolecular binding events, which are favored with respect to intermolecular binding in solution, can afford quantitative amounts of a given supramolecular species under thermodynamic control. The size of the assembly depends on geometric issues such as the monomer structure and the directionality of the binding interaction, whereas the fidelity achieved relies largely on structural preorganization, low degrees of conformational flexibility, and templating effects. Here, we discuss several examples described in the literature in which cycles of different sizes, from dimers to hexamers, are studied by diverse solution or surface characterization techniques. PMID:27308207

  13. Molecular Dynamics Study of Solute Pinning Effects on Grain Boundary Migration in the Aluminum Magnesium Alloy System

    NASA Astrophysics Data System (ADS)

    Rahman, Md. Jahidur; Zurob, Hatem S.; Hoyt, Jeffrey J.

    2016-04-01

    Molecular dynamics simulation, combined with the artificial driving force technique, has been used to study solute interactions with migrating grain boundaries, especially low angle boundaries, in the Al-Mg alloy system. The motion of [112] symmetric tilt boundaries was investigated employing two different approaches at 300 K (27 °C). In the first approach, where solute atoms are segregated and surround the intrinsic dislocations at the grain boundary, a strong solute pinning effect was observed at all misorientations and at different Mg concentrations. A minimum driving force is found to be required for overcoming the barrier produced by the segregated solute at the boundary and a high magnitude of threshold force was observed in all alloys examined. In the alternative approach, where solutes are distributed in a confined region away from the grain boundary, we find that the velocity-driving force behavior in the high driving pressure regime depends on solute concentration, consistent with a recent solute pinning model by Hersent et al. The distributed solute approach provided less pining effect on low angle grain boundary migration compared to that of segregated solutes. The relationship between the restraining force and the solute concentration was computed and, when fit to the Hersent et al. analysis, the solute pinning constant was found to be α = 35 ± 7 MPa for a 7.785 deg boundary in the Al-Mg binary system.

  14. Multiple solution of linear algebraic systems by an iterative method with recomputed preconditioner in the analysis of microstrip structures

    NASA Astrophysics Data System (ADS)

    Ahunov, Roman R.; Kuksenko, Sergey P.; Gazizov, Talgat R.

    2016-06-01

    A multiple solution of linear algebraic systems with dense matrix by iterative methods is considered. To accelerate the process, the recomputing of the preconditioning matrix is used. A priory condition of the recomputing based on change of the arithmetic mean of the current solution time during the multiple solution is proposed. To confirm the effectiveness of the proposed approach, the numerical experiments using iterative methods BiCGStab and CGS for four different sets of matrices on two examples of microstrip structures are carried out. For solution of 100 linear systems the acceleration up to 1.6 times, compared to the approach without recomputing, is obtained.

  15. A join algorithm for combining AND parallel solutions in AND/OR parallel systems

    SciTech Connect

    Ramkumar, B. ); Kale, L.V. )

    1992-02-01

    When two or more literals in the body of a Prolog clause are solved in (AND) parallel, their solutions need to be joined to compute solutions for the clause. This is often a difficult problem in parallel Prolog systems that exploit OR and independent AND parallelism in Prolog programs. In several AND/OR parallel systems proposed recently, this problem is side-stepped at the cost of unexploited OR parallelism in the program, in part due to the complexity of the backtracking algorithm beneath AND parallel branches. In some cases, the data dependency graphs used by these systems cannot represent all the exploitable independent AND parallelism known at compile time. In this paper, we describe the compile time analysis for an optimized join algorithm for supporting independent AND parallelism in logic programs efficiently without leaving and OR parallelism unexploited. We then discuss how this analysis can be used to yield very efficient runtime behavior. We also discuss problems associated with a tree representation of the search space when arbitrarily complex data dependency graphs are permitted. We describe how these problems can be resolved by mapping the search space onto data dependency graphs themselves. The algorithm has been implemented in a compiler for parallel Prolog based on the reduce-OR process model. The algorithm is suitable for the implementation of AND/OR systems on both shared and nonshared memory machines. Performance on benchmark programs.

  16. Solution of linear systems in arterial fluid mechanics computations with boundary layer mesh refinement

    NASA Astrophysics Data System (ADS)

    Manguoglu, Murat; Takizawa, Kenji; Sameh, Ahmed H.; Tezduyar, Tayfun E.

    2009-10-01

    Computation of incompressible flows in arterial fluid mechanics, especially because it involves fluid-structure interaction, poses significant numerical challenges. Iterative solution of the fluid mechanics part of the equation systems involved is one of those challenges, and we address that in this paper, with the added complication of having boundary layer mesh refinement with thin layers of elements near the arterial wall. As test case, we use matrix data from stabilized finite element computation of a bifurcating middle cerebral artery segment with aneurysm. It is well known that solving linear systems that arise in incompressible flow computations consume most of the time required by such simulations. For solving these large sparse nonsymmetric systems, we present effective preconditioning techniques appropriate for different stages of the computation over a cardiac cycle.

  17. Matrix-free methods in the solution of stiff systems of ODE's

    SciTech Connect

    Brown, P.N.; Hindmarsh, A.C.

    1983-11-01

    This is an informal preliminary report, on a study of a matrix-free method for solving stiff systems of ordinary differential equations (ODE's). In the numerical time integration of stiff ODE initial value problems by BDF methods, the resulting nonlinear algebraic system is usually solved by a modified Newton method and an appropriate linear sytem algorithm. In place of that, we substitute Newton's method (unmodified) coupled with an iterative linear system method. The latter is a projection method called the Incomplete Orthogonalization Method (IOM), developed mainly by Y. Saad. A form of IOM, with scaling included to enhance robustness, is studied in the setting of Inexact Newton Methods, and implemented in a way that requires no matrix storage whatever. Tests on several stiff problems, of sizes up to 5000, show the method to be quite effective, and much more economical, in both computational cost and storage, than standard solution methods.

  18. Matrix equation decomposition and parallel solution of systems resulting from unstructured finite element problems in electromagnetics

    SciTech Connect

    Cwik, T.; Katz, D.S.

    1996-12-31

    Finite element modeling has proven useful for accurately simulating scattered or radiated electromagnetic fields from complex three-dimensional objects whose geometry varies on the scale of a fraction of an electrical wavelength. An unstructured finite element model of realistic objects leads to a large, sparse, system of equations that needs to be solved efficiently with regard to machine memory and execution time. Both factorization and iterative solvers can be used to produce solutions to these systems of equations. Factorization leads to high memory requirements that limit the electrical problem size of three-dimensional objects that can be modeled. An iterative solver can be used to efficiently solve the system without excessive memory use and in a minimal amount of time if the convergence rate is controlled.

  19. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system.

    PubMed

    Gao, Shengkui; Mondal, Suman B; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

    2015-01-01

    Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use. PMID:25607724

  20. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system

    NASA Astrophysics Data System (ADS)

    Gao, Shengkui; Mondal, Suman B.; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

    2015-01-01

    Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use.

  1. Photometric Solution and Frequency Analysis of the oEA System EW Boo

    NASA Astrophysics Data System (ADS)

    Zhang, X. B.; Luo, Y. P.; Wang, K.

    2015-03-01

    We present the first photometric solution and frequency analysis of the neglected oscillating Algol-type (oEA) binary EW Boo. B- and V-band light curves of the star were obtained on 11 nights in 2014. Using the Wilson-Devinney code, the eclipsing light curves were synthesized and the first photometric solution was derived for the binary system. The results reveal that EW Boo could be a semi-detached system with the less-massive secondary component filling its Roche lobe. By subtracting the eclipsing light changes from the data, we obtained the intrinsic pulsating light curves of the hotter, massive primary component. Frequency analysis of residual light shows multi-mode pulsation with the dominant period at 0.01909 days. A preliminary mode identification suggests that the star could be pulsating in non-radial (l = 1) modes. The long-term orbital period variation of the system was also investigated for the first time. An improved orbital period and new ephemerides of the eclipsing binary are given. The O-C analysis indicates a secular period increasing at a rate of dP/dt=2.9× {{10}-7} days y{{r}-1}, which could be interpreted as mass transfer from the cooler secondary to the primary component.

  2. Image overlay solution based on threshold detection for a compact near infrared fluorescence goggle system

    PubMed Central

    Gao, Shengkui; Mondal, Suman B.; Zhu, Nan; Liang, RongGuang; Achilefu, Samuel; Gruev, Viktor

    2015-01-01

    Abstract. Near infrared (NIR) fluorescence imaging has shown great potential for various clinical procedures, including intraoperative image guidance. However, existing NIR fluorescence imaging systems either have a large footprint or are handheld, which limits their usage in intraoperative applications. We present a compact NIR fluorescence imaging system (NFIS) with an image overlay solution based on threshold detection, which can be easily integrated with a goggle display system for intraoperative guidance. The proposed NFIS achieves compactness, light weight, hands-free operation, high-precision superimposition, and a real-time frame rate. In addition, the miniature and ultra-lightweight light-emitting diode tracking pod is easy to incorporate with NIR fluorescence imaging. Based on experimental evaluation, the proposed NFIS solution has a lower detection limit of 25 nM of indocyanine green at 27 fps and realizes a highly precise image overlay of NIR and visible images of mice in vivo. The overlay error is limited within a 2-mm scale at a 65-cm working distance, which is highly reliable for clinical study and surgical use. PMID:25607724

  3. Complete solution of dynamical system associated with Ashkin-Teller lattice model

    NASA Astrophysics Data System (ADS)

    Moritz, B.; Schwalm, W.; Schwalm, M.

    2001-03-01

    Discrete dynamical systems of Cremona maps in n variables are well studied in connection with solvable lattice models, e.g. by Maillard and others in search of symmetries of the Yang-Baxter equations. Here we give an explicit solution to the dynamics of a Cremona map associated with the Ashkin-Teller model. Starting from the matrix of Boltzmann weights w, x, and y, of the Ashkin-Teller model, [ m = [ w & x & y & x ŗx & w & x & y ŗy & x & w & x ŗx & y & x & w ŗ] ] Bellon and Maillard derive a dynamical system for the map I circ J, with I a matrix inversion and J taking the reciprocal of each matrix entry. These recursions admit dilation, and there is an additional conserved quantity, resulting in a complete linearization of the map. We give an explicit solution of this dynamical system for w, x and y as functions of the number n of iterations.

  4. Photometric solution and frequency analysis of the oEA system EW Boo

    SciTech Connect

    Zhang, X. B.; Wang, K.; Luo, Y. P.

    2015-03-01

    We present the first photometric solution and frequency analysis of the neglected oscillating Algol-type (oEA) binary EW Boo. B- and V-band light curves of the star were obtained on 11 nights in 2014. Using the Wilson–Devinney code, the eclipsing light curves were synthesized and the first photometric solution was derived for the binary system. The results reveal that EW Boo could be a semi-detached system with the less-massive secondary component filling its Roche lobe. By subtracting the eclipsing light changes from the data, we obtained the intrinsic pulsating light curves of the hotter, massive primary component. Frequency analysis of residual light shows multi-mode pulsation with the dominant period at 0.01909 days. A preliminary mode identification suggests that the star could be pulsating in non-radial (l = 1) modes. The long-term orbital period variation of the system was also investigated for the first time. An improved orbital period and new ephemerides of the eclipsing binary are given. The O−C analysis indicates a secular period increasing at a rate of dP/dt=2.9×10{sup −7} days yr{sup −1}, which could be interpreted as mass transfer from the cooler secondary to the primary component.

  5. Novel DC ring topology and protection system - a comprehensive solution for mega city power grids

    NASA Astrophysics Data System (ADS)

    Haj-Maharsi, Mohamed Yassine

    2009-07-01

    The development of mega cities leads to increased load concentration and brings additional challenges to managing the electrical grid while keeping power available for critical loads. Techniques using FACTS devices are being applied to alleviate power management difficulties and to confine faults in their originating areas in order to limit the risk of cascading failures in the grid. The addition of many FACTS devices often results in control and protection coordination difficulties, power oscillations between connected networks, subsynchronous resonance problems, and torsional interactions with nearby generator units. The most effective solution is obtained when the individual AC subsystems representing sources and loads are decoupled so a fault in a given subsystem is not propagated to another subsystem. This solution can be achieved by the deployment of a DC system where power sources and loads are connected to the DC bus through voltage source converters. For a mega city, this would be conceived as a DC ring feeding multiple loads and connected to remote and local power sources. Unfortunately, the lack of fast DC circuit breakers has been one of the key issues affecting extensive applications of DC systems with common DC buses; a DC fault would discharge all the capacitors of the DC bus and cause delays in system recovery and possibly a wide system collapse. In this research, I provide a comprehensive solution to mega city power grid problems by proposing a DC system topology that enables grid expansions without affecting existing protection settings or changing existing AC breaker ratings. I also propose the means for protecting the DC system by designing a fast DC breaker and developing a control algorithm capable of isolating DC faults without blocking converter stations or depleting DC bus capacitors. My contribution is three folds: (1) I modeled and simulated Shanghai power grid and performed a study to identify short circuit and voltage stability problems

  6. FRW solutions and holography from uplifted AdS/CFT systems

    NASA Astrophysics Data System (ADS)

    Dong, Xi; Horn, Bart; Matsuura, Shunji; Silverstein, Eva; Torroba, Gonzalo

    2012-05-01

    Starting from concrete AdS/CFT dual pairs, one can introduce ingredients which produce cosmological solutions, including metastable de Sitter and its decay to nonaccelerating Friedmann-Robertson-Walker. We present simple Friedmann-Robertson-Walker solutions sourced by magnetic flavor branes and analyze correlation functions and particle and brane dynamics. To obtain a holographic description, we exhibit a time-dependent warped metric on the solution and interpret the resulting redshifted region as a Lorentzian low energy effective field theory in one fewer dimension. At finite times, this theory has a finite cutoff, a propagating lower-dimensional graviton, and a finite covariant entropy bound, but at late times the lower-dimensional Planck mass and entropy go off to infinity in a way that is dominated by contributions from the low energy effective theory. This opens up the possibility of a precise dual at late times. We reproduce the time-dependent growth of the number of degrees of freedom in the system via a count of available microscopic states in the corresponding magnetic brane construction.

  7. A recourse-based solution approach to the design of fuel cell aeropropulsion systems

    NASA Astrophysics Data System (ADS)

    Choi, Taeyun Paul

    In order to formulate a nondeterministic solution approach that capitalizes on the practice of compensatory design, this research introduces the notion of recourse. Within the context of engineering an aerospace system, recourse is defined as a set of corrective actions that can be implemented in stages later than the current design phase to keep critical system-level figures of merit within the desired target ranges, albeit at some penalty. Recourse programs also introduce the concept of stages to optimization formulations, and allow each stage to encompass as many sequences or events as determined necessary to solve the problem at hand. A two-part strategy, which partitions the design activities into stages, is proposed to model the bi-phasal nature of recourse. The first stage is defined as the time period in which an a priori design is identified before the exact values of the uncertain parameters are known. In contrast, the second stage is a period occurring some time after the first stage, when an a posteriori correction can be made to the first-stage design, should the realization of uncertainties impart infeasibilities. Penalizing costs are attached to the second-stage corrections to reflect the reality that getting it done right the first time is almost always less costly than fixing it after the fact. Consequently, the goal of the second stage becomes identifying an optimal solution with respect to the second-stage penalty, given the first-stage design, as well as a particular realization of the random parameters. This two-stage model is intended as an analogue of the traditional practice of monitoring and managing key Technical Performance Measures (TPMs) in aerospace systems development settings. One obvious weakness of the two-stage strategy as presented above is its limited applicability as a forecasting tool. Not only cannot the second stage be invoked without a first-stage starting point, but also the second-stage solution differs from one specific

  8. An efficient parallel algorithm for the solution of a tridiagonal linear system of equations

    NASA Technical Reports Server (NTRS)

    Stone, H. S.

    1971-01-01

    Tridiagonal linear systems of equations are solved on conventional serial machines in a time proportional to N, where N is the number of equations. The conventional algorithms do not lend themselves directly to parallel computations on computers of the ILLIAC IV class, in the sense that they appear to be inherently serial. An efficient parallel algorithm is presented in which computation time grows as log sub 2 N. The algorithm is based on recursive doubling solutions of linear recurrence relations, and can be used to solve recurrence relations of all orders.

  9. Exact solution of the pairing problem for spherical and deformed systems

    NASA Astrophysics Data System (ADS)

    Qi, Chong; Chen, Tao

    2015-11-01

    There has been increasing interest in studying the Richardson model from which one can derive the exact solution for certain pairing Hamiltonians. However, it is still a numerical challenge to solve the nonlinear equations involved. In this paper we tackle this problem by employing a simple hybrid polynomial approach. The method is found to be robust and is valid for both deformed and nearly spherical nuclei. It also provides important and convenient initial guesses for spherical systems with large degeneracy. As an example, we apply the method to study the shape coexistence in neutron-rich Ni isotopes.

  10. Boundedness of the solutions for certain classes of fractional differential equations with application to adaptive systems.

    PubMed

    Aguila-Camacho, Norelys; Duarte-Mermoud, Manuel A

    2016-01-01

    This paper presents the analysis of three classes of fractional differential equations appearing in the field of fractional adaptive systems, for the case when the fractional order is in the interval α∈(0,1] and the Caputo definition for fractional derivatives is used. The boundedness of the solutions is proved for all three cases, and the convergence to zero of the mean value of one of the variables is also proved. Applications of the obtained results to fractional adaptive schemes in the context of identification and control problems are presented at the end of the paper, including numerical simulations which support the analytical results. PMID:26632495

  11. An efficient parallel algorithm for the solution of a tridiagonal linear system of equations.

    NASA Technical Reports Server (NTRS)

    Stone, H. S.

    1973-01-01

    Tridiagonal linear systems of equations can be solved on conventional serial machines in a time proportional to N, where N is the number of equations. The conventional algorithms do not lend themselves directly to parallel computation on computers of the Illiac IV class, in the sense that they appear to be inherently serial. An efficient parallel algorithm is presented in which computation time grows as log(sub-2) N. The algorithm is based on recursive doubling solutions of linear recurrence relations, and can be used to solve recurrence relations of all orders.

  12. Absence of solutions of differential inequalities and systems of hyperbolic type in conic domains

    NASA Astrophysics Data System (ADS)

    Laptev, G. G.

    2002-12-01

    We establish conditions sufficient for the absence of global solutions of semilinear hyperbolic inequalities and systems in conic domains of the Euclidean space \\mathbb R^N. We consider a model problem in a cone K: that given by the inequality \\displaystyle \\dfrac{\\partial^2u}{\\partial t^2}-\\Delta u\\geqslant \\vert u\\vert^q, \\qquad (x,t)\\in K\\times(0,\\infty), The proof is based on the test-function method developed by Veron, Mitidieri, Pokhozhaev, and Tesei.

  13. Thermodynamic characteristics of the heparin-leucine-CaCl2 system in a diluted physiological solution

    NASA Astrophysics Data System (ADS)

    Nikolaeva, L. S.; Belov, G. V.; Rulev, Yu. A.; Semenov, A. N.

    2013-03-01

    Chemical equilibria in aqueous solutions of high-molecular weight heparin (Na4hep) and leucine (HLeu) are calculated through the mathematical modeling of chemical equilibria based on representative experimental pH titration data. In addition, chemical equilibria in the CaCl2-Na4hep-HLeu-H2O-NaCl system in the presence of 0.154M NaCl background electrolyte at a temperature of 37°C in the range of 2.30 ≤ pH ≤ 10.50 and initial concentrations of basic components n × 10-3 M ( n ≤ 4).

  14. 78 FR 15715 - Excelerate Liquefaction Solutions I, LLC; Lavaca Bay Pipeline System, LLC; Notice of Intent To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ... generation system; A cooling water system and instrument air package; A cold vent/ground flare; A fire water... Energy Regulatory Commission Excelerate Liquefaction Solutions I, LLC; Lavaca Bay Pipeline System, LLC... Pipeline System, LLC (LBPS) (collectively referred to as ELS) in Calhoun and Jackson Counties, Texas....

  15. A comparison between ammonia-water and water-lithium bromide solutions in vapor absorption refrigeration systems

    SciTech Connect

    Horuz, I.

    1998-07-01

    A Vapor Absorption Refrigeration (VAR) System is similar to a Vapor Compression Refrigeration (VCR) System. In both systems the required refrigeration is provided by refrigerants vaporizing in the evaporator. However, in the VAR System, a physico-chemical process replaces the mechanical process of the VCR system and heat rather than a mechanical and electrical energy is used. The advantages of this system lie in the possibility of utilizing of waste energy from industrial plants as well as of using solar energy. The study included an investigation to analyze the Vapor Absorption Refrigeration systems using ammonia-water and water-lithium bromide solutions. A fundamental VAR system is described and the operating sequence is explained. Since the most common VAR systems use ammonia-water solution with ammonia as the refrigerant and water-lithium bromide solution with water as the refrigerant, the comparison of the two is presented in respect of the coefficient of performance (COP), the cooling capacity and the maximum and minimum system pressures. It is concluded that the VAR system using water-lithium bromide solution provided better performance than the system using ammonia-water solution. However, there are some points to be considered such as: the danger of crystallization and impossibility of operating in very low temperatures because of the use of water as the refrigerant.

  16. System design optimization for a Mars-roving vehicle and perturbed-optimal solutions in nonlinear programming

    NASA Technical Reports Server (NTRS)

    Pavarini, C.

    1974-01-01

    Work in two somewhat distinct areas is presented. First, the optimal system design problem for a Mars-roving vehicle is attacked by creating static system models and a system evaluation function and optimizing via nonlinear programming techniques. The second area concerns the problem of perturbed-optimal solutions. Given an initial perturbation in an element of the solution to a nonlinear programming problem, a linear method is determined to approximate the optimal readjustments of the other elements of the solution. Then, the sensitivity of the Mars rover designs is described by application of this method.

  17. The model and its solution's uniqueness of a portable 3D vision coordinate measuring system

    NASA Astrophysics Data System (ADS)

    Huang, Fengshan; Qian, Huifen

    2009-11-01

    The portable three-dimensional vision coordinate measuring system, which consists of a light pen, a CCD camera and a laptop computer, can be widely applied in most coordinate measuring fields especially on the industrial spots. On the light pen there are at least three point-shaped light sources (LEDs) acting as the measured control characteristic points and a touch trigger probe with a spherical stylus which is used to contact the point to be measured. The most important character of this system is that three light sources and the probe stylus are aligned in one line with known positions. In building and studying this measuring system, how to construct the system's mathematical model is the most key problem called Perspective of Three-Collinear-points Problem, which is a particular case of Perspective of Three-points Problem (P3P). On the basis of P3P and spatial analytical geometry theory, the system's mathematical model is established. What's more, it is verified that Perspective of Three-Collinear-points Problem has a unique solution. And the analytical equations of the measured point's coordinates are derived by using the system's mathematical model and the restrict condition that three light sources and the probe stylus are aligned in one line. Finally, the effectiveness of the mathematical model is confirmed by experiments.

  18. Human-machine cooperation: a solution for life-critical systems?

    PubMed

    Millot, Patrick; Boy, Guy A

    2012-01-01

    Decision-making plays an important role in life-critical systems. It entails cognitive functions such as monitoring, as well as fault prevention and recovery. Three kinds of objectives are typically considered: safety, efficiency and comfort. People involved in the control and management of such systems provide two kinds of contributions: positive with their unique involvement and capacity to deal with the unexpected; and negative with their ability to make errors. In the negative view, people are the problem and need to be supervised by regulatory systems in the form of operational constraints or by design. In the positive view, people are the solution and lead the game; they are decision-makers. The former view also deals with error resistance, and the latter with error tolerance, which, for example, enables cooperation between people and decision support systems (DSS). In the real life, both views should be considered with respect to appropriate situational factors, such as time constraints and very dangerous environments. This is known as function allocation between people and systems. This paper presents a possibility to reconcile both approaches into a joint human-machine organization, where the main dimensioning factors are safety and complexity. A framework for cooperative and fault tolerant systems is proposed, and illustrated by an example in Air Traffic Control. PMID:22317421

  19. Electrochemiluminescence of terbium (III)-two fluoroquinolones-sodium sulfite system in aqueous solution

    NASA Astrophysics Data System (ADS)

    Chen, Shi-lv; Ding, Fen; Liu, Yu; Zhao, Hui-chun

    2006-05-01

    The electrochemiluminescence (ECL) of Tb 3+-enoxacin-Na 2SO 3 system (ENX system) and Tb 3+-ofloxacin-Na 2SO 3 system (OFLX system) in aqueous solution is reported. ECL is generated by the oxidation of Na 2SO 3, which is enhanced by Tb 3+-fluoroquinolone (FQ) complex. The ECL intensity peak versus potential corresponds to oxidation of Na 2SO 3, and the ECL emission spectra (the peaks are at 490, 545, 585 and 620 nm) match the characteristic emission spectrum of Tb 3+, indicating that the emission is from the excited state of Tb 3+. The mechanism of ECL is proposed and the difference of ECL intensity between ENX system and OFLX system is explained. Conditions for ECL emission were optimized. The linear range of ECL intensity versus concentrations of pharmaceuticals is 2.0 × 10 -10-8.0 × 10 -7 mol l -1 for ENX and 6.0 × 10 -10-6.0 × 10 -7 mol l -1 for OFLX, respectively. A theoretical limit of detection is 5.4 × 10 -11 mol l -1 for ENX and 1.6 × 10 -10 mol l -1 for OFLX, respectively. The ECL was satisfactorily applied to the determination of the two FQs in dosage form and urine sample.

  20. 77 FR 58424 - Drucker, Inc., DynaMotive Energy Systems Corp., and Gate to Wire Solutions, Inc., Order of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Drucker, Inc., DynaMotive Energy Systems Corp., and Gate to Wire Solutions, Inc., Order of... current and accurate information concerning the securities of Gate to Wire Solutions, Inc. because it...

  1. The asymptotic behaviour of the solution to a system of differential equations with a small parameter and singular initial point

    SciTech Connect

    Il'in, Arlen M; Khachay, Oleg Yu; Leonychev, Yurii A

    2010-02-28

    The initial value problem for a system of nonlinear ordinary differential equations with a small parameter multiplying the highest derivative is investigated. In a neighbourhood of the initial point the asymptotic behaviour of the solution has quite a complicated structure. A uniform asymptotic approximation to the solution up to an arbitrary power of the small parameter is constructed and substantiated. Bibliography: 3 titles.

  2. A Solution Space for a System of Null-State Partial Differential Equations: Part 4

    NASA Astrophysics Data System (ADS)

    Flores, Steven M.; Kleban, Peter

    2015-01-01

    This article is the last of four that completely and rigorously characterize a solution space for a homogeneous system of 2 N + 3 linear partial differential equations in 2 N variables that arises in conformal field theory (CFT) and multiple Schramm-Löwner evolution (SLE). The system comprises 2 N null-state equations and three conformal Ward identities that govern CFT correlation functions of 2 N one-leg boundary operators. In the first two articles (Flores and Kleban in Commun Math Phys, 2012; Flores and Kleban, in Commun Math Phys, 2014), we use methods of analysis and linear algebra to prove that dim , with C N the Nth Catalan number. Using these results in the third article (Flores and Kleban, in Commun Math Phys, 2013), we prove that dim and is spanned by (real-valued) solutions constructed with the Coulomb gas (contour integral) formalism of CFT. In this article, we use these results to prove some facts concerning the solution space . First, we show that each of its elements equals a sum of at most two distinct Frobenius series in powers of the difference between two adjacent points (unless is odd, in which case a logarithmic term may appear). This establishes an important element in the operator product expansion for one-leg boundary operators, assumed in CFT. We also identify particular elements of , which we call connectivity weights, and exploit their special properties to conjecture a formula for the probability that the curves of a multiple-SLE process join in a particular connectivity. This leads to new formulas for crossing probabilities of critical lattice models inside polygons with a free/fixed side-alternating boundary condition, which we derive in Flores et al. (Partition functions and crossing probabilities for critical systems inside polygons, in preparation). Finally, we propose a reason for why the exceptional speeds [certain values that appeared in the analysis of the Coulomb gas solutions in Flores and Kleban (Commun Math Phys, 2013)] and

  3. Blow-up of weak solutions to a chemotaxis system under influence of an external chemoattractant

    NASA Astrophysics Data System (ADS)

    Black, Tobias

    2016-06-01

    We study nonnnegative radially symmetric solutions of the parabolic–elliptic Keller–Segel whole space system {ut=Δu‑∇ṡ(u∇v), x∈Rn,t>0,0=Δv+u+f(x), x∈Rn,t>0,u(x,0)=u0(x), x∈Rn, with prototypical external signal production f(x):={f0|x|‑α,if |x|⩽R‑ρ,0,if |x|⩾R+ρ, for R\\in (0,1) and ρ \\in ≤ft(0,\\frac{R}{2}\\right) , which is still integrable but not of class {{L}\\frac{n{2}+{δ0}}}≤ft({{{R}}n}\\right) for some {δ0}\\in ≤ft[0,1\\right) . For corresponding parabolic-parabolic Neumann-type boundary-value problems in bounded domains Ω , where f\\in {{L}\\frac{n{2}+{δ0}}}(Ω ){\\cap}{{C}α}(Ω ) for some {δ0}\\in (0,1) and α \\in (0,1) , it is known that the system does not emit blow-up solutions if the quantities \\parallel {{u}0}{{\\parallel}{{L\\frac{n{2}+{δ0}}}(Ω )}},\\parallel f{{\\parallel}{{L\\frac{n{2}+{δ0}}}(Ω )}} and \\parallel {{v}0}{{\\parallel}{{Lθ}(Ω )}} , for some θ >n , are all bounded by some \\varepsilon >0 small enough. We will show that whenever {{f}0}>\\frac{2n}α(n-2)(n-α ) and {{u}0}\\equiv {{c}0}>0 in \\overline{{{B}1}(0)} , a measure-valued global-in-time weak solution to the system above can be constructed which blows up immediately. Since these conditions are independent of R\\in (0,1) and c 0  >  0, we obtain a strong indication that in fact {δ0}=0 is critical for the existence of global bounded solutions under a smallness conditions as described above.

  4. Thermodynamic properties of solutions in metastable systems under negative or positive pressures

    NASA Astrophysics Data System (ADS)

    Mercury, Lionel; Azaroual, Mohamed; Zeyen, Hermann; Tardy, Yves

    2003-05-01

    Metastable systems are created when the interface between the atmosphere (in which P atm = 1 bar) and water forms a spherical meniscus either concave toward the air (water filling capillaries, wherein P water < P atm) or convex toward the air (fog water droplet, wherein P water > P atm). Soil water, undergoing negative pressure ("capillary potential") remains bound to the solid matrix (instead of flowing downward) by the capillary meniscus, concave toward the undersaturated dry atmosphere. The positive counterpart of tensile water in soils is the pressurized water contained in fine droplets suspended in oversaturated humid air, as in clouds. All these systems are anisobaric domains the phases of which have different pressures. Geochemical consequences of such characteristics are assessed here by calculating the consequences of the positive or negative water potential on the equilibrium constants of reactions taking place in stretched or pressurized aqueous solutions. Thermodynamic properties of aqueous species are obtained by using the TH model, used explicitly for positive pressures but extrapolated to negative ones for soil solutions. It appears that soil water dissolves gases, offering an alternative explanation of the observed enrichment of atmospheric noble gases in groundwater and of carbonic gas in the unsaturated zone below the root zone. Water droplets obviously show the opposite behavior, that is, a decreasing dissolutive capability with decreasing droplet size (water pressure increases), inducing some climatic consequences. An application of this approach to the solid-solution equilibria is performed by comparing experimental solubility of amorphous silica in unsaturated media on the one hand, to theoretical calculations taking account of the negative water pressure on the other hand. This comparison outlines the potential complexity of anisobaric situations in nature and the necessity to develop a suitable approach for solid pressure.

  5. Pseudo almost periodic solutions to some systems of nonlinear hyperbolic second-order partial differential equations

    NASA Astrophysics Data System (ADS)

    Al-Islam, Najja Shakir

    In this Dissertation, the existence of pseudo almost periodic solutions to some systems of nonlinear hyperbolic second-order partial differential equations is established. For that, (Al-Islam [4]) is first studied and then obtained under some suitable assumptions. That is, the existence of pseudo almost periodic solutions to a hyperbolic second-order partial differential equation with delay. The second-order partial differential equation (1) represents a mathematical model for the dynamics of gas absorption, given by uxt+a x,tux=Cx,t,u x,t , u0,t=4 t, 1 where a : [0, L] x RR , C : [0, L] x R x RR , and ϕ : RR are (jointly) continuous functions ( t being the greatest integer function) and L > 0. The results in this Dissertation generalize those of Poorkarimi and Wiener [22]. Secondly, a generalization of the above-mentioned system consisting of the non-linear hyperbolic second-order partial differential equation uxt+a x,tux+bx,t ut+cx,tu=f x,t,u, x∈ 0,L,t∈ R, 2 equipped with the boundary conditions ux,0 =40x, u0,t=u 0t, uxx,0=y 0x, x∈0,L, t∈R, 3 where a, b, c : [0, L ] x RR and f : [0, L] x R x RR are (jointly) continuous functions is studied. Under some suitable assumptions, the existence and uniqueness of pseudo almost periodic solutions to particular cases, as well as the general case of the second-order hyperbolic partial differential equation (2) are studied. The results of all studies contained within this text extend those obtained by Aziz and Meyers [6] in the periodic setting.

  6. Approximate N-Player Nonzero-Sum Game Solution for an Uncertain Continuous Nonlinear System.

    PubMed

    Johnson, Marcus; Kamalapurkar, Rushikesh; Bhasin, Shubhendu; Dixon, Warren E

    2015-08-01

    An approximate online equilibrium solution is developed for an N -player nonzero-sum game subject to continuous-time nonlinear unknown dynamics and an infinite horizon quadratic cost. A novel actor-critic-identifier structure is used, wherein a robust dynamic neural network is used to asymptotically identify the uncertain system with additive disturbances, and a set of critic and actor NNs are used to approximate the value functions and equilibrium policies, respectively. The weight update laws for the actor neural networks (NNs) are generated using a gradient-descent method, and the critic NNs are generated by least square regression, which are both based on the modified Bellman error that is independent of the system dynamics. A Lyapunov-based stability analysis shows that uniformly ultimately bounded tracking is achieved, and a convergence analysis demonstrates that the approximate control policies converge to a neighborhood of the optimal solutions. The actor, critic, and identifier structures are implemented in real time continuously and simultaneously. Simulations on two and three player games illustrate the performance of the developed method. PMID:25312943

  7. Algebraic solutions of shape-invariant position-dependent effective mass systems

    NASA Astrophysics Data System (ADS)

    Amir, Naila; Iqbal, Shahid

    2016-06-01

    Keeping in view the ordering ambiguity that arises due to the presence of position-dependent effective mass in the kinetic energy term of the Hamiltonian, a general scheme for obtaining algebraic solutions of quantum mechanical systems with position-dependent effective mass is discussed. We quantize the Hamiltonian of the pertaining system by using symmetric ordering of the operators concerning momentum and the spatially varying mass, initially proposed by von Roos and Lévy-Leblond. The algebraic method, used to obtain the solutions, is based on the concepts of supersymmetric quantum mechanics and shape invariance. In order to exemplify the general formalism a class of non-linear oscillators has been considered. This class includes the particular example of a one-dimensional oscillator with different position-dependent effective mass profiles. Explicit expressions for the eigenenergies and eigenfunctions in terms of generalized Hermite polynomials are presented. Moreover, properties of these modified Hermite polynomials, like existence of generating function and recurrence relations among the polynomials have also been studied. Furthermore, it has been shown that in the harmonic limit, all the results for the linear harmonic oscillator are recovered.

  8. Groundwater artificial recharge solutions for integrated management of watersheds and aquifer systems under extreme drought scenarios

    NASA Astrophysics Data System (ADS)

    Lobo-Ferreira, Joao-Paulo; Oliveira, Luís.; Diamantino, Catarina

    2010-05-01

    The paper addresses groundwater artificial recharge solutions for integrated management of watersheds and aquifer systems under extreme drought scenarios. The conceptual idea of Aquifer Storage and Recovery (ASR) is considered as one of the scientific based solutions towards scientific based mitigation measures to climate variability and change in many parts of the world. In Portugal two European Union sponsored 6th Framework Programme for Research Projects have been addressing this topic, namely GABARDINE Project on "Groundwater artificial recharge based on alternative sources of water: Advanced integrated technologies and management" and the Coordinated Action ASEMWATERNet, a "Multi-Stakeholder Platform for ASEM S&T Cooperation on Sustainable Water Use". An application of Aquifer Storage and Recovery methodologies aiming drought mitigation and Integrated Water Resource Management of the Algarve (Portugal). The technique of artificial recharge of groundwater is used in many parts of the world with several aims, e.g. water storing in appropriate aquifers for the mitigation of future water needs during droughts or as protection against pollution or even for the recovery of groundwater quality. Artificial recharge of the aquifer systems of Campina de Faro and Silves-Querença is addressed in this paper, proposed to be an alternative to decrease the vulnerability of the Algarve to a future drought. Integrated management of water resources in the Algarve is not a clear issue since the last decade, when groundwater resources that supplied almost all water needs, have been drastically replaced by surface water stored in new reservoirs.

  9. A modern solver framework to manage solution algorithms in the Community Earth System Model

    SciTech Connect

    Evans, Katherine J; Worley, Patrick H; Nichols, Dr Jeff A; WhiteIII, James B; Salinger, Andy; Price, Stephen; Lemieux, Jean-Francois; Lipscomb, William; Perego, Mauro; Vertenstein, Mariana; Edwards, Jim

    2012-01-01

    Global Earth-system models (ESM) can now produce simulations that resolve ~50 km features and include finer-scale, interacting physical processes. In order to achieve these scale-length solutions, ESMs require smaller time steps, which limits parallel performance. Solution methods that overcome these bottlenecks can be quite intricate, and there is no single set of algorithms that perform well across the range of problems of interest. This creates significant implementation challenges, which is further compounded by complexity of ESMs. Therefore, prototyping and evaluating new algorithms in these models requires a software framework that is flexible, extensible, and easily introduced into the existing software. We describe our efforts to create a parallel solver framework that links the Trilinos library of solvers to Glimmer-CISM, a continental ice sheet model used in the Community Earth System Model (CESM). We demonstrate this framework within both current and developmental versions of Glimmer-CISM and provide strategies for its integration into the rest of the CESM.

  10. MBSSAS: A code for the computation of margules parameters and equilibrium relations in binary solid-solution aqueous-solution systems

    USGS Publications Warehouse

    Glynn, P.D.

    1991-01-01

    The computer code MBSSAS uses two-parameter Margules-type excess-free-energy of mixing equations to calculate thermodynamic equilibrium, pure-phase saturation, and stoichiometric saturation states in binary solid-solution aqueous-solution (SSAS) systems. Lippmann phase diagrams, Roozeboom diagrams, and distribution-coefficient diagrams can be constructed from the output data files, and also can be displayed by MBSSAS (on IBM-PC compatible computers). MBSSAS also will calculate accessory information, such as the location of miscibility gaps, spinodal gaps, critical-mixing points, alyotropic extrema, Henry's law solid-phase activity coefficients, and limiting distribution coefficients. Alternatively, MBSSAS can use such information (instead of the Margules, Guggenheim, or Thompson and Waldbaum excess-free-energy parameters) to calculate the appropriate excess-free-energy of mixing equation for any given SSAS system. ?? 1991.

  11. UBV Photometry, Times of Minimum, and Light Curve Solutions for the Algol system, YY Cet

    NASA Astrophysics Data System (ADS)

    Ponce, V.; Williamon, R.; Sowell, J.

    1999-12-01

    YY Cet is an Algol system with partial eclipses and a period of 19 hours. The components appear to be slightly evolved A/F and G/K stars. UBV photometry has been acquired over four seasons with the 36-inch telescope at the DeKalb County (GA) School System's Fernbank Science Center. Times of minimum have been determined per filter and season, and a literature search has provided additional values for examining the possibility of period changes. Preliminary light curve solutions using all of our data have been derived with the Wilson-Devinney binary star code. V. Ponce wishes to acknowledge support from the NSF's Research Experiences for Undergraduates (REU) program administered through the Georgia Institute of Technology.

  12. An automatic multigrid method for the solution of sparse linear systems

    NASA Technical Reports Server (NTRS)

    Shapira, Yair; Israeli, Moshe; Sidi, Avram

    1993-01-01

    An automatic version of the multigrid method for the solution of linear systems arising from the discretization of elliptic PDE's is presented. This version is based on the structure of the algebraic system solely, and does not use the original partial differential operator. Numerical experiments show that for the Poisson equation the rate of convergence of our method is equal to that of classical multigrid methods. Moreover, the method is robust in the sense that its high rate of convergence is conserved for other classes of problems: non-symmetric, hyperbolic (even with closed characteristics) and problems on non-uniform grids. No double discretization or special treatment of sub-domains (e.g. boundaries) is needed. When supplemented with a vector extrapolation method, high rates of convergence are achieved also for anisotropic and discontinuous problems and also for indefinite Helmholtz equations. A new double discretization strategy is proposed for finite and spectral element schemes and is found better than known strategies.

  13. A hybrid disturbance rejection control solution for variable valve timing system of gasoline engines.

    PubMed

    Xie, Hui; Song, Kang; He, Yu

    2014-07-01

    A novel solution for electro-hydraulic variable valve timing (VVT) system of gasoline engines is proposed, based on the concept of active disturbance rejection control (ADRC). Disturbances, such as oil pressure and engine speed variations, are all estimated and mitigated in real-time. A feed-forward controller was added to enhance the performance of the system based on a simple and static first principle model, forming a hybrid disturbance rejection control (HDRC) strategy. HDRC was validated by experimentation and compared with an existing manually tuned proportional-integral (PI) controller. The results show that HDRC provided a faster response and better tolerance of engine speed and oil pressure variations. PMID:24238361

  14. Normal form solutions of dynamical systems in the basin of attraction of their fixed points

    NASA Astrophysics Data System (ADS)

    Bountis, Tassos; Tsarouhas, George; Herman, Russell

    1998-10-01

    The normal form theory of Poincaré, Siegel and Arnol'd is applied to an analytically solvable Lotka-Volterra system in the plane, and a periodically forced, dissipative Duffing's equation with chaotic orbits in its 3-dimensional phase space. For the planar model, we determine exactly how the convergence region of normal forms about a nodal fixed point is limited by the presence of singularities of the solutions in the complex t-plane. Despite such limitations, however, we show, in the case of a periodically driven system, that normal forms can be used to obtain useful estimates of the basin of attraction of a stable fixed point of the Poincaré map, whose ``boundary'' is formed by the intersecting invariant manifolds of a second hyperbolic fixed point nearby.

  15. The ITER divertor Thomson scattering system: engineering and advanced hardware solutions

    NASA Astrophysics Data System (ADS)

    Mukhin, E. E.; Semenov, V. V.; Razdobarin, A. G.; Tolstyakov, S. Yu; Kochergin, M. M.; Kurskiev, G. S.; Berezutsky, A. A.; Podushnikova, K. A.; Masyukevich, S. V.; Chernakov, P. V.; Borovkov, A. I.; Modestov, V. S.; Nemov, A. S.; Voinov, A. S.; Kornev, A. F.; Stupnikov, V. K.; Borisov, A. A.; Baranov, G. N.; Koval, A. N.; Makushina, A. F.; Yelizarov, B. A.; Kukushkin, A. S.; Encheva, A.; Andrew, P.

    2012-02-01

    A divertor Thomson scattering (TS) system being developed for ITER has incorporated proven solutions from currently available TS systems. On the other hand any ITER diagnostic has to operate in a hostile environment and very restricted access geometry. Therefore the operation in an environment of intensive stray light, plasma background radiation, the necessity meet the requirement using only a 20 mm gap between divertor cassettes for plasma diagnosis as well as to measure plasma temperatures as low as 1 eV severely constrain the divertor TS diagnostic design. The challenging solutions of this novel diagnostic system which has to ensure its steady performance and also the operability and maintenance are the focus of this report. One of the most demanding parts of the in-vessel diagnostic equipment development is the design assessment using different engineering analyses. The task definition and first results of thermal, e/m and seismic analyses are provided. The process of further improving of the design involves identification of susceptible areas and multiple iterations of the design, as needed. One of the key points for all Thomson scattering diagnostics are the laser capabilities. A high-performance and high-power laser system using a steady-state and high-repetitive mode Nd:YAG laser (2J, 50-100Hz, 3ns) has been developed. The reduced laser pulse duration matched with high-speed low-noise APD detector can be very important under high background light level. For diagnostics such as Thomson scattering and Raman spectroscopy, a high-degree of discrimination against stray light at the laser wavelength is required for successful detection of wavelength-shifted light from the laser-plasma interaction region. For this case of high stray light level, a triple grating polychromator characterized by high rejection and high transmission has been designed and developed. The novel polychromator design minimizes stray light while still maintaining a relatively high

  16. Multiparametric Flow System for the Automated Determination of Sodium, Potassium, Calcium, and Magnesium in Large-Volume Parenteral Solutions and Concentrated Hemodialysis Solutions

    PubMed Central

    Pistón, Mariela; Dol, Isabel

    2006-01-01

    A multiparametric flow system based on multicommutation and binary sampling has been designed for the automated determination of sodium, potassium, calcium, and magnesium in large-volume parenteral solutions and hemodialysis concentrated solutions. The goal was to obtain a computer-controlled system capable of determining the four metals without extensive modifications. The system involved the use of five solenoid valves under software control, allowing the establishment of the appropriate flow conditions for each analyte, that is, sample size, dilution, reagent addition, and so forth. Detection was carried out by either flame atomic emission spectrometry (sodium, potassium) or flame atomic absorption spectrometry (calcium, magnesium). The influence of several operating parameters was studied. Validation was carried out by analyzing artificial samples. Figures of merit obtained include linearity, accuracy, precision, and sampling frequency. Linearity was satisfactory: sodium, r 2 >0.999 ( 0.5 – 3.5 g/L), potassium, r 2 >0.996 (50–150 mg/L), calcium, r 2 >0.999 (30–120 mg/L), and magnesium, r 2 >0.999 (20–40 mg/L). Precision ( s r , %, n=5 ) was better than 2.1 %, and accuracy (evaluated through recovery assays) was in the range of 99.8 %– 101.0 % (sodium), 100.8 – 102.5 % (potassium), 97.3 %– 101.3 % (calcium), and 97.1 %– 99.8 % (magnesium). Sampling frequencies ( h −1 ) were 70 (sodium), 75 (potassium), 70 (calcium), and 58 (magnesium). According to the results obtained, the use of an automated multiparametric system based on multicommutation offers several advantages for the quality control of large-volume parenteral solutions and hemodialysis concentrated solutions. PMID:17671619

  17. Solute transport modelling in a coupled water and heat flow system applied to cold regions hydrogeology

    NASA Astrophysics Data System (ADS)

    Frampton, Andrew; Destouni, Georgia

    2016-04-01

    In cold regions, flow in the unsaturated zone is highly dynamic with seasonal variability and changes in temperature, moisture, and heat and water fluxes, all of which affect ground freeze-thaw processes and influence transport of inert and reactive waterborne substances. In arctic permafrost environments, near-surface groundwater flow is further restricted to a relatively shallow and seasonally variable active layer, confined by perennially frozen ground below. The active layer is typically partially saturated with ice, liquid water and air, and is strongly dependent on seasonal temperature fluctuations, thermal forcing and infiltration patterns. Here there is a need for improved understanding of the mechanisms controlling subsurface solute transport in the partially saturated active layer zone. Studying solute transport in cold regions is relevant to improve the understanding of how natural and anthropogenic pollution may change as activities in arctic and sub-arctic regions increase. It is also particularly relevant for understanding how dissolved carbon is transported in coupled surface and subsurface hydrological systems under climate change, in order to better understand the permafrost-hydrological-carbon climate feedback. In this contribution subsurface solute transport under surface warming and degrading permafrost conditions is studied using a physically based model of coupled cryotic and hydrogeological flow processes combined with a particle tracking method. Changes in subsurface water flows and solute transport travel times are analysed for different modelled geological configurations during a 100-year warming period. Results show that for all simulated cases, the minimum and mean travel times increase non-linearly with warming irrespective of geological configuration and heterogeneity structure. The travel time changes are shown to depend on combined warming effects of increase in pathway length due to deepening of the active layer, reduced transport

  18. Analytical direct solutions of the Risley prism systems for tracking and pointing.

    PubMed

    Peng, Qi; Wang, Xinghui; Ren, Ge; Chen, Hongbin; Cao, Lei; Wang, Jihong

    2014-05-01

    The Risley prism systems, which had many different configurations, are only composed of two wedge prisms. The expressions of the direction cosines of the refractive ray of the two wedge prisms are given by nonparaxial ray tracing in a local coordinate referenced to the wedge prism, and the power of ray deviation of the two wedge prisms are shown by curves for systems using prisms of different materials and opening angles. The analytical direct solutions of the Risley prism systems are derived from the expressions of the direction cosines of the wedge prism through the coordinate transformation, and are also deduced from the two exact orientations for the same pointing position of precision tracking and pointing systems, which arise from applications of the Risley prisms to free-space communications. The exact expressions for the problem of precision tracking are generalized to investigate the synthesis of tracking a given target, i.e., to track a desirable path on some plane perpendicular to the optical axis of the system by controlling the circular motion of the two prisms. PMID:24921893

  19. Absorption and spectra of optical parameters in amorphous solid solutions of the Se-S system

    SciTech Connect

    Djalilov, N. Z.; Damirov, G. M.

    2011-04-15

    A study of the optical properties of the Se-S system has revealed a correlation between the dependences of optical absorption coefficient {alpha}, effective concentration of charged defects N{sub t}, and characteristic energy E{sub 0} corresponding to the Urbach optical absorption in the spectral region where the Urbach rule works for the Se-S system on the S concentration. These optical properties are controlled by charged defects. It is shown that concentrations of intrinsic charged defects can be changed by variation in composition of the Se-S system. Reflectance spectra of amorphous solid solutions of the Se-S system are studied within the energy range 1-6 eV. Using the Kramers-Kronig method, spectral dependences of optical constants and derivative optical and dielectric functions are calculated. Variation in the spectra of optical parameters with composition of the Se-S system are explained within a cluster model in which the density of electron states is a function of atomic configurations in clusters, i.e., of the character of a short-range order.

  20. Analysis of an anisotropic coastal aquifer system using variable-density flow and solute transport simulation

    USGS Publications Warehouse

    Souza, W.R.; Voss, C.I.

    1987-01-01

    The groundwater system in southern Oahu, Hawaii consists of a thick, areally extensive freshwater lens overlying a zone of transition to a thick saltwater body. This system is analyzed in cross section with a variable-density groundwater flow and solute transport model on a regional scale. The simulation is difficult, because the coastal aquifer system has a saltwater transition zone that is broadly dispersed near the discharge area, but is very sharply defined inland. Steady-state simulation analysis of the transition zone in the layered basalt aquifer of southern Oahu indicates that a small transverse dispersivity is characteristic of horizontal regional flow. Further, in this system flow is generally parallel to isochlors and steady-state behavior is insensitive to the longitudinal dispersivity. Parameter analysis identifies that only six parameters control the complex hydraulics of the system: horizontal and vertical hydraulic conductivity of the basalt aquifer; hydraulic conductivity of the confining "caprock" layer; leakance below the caprock; specific yield; and aquifer matrix compressibility. The best-fitting models indicate the horizontal hydraulic conductivity is significantly greater than the vertical hydraulic conductivity. These models give values for specific yield and aquifer compressibility which imply a considerable degree of compressive storage in the water table aquifer. ?? 1987.

  1. Development of A General Principle Solution Forisoagrinet Compliant Networking System Components in Animal Husbandry

    NASA Astrophysics Data System (ADS)

    Kuhlmann, Arne; Herd, Daniel; Röβler, Benjamin; Gallmann, Eva; Jungbluth, Thomas

    In pig production software and electronic systems are widely used for process control and management. Unfortunately most devices on farms are proprietary solutions and autonomically working. To unify data communication of devices in agricultural husbandry, the international standard ISOagriNET (ISO 17532:2007) was developed. It defines data formats and exchange protocols, to link up devices like climate controls, feeding systems and sensors, but also management software. The aim of the research project, "Information and Data Collection in Livestock Systems" is to develop an ISOagriNET compliant IT system, a so called Farming Cell. It integrates all electronic components to acquire the available data and information for pig fattening. That way, an additional benefit to humans, animals and the environment regarding process control and documentation, can be generated. Developing the Farming Cell is very complex; in detail it is very difficult and long-winded to integrate hardware and software by various vendors into an ISOagriNET compliant IT system. This ISOagriNET prototype shows as a test environment the potential of this new standard.

  2. Monotonicity and 1-Dimensional Symmetry for Solutions of an Elliptic System Arising in Bose-Einstein Condensation

    NASA Astrophysics Data System (ADS)

    Farina, Alberto; Soave, Nicola

    2014-07-01

    We study monotonicity and 1-dimensional symmetry for positive solutions with algebraic growth of the following elliptic system: for every dimension . In particular, we prove a Gibbons-type conjecture proposed by Berestycki et al.

  3. A full automatic device for sampling small solution volumes in photometric titration procedure based on multicommuted flow system.

    PubMed

    Borges, Sivanildo S; Vieira, Gláucia P; Reis, Boaventura F

    2007-01-01

    In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (lambda=545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (lambda=930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105 mul, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%. PMID:18317510

  4. A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System

    PubMed Central

    Borges, Sivanildo S.; Vieira, Gláucia P.; Reis, Boaventura F.

    2007-01-01

    In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (λ=545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (λ=930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105 μl, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%. PMID:18317510

  5. Modeling of early age loss of lithium ions from pore solution of cementitious systems treated with lithium nitrate

    SciTech Connect

    Kim, Taehwan Olek, Jan

    2015-01-15

    Addition of lithium nitrate admixture to the fresh concrete mixture helps to minimize potential problems related to alkali-silica reaction. For this admixture to function as an effective ASR control measure, it is imperative that the lithium ions remain in the pore solution. However, it was found that about 50% of the originally added lithium ions are removed from the pore solution during early stages of hydration. This paper revealed that the magnitude of the Li{sup +} ion loss is highly dependent on the concentration of Li{sup +} ions in the pore solution and the hydration rate of the cementitious systems. Using these findings, an empirical model has been developed which can predict the loss of Li{sup +} ions from the pore solution during the hydration period. The proposed model can be used to investigate the effects of mixture parameters on the loss of Li{sup +} ions from the pore solution of cementitious system.

  6. Amoebicidal activity of a preserved contact lens multipurpose disinfecting solution compared to a disinfection/neutralisation peroxide system.

    PubMed

    Buck, S L; Rosenthal, R A; Abshire, R L

    1998-01-01

    The amoebicidal activity of a contact lens multipurpose disinfecting solution (MPDS) containing polyquaternium-1 and myristamidopropyl dimethylamine was compared to a disinfection/neutralisation peroxide system against Acanthamoeba castellanii and Acanthamoeba polyphaga trophozoites and cysts. A quantitative microtitre method was used to evaluate the solutions. The MPDS showed similar amoebicidal activity to the disinfection/neutralisation peroxide system against the trophozoites of both species and equal or more rapid activity against the cysts of both species. PMID:16303382

  7. A Solution-Based Intelligent Tutoring System Integrated with an Online Game-Based Formative Assessment: Development and Evaluation

    ERIC Educational Resources Information Center

    Hooshyar, Danial; Ahmad, Rodina Binti; Yousefi, Moslem; Fathi, Moein; Abdollahi, Abbas; Horng, Shi-Jinn; Lim, Heuiseok

    2016-01-01

    Nowadays, intelligent tutoring systems are considered an effective research tool for learning systems and problem-solving skill improvement. Nonetheless, such individualized systems may cause students to lose learning motivation when interaction and timely guidance are lacking. In order to address this problem, a solution-based intelligent…

  8. Generalized Darboux transformation and rogue wave solution of the coherently-coupled nonlinear Schrödinger system

    NASA Astrophysics Data System (ADS)

    Zhang, Hai-Qiang; Yuan, Sha-Sha; Wang, Yue

    2016-05-01

    In this paper, the generalized Darboux transformation for the coherently-coupled nonlinear Schrödinger (CCNLS) system is constructed in terms of determinant representations. Based on the Nth-iterated formula, the vector bright soliton solution and vector rogue wave solution are systematically derived under the nonvanishing background. The general first-order vector rogue wave solution can admit many different fundamental patterns including eye-shaped and four-petaled rogue waves. It is believed that there are many more abundant patterns for high order vector rogue waves in CCNLS system.

  9. Exact Solutions for the Integrable Sixth-Order Drinfeld-Sokolov-Satsuma-Hirota System by the Analytical Methods

    PubMed Central

    Manafian Heris, Jalil; Lakestani, Mehrdad

    2014-01-01

    We establish exact solutions including periodic wave and solitary wave solutions for the integrable sixth-order Drinfeld-Sokolov-Satsuma-Hirota system. We employ this system by using a generalized (G′/G)-expansion and the generalized tanh-coth methods. These methods are developed for searching exact travelling wave solutions of nonlinear partial differential equations. It is shown that these methods, with the help of symbolic computation, provide a straightforward and powerful mathematical tool for solving nonlinear partial differential equations. PMID:27437479

  10. Internet Protocol Display Sharing Solution for Mission Control Center Video System

    NASA Technical Reports Server (NTRS)

    Brown, Michael A.

    2009-01-01

    With the advent of broadcast television as a constant source of information throughout the NASA manned space flight Mission Control Center (MCC) at the Johnson Space Center (JSC), the current Video Transport System (VTS) characteristics provides the ability to visually enhance real-time applications as a broadcast channel that decision making flight controllers come to rely on, but can be difficult to maintain and costly. The Operations Technology Facility (OTF) of the Mission Operations Facility Division (MOFD) has been tasked to provide insight to new innovative technological solutions for the MCC environment focusing on alternative architectures for a VTS. New technology will be provided to enable sharing of all imagery from one specific computer display, better known as Display Sharing (DS), to other computer displays and display systems such as; large projector systems, flight control rooms, and back supporting rooms throughout the facilities and other offsite centers using IP networks. It has been stated that Internet Protocol (IP) applications are easily readied to substitute for the current visual architecture, but quality and speed may need to be forfeited for reducing cost and maintainability. Although the IP infrastructure can support many technologies, the simple task of sharing ones computer display can be rather clumsy and difficult to configure and manage to the many operators and products. The DS process shall invest in collectively automating the sharing of images while focusing on such characteristics as; managing bandwidth, encrypting security measures, synchronizing disconnections from loss of signal / loss of acquisitions, performance latency, and provide functions like, scalability, multi-sharing, ease of initial integration / sustained configuration, integration with video adjustments packages, collaborative tools, host / recipient controllability, and the utmost paramount priority, an enterprise solution that provides ownership to the whole

  11. A survey of COTS wireless transceiver solutions for unmanned/unattended homeland defense systems

    NASA Astrophysics Data System (ADS)

    Wurth, Timothy J.; Wells, Jeffrey S.; Trimble, Michael L.

    2004-08-01

    As the war on terrorism continues abroad, the need to maintain security at home remains a major concern. Every aspect of the security effort can benefit from rapid information transfer. Advances in Commercial-Off-the-Shelf (COTS) radios make them valuable in applications ranging from deployed sensors on unsecured borders, to organizing an emergency response team. Additionally, the reduced cost and availability of these transceivers make them a viable alternative to custom developments. As an example, COTS radios can serve as the communication element in Unattended Ground Sensor (UGS) and munitions systems. Other applications include networked sonobuoys and networked RFID tracking. An additional advantage of COTS solutions is that they are available in a small form factor. They have extremely small mechanical outlines and are easily installed in systems requiring miniature designs and light payloads such as man-pack emplaced radios for the Army"s Future Combat System (FCS), as well as missions carried out by Unmanned Aerial Vehicles (UAV). The availability of the COTS radios result in a low-cost alternative for communication links that are applicable to military and Homeland Defense projects. They provide an easily obtainable, low-cost radio alternative enabling quick design cycles to meet mission timeliness. COTS solutions eliminate months from a typical design cycle and have many features already implemented such as ad-hoc routing and encryption. This enables robust hardware to be fielded quickly when a new need arises. The focus of this paper is to identify different COTS modules that can efficiently and cost effectively be applied to these and other various applications.

  12. Optimal control of quantum dissipative dynamics: Analytic solution for cooling the three-level Λ system

    NASA Astrophysics Data System (ADS)

    Sklarz, Shlomo E.; Tannor, David J.; Khaneja, Navin

    2004-05-01

    We study the problem of optimal control of dissipative quantum dynamics. Although under most circumstances dissipation leads to an increase in entropy (or a decrease in purity) of the system, there is an important class of problems for which dissipation with external control can decrease the entropy (or increase the purity) of the system. An important example is laser cooling. In such systems, there is an interplay of the Hamiltonian part of the dynamics, which is controllable, and the dissipative part of the dynamics, which is uncontrollable. The strategy is to control the Hamiltonian portion of the evolution in such a way that the dissipation causes the purity of the system to increase rather than decrease. The goal of this paper is to find the strategy that leads to maximal purity at the final time. Under the assumption that Hamiltonian control is complete and arbitrarily fast, we provide a general framework by which to calculate optimal cooling strategies. These assumptions lead to a great simplification, in which the control problem can be reformulated in terms of the spectrum of eigenvalues of ρ , rather than ρ itself. By combining this formulation with the Hamilton-Jacobi-Bellman theorem we are able to obtain an equation for the globally optimal cooling strategy in terms of the spectrum of the density matrix. For the three-level Λ system, we provide a complete analytic solution for the optimal cooling strategy. For this system it is found that the optimal strategy does not exploit system coherences and is a “greedy” strategy, in which the purity is increased maximally at each instant.

  13. Optimal control of quantum dissipative dynamics: Analytic solution for cooling the three-level {lambda} system

    SciTech Connect

    Sklarz, Shlomo E.; Tannor, David J.; Khaneja, Navin

    2004-05-01

    We study the problem of optimal control of dissipative quantum dynamics. Although under most circumstances dissipation leads to an increase in entropy (or a decrease in purity) of the system, there is an important class of problems for which dissipation with external control can decrease the entropy (or increase the purity) of the system. An important example is laser cooling. In such systems, there is an interplay of the Hamiltonian part of the dynamics, which is controllable, and the dissipative part of the dynamics, which is uncontrollable. The strategy is to control the Hamiltonian portion of the evolution in such a way that the dissipation causes the purity of the system to increase rather than decrease. The goal of this paper is to find the strategy that leads to maximal purity at the final time. Under the assumption that Hamiltonian control is complete and arbitrarily fast, we provide a general framework by which to calculate optimal cooling strategies. These assumptions lead to a great simplification, in which the control problem can be reformulated in terms of the spectrum of eigenvalues of {rho}, rather than {rho} itself. By combining this formulation with the Hamilton-Jacobi-Bellman theorem we are able to obtain an equation for the globally optimal cooling strategy in terms of the spectrum of the density matrix. For the three-level {lambda} system, we provide a complete analytic solution for the optimal cooling strategy. For this system it is found that the optimal strategy does not exploit system coherences and is a 'greedy' strategy, in which the purity is increased maximally at each instant.

  14. A liquid flatjet system for solution phase soft-x-ray spectroscopy

    PubMed Central

    Ekimova, Maria; Quevedo, Wilson; Faubel, Manfred; Wernet, Philippe; Nibbering, Erik T. J.

    2015-01-01

    We present a liquid flatjet system for solution phase soft-x-ray spectroscopy. The flatjet set-up utilises the phenomenon of formation of stable liquid sheets upon collision of two identical laminar jets. Colliding the two single water jets, coming out of the nozzles with 50 μm orifices, under an impact angle of 48° leads to double sheet formation, of which the first sheet is 4.6 mm long and 1.0 mm wide. The liquid flatjet operates fully functional under vacuum conditions (<10−3 mbar), allowing soft-x-ray spectroscopy of aqueous solutions in transmission mode. We analyse the liquid water flatjet thickness under atmospheric pressure using interferomeric or mid-infrared transmission measurements and under vacuum conditions by measuring the absorbance of the O K-edge of water in transmission, and comparing our results with previously published data obtained with standing cells with Si3N4 membrane windows. The thickness of the first liquid sheet is found to vary between 1.4–3 μm, depending on the transverse and longitudinal position in the liquid sheet. We observe that the derived thickness is of similar magnitude under 1 bar and under vacuum conditions. A catcher unit facilitates the recycling of the solutions, allowing measurements on small sample volumes (∼10 ml). We demonstrate the applicability of this approach by presenting measurements on the N K-edge of aqueous NH4+. Our results suggest the high potential of using liquid flatjets in steady-state and time-resolved studies in the soft-x-ray regime. PMID:26798824

  15. Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions

    PubMed Central

    DeJong, Jason T.; Soga, Kenichi; Banwart, Steven A.; Whalley, W. Richard; Ginn, Timothy R.; Nelson, Douglas C.; Mortensen, Brina M.; Martinez, Brian C.; Barkouki, Tammer

    2011-01-01

    Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming—these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that ‘soil engineering in vivo’, wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon—effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized. PMID:20829246

  16. A liquid flatjet system for solution phase soft-x-ray spectroscopy.

    PubMed

    Ekimova, Maria; Quevedo, Wilson; Faubel, Manfred; Wernet, Philippe; Nibbering, Erik T J

    2015-09-01

    We present a liquid flatjet system for solution phase soft-x-ray spectroscopy. The flatjet set-up utilises the phenomenon of formation of stable liquid sheets upon collision of two identical laminar jets. Colliding the two single water jets, coming out of the nozzles with 50 μm orifices, under an impact angle of 48° leads to double sheet formation, of which the first sheet is 4.6 mm long and 1.0 mm wide. The liquid flatjet operates fully functional under vacuum conditions (<10(-3) mbar), allowing soft-x-ray spectroscopy of aqueous solutions in transmission mode. We analyse the liquid water flatjet thickness under atmospheric pressure using interferomeric or mid-infrared transmission measurements and under vacuum conditions by measuring the absorbance of the O K-edge of water in transmission, and comparing our results with previously published data obtained with standing cells with Si3N4 membrane windows. The thickness of the first liquid sheet is found to vary between 1.4-3 μm, depending on the transverse and longitudinal position in the liquid sheet. We observe that the derived thickness is of similar magnitude under 1 bar and under vacuum conditions. A catcher unit facilitates the recycling of the solutions, allowing measurements on small sample volumes (∼10 ml). We demonstrate the applicability of this approach by presenting measurements on the N K-edge of aqueous NH4 (+). Our results suggest the high potential of using liquid flatjets in steady-state and time-resolved studies in the soft-x-ray regime. PMID:26798824

  17. Soil engineering in vivo: harnessing natural biogeochemical systems for sustainable, multi-functional engineering solutions.

    PubMed

    DeJong, Jason T; Soga, Kenichi; Banwart, Steven A; Whalley, W Richard; Ginn, Timothy R; Nelson, Douglas C; Mortensen, Brina M; Martinez, Brian C; Barkouki, Tammer

    2011-01-01

    Carbon sequestration, infrastructure rehabilitation, brownfields clean-up, hazardous waste disposal, water resources protection and global warming-these twenty-first century challenges can neither be solved by the high-energy consumptive practices that hallmark industry today, nor by minor tweaking or optimization of these processes. A more radical, holistic approach is required to develop the sustainable solutions society needs. Most of the above challenges occur within, are supported on, are enabled by or grown from soil. Soil, contrary to conventional civil engineering thought, is a living system host to multiple simultaneous processes. It is proposed herein that 'soil engineering in vivo', wherein the natural capacity of soil as a living ecosystem is used to provide multiple solutions simultaneously, may provide new, innovative, sustainable solutions to some of these great challenges of the twenty-first century. This requires a multi-disciplinary perspective that embraces the science of biology, chemistry and physics and applies this knowledge to provide multi-functional civil and environmental engineering designs for the soil environment. For example, can native soil bacterial species moderate the carbonate cycle in soils to simultaneously solidify liquefiable soil, immobilize reactive heavy metals and sequester carbon-effectively providing civil engineering functionality while clarifying the ground water and removing carbon from the atmosphere? Exploration of these ideas has begun in earnest in recent years. This paper explores the potential, challenges and opportunities of this new field, and highlights one biogeochemical function of soil that has shown promise and is developing rapidly as a new technology. The example is used to propose a generalized approach in which the potential of this new field can be fully realized. PMID:20829246

  18. Analytic solution of relaxation in a system with exponential transition probabilities. III. Macroscopic disequilibrium

    NASA Astrophysics Data System (ADS)

    Forst, Wendell

    1984-03-01

    The exponential transition probability, in the version that permits an analytical solution of the relaxation problem, is used to compute a number of macroscopic (bulk) observables for a model system based on multiphoton excitation of SF6 coupled to a rare-gas heat bath. Two extreme cases are considered: Initial excitation as a delta function, or as a Poisson distribution. It turns out that regardless of initial conditions, all macroscopic observables are functions of time, including the relaxation time, so that the system does not undergo simple exponential decay. This is because the first moment of the exponential transition probability does not satisfy the linear ``sum rule.'' The exponential transition probability causes the overall (or bulk) average of energy transferred (<<ΔE>>) to be constrained to a maximum which is independent of the nature and level of initial excitation, thus producing a bottleneck in the macroscopic relaxation process when excitation is sufficiently high. The consequence is that the initially more highly excited system takes longer to reach steady state, with a relaxation time that is initially nearly proportional to initial excitation and which decreases as the system approaches steady state. It is only in the immediate vicinity of steady state that simple exponential relaxation takes place, with the shortest relaxation time. Several consequences of this, particularly the population distribution as a function of time, are illustrated and discussed.

  19. Designing Solutions for the Retirement System – In Search of Balance between Economy and Health

    PubMed Central

    Romaniuk, Piotr; Brukało, Katarzyna

    2016-01-01

    Social security system currently faces a number of difficulties arising of changes in the demographic structure of societies, like the decrease in fertility, lengthening of life expectancy, and unfavorable change in the proportion of the population receiving retirement benefits to the population in working age. In result, social security systems are being subjected to transition aimed at securing their financial stability, part of which is a tendency to rise the retirement age and eliminate all the incentives to prematurely exit the labor market. On the other hand, this process of transition, as observed in Poland, is being driven mainly by political processes and due to economic reasons, while lacking public health evidence. This raises a danger that in final result the financial savings will be illusory only and that the final configuration of the system will be inconsistent with the actual social needs of the population and will not efficiently protect against the social risks. In this article, we present arguments for using the Healthy Life Years indicator in analyses relating to the performance of social security systems. The indicator may help to reflect differences in health status of different professional groups and adjust system’s solutions to conditions characterizing these groups, in terms of both risk protection and prevention.

  20. Solution of dense systems of linear equations in electromagnetic scattering calculations

    SciTech Connect

    Rahola, J.

    1994-12-31

    The discrete-dipole approximation (DDA) is a method for calculating the scattering of light by an irregular particle. The DDA has been used for example in calculations of optical properties of cosmic dust. In this method the particle is approximated by interacting electromagnetic dipoles. Computationally the DDA method includes the solution of large dense systems of linear equations where the coefficient matrix is complex symmetric. In the author`s work, the linear systems of equations are solved by various iterative methods such as the conjugate gradient method applied to the normal equations and QMR. The linear systems have rather low condition numbers due to which many iterative methods perform quite well even without any preconditioning. Some possible preconditioning strategies are discussed. Finally, some fast special methods for computing the matrix-vector product in the iterative methods are considered. In some cases, the matrix-vector product can be computed with the fast Fourier transform, which enables the author to solve dense linear systems of hundreds of thousands of unknowns.

  1. Exact solutions and residual symmetries of the Ablowitz-Kaup-Newell-Segur system

    NASA Astrophysics Data System (ADS)

    Liu, Ping; Zeng, Bao-Qing; Yang, Jian-Rong; Ren, Bo

    2015-01-01

    The residual symmetries of the Ablowitz-Kaup-Newell-Segur (AKNS) equations are obtained by the truncated Painlevé analysis. The residual symmetries for the AKNS equations are proved to be nonlocal and the nonlocal residual symmetries are extended to the local Lie point symmetries of a prolonged AKNS system. The local Lie point symmetries of the prolonged AKNS equations are composed of the residual symmetries and the standard Lie point symmetries, which suggests that the residual symmetry method is a useful complement to the classical Lie group theory. The calculation on the symmetries shows that the enlarged equations are invariant under the scaling transformations, the space-time translations, and the shift translations. Three types of similarity solutions and the reduction equations are demonstrated. Furthermore, several types of exact solutions for the AKNS equations are obtained with the help of the symmetry method and the Bäcklund transformations between the AKNS equations and the Schwarzian AKNS equation. Project supported by the National Natural Science Foundation of China (Grant Nos. 11305031, 11365017, and 11305106), the Natural Science Foundation of Guangdong Province, China (Grant No. S2013010011546), the Natural Science Foundation of Zhejiang Province, China (Grant No. LQ13A050001), the Science and Technology Project Foundation of Zhongshan, China (Grant Nos. 2013A3FC0264 and 2013A3FC0334), and the Training Programme Foundation for Outstanding Young Teachers in Higher Education Institutions of Guangdong Province, China (Grant No. Yq2013205).

  2. Single fermion Green's function in the quantum ordered Fermi-system: Analytic solution

    NASA Astrophysics Data System (ADS)

    Mukhin, S. I.; Galimzyanov, T. R.

    2012-06-01

    An exact self-consistent solution for a finite temperature quantum-ordered state of correlated electron system found previously (Mukhin, 2009, 2011) is used to derive the fermionic single-particle Green's function. The quantum order parameter (QOP) found in the form of a periodic (elliptic Jacoby) function of the Matsubara's imaginary time (Mukhin, 2009), plays the role of effective scattering potential seen by electrons. The analytic solution for the Green's function demonstrates the following new features: (1) the pseudo-gap behavior of the single-electron density of states (DOS) near the (shifted) Fermi-level;(2) the side-bands of decreasing intensity away from the Fermi-level; (3) scaling of the quasi-particle energies with the QOP amplitude; (4) fermionic quasi-particles in the QOP state are combined from two confined “odd” and “even” fermions that separately would be unstable. The false-color plot of single-fermion DOS in the limit of a periodic kink-like Matsubara time-dependence of QOP is presented and could be used as prediction for the ARPES experiments. The plot of the DOS transfer between different energies at the “fermi-surface” momentum for a given kink-like QOP is also presented. Some possibly observable consequences of the found finger-prints are discussed.

  3. An Analytical Solution of Radiative Transfer in the Coupled Atmosphere-Ocean System with Rough Surface

    NASA Technical Reports Server (NTRS)

    Jin, Zhonghai; Charlock, Thomas P.; Rutledge, Ken; Knut Stamnes; Wang, Yingjian

    2006-01-01

    Using the efficient discrete-ordinate method, we present an analytical solution for radiative transfer in the coupled atmosphere-ocean system with rough air-water interface. The theoretical formulations of the radiative transfer equation and solution are described. The effects of surface roughness on radiation field in the atmosphere and ocean are studied and compared with measurements. The results show that ocean surface roughness has significant effects on the upwelling radiation in the atmosphere and the downwelling radiation in the ocean. As wind speed increases, the angular domain of sunglint broadens, the surface albedo decreases, and the transmission to ocean increases. The downward radiance field in the upper ocean is highly anisotropic, but this anisotropy decreases rapidly as surface wind increases and as depth in ocean increases. The effects of surface roughness on radiation also depend greatly on both wavelength and angle of incidence (i.e., solar elevation); these effects are significantly smaller throughout the spectrum at high sun. The model-observation discrepancies may indicate that the Cox-Munk surface roughness model is not sufficient for high wind conditions.

  4. Motion control solution for new PLC-based standard development platform for VLT instrument control systems

    NASA Astrophysics Data System (ADS)

    Popovic, D.; Brast, R.; Di Lieto, N.; Kiekebusch, M.; Knudstrup, J.; Lucuix, C.

    2014-07-01

    More than a decade ago, due to obsolescence issues, ESO initiated the design and implementation of a custom-made CANbus based motion controller (CAN-RMC) to provide, together with a tailor-made software library (motor library), the motion control capabilities for the VME platform needed for the second generation VLT/VLTI instruments. The CAN-RMC controller has been successfully used in a number of VLT instruments but it has high production costs compared to the commercial off-the-shelf (COTS) industrial solutions available on the market today. In the scope of the selection of a new PLC-based platform for the VLT instrument control systems, ESO has evaluated motion control solutions from the company Beckhoff. This paper presents the investigation, implementation and testing of the PLC/TwinCAT/EtherCAT motion controllers for DC and stepper motors and their adaptation and integration into the VLT instrumentation framework. It reports functional and performance test results for the most typical use cases of astronomical instruments like initialization sequences, tracking, switch position detections, backslash compensation, brake handling, etc. In addition, it gives an overview of the main features of TwinCAT NC/PTP, PLCopen MC, EtherCAT motion control terminals and the engineering tools like TwinCAT Scope that are integrated into the development environment and simplify software development, testing and commissioning of motorized instrument functions.

  5. Closed-form solutions for linear regulator-design of mechanical systems including optimal weighting matrix selection

    NASA Technical Reports Server (NTRS)

    Hanks, Brantley R.; Skelton, Robert E.

    1991-01-01

    This paper addresses the restriction of Linear Quadratic Regulator (LQR) solutions to the algebraic Riccati Equation to design spaces which can be implemented as passive structural members and/or dampers. A general closed-form solution to the optimal free-decay control problem is presented which is tailored for structural-mechanical systems. The solution includes, as subsets, special cases such as the Rayleigh Dissipation Function and total energy. Weighting matrix selection is a constrained choice among several parameters to obtain desired physical relationships. The closed-form solution is also applicable to active control design for systems where perfect, collocated actuator-sensor pairs exist. Some examples of simple spring mass systems are shown to illustrate key points.

  6. Active solute transport across frog skin and epithelial cell systems according to the association-induction hypothesis.

    PubMed

    Ling, G N

    1981-01-01

    The phenomenon of transport of ions, sugars, amino acids, etc. across frog skin and other epithelial systems has been commonly interpreted on the basis of the membrane-pump theory, according to which asymmetry in solute distribution as well as transport into and out of all living cells results from the permeability properties and "pump" activities of the membrane. In the present review, certain findings in the field of transepithelial transport of solutes are given new interpretation on the basis of molecular mechanisms introduced in the association-induction hypothesis, according to which "active transport" of solutes occurs only across bifacial cell systems like frog skin and intestinal epithelium but not in the maintenance of steady levels of solutes in unifacial cell systems such as muscle, nerve, and red blood cells. PMID:7330099

  7. Internet-Based Solutions for Manufacturing Enterprise Systems Interoperability - A Standards Perspective

    SciTech Connect

    Ivezic, Nenad; Kulvatunyou, Boonserm; Jones, Albert

    2004-10-01

    This chapter reviews efforts of selected standards consortia to develop Internet-based approaches for interoperable manufacturing enterprise information systems. The focus of the chapter is on the efforts to capture common meaning of data exchanged among interoperable information systems inside and outside a manufacturing enterprise. We start this chapter by giving a general overview of the key concepts in standards approaches to enable interoperable manufacturing enterprise systems. These approaches are compared on the basis of several characteristics found in standards frameworks such as horizontal or vertical focus of the standard, the standard message content definitions, the standard process definitions, and dependence on specific standard messaging solutions. After this initial overview, we establish one basis for reasoning about interoperable information systems by recognizing key manufacturing enterprise objects managed and exchanged both inside and outside the enterprise. Such conceptual objects are coarse in granularity and are meant to drive semantic definitions of data interchanges by providing a shared context for data dictionaries detailing the semantics of these objects and interactions or processes involved in data exchange. In the case of intra-enterprise interoperability, we recognize enterprise information processing activities, responsibilities, and those high-level conceptual objects exchanged in interactions among systems to fulfill the assigned responsibilities. Here, we show a mapping of one content standard onto the identified conceptual objects. In the case of inter-enterprise interoperability, we recognize key business processes areas and enumerate high-level conceptual objects that need to be exchanged among supply chain or trading partners. Here, we also show example mappings of representative content standards onto the identified conceptual objects. We complete this chapter by providing an account of some advanced work to enhance

  8. The solution of non-linear hyperbolic equation systems by the finite element method

    NASA Technical Reports Server (NTRS)

    Loehner, R.; Morgan, K.; Zienkiewicz, O. C.

    1984-01-01

    A finite-element method for the solution of nonlinear hyperbolic systems of equations, such as those encountered in non-self-adjoint problems of transient phenomena in convection-diffusion or in the mixed representation of wave problems, is developed and demonstrated. The problem is rewritten in moving coordinates and reinterpolated to the original mesh by a Taylor expansion prior to a standard Galerkin spatial discretization, and it is shown that this procedure is equivalent to the time-discretization approach of Donea (1984). Numerical results for sample problems are presented graphically, including such shallow-water problems as the breaking of a dam, the shoaling of a wave, and the outflow of a river; compressible flows such as the isothermal flow in a nozzle and the Riemann shock-tube problem; and the two-dimensional scalar-advection, nonlinear-shallow-water, and Euler equations.

  9. CTE Solvability, Nonlocal Symmetry and Explicit Solutions of Modified Boussinesq System

    NASA Astrophysics Data System (ADS)

    Ren, Bo; Cheng, Xue-Ping

    2016-07-01

    A consistent tanh expansion (CTE) method is used to study the modified Boussinesq equation. It is proved that the modified Boussinesq equation is CTE solvable. The soliton-cnoidal periodic wave is explicitly given by a nonanto-BT theorem. Furthermore, the nonlocal symmetry for the modified Boussinesq equation is obtained by the Painlevé analysis. The nonlocal symmetry is localized to the Lie point symmetry by introducing one auxiliary dependent variable. The finite symmetry transformation related with the nonlocal symemtry is obtained by solving the initial value problem of the prolonged systems. Thanks to the localization process, many interaction solutions among solitons and other complicated waves are computed through similarity reductions. Some special concrete soliton-cnoidal wave interaction behaviors are studied both in analytical and graphical ways. Supported by the National Natural Science Foundation of China under Grant Nos. 11305106 and 11505154

  10. Phenix - a comprehensive python-based system for macromolecular structure solution

    SciTech Connect

    Terwilliger, Thomas C; Hung, Li - Wei; Adams, Paul D; Afonine, Pavel V; Bunkoczi, Gabor; Chen, Vincent B; Davis, Ian; Echols, Nathaniel; Headd, Jeffrey J; Grosse Kunstleve, Ralf W; Mccoy, Airlie J; Moriarty, Nigel W; Oeffner, Robert; Read, Randy J; Richardson, David C; Richardson, Jane S; Zwarta, Peter H

    2009-01-01

    Macromolecular X-ray crystallography is routinely applied to understand biological processes at a molecular level. However, significant time and effort are still required to solve and complete many of these structures because of the need for manual interpretation of complex numerical data using many software packages, and the repeated use of interactive three-dimensional graphics. Phenix has been developed to provide a comprehensive system for crystallographic structure solution with an emphasis on automation of all procedures. This has relied on the development of algorithms that minimize or eliminate subjective input, the development of algorithms that automate procedures that are traditionally performed by hand, and finally the development of a framework that allows a tight integration between the algorithms.

  11. Solutions Network Formulation Report. Integrating Salinity Measurements from Aquarius into the Harmful Algal Blooms Observing System

    NASA Technical Reports Server (NTRS)

    Anderson, Daniel; Lewis, David; Hilbert, Kent

    2007-01-01

    This Candidate Solution suggests the use of Aquarius sea surface salinity measurements to improve the NOAA/NCDDC (National Oceanic and Atmospheric Administration s National Coastal Data Development Center) HABSOS (Harmful Algal Blooms Observing System) DST (decision support tool) by enhancing development and movement forecasts of HAB events as well as potential species identification. In the proposed configuration, recurring salinity measurements from the Aquarius mission would augment HABSOS sea surface temperature and in situ ocean current measurements. Thermohaline circulation observations combined with in situ measurements increase the precision of HAB event movement forecasting. These forecasts allow coastal managers and public health officials to make more accurate and timely warnings to the public and to better direct science teams to event sites for collection and further measurements.

  12. Recovery of uranium from dilute solution using liquid emulsion membrane system

    SciTech Connect

    Mukhopadhyay, S.; Ghosh, S.K.; Juvekar, V.A.

    2008-07-01

    The liquid emulsion membrane (LEM) technique has great potential for application in the nuclear industry for large interfacial area, low consumption of organics, and high recovery from dilute streams. A LEM system composed DEHPA-kerosene-SPAN80-HNO{sub 3} has been developed for recovery of uranium from dilute nitrate solution, which gives 98% extraction and 88% stripping in a single stage. An attempt has been made to understand the mechanism of the LEM process, in which phenomena like per-traction, occlusion, swelling, and leakage occur simultaneously. The effect of various parameters on these phenomena has been described with a mathematical model, which is able to explain the experimental findings. (authors)

  13. An iterative method for the solution of nonlinear systems using the Faber polynomials for annular sectors

    SciTech Connect

    Myers, N.J.

    1994-12-31

    The author gives a hybrid method for the iterative solution of linear systems of equations Ax = b, where the matrix (A) is nonsingular, sparse and nonsymmetric. As in a method developed by Starke and Varga the method begins with a number of steps of the Arnoldi method to produce some information on the location of the spectrum of A. This method then switches to an iterative method based on the Faber polynomials for an annular sector placed around these eigenvalue estimates. The Faber polynomials for an annular sector are used because, firstly an annular sector can easily be placed around any eigenvalue estimates bounded away from zero, and secondly the Faber polynomials are known analytically for an annular sector. Finally the author gives three numerical examples, two of which allow comparison with Starke and Varga`s results. The third is an example of a matrix for which many iterative methods would fall, but this method converges.

  14. The search for high level parallelism for the iterative solution of large sparse linear systems

    SciTech Connect

    Young, D.M.

    1988-07-01

    In this paper the author is concerned with the numerical solution, based on iterative methods, of large sparse systems of linear algebraic equations of the type which arise in the numerical solution of elliptic and parabolic partial differential equations by finite difference or finite element methods. He considers linear systems of the form Au = b where A is a given N x N matrix which is large and sparse and where b is a given N x 1 column vector. He will assumes that A is symmetric and positive definite (SPD). He considers iterative algorithms which consist of a basic iterative method, such as the Richardson, Jacobi, SSOR or incomplete Cholesky method, combined with an acceleration procedure such as Chebyshev acceleration or conjugate gradient acceleration. The object of this paper is, however, to examine some high-level methods for achieving parallelism. Such techniques involve only matrix/vector operations and do not involve working with blocks of the matrix, subdividing the region, or using different meshes. It is expected that if effective high-level methods could be developed, they could be combined with block and domain decomposition methods, and related methods, to obtain even greater speedups. It is also expected that by working at a higher level it will eventually be possible to develop general purpose software for parallel machines similar to the ITPACK software packages which have already been developed for sequential and vector machines. The discussion here is primarily devoted to describing various techniques which the author and others have considered for obtaining high-level parallelism. The author plans to continue research on these techniques and eventually to develop algorithms and programs for multiprocessors based on them.

  15. Solute carrier 41A3 encodes for a mitochondrial Mg(2+) efflux system.

    PubMed

    Mastrototaro, Lucia; Smorodchenko, Alina; Aschenbach, Jörg R; Kolisek, Martin; Sponder, Gerhard

    2016-01-01

    The important role of magnesium (Mg(2+)) in normal cellular physiology requires flexible, yet tightly regulated, intracellular Mg(2+) homeostasis (IMH). However, only little is known about Mg(2+) transporters of subcellular compartments such as mitochondria, despite their obvious importance for the deposition and reposition of intracellular Mg(2+) pools. In particular, knowledge about mechanisms responsible for extrusion of Mg(2+) from mitochondria is lacking. Based on circumstantial evidence, two possible mechanisms of Mg(2+) release from mitochondria were predicted: (1) Mg(2+) efflux coupled to ATP translocation via the ATP-Mg/Pi carrier, and (2) Mg(2+) efflux via a H(+)/Mg(2+) exchanger. Regardless, the identity of the H(+)-coupled Mg(2+) efflux system is unknown. We demonstrate here that member A3 of solute carrier (SLC) family 41 is a mitochondrial Mg(2+) efflux system. Mitochondria of HEK293 cells overexpressing SLC41A3 exhibit a 60% increase in the extrusion of Mg(2+) compared with control cells. This efflux mechanism is Na(+)-dependent and temperature sensitive. Our data identify SLC41A3 as the first mammalian mitochondrial Mg(2+) efflux system, which greatly enhances our understanding of intracellular Mg(2+) homeostasis. PMID:27302215

  16. Solute carrier 41A3 encodes for a mitochondrial Mg2+ efflux system

    PubMed Central

    Mastrototaro, Lucia; Smorodchenko, Alina; Aschenbach, Jörg R.; Kolisek, Martin; Sponder, Gerhard

    2016-01-01

    The important role of magnesium (Mg2+) in normal cellular physiology requires flexible, yet tightly regulated, intracellular Mg2+ homeostasis (IMH). However, only little is known about Mg2+ transporters of subcellular compartments such as mitochondria, despite their obvious importance for the deposition and reposition of intracellular Mg2+ pools. In particular, knowledge about mechanisms responsible for extrusion of Mg2+ from mitochondria is lacking. Based on circumstantial evidence, two possible mechanisms of Mg2+ release from mitochondria were predicted: (1) Mg2+ efflux coupled to ATP translocation via the ATP-Mg/Pi carrier, and (2) Mg2+ efflux via a H+/Mg2+ exchanger. Regardless, the identity of the H+-coupled Mg2+ efflux system is unknown. We demonstrate here that member A3 of solute carrier (SLC) family 41 is a mitochondrial Mg2+ efflux system. Mitochondria of HEK293 cells overexpressing SLC41A3 exhibit a 60% increase in the extrusion of Mg2+ compared with control cells. This efflux mechanism is Na+-dependent and temperature sensitive. Our data identify SLC41A3 as the first mammalian mitochondrial Mg2+ efflux system, which greatly enhances our understanding of intracellular Mg2+ homeostasis. PMID:27302215

  17. Degradation of carbon tetrachloride in aqueous solution in the thermally activated persulfate system.

    PubMed

    Xu, Minhui; Gu, Xiaogang; Lu, Shuguang; Qiu, Zhaofu; Sui, Qian; Miao, Zhouwei; Zang, Xueke; Wu, Xiaoliang

    2015-04-01

    Thermal activation of persulfate (PS) has been identified to be effective in the destruction of organic pollutants. The feasibility of carbon tetrachloride (CT) degradation in the thermally activated PS system was evaluated. The experimental results showed that CT could be readily degraded at 50 °C with a PS concentration of 0.5M, and CT degradation and PS consumption followed the pseudo-first order kinetic model. Superoxide radical anion (O2(*-)) was the predominant radical species responsible for CT degradation and the split of CCl was proposed as the possible reaction pathways for CT degradation. The process of CT degradation was accelerated by higher PS dose and lower initial CT concentration. No obvious effect of the initial pH on the degradation of CT was observed in the thermally activated PS system. Cl(*-), HCO3(*-), and humic acid (HA) had negative effects on CT degradation. In addition, the degradation of CT in the thermally activated PS system could be significantly promoted by the solvents addition to the solution. In conclusion, the thermally activated PS process is a promising option in in-situ chemical oxidation/reduction remediation for degrading highly oxidized organic contaminants such as CT that is widely detected in contaminated sites. PMID:25544995

  18. Optimal criteria for blowup of radial and N-symmetric solutions of chemotaxis systems

    NASA Astrophysics Data System (ADS)

    Biler, Piotr; Karch, Grzegorz; Zienkiewicz, Jacek

    2015-12-01

    A simple proof of concentration of mass equal to 8π for blowing up N-symmetric solutions of the Keller-Segel model of chemotaxis in two dimensions with large N is given. Moreover, a criterion for blowup of solutions in terms of the radial initial concentrations, related to suitable Morrey spaces norms, is derived for radial solutions of chemotaxis in several dimensions. This condition is, in a sense, complementary to the one guaranteeing the global-in-time existence of solutions.

  19. Use of numerically generated body-fitted coordinate systems for solution of the Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Thompson, J. F.; Mastin, C. W.; Thames, F. C.; Shanks, S. P.

    1975-01-01

    A procedure for numerical solution of the time-dependent, two-dimensional incompressible Navier-Stokes equations that can treat the unsteady laminar flow about bodies of arbitrary shape, such as two-dimensional airfoils, multiple airfoils, and submerged hydrofoils, as naturally as it can deal with the flow about simple bodies. The solution is based on a method of automatic numerical generation of a general curvilinear coordinate system with coordinate lines coincident with all boundaries of a general multiconnected region containing any number of arbitrarily shaped bodies. The curvilinear coordinates are generated as the solution of two elliptical partial differential equations with Dirichlet boundary conditions, one coordinate being specified to be constant on each of the boundaries, and a distribution of the other being specified along the boundaries. The solution compares excellently with the Blasius boundary layer solution for the flow past a semiinfinite flat plate.

  20. Global structure stability of Riemann solutions of quasilinear hyperbolic systems of conservation laws: shocks and contact discontinuities

    NASA Astrophysics Data System (ADS)

    Kong, De-Xing

    In this paper, the author proves the global structure stability of the Lax's Riemann solution u=U( {x}/{t}) , containing only shocks and contact discontinuities, of general n× n quasilinear hyperbolic system of conservation laws. More precisely, the author proves the global existence and uniqueness of the piecewise C1 solution u= u( t, x) of a class of generalized Riemann problem, which can be regarded as a perturbation of the corresponding Riemann problem, for the quasilinear hyperbolic system of conservation laws; moreover, this solution has a global structure similar to that of the solution u=U( {x}/{t}) . Combining the results in Kong (Global structure instability of Riemann solutions of quasilinear hyperbolic systems of conservation laws: rarefaction waves, to appear), the author proves that the Lax's Riemann solution of general n× n quasilinear hyperbolic system of conservation laws is globally structurally stable if and only if it contains only non-degenerate shocks and contact discontinuities, but no rarefaction waves and other weak discontinuities.

  1. Reply to Dr. Stoesselfs Comment on "Reaction paths and equilibrium end-points in solid-solution aqueous-solution systems"

    NASA Astrophysics Data System (ADS)

    Glynn, Pierre D.; Reardon, Eric J.; Plummer, L. Niel; Busenberg, Eurybiades

    1992-06-01

    In reply to the Critical Comment of R. K. Stoessell (this issue), limiting activity coefficients of bromide in halite ( γNaBr) have been calculated by least-squares fitting of SIMONS et al.'s (1952) bromide distribution coefficient data for the Na(Cl,Br)-NaOH-H 2O system at 35°C. Regular and subregular solidsolution model fits give γNaBr = 7.4 and γNaBr = 8.8, respectively. The Br contents of halite at equilibrium with seawater at initial halite saturation, calculated from the regular and subregular fits, are 17 ppm and 14 ppm, respectively. A survey of literature data for trace bromide in halite shows a wide spread in distribution coefficients, with lower values ( DBr≈ 0.01) reported by BLOCH and SCHNERB (1953), PUCHELT et al. (1972), and LUTZ (1975), and higher values ( DBr- ≈ 0.03) reported by BRAITSCH and HERRMANN (1963), KüHN (1968), HERRMANN (1972), HERRMANN (1980), MCCAFFREY et al. (1987), VALIASHKO et al. (1976), VALIASHKO and LAVROVA (1976), and Fontes (pers. commun., 1990). The measurement of stoichiometric saturation states for halite (or sylvite) with trace bromide mole-fractions is not practical, given the insensitivity of the measured solubilities on the bromide mole-fractions. Distribution coefficient measurements, with proof of thermodynamic equilibrium, need to be obtained instead, to conclusively determine the thermodynamic-mixing properties of both Na(Cl,Br) and K(Cl,Br) solidsolution series at very low mole-fractions of bromide. The applicability of the stoichiometric saturation concept to the interpretation of precipitation processes is questionable, primarily because the concept requires solid-solutions to behave as one-component solids with fixed composition. Lippmann diagrams are useful in depicting stoichiometric saturation, endmember saturation, and thermodynamic equilibrium states in binary-solid-solution aqueous-solution systems. Lippmann diagrams can contribute a better understanding of these systems, regardless of the

  2. Analytical solutions of one-dimensional multispecies reactive transport in a permeable reactive barrier-aquifer system.

    PubMed

    Mieles, John; Zhan, Hongbin

    2012-06-01

    The permeable reactive barrier (PRB) remediation technology has proven to be more cost-effective than conventional pump-and-treat systems, and has demonstrated the ability to rapidly reduce the concentrations of specific chemicals of concern (COCs) by up to several orders of magnitude in some scenarios. This study derives new steady-state analytical solutions to multispecies reactive transport in a PRB-aquifer (dual domain) system. The advantage of the dual domain model is that it can account for the potential existence of natural degradation in the aquifer, when designing the required PRB thickness. The study focuses primarily on the steady-state analytical solutions of the tetrachloroethene (PCE) serial degradation pathway and secondly on the analytical solutions of the parallel degradation pathway. The solutions in this study can also be applied to other types of dual domain systems with distinct flow and transport properties. The steady-state analytical solutions are shown to be accurate and the numerical program RT3D is selected for comparison. The results of this study are novel in that the solutions provide improved modeling flexibility including: 1) every species can have unique first-order reaction rates and unique retardation factors, and 2) daughter species can be modeled with their individual input concentrations or solely as byproducts of the parent species. The steady-state analytical solutions exhibit a limitation that occurs when interspecies reaction rate factors equal each other, which result in undefined solutions. Excel spreadsheet programs were created to facilitate prompt application of the steady-state analytical solutions, for both the serial and parallel degradation pathways. PMID:22579667

  3. A System-on-Chip Solution for Point-of-Care Ultrasound Imaging Systems: Architecture and ASIC Implementation.

    PubMed

    Kang, Jeeun; Yoon, Changhan; Lee, Jaejin; Kye, Sang-Bum; Lee, Yongbae; Chang, Jin Ho; Kim, Gi-Duck; Yoo, Yangmo; Song, Tai-kyong

    2016-04-01

    In this paper, we present a novel system-on-chip (SOC) solution for a portable ultrasound imaging system (PUS) for point-of-care applications. The PUS-SOC includes all of the signal processing modules (i.e., the transmit and dynamic receive beamformer modules, mid- and back-end processors, and color Doppler processors) as well as an efficient architecture for hardware-based imaging methods (e.g., dynamic delay calculation, multi-beamforming, and coded excitation and compression). The PUS-SOC was fabricated using a UMC 130-nm NAND process and has 16.8 GFLOPS of computing power with a total equivalent gate count of 12.1 million, which is comparable to a Pentium-4 CPU. The size and power consumption of the PUS-SOC are 27×27 mm(2) and 1.2 W, respectively. Based on the PUS-SOC, a prototype hand-held US imaging system was implemented. Phantom experiments demonstrated that the PUS-SOC can provide appropriate image quality for point-of-care applications with a compact PDA size ( 200×120×45 mm(3)) and 3 hours of battery life. PMID:26954842

  4. System-in-package solution for a low-power active electrode module.

    PubMed

    Gaio, Nikolas; Gao, Linping; Cai, Jinhe; Zhang, Jinyong; Wang, Lei

    2014-01-01

    This paper presents the design of system in package for a low-power active electrode module. The main aim of this research is to provide a low-cost, high-density, and high-quality module, exploiting the features of a System-in-Package (SiP) solution. To the best knowledge of the authors, this is the first time that SiP technology has been used in the development of a modular active electrode. Two SiPs have been designed and one of them has been fabricated and tested. The dimensions of the latter are 7×7×1 mm and it was designed taking in account the necessity of soldering it by hand. On the contrary, the other package dimensions are 4.5×4.5×1 mm and it was designed for fully exploiting the latest technologies available to authors. The SiPs have been designed to be reused in different electrocardiogram (ECG) systems and are easy to solder using ball grids arrays (BGA) and land grids arrays (LGA) as second level interconnection; both these features allow to reduce the time to market of the supra-system including the module. The active electrode presents a bandwidth which ranges from 7.9 mHz to 300 Hz and it has a mid-band gain which can be set to a maximum value of 40 dB. The fabricated SiP has been tested on a printed circuit board (PCB), with an input signal generated by a Dimetek iBUSS-P biomedical signal simulator showing a satisfying functioning of the SiP. PMID:25571119

  5. Activities of the components in a spinel solid solution of the Fe-Al-O system

    NASA Astrophysics Data System (ADS)

    Lykasov, A. A.; Kimyashev, A. A.

    2011-09-01

    The conditions of the equilibrium between the Fe3O4-FeAl2O4 solution and wustite are determined by measuring the EMF of galvanic cells containing a solid electrolyte, and the activities of the components in the Fe3O4-FeAl2O4 solution are calculated by treating the results of the experiment on the equilibrium between the spinel solution and wustite. Their properties are found to be different from those of ideal solutions at temperatures of 1000-1300 K. A significant positive deviation from the Raoult's law is believed to indicate the tendency of the solution to decompose. The experimental data are treated in terms of the theory of regular solutions, assuming the energy of mixing to be a function of temperature only. The critical temperature of decomposition for the Fe3O4-FeAl2O4 solution is found to be 1084 K.

  6. Positive periodic solution of a general discrete non-autonomous difference system of plankton allelopathy with delays

    NASA Astrophysics Data System (ADS)

    Liu, Zhijun; Chen, Lansun

    2006-12-01

    The main purpose of this paper is to investigate a discrete time non-autonomous difference system of plankton allelopathy with delays. By employing continuous theorem proposed by Gains and Mawhin and some new techniques, a set of verifiable sufficient criteria are established for the existence of at least one strictly positive (componentwise) periodic solution, and as an application, we also examine some special case, showing that these conditions are similar to those of continuous differential system. It is also shown that the time delays are harmless for the existence of positive periodic solutions of system.

  7. Existence and stability of almost periodic solutions of nonautonomous competitive systems with weak Allee effect and delays

    NASA Astrophysics Data System (ADS)

    Wu, Wanqin; Ye, Yuan

    2009-11-01

    In this paper, a class of nonautonomous Lotka-Volterra type multispecies competitive systems with weak Allee effect and delays are considered. By using Mawhin's continuation theorem of coincidence degree theory, we obtain some sufficient conditions for the existence of almost periodic solutions for the Lotka-Volterra system. On the case of no delays of Allee effects, by constructing a suitable Lyapunov function, we get a sufficient condition for the globally attractivity of the almost periodic solution for the Lotka-Volterra system. Moreover, we also present an illustrative example to show the effectiveness of our results.

  8. Deriving the New Traveling Wave Solutions for the Nonlinear Dispersive Equation, KdV-ZK Equation and Complex Coupled KdV System Using Extended Simplest Equation Method

    NASA Astrophysics Data System (ADS)

    Mohammed, K. Elboree

    2015-10-01

    In this paper, we investigate the traveling wave solutions for the nonlinear dispersive equation, Korteweg-de Vries Zakharov-Kuznetsov (KdV-ZK) equation and complex coupled KdV system by using extended simplest equation method, and then derive the hyperbolic function solutions include soliton solutions, trigonometric function solutions include periodic solutions with special values for double parameters and rational solutions. The properties of such solutions are shown by figures. The results show that this method is an effective and a powerful tool for handling the solutions of nonlinear partial differential equations (NLEEs) in mathematical physics.

  9. New steady-state models for water-limited cropping systems using saline irrigation waters: Analytical solutions and applications

    NASA Astrophysics Data System (ADS)

    Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.; Suarez, D. L.

    2014-12-01

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems modeling framework that accounts for reduced plant water uptake due to root zone salinity. Two new explicit, closed-form analytical solutions for the root zone solute concentration profile are obtained, corresponding to two alternative functional forms of the uptake reduction function. The solutions express a general relationship between irrigation water salinity, irrigation rate, crop salt tolerance, crop transpiration, and (using standard approximations) crop yield. Example applications are illustrated, including the calculation of irrigation requirements for obtaining targeted submaximal yields, and the generation of crop-water production functions for varying irrigation waters, irrigation rates, and crops. Model predictions are shown to be mostly consistent with existing models and available experimental data. Yet the new solutions possess clear advantages over available alternatives, including: (i) the new solutions were derived from a complete physical-mathematical description of the system, rather than based on an ad hoc formulation; (ii) the new analytical solutions are explicit and can be evaluated without iterative techniques; (iii) the solutions permit consideration of two common functional forms of salinity induced reductions in crop water uptake, rather than being tied to one particular representation; and (iv) the utilized modeling framework is compatible with leading transient-state numerical models.

  10. The box ball system and the N-soliton solution of the ultradiscrete KdV equation

    NASA Astrophysics Data System (ADS)

    Mada, Jun; Idzumi, Makoto; Tokihiro, Tetsuji

    2008-05-01

    Any state of the box-ball system (BBS) together with its time evolution is described by the N-soliton solution (with appropriate choice of N) of the ultradiscrete KdV equation. It is shown that simultaneous elimination of all '10'-walls in a state of the BBS corresponds exactly to reducing the parameters that determine 'the size of a soliton' by one. This observation leads to an expression for the solution to the initial-value problem (IVP) for the BBS. Expressions for the solution to the IVP for the ultradiscrete Toda molecule equation and the periodic BBS are also presented.

  11. Preferential interactions determine protein solubility in three-component solutions: the MgCl2 system.

    PubMed

    Arakawa, T; Bhat, R; Timasheff, S N

    1990-02-20

    The correlation between protein solubility and the preferential interactions of proteins with solvent components was critically examined with aqueous MgCl2 as the solvent system. Preferential interaction and solubility measurements with three proteins, beta-lactoglobulin, bovine serum albumin, and lysozyme, resulted in similar patterns of interaction. At acid pH (pH 2-3) and lower salt concentrations (less than 2 M), the proteins were preferentially hydrated, while at higher salt concentrations, the interaction was either that of preferential salt binding or low salt exclusion. At pH 4.5-5, all three proteins exhibited either very low preferential hydration or preferential binding of MgCl2. These results were analyzed in terms of the balance between salt binding and salt exclusion attributed to the increase in the surface tension of water by salts, which is invariant with conditions. It was shown that the increase in salt binding at high salt concentration is a reflection of mass action, while its decrease at acid pH is due to the electrostatic repulsion between Mg2+ ions and the high net positive charge on the protein. The preferential interaction pattern was paralleled by the variation of protein solubility with solvent conditions. Calculation of the transfer free energies from water to the salt solutions for proteins in solution and in the precipitate showed dependencies on salt concentration. This indicates that the nature of interactions between proteins and solvent components is the same in solution and in the solid state, which implies no change in protein structure during precipitation. Analysis of the transfer free energies and preferential interaction parameter in terms of the salting-in, salting-out, and weak ion binding contributions has led to the conclusions that, when the weak ion binding contribution is small, the predominant protein-salt interaction must be that of preferential salt exclusion most probably caused by the increase of the surface

  12. Chromospheric Activity and Orbital Solution of Six New Late-type Spectroscopic Binary Systems

    NASA Astrophysics Data System (ADS)

    Gálvez, M. C.; Montes, D.; Fernández-Figueroa, M. J.; López-Santiago, J.

    2006-08-01

    We present here the results of our high resolution echelle spectroscopic observations of six recently identified spectroscopic binary systems with late-type stellar components (HD 82159 (BD + 11 2052 A); HIP 63322 (BD + 39 2587); HD 160934 (RE J1738 + 611); HD 89959 (BD + 41 2078); HD 143705 (BD + 29 2752); HD 138157 (OX Ser)). The orbital solution has been obtained using precise radial velocities determined by cross-correlation with radial velocity standard stars as well as previous values reported by other authors. These multiwavelength optical observations allow us to study the chromosphere of these active binary systems using the information provided by several optical spectroscopic features (from Ca II H & K to Ca II IRT lines) that are formed at different heights in the chromosphere. The chromospheric contribution in these lines has been determined using the spectral subtraction technique. In addition, we have determined rotational velocities (vsin i), lithium (Li I λ 6707.8 Å) abundance, and kinematic properties (membership in representative young disk stellar kinematic groups).

  13. Towards a mLearning training solution to the adoption of a CPOE system.

    PubMed

    Pakonstantinou, Despoina; Poulymenopoulou, Mikaela; Malamateniou, Flora; Vassilacopoulos, George

    2012-01-01

    Computerized Physician Order Entry (CPOE) has been introduced as a solution that can fundamentally change the way healthcare is provided, affecting all types of healthcare stakeholders and improving healthcare decisions, patient outcomes, patient safety and efficiency. However, a relatively small proportion of healthcare organizations have implemented CPOE systems, due to its technological complexity and to its low acceptance rate by healthcare professionals who largely disregard the value of CPOE in efficient healthcare delivery. An online training facility embedded within a CPOE service may increase the likelihood of its adoption by healthcare professionals as it offers them guidelines on how to perform each task of the CPOE service. In contrast to CPOE, on the other hand, handheld devices and other mobile technologies have showed an increased adoption rate. This paper considers a CPOE service that can be accessed by authorized healthcare professionals through their mobile devices anytime anywhere, and allows embedded training content, which has been developed through a learning management system (LMS) to be presented to the user automatically upon request. PMID:22874338

  14. A variational calculus for discontinuous solutions of systems of conservation laws

    SciTech Connect

    Bressan, A.; Marson, A.

    1995-12-31

    This paper is concerned with the Cauchy problem for the perturbed system of conservation laws in a single space variable: u{sub t} + [F(u)]{sub x} = h(t,x,u) u(0,x) = u(x), where F:IR{sup n} {r_arrow} IR{sup n} and h : [0, +{infinity}] x IR x IR{sup n} {r_arrow} IR{sup n} are smooth maps. We assume that the system (1) is strictly hyperbolic, and that each characteristic field is either linearly degenerate or genuinely nonlinear in the sense of Lax [8]. Given a piecewise Lipschitz continuous solution u = u(t,x) of (1), we shall study the behavior of first-order variations of u, by defining a suitable class of {open_quotes}generalized tangent vectors{close_quotes} and determining their evolution in time. More precisely, consider a family of initial conditions u(0,x) = {anti u}{sup {var_epsilon}}(x) depending on a small parameter {var_epsilon}(x) depending on a small parameter {var_epsilon}, and assume that {anti u}{sup {var_epsilon}} admits an expansion of the form {anti u}{sup {var_epsilon}}(x) = {anti u}(x) + {var_epsilon}{anti v}(x) + o({var_epsilon}). 13 refs.

  15. Citric Acid-Modified Fenton's Reaction for the Oxidation of Chlorinated Ethylenes in Soil Solution Systems

    SciTech Connect

    Seol, Yongkoo; Javandel, Iraj

    2008-03-15

    Fenton's reagent, a solution of hydrogen peroxide and ferrous iron catalyst, is used for an in-situ chemical oxidation of organic contaminants. Sulfuric acid is commonly used to create an acidic condition needed for catalytic oxidation. Fenton's reaction often involves pressure buildup and precipitation of reaction products, which can cause safety hazards and diminish efficiency. We selected citric acid, a food-grade substance, as an acidifying agent to evaluate its efficiencies for organic contaminant removal in Fenton's reaction, and examined the impacts of using citric acid on the unwanted reaction products. A series of batch and column experiments were performed with varying H{sub 2}O{sub 2} concentrations to decompose selected chlorinated ethylenes. Either dissolved iron from soil or iron sulfate salt was added to provide the iron catalyst in the batch tests. Batch experiments revealed that both citric and sulfuric acid systems achieved over 90% contaminant removal rates, and the presence of iron catalyst was essential for effective decontamination. Batch tests with citric acid showed no signs of pressure accumulation and solid precipitations, however the results suggested that an excessive usage of H{sub 2}O{sub 2} relative to iron catalysts (Fe{sup 2+}/H{sub 2}O{sub 2} < 1/330) would result in lowering the efficiency of contaminant removal by iron chelations in the citric acid system. Column tests confirmed that citric acid could provide suitable acidic conditions to achieve higher than 55% contaminant removal rates.

  16. Global existence and decay of solution for the nonisentropic Euler-Maxwell system with a nonconstant background density

    NASA Astrophysics Data System (ADS)

    Wang, Weike; Xu, Xin

    2016-06-01

    In this paper, the Cauchy problem for the nonisentropic Euler-Maxwell system with a nonconstant background density is studied. The global existence of classical solution is constructed in three space dimensions provided the initial perturbation is sufficiently small. The proof is mainly based on classical energy estimate and the techniques of symmetrizer. And the time decay of the solution is also established by combining the decay estimate of the Green's function with some time-weighted estimate.

  17. Kangaroo mother care: a multi-country analysis of health system bottlenecks and potential solutions

    PubMed Central

    2015-01-01

    Background Preterm birth is now the leading cause of under-five child deaths worldwide with one million direct deaths plus approximately another million where preterm is a risk factor for neonatal deaths due to other causes. There is strong evidence that kangaroo mother care (KMC) reduces mortality among babies with birth weight <2000 g (mostly preterm). KMC involves continuous skin-to-skin contact, breastfeeding support, and promotion of early hospital discharge with follow-up. The World Health Organization has endorsed KMC for stabilised newborns in health facilities in both high-income and low-resource settings. The objectives of this paper are to: (1) use a 12-country analysis to explore health system bottlenecks affecting the scale-up of KMC; (2) propose solutions to the most significant bottlenecks; and (3) outline priority actions for scale-up. Methods The bottleneck analysis tool was applied in 12 countries in Africa and Asia as part of the Every Newborn Action Plan process. Country workshops involved technical experts to complete the survey tool, which is designed to synthesise and grade health system "bottlenecks", factors that hinder the scale-up, of maternal-newborn intervention packages. We used quantitative and qualitative methods to analyse the bottleneck data, combined with literature review, to present priority bottlenecks and actions relevant to different health system building blocks for KMC. Results Marked differences were found in the perceived severity of health system bottlenecks between Asian and African countries, with the former reporting more significant or very major bottlenecks for KMC with respect to all the health system building blocks. Community ownership and health financing bottlenecks were significant or very major bottlenecks for KMC in both low and high mortality contexts, particularly in South Asia. Significant bottlenecks were also reported for leadership and governance and health workforce building blocks. Conclusions There

  18. New solutions for standardization, monitoring and quality management of fluorescence-based imaging systems (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Royon, Arnaud; Papon, Gautier

    2016-03-01

    Fluorescence microscopes have become ubiquitous in life sciences laboratories, including those focused on pharmaceuticals, diagnosis, and forensics. For the past few years, the need for both performance guarantees and quantifiable results has driven development in this area. However, the lack of appropriate standards and reference materials makes it difficult or impossible to compare the results of two fluorescence microscopes, or to measure performance fluctuations of one microscope over time. Therefore, the operation of fluorescence microscopes is not monitored as often as their use warrants - an issue that is recognized by both systems manufacturers and national metrology institutes. We have developed a new process that enables the etching of long-term stable fluorescent patterns with sub-micrometer sizes in three dimensions inside glass. In this paper, we present, based on this new process, a fluorescent multi-dimensional ruler and a dedicated software that are suitable for monitoring and quality management of fluorescence-based imaging systems (wide-field, confocal, multiphoton, high content machines). In addition to fluorescence, the same patterns exhibit bright- and dark-field contrast, DIC, and phase contrast, which make them also relevant to monitor these types of microscopes. Non-exhaustively, this new solution enables the measurement of: The stage repositioning accuracy; The illumination and detection homogeneities; The field flatness; The detectors' characteristics; The lateral and axial spatial resolutions; The spectral response (spectrum, intensity and lifetime) of the system. Thanks to the stability of the patterns, microscope performance assessment can be carried out as well in a daily basis as in the long term.

  19. Thermodynamics of Dilute Solutions.

    ERIC Educational Resources Information Center

    Jancso, Gabor; Fenby, David V.

    1983-01-01

    Discusses principles and definitions related to the thermodynamics of dilute solutions. Topics considered include dilute solution, Gibbs-Duhem equation, reference systems (pure gases and gaseous mixtures, liquid mixtures, dilute solutions), real dilute solutions (focusing on solute and solvent), terminology, standard states, and reference systems.…

  20. "A Fiberoptic Local-Area-Network Solution For Tactical Command And Control Systems"

    NASA Astrophysics Data System (ADS)

    Vlasak, Weldon; Pfister, Gerhard

    1983-11-01

    This paper examines key network requirements for the elements of distributed tactical command and control system. System concepts are evolved that support implementation solutions with emphasis on advanced technologies. Mobile command and control elements of ground and air forces are becoming more vulnerable in an ever increasing threat environment. This vulnerability is caused by the employment of these elements in a manner characterized by functional and physical centralization. A command and control unit typically consists of a centralized operations center surrounded by closely clustered communications and surveillance equipments. Because these elements have different deployment and employment requirements, the command and control unit is not optimized in terms of survivability, mobility, effectiveness, and operational flexibility. In recent years, convincing arguments have been put forth to the effect that distributed operations centers, redundantly structured communication functions, and netted surveillance systems can provide the necessary attributes to be effective in the advanced threat environment. Current technology does not meet the requirements of such a system. A local area network provides a power interconnection mechanism for the distributed elements of the command and control system. The requirements are for a rapid, efficient, and reliable means of transferring voice and data communications between elements. The topology of such a network must primarily consider survivability and reliability of communications interchanges with special emphasis on continued operations under degraded conditions. When such conditions occur, e.g., the result of combat attrition, a complete command and control capability should remain even though it may be at somewhat of a reduced capacity. The interconnection medium for the local area network should be immune to external disruptions, e.g., EMI, EMP, or C3CM, and should have a wide transmission bandwidth with a minimum

  1. The effects of magnetic fields exposure on relative permittivity of saline solutions measured by a high resolution SPR system.

    PubMed

    Jiang, Li; Zhao, Xinyuan; Fei, Yue; Yu, Dongdong; Qian, Jun; Tong, Jinguang; Chen, Guangdi; He, Sailing

    2016-01-01

    A measurement system for the relative permittivity of a physiological solution under 50 Hz magnetic fields (MF) is presented. It is based on a phase-sensitive surface plasmon resonance (SPR) system. Relative permittivity was analyzed for different solute concentrations of sodium chloride under various MF exposure parameters. We found that MF exposure at 0.2-4.0 mT step-wise decreased significantly the SPR phase signal of a 0.9% sodium chloride solution while 0.1 mT of MF exposure did not. The decreases in the SPR phase signal depended on the duration of MF exposure, and the signal reached a plateau after 15 min of exposure. Interestingly, the decreased SPR phase signal showed a gradual increase and approached the background level when the exposure was drawn off. In addition, we found that the response of the sodium chloride solution to MF also depended on its concentration. In brief, the relative permittivity of sodium chloride in solutions appears to be practically affected by 50 Hz MF exposure. Our data indicates that the relative permittivity of the saline solution influenced by MF exposure should be considered when investigating the biological effects of MF exposure on organisms in experimental study. PMID:27121618

  2. The effects of magnetic fields exposure on relative permittivity of saline solutions measured by a high resolution SPR system

    NASA Astrophysics Data System (ADS)

    Jiang, Li; Zhao, Xinyuan; Fei, Yue; Yu, Dongdong; Qian, Jun; Tong, Jinguang; Chen, Guangdi; He, Sailing

    2016-04-01

    A measurement system for the relative permittivity of a physiological solution under 50 Hz magnetic fields (MF) is presented. It is based on a phase-sensitive surface plasmon resonance (SPR) system. Relative permittivity was analyzed for different solute concentrations of sodium chloride under various MF exposure parameters. We found that MF exposure at 0.2–4.0 mT step-wise decreased significantly the SPR phase signal of a 0.9% sodium chloride solution while 0.1 mT of MF exposure did not. The decreases in the SPR phase signal depended on the duration of MF exposure, and the signal reached a plateau after 15 min of exposure. Interestingly, the decreased SPR phase signal showed a gradual increase and approached the background level when the exposure was drawn off. In addition, we found that the response of the sodium chloride solution to MF also depended on its concentration. In brief, the relative permittivity of sodium chloride in solutions appears to be practically affected by 50 Hz MF exposure. Our data indicates that the relative permittivity of the saline solution influenced by MF exposure should be considered when investigating the biological effects of MF exposure on organisms in experimental study.

  3. The effects of magnetic fields exposure on relative permittivity of saline solutions measured by a high resolution SPR system

    PubMed Central

    Jiang, Li; Zhao, Xinyuan; Fei, Yue; Yu, Dongdong; Qian, Jun; Tong, Jinguang; Chen, Guangdi; He, Sailing

    2016-01-01

    A measurement system for the relative permittivity of a physiological solution under 50 Hz magnetic fields (MF) is presented. It is based on a phase-sensitive surface plasmon resonance (SPR) system. Relative permittivity was analyzed for different solute concentrations of sodium chloride under various MF exposure parameters. We found that MF exposure at 0.2–4.0 mT step-wise decreased significantly the SPR phase signal of a 0.9% sodium chloride solution while 0.1 mT of MF exposure did not. The decreases in the SPR phase signal depended on the duration of MF exposure, and the signal reached a plateau after 15 min of exposure. Interestingly, the decreased SPR phase signal showed a gradual increase and approached the background level when the exposure was drawn off. In addition, we found that the response of the sodium chloride solution to MF also depended on its concentration. In brief, the relative permittivity of sodium chloride in solutions appears to be practically affected by 50 Hz MF exposure. Our data indicates that the relative permittivity of the saline solution influenced by MF exposure should be considered when investigating the biological effects of MF exposure on organisms in experimental study. PMID:27121618

  4. A Rationale for System-Dependent Advantages and Disadvantages of Solution Crystal Growth at Low Gravity

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz; Vekilov, Peter G.; Lin, Hong; Alexander, J. Iwan D.

    1997-01-01

    Protein crystallization experiments at reduced gravity have yielded crystals that, depending on the specific material, are either superior or inferior in their structural perfection compared to counterparts grown at normal gravity. A reduction of the crystals' quality due to their growth at low gravity cannot be understood from existing models. Our experimental investigations of the ground-based crystallization of the protein lysozyme have revealed pronounced unsteady growth layer dynamics and associated defect formation under steady external conditions. Through scaling analysis and numerical simulations we show that the observed fluctuations originate from the coupling of bulk transport with non-linear interface kinetics under mixed kinetics-transport control of the growth rate. The amplitude of the fluctuations is smallest when either transport or interfacial kinetics dominate the control of the crystallization process. Thus, depending on the specific system, crystal quality may be improved by either enhancing or suppressing the transport in the solution. These considerations provide, for the first time, a material-dependent rationale for the advantages, as well as the disadvantages, of reduced gravity for (protein) crystallization.

  5. High-performance CMOS image sensors at BAE SYSTEMS Imaging Solutions

    NASA Astrophysics Data System (ADS)

    Vu, Paul; Fowler, Boyd; Liu, Chiao; Mims, Steve; Balicki, Janusz; Bartkovjak, Peter; Do, Hung; Li, Wang

    2012-07-01

    In this paper, we present an overview of high-performance CMOS image sensor products developed at BAE SYSTEMS Imaging Solutions designed to satisfy the increasingly challenging technical requirements for image sensors used in advanced scientific, industrial, and low light imaging applications. We discuss the design and present the test results of a family of image sensors tailored for high imaging performance and capable of delivering sub-electron readout noise, high dynamic range, low power, high frame rates, and high sensitivity. We briefly review the performance of the CIS2051, a 5.5-Mpixel image sensor, which represents our first commercial CMOS image sensor product that demonstrates the potential of our technology, then we present the performance characteristics of the CIS1021, a full HD format CMOS image sensor capable of delivering sub-electron read noise performance at 50 fps frame rate at full HD resolution. We also review the performance of the CIS1042, a 4-Mpixel image sensor which offers better than 70% QE @ 600nm combined with better than 91dB intra scene dynamic range and about 1 e- read noise at 100 fps frame rate at full resolution.

  6. Degradation of Acid Orange 7 in an Atmospheric-Pressure Plasma-Solution System (Gliding Discharge)

    NASA Astrophysics Data System (ADS)

    NI, Mingjiang; YANG, Huan; CHEN, Tong; ZHANG, Hao; WU, Angjian; DU, Changming; LI, Xiaodong

    2015-03-01

    In this work, a plasma-solution system was applied to the degradation of Acid Orange 7 (AO7). The effects of initial concentration and type of feed gases (air, oxygen, nitrogen or argon) were studied. As the initial concentration increased from 100 mg/L to 160 mg/L, the discolouration rate of AO7 decreased from 99.3% to 95.9%, whereas the COD removal rate decreased from 37.9% to 22.6%. Air provided the best discolouration and COD removal rates (99.3% and 37.9%, respectively). In the presence of a zero-valent iron (ZVI) catalyst, the AO7 COD removal rate increased to 76.4%. The degradation products were analysed by a GC-MS, revealing that the degradation of the dye molecule was initiated through the cleavage of the -N=N- bond before finally being converted to organic acids. supported by National Natural Science Foundation of China (Nos. 50908237, 51076142) and the Open Foundation of the State Key Laboratory of Clean Energy Utilization of China (No. ZJUCEU2009008)

  7. Multi-equilibrium system based on sertraline and β-cyclodextrin supramolecular complex in aqueous solution.

    PubMed

    Passos, Joel J; De Sousa, Frederico B; Lula, Ivana S; Barreto, Elison A; Lopes, Juliana Fedoce; De Almeida, Wagner B; Sinisterra, Rubén D

    2011-12-12

    Sertraline (SRT) is a widely used antidepressant whose poor solubility in water limits its oral applicability. Thus, the aim of this work was the evaluation of a multi-equilibrium system based on β-cyclodextrin (βCD) and SRT. The inclusion compounds (ICs) were investigated by infrared spectroscopy, isothermal titration calorimetry (ITC) and (1)H and 2D ROESY nuclear magnetic resonance experiments. SRT solubility was predicted in vitro in water and biomimetic fluids. The SRT in presence of βCD at 1:1 and 1:2 molar ratios was more soluble than free SRT in all biomimetics media investigated. The FTIR-HATR showed that βCD νC-O-C stretching band was reduced in presence of SRT, suggesting the interactions between them. Additionally, titration process and Job's plot provided information on the ICs stoichiometry and evidenced the multi-equilibrium coexistence in aqueous solution. According to the ITC, SRT:βCD interaction process was spontaneous and exothermic with a high affinity binding constant (K=14,726 M(-1)). Additionally, the stoichiometry coefficient (n) was 1.63, which was comparable to that found by FITR-HATR. The (1)H and 2D ROESY verified multiple SRT sites included into the host cavity. Theoretical calculations depicted the relative energy of different proposed ICs structures, in which the 1:2 IC was the most stable. PMID:21963467

  8. Solute diffusion through fibrotic tissue formed around protective cage system for implantable devices.

    PubMed

    Prihandana, Gunawan Setia; Ito, Hikaru; Tanimura, Kohei; Yagi, Hiroshi; Hori, Yuki; Soykan, Orhan; Sudo, Ryo; Miki, Norihisa

    2015-08-01

    This article presents the concept of an implantable cage system that can house and protect implanted biomedical sensing and therapeutic devices in the body. Cylinder-shaped cages made of porous polyvinyl alcohol (PVA) sheets with an 80-µm pore size and/or stainless steel meshes with 0.54-mm openings were implanted subcutaneously in the dorsal region of rats for 5 weeks. Analysis of the explanted cages showed the formation of fibrosis tissue around the cages. PVA cages had fibrotic tissue growing mostly along the outer surface of cages, while stainless steel cages had fibrotic tissue growing into the inside surface of the cage structure, due to the larger porosity of the stainless steel meshes. As the detection of target molecules with short time lags for biosensors and mass transport with low diffusion resistance into and out of certain therapeutic devices are critical for the success of such devices, we examined whether the fibrous tissue formed around the cages were permeable to molecules of our interest. For that purpose, bath diffusion and microfluidic chamber diffusion experiments using solutions containing the target molecules were performed. Diffusion of sodium, potassium and urea through the fibrosis tissue was confirmed, thus suggesting the potential of these cylindrical cages surrounded by fibrosis tissue to successfully encase implantable sensors and therapeutic apparatus. PMID:25303239

  9. Iterative solution of dense linear systems arising from the electrostatic integral equation in MEG.

    PubMed

    Rahol, Jussi; Tissari, Satu

    2002-03-21

    We study the iterative solution of dense linear systems that arise from boundary element discretizations of the electrostatic integral equation in magnetoencephalography (MEG). We show that modern iterative methods can be used to decrease the total computation time by avoiding the time-consuming computation of the LU decomposition of the coefficient matrix. More importantly, the modern iterative methods make it possible to avoid the explicit formation of the coefficient matrix which is needed when a large number of unknowns are used. To study the convergence of iterative solvers we examine the eigenvalue distributions of the coefficient matrices. For the sphere we show how the eigenvalues of the integral operator are approximated by the eigenvalues of the coefficient matrix when the collocation and Galerkin methods are used as discretization methods. The collocation method approximates the eigenvalues of the integral operator directly. The Galerkin method produces a coefficient matrix that needs to be preconditioned in order to maintain optimal convergence speed. With the ILU(0) preconditioner iterative methods converge fast and independent of the number of discretization points for both the collocation and Galerkin approaches. The preconditioner has no significant effect on the total computational time. PMID:11936181

  10. Iterative solution of dense linear systems arising from the electrostatic integral equation in MEG

    NASA Astrophysics Data System (ADS)

    Rahola, Jussi; Tissari, Satu

    2002-03-01

    We study the iterative solution of dense linear systems that arise from boundary element discretizations of the electrostatic integral equation in magnetoencephalography (MEG). We show that modern iterative methods can be used to decrease the total computation time by avoiding the time-consuming computation of the LU decomposition of the coefficient matrix. More importantly, the modern iterative methods make it possible to avoid the explicit formation of the coefficient matrix which is needed when a large number of unknowns are used. To study the convergence of iterative solvers we examine the eigenvalue distributions of the coefficient matrices. For the sphere we show how the eigenvalues of the integral operator are approximated by the eigenvalues of the coefficient matrix when the collocation and Galerkin methods are used as discretization methods. The collocation method approximates the eigenvalues of the integral operator directly. The Galerkin method produces a coefficient matrix that needs to be preconditioned in order to maintain optimal convergence speed. With the ILU(0) preconditioner iterative methods converge fast and independent of the number of discretization points for both the collocation and Galerkin approaches. The preconditioner has no significant effect on the total computational time.

  11. Implicit time-integration method for simultaneous solution of a coupled non-linear system

    NASA Astrophysics Data System (ADS)

    Watson, Justin Kyle

    Historically large physical problems have been divided into smaller problems based on the physics involved. This is no different in reactor safety analysis. The problem of analyzing a nuclear reactor for design basis accidents is performed by a handful of computer codes each solving a portion of the problem. The reactor thermal hydraulic response to an event is determined using a system code like TRAC RELAP Advanced Computational Engine (TRACE). The core power response to the same accident scenario is determined using a core physics code like Purdue Advanced Core Simulator (PARCS). Containment response to the reactor depressurization in a Loss Of Coolant Accident (LOCA) type event is calculated by a separate code. Sub-channel analysis is performed with yet another computer code. This is just a sample of the computer codes used to solve the overall problems of nuclear reactor design basis accidents. Traditionally each of these codes operates independently from each other using only the global results from one calculation as boundary conditions to another. Industry's drive to uprate power for reactors has motivated analysts to move from a conservative approach to design basis accident towards a best estimate method. To achieve a best estimate calculation efforts have been aimed at coupling the individual physics models to improve the accuracy of the analysis and reduce margins. The current coupling techniques are sequential in nature. During a calculation time-step data is passed between the two codes. The individual codes solve their portion of the calculation and converge to a solution before the calculation is allowed to proceed to the next time-step. This thesis presents a fully implicit method of simultaneous solving the neutron balance equations, heat conduction equations and the constitutive fluid dynamics equations. It discusses the problems involved in coupling different physics phenomena within multi-physics codes and presents a solution to these problems

  12. Strictly Physical Global Weak Solutions of a Navier-Stokes Q-tensor System with Singular Potential

    NASA Astrophysics Data System (ADS)

    Wilkinson, Mark

    2015-10-01

    We study the existence, regularity and so-called `strict physicality' of global weak solutions of a Beris-Edwards system which is proposed as a model for the incompressible flow of nematic liquid crystal materials. An important contribution to the dynamics comes from a singular potential introduced by John Ball and Apala Majumdar which replaces the commonly employed Landau-de Gennes bulk potential. This is built into our model to ensure that a natural physical constraint on the eigenvalues of the Q-tensor order parameter is respected by the dynamics of this system. Moreover, by a maximum principle argument, we are able to construct global strong solutions in dimension two.

  13. Exhaustive derivation of static self-consistent multisoliton solutions in the matrix Bogoliubov-de Gennes systems

    NASA Astrophysics Data System (ADS)

    Takahashi, Daisuke A.

    2016-04-01

    The matrix-generalized Bogoliubov-de Gennes systems have recently been considered by the present author [Phys. Rev. B 93, 024512 (2016)], and time-dependent and self-consistent multisoliton solutions have been constructed based on the ansatz method. In this paper, restricting the problem to the static case, we exhaustively determine the self-consistent solutions using the inverse scattering theory. Solving the gap equation, we rigorously prove that the self-consistent potential must be reflectionless. As a supplementary topic, we elucidate the relation between the stationary self-consistent potentials and the soliton solutions in the matrix nonlinear Schrödinger equation. Asymptotic formulae of multisoliton solutions for sufficiently isolated solitons are also presented.

  14. On uniqueness theorem on weak solutions to the parabolic-parabolic Keller-Segel system of degenerate and singular types

    NASA Astrophysics Data System (ADS)

    Miura, Masanari; Sugiyama, Yoshie

    2014-12-01

    The uniqueness of weak solutions to the parabolic-parabolic Keller-Segel systems (KS)m below with m>max⁡{1/2 >-1n,0} is proved in the class of Hölder continuous functions for any space dimension n. Since Hölder continuity is an optimal regularity for weak solutions of the porous medium equation, it seems to be reasonable to investigate its uniqueness in such a class of solutions. Our proof is based on the standard duality argument coupled with vanishing viscosity method which recovers degeneracy for m>1, and which removes singularities for 0solutions.

  15. Treatment of neonatal infections: a multi-country analysis of health system bottlenecks and potential solutions

    PubMed Central

    2015-01-01

    Background Around one-third of the world's 2.8 million neonatal deaths are caused by infections. Most of these deaths are preventable, but occur due to delays in care-seeking, and access to effective antibiotic treatment with supportive care. Understanding variation in health system bottlenecks to scale-up of case management of neonatal infections and identifying solutions is essential to reduce mortality, and also morbidity. Methods A standardised bottleneck analysis tool was applied in 12 countries in Africa and Asia as part of the development of the Every Newborn Action Plan. Country workshops involved technical experts to complete a survey tool, to grade health system "bottlenecks" hindering scale up of maternal-newborn intervention packages. Quantitative and qualitative methods were used to analyse the data, combined with literature review, to present priority bottlenecks and synthesise actions to improve case management of newborn infections. Results For neonatal infections, the health system building blocks most frequently graded as major or significant bottlenecks, irrespective of mortality context and geographical region, were health workforce (11 out of 12 countries), and community ownership and partnership (11 out of 12 countries). Lack of data to inform decision making, and limited funding to increase access to quality neonatal care were also major challenges. Conclusions Rapid recognition of possible serious bacterial infection and access to care is essential. Inpatient hospital care remains the first line of treatment for neonatal infections. In situations where referral is not possible, the use of simplified antibiotic regimens for outpatient management for non-critically ill young infants has recently been reported in large clinical trials; WHO is developing a guideline to treat this group of young infants. Improving quality of care through more investment in the health workforce at all levels of care is critical, in addition to ensuring development

  16. Analytical solutions for a two-level system driven by a class of chirped pulses

    SciTech Connect

    Jha, Pankaj K.; Rostovtsev, Yuri V.

    2010-07-15

    We present analytical solutions for the problem of a two-level atom driven by a class of chirped pulses. The solutions are given in terms of Heun functions. By use of the appropriate chirping parameters, an enhancement of four orders of magnitude in the population transfer is obtained.

  17. Understanding sub-surface solute distributions and salinization mechanisms in a tropical coastal floodplain groundwater system

    NASA Astrophysics Data System (ADS)

    Lenahan, Matthew J.; Bristow, Keith L.

    2010-09-01

    SummaryThe Burdekin coastal floodplain aquifer is a tropical groundwater system exploited for irrigated agriculture that has exhibited increases in groundwater salinity since regular monitoring was introduced in the 1960s. Evapotranspiration of irrigation water, displacement of unsaturated zone solutes, enhanced mixing with relict seawater and seawater intrusion are mechanisms considered to explain the observed increase. The floodplain aquifer is comprised of complex successions of Quaternary terrigenous and marine sediments hosting groundwater with Cl - concentrations from <50 mg/l to >50,000 mg/l. The lowest salinity groundwater is found adjacent to the Burdekin River and within palaeochannels dissecting the floodplain. Cl - concentrations <100 mg/l, together with NO3-/Cl mass ratios >0.1 indicate the fresh groundwater originates from vertical infiltration of rainwater and irrigation water entrained with agricultural nitrogen through the coarse-grained palaeochannel sediments. Na/Cl ratios similar to the Burdekin River indicate that lateral discharge from the river channel to the floodplain aquifer also accounts for the distribution of low-salinity groundwater. Tidal and near-shore marine sediments deposited during Pleistocene and Holocene high sea level stands host highly saline groundwater (Cl - 20,000-80,000 mg/l) up to 15 km inland. In many areas of the floodplain, nested piezometer locations reveal older, more saline water at depth. Na and Cl - concentrations of more than 8000 floodplain groundwater samples collected over a 40 yr period fall on a mixing line between river water/fresh groundwater and modern/relict seawater indicating that intermediate salinity waters have evolved over time through varying degrees of mixing between the two end-member compositions. Temporal trends in Na and Cl - concentrations indicate that increases in groundwater salinity across the floodplain are primarily due to this mixing process, and that evapotranspiration from

  18. Analysis of Residential System Strategies Targeting Least-Cost Solutions Leading to Net Zero Energy Homes: Preprint

    SciTech Connect

    Anderson, R.; Christensen, C.; Horowitz, S.

    2006-04-01

    The U. S. Department of Energy's Building America residential systems research project uses an analysis-based system research approach to identify research priorities, identify technology gaps and opportunities, establish a consistent basis to track research progress, and identify system solutions that are most likely to succeed as the initial targets for residential system research projects. This report describes the analysis approach used by the program to determine the most cost-effective pathways to achieve whole-house energy-savings goals. This report also provides an overview of design/technology strategies leading to net zero energy buildings as the basis for analysis of future residential system performance.

  19. Optimal system and exact solutions for the generalized system of 2-dimensional Burgers equations with infinite Reynolds number

    NASA Astrophysics Data System (ADS)

    Abdulwahhab, Muhammad Alim

    2015-01-01

    One of the equations used for studying fluid turbulence is the 2D Burgers equations. Researchers have used various numerical methods to compute the values of the velocity components at different Reynolds number and other parameters of choice. Reynolds number is important in analyzing any type of flow when there is substantial velocity gradient. It indicates the relative significance of the viscous effect compared to the inertia effect. Results available in the literature for the 2D Burgers equations are either for laminar flow which occurs at low Reynolds numbers or for turbulent flow which occurs at high Reynolds numbers. These results cannot be used for superfluidity, the hallmark property of quantum fluids, where Reynolds number is infinite. Although Reynolds number may not be infinite in some superfluid turbulence (Barenghi, 2008; Vinen, 2005) [1,2], it is definitely the case at zero-temperature limit (Sasa and Machida, 2011) [3]. Based on this assumption, we analyse the 2D Burgers equation at infinite Reynolds number using Lie group method. Optimal system of one-dimensional subalgebras is derived and used to obtain generalized distinct exact solutions of the velocity components.

  20. Quantum dynamics of incoherently driven V-type systems: Analytic solutions beyond the secular approximation.

    PubMed

    Dodin, Amro; Tscherbul, Timur V; Brumer, Paul

    2016-06-28

    Closed-form analytic solutions to non-secular Bloch-Redfield master equations for quantum dynamics of a V-type system driven by weak coupling to a thermal bath, relevant to light harvesting processes, are obtained and discussed. We focus on noise-induced Fano coherences among the excited states induced by incoherent driving of the V-system initially in the ground state. For suddenly turned-on incoherent driving, the time evolution of the coherences is determined by the damping parameter ζ=12(γ1+γ2)/Δp, where γi are the radiative decay rates of the excited levels i = 1, 2, and Δp=Δ(2)+(1-p(2))γ1γ2 depends on the excited-state level splitting Δ > 0 and the angle between the transition dipole moments in the energy basis. The coherences oscillate as a function of time in the underdamped limit (ζ ≫ 1), approach a long-lived quasi-steady state in the overdamped limit (ζ ≪ 1), and display an intermediate behavior at critical damping (ζ = 1). The sudden incoherent turn-on is shown to generate a mixture of excited eigenstates |e1〉 and |e2〉 and their in-phase coherent superposition |ϕ+〉=1r1+r2(r1|e1〉+r2|e2〉), which is remarkably long-lived in the overdamped limit (where r1 and r2 are the incoherent pumping rates). Formation of this coherent superposition enhances the decay rate from the excited states to the ground state. In the strongly asymmetric V-system where the coupling strengths between the ground state and the excited states differ significantly, additional asymptotic quasistationary coherences are identified, which arise due to slow equilibration of one of the excited states. Finally, we demonstrate that noise-induced Fano coherences are maximized with respect to populations when r1 = r2 and the transition dipole moments are fully aligned. PMID:27369498

  1. Quantum dynamics of incoherently driven V-type systems: Analytic solutions beyond the secular approximation

    NASA Astrophysics Data System (ADS)

    Dodin, Amro; Tscherbul, Timur V.; Brumer, Paul

    2016-06-01

    Closed-form analytic solutions to non-secular Bloch-Redfield master equations for quantum dynamics of a V-type system driven by weak coupling to a thermal bath, relevant to light harvesting processes, are obtained and discussed. We focus on noise-induced Fano coherences among the excited states induced by incoherent driving of the V-system initially in the ground state. For suddenly turned-on incoherent driving, the time evolution of the coherences is determined by the damping parameter ζ = /1 2 ( γ 1 + γ 2) / Δ p , where γi are the radiative decay rates of the excited levels i = 1, 2, and Δ p = √{ Δ 2 + ( 1 - p 2) γ 1 γ 2 } depends on the excited-state level splitting Δ > 0 and the angle between the transition dipole moments in the energy basis. The coherences oscillate as a function of time in the underdamped limit (ζ ≫ 1), approach a long-lived quasi-steady state in the overdamped limit (ζ ≪ 1), and display an intermediate behavior at critical damping (ζ = 1). The sudden incoherent turn-on is shown to generate a mixture of excited eigenstates |e1> and |e2> and their in-phase coherent superposition | ϕ + > = /1 √{ r 1 + r 2 } ( √{ r 1 } | e 1 > + √{ r 2 } | e 2 >) , which is remarkably long-lived in the overdamped limit (where r1 and r2 are the incoherent pumping rates). Formation of this coherent superposition enhances the decay rate from the excited states to the ground state. In the strongly asymmetric V-system where the coupling strengths between the ground state and the excited states differ significantly, additional asymptotic quasistationary coherences are identified, which arise due to slow equilibration of one of the excited states. Finally, we demonstrate that noise-induced Fano coherences are maximized with respect to populations when r1 = r2 and the transition dipole moments are fully aligned.

  2. An implicit difference scheme for the long-time evolution of localized solutions of a generalized Boussinesq system

    SciTech Connect

    Christov, C.I.; Maugin, G.A.

    1995-01-01

    We consider the nonlinear system of equations built up from a generalized Boussinesq equation coupled with a wave equation which is a model for the one-dimensional dynamics of phases in martensitic alloys. The strongly implicit scheme employing Newton`s quasilinearisation allows us to track the long time evolution of the localized solutions of the system. Two distinct classes of solutions are encountered for the pure Boussinesq equation. The first class consists of oscillatory pulses whose envelopes are localized waves. The second class consists of smoother solutions whose shapes are either heteroclinic (kinks) or homoclinic (bumps). The homoclinics decrease in amplitude with time while their support increases. An appropriate self-similar scaling is found analytically and confirmed by the direct numerical simulations to high accuracy. The rich phenomenology resulting from the coupling with the wave equation is also investigated. 11 refs., 12 figs., 2 tabs.

  3. Mellin transform approach for the solution of coupled systems of fractional differential equations

    NASA Astrophysics Data System (ADS)

    Butera, Salvatore; Di Paola, Mario

    2015-01-01

    In this paper, the solution of a multi-order, multi-degree-of-freedom fractional differential equation is addressed by using the Mellin integral transform. By taking advantage of a technique that relates the transformed function, in points of the complex plane differing in the value of their real part, the solution is found in the Mellin domain by solving a linear set of algebraic equations. The approximate solution of the differential (or integral) equation is restored, in the time domain, by using the inverse Mellin transform in its discretized form.

  4. Bifurcation under parameter change of Riemann solutions for nonstrictly hyperbolic systems

    NASA Astrophysics Data System (ADS)

    Matos, V.; Azevedo, A. V.; Da Mota, J. C.; Marchesin, D.

    2015-08-01

    We study the bifurcation of Riemann solutions due to parameter change that alters the type of an umbilic point existing in state space. Solutions with data near generic umbilic points are primarily determined by the local quadratic expansion of flux functions. We observe that near an umbilic point, the bifurcation of the solution is essentially local and its behavior depends solely on the cubic expansion of the flux functions. These phenomena are illustrated for immiscible three-phase flow in porous media, which looses strict hyperbolicity at an isolated point in the interior of the oil-water-gas saturation triangle.

  5. Transportation Problems in Special Education Programs in Rural Areas - A Specific Solution and Some Suggestions for Delivery System Development.

    ERIC Educational Resources Information Center

    Brody, Z. H.

    The paper describes transportation problems encountered and solutions employed in delivering systems of comprehensive services to handicapped children in Anderson County, Tennessee, a predominantly rural area with considerable mountain area. Detailed are methods of transportation utilized in the four different program areas of the county special…

  6. The existence of positive periodic solutions of a generalized N-species Gilpin-Ayala impulsive competition system.

    PubMed

    Li, Meili; Han, Maoan; Kou, Chunhai

    2008-10-01

    In this paper, the existence of positive periodic solutions of a class of periodic -species Gilpin-Ayala impulsive competition systems is studied. By using the continuation theorem of coincidence degree theory, a set of easily verifiable sufficient conditions is obtained. Our results are general enough to include some known results in this area. PMID:19278283

  7. Single cell performance studies on the Fe/Cr Redox Energy Storage System using mixed reactant solutions at elevated temperature

    NASA Technical Reports Server (NTRS)

    Gahn, R. F.; Hagedorn, N. H.; Ling, J. S.

    1983-01-01

    Experimental studies in a 14.5 sq cm single cell system using mixed reactant solutions at 65 C are described. Systems were tested under isothermal conditions i.e., reactants and the cell were at the same temperature. Charging and discharging performance were evaluted by measuring watt-hour and coulombic efficiencies, voltage-current relationships, hydrogen evolution and membrane resistivity. Watt-hour efficiencies ranged from 86% at 43 ma/sq cm to 75% at 129 ma/sq cm with corresponding coulombic efficiencies of 92% and 97%, respectively. Hydrogen evolution was less than 1% of the charge coulombic capacity during charge-discharge cycling. Bismuth and bismuth-lead catalyzed chromium electrodes maintained reversible performance and low hydrogen evolution under normal and adverse cycling conditions. Reblending of the anode and cathode solutions was successfully demonstrated to compensate for osmotic volume changes. Improved performance was obtained with mixed reactant systems in comparison to the unmixed reactant systems.

  8. Drag reduction by coupled systems: microbubble injection with homogeneous polymer and surfactant solutions

    NASA Astrophysics Data System (ADS)

    Fontaine, A. A.; Deutsch, S.; Brungart, T. A.; Petrie, H. L.; Fenstermacker, M.

    The influence of homogeneous surfactant and homogeneous polymer solutions on the performance of microbubble skin friction reduction was investigated on an axisymmetric body. Carbon dioxide was injected into water, homogeneous surfactant (Aerosol OT) solutions, and homogeneous dilute polymer (Polyethylene oxide) solutions. Integrated skin friction measurements were obtained at two freestream velocities as a function of gas injection rate and polyethylene-oxide concentration. A moderate (50%) decrease in surface tension had little to no effect on the drag reducing characteristics of microbubble injection. At similar gas injection rates, microbubble injection exhibited more drag reduction in the polymer solutions than obtained with microbubble injection into water. However, the increased drag reduction obtained with polymer additives was no more than a multiplicative factor related to the baseline levels of drag reduction achieved by the individual methods, and suggests the mechanism for microbubble skin friction reduction acts independently of the polymer drag reduction.

  9. Cesaro-One Summability and Uniform Convergence of Solutions of a Sturm-Liouville System

    SciTech Connect

    Baty, R.S.; Tucker, D.H.

    1999-01-26

    Galerkin methods are used in separable Hilbert spaces to construct and compute L{sup 2} [0,{pi}] solutions to large classes of differential equations. In this note a Galerkin method is used to construct series solutions of a nonhomogeneous Sturm-Liouville problem defined on [0,{pi}]. The series constructed are shown to converge to a specified du Bois-Reymond function f in L{sup 2} [0,{pi}]. It is then shown that the series solutions can be made to converge uniformly to the specified du Bois-Reymond function when averaged by the Ces{'a}ro-one summability method. Therefore, in the Ces{'a}ro-one sense, every continuous function f on [0,{pi}] is the uniform limit of solutions of nonhomogeneous Sturm-Liouville problems.

  10. A Particular Solution of a Painlevé System in Terms of the Hypergeometric Function n+1Fn

    NASA Astrophysics Data System (ADS)

    Suzuki, Takao

    2010-10-01

    In a recent work, we proposed the coupled Painlevé VI system with A2n+1(1)-symmetry, which is a higher order generalization of the sixth Painlevé equation (PVI). In this article, we present its particular solution expressed in terms of the hypergeometric function n+1Fn. We also discuss a degeneration structure of the Painlevé system derived from the confluence of n+1Fn.

  11. Bäcklund transformations, Lax system, conservation laws and multisoliton solutions for Jimbo-Miwa equation with Bell-polynomials

    NASA Astrophysics Data System (ADS)

    Singh, Manjit; Gupta, R. K.

    2016-08-01

    Based on binary Bell polynomial approach, the bilinear equation and B a ¨cklund transformations for (3+1)-dimensional Jimbo-Miwa equation are obtained. By virtue of Cole-Hopf transformation, Lax system is constructed by direct linearization of coupled system of binary Bell polynomials. Furthermore, infinite conservation laws are obtained from two field condition in quick and natural way. Finally, a test function of extended three wave method is used to construct multisoliton solutions via bilinear equation.

  12. A Solution Space for a System of Null-State Partial Differential Equations: Part 2

    NASA Astrophysics Data System (ADS)

    Flores, Steven M.; Kleban, Peter

    2015-01-01

    This article is the second of four that completely and rigorously characterize a solution space for a homogeneous system of 2 N + 3 linear partial differential equations in 2 N variables that arises in conformal field theory (CFT) and multiple Schramm-Löwner evolution (SLE). The system comprises 2 N null-state equations and three conformal Ward identities which govern CFT correlation functions of 2 N one-leg boundary operators. In the first article (Flores and Kleban, Commun Math Phys, arXiv:1212.2301, 2012), we use methods of analysis and linear algebra to prove that dim , with C N the Nth Catalan number. The analysis of that article is complete except for the proof of a lemma that it invokes. The purpose of this article is to provide that proof. The lemma states that if every interval among ( x 2, x 3), ( x 3, x 4),…,( x 2 N-1, x 2 N ) is a two-leg interval of (defined in Flores and Kleban, Commun Math Phys, arXiv:1212.2301, 2012), then F vanishes. Proving this lemma by contradiction, we show that the existence of such a nonzero function implies the existence of a non-vanishing CFT two-point function involving primary operators with different conformal weights, an impossibility. This proof (which is rigorous in spite of our occasional reference to CFT) involves two different types of estimates, those that give the asymptotic behavior of F as the length of one interval vanishes, and those that give this behavior as the lengths of two intervals vanish simultaneously. We derive these estimates by using Green functions to rewrite certain null-state PDEs as integral equations, combining other null-state PDEs to obtain Schauder interior estimates, and then repeatedly integrating the integral equations with these estimates until we obtain optimal bounds. Estimates in which two interval lengths vanish simultaneously divide into two cases: two adjacent intervals and two non-adjacent intervals. The analysis of the latter case is similar to that for one vanishing

  13. Conceptual design of a closed loop nutrient solution delivery system for CELSS implementation in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.; Oleson, Mel W.; Cullingford, Hatice S.

    1990-01-01

    Described here are the results of a study to develop a conceptual design for an experimental closed loop fluid handling system capable of monitoring, controlling, and supplying nutrient solution to higher plants. The Plant Feeder Experiment (PFE) is designed to be flight tested in a microgravity environment. When flown, the PFX will provide information on both the generic problems of microgravity fluid handling and the specific problems associated with the delivery of the nutrient solution in a microgravity environment. The experimental hardware is designed to fit into two middeck lockers on the Space Shuttle, and incorporates several components that have previously been flight tested.

  14. Anomalous Diffusion in Polymer Solution as Probed by Fluorescence Correlation Spectroscopy and Its Universal Importance in Biological Systems

    NASA Astrophysics Data System (ADS)

    Ushida, Kiminori

    2008-02-01

    Experimental evidence of anomalous diffusion occurring in an inhomogeneous media (hyaluronan aquous solution) was obtained by use of fluorescence correlation spectroscopy (FCS) combined with other techniques (PFG-NMR and Photochemical reactions). The diffusion coefficient was obtained as a function of diffusion time or diffusion distance. Since this polymer solution can be regarded as a model system of extracellular matrices (ECMs), intercellular communication, which takes part in ECM, is greatly influenced by this anomalous diffusion mode. Therefore universal importance of anomalous diffusion in biological activity is identified in this series of independent experiments to measure diffusion coefficients.

  15. Bäcklund transformations, soliton solutions and wave functions of Kaup-Newell and Wadati-Konno-Ichikawa systems

    NASA Astrophysics Data System (ADS)

    Rangwala, Abbas A.; Rao, Jyoti A.

    1990-05-01

    Using the Bargmann-Darboux method, the Bäcklund transformations, n-soliton solutions and corresponding wave functions of the Kaup-Newell and Wadati-Konno-Ichikawa systems are obtained. These results culminate in an algebraic recursive procedure for the determination of multisoliton solutions and their wave functions of the derivative and mixed derivative nonlinear Schrödinger equations iQt+Qxx∓iα(||Q||2Q)x ±β||Q||2Q=0, α>0, β≥0.

  16. Extended molecular Ornstein-Zernike integral equation for fully anisotropic solute molecules: Formulation in a rectangular coordinate system

    NASA Astrophysics Data System (ADS)

    Ishizuka, Ryosuke; Yoshida, Norio

    2013-08-01

    An extended molecular Ornstein-Zernike (XMOZ) integral equation is formulated to calculate the spatial distribution of solvent around a solute of arbitrary shape and solid surfaces. The conventional MOZ theory employs spherical harmonic expansion technique to treat the molecular orientation of components of solution. Although the MOZ formalism is fully exact analytically, the truncation of the spherical harmonic expansion requires at a finite order for numerical calculation and causes the significant error for complex molecules. The XMOZ integral equation is the natural extension of the conventional MOZ theory to a rectangular coordinate system, which is free from the truncation of spherical harmonic expansion with respect to solute orientation. In order to show its applicability, we applied the XMOZ theory to several systems using the hypernetted-chain (HNC) and Kovalenko-Hirata approximations. The quality of results obtained within our theory is discussed by comparison with values from the conventional MOZ theory, molecular dynamics simulation, and three-dimensional reference interaction site model theory. The spatial distributions of water around the complex of non-charged sphere and dumbbell were calculated. Using this system, the approximation level of the XMOZ and other methods are discussed. To assess our theory, we also computed the excess chemical potentials for three realistic molecules (water, methane, and alanine dipeptide). We obtained the qualitatively reasonable results by using the XMOZ/HNC theory. The XMOZ theory covers a wide variety of applications in solution chemistry as a useful tool to calculate solvation thermodynamics.

  17. Extended molecular Ornstein-Zernike integral equation for fully anisotropic solute molecules: formulation in a rectangular coordinate system.

    PubMed

    Ishizuka, Ryosuke; Yoshida, Norio

    2013-08-28

    An extended molecular Ornstein-Zernike (XMOZ) integral equation is formulated to calculate the spatial distribution of solvent around a solute of arbitrary shape and solid surfaces. The conventional MOZ theory employs spherical harmonic expansion technique to treat the molecular orientation of components of solution. Although the MOZ formalism is fully exact analytically, the truncation of the spherical harmonic expansion requires at a finite order for numerical calculation and causes the significant error for complex molecules. The XMOZ integral equation is the natural extension of the conventional MOZ theory to a rectangular coordinate system, which is free from the truncation of spherical harmonic expansion with respect to solute orientation. In order to show its applicability, we applied the XMOZ theory to several systems using the hypernetted-chain (HNC) and Kovalenko-Hirata approximations. The quality of results obtained within our theory is discussed by comparison with values from the conventional MOZ theory, molecular dynamics simulation, and three-dimensional reference interaction site model theory. The spatial distributions of water around the complex of non-charged sphere and dumbbell were calculated. Using this system, the approximation level of the XMOZ and other methods are discussed. To assess our theory, we also computed the excess chemical potentials for three realistic molecules (water, methane, and alanine dipeptide). We obtained the qualitatively reasonable results by using the XMOZ/HNC theory. The XMOZ theory covers a wide variety of applications in solution chemistry as a useful tool to calculate solvation thermodynamics. PMID:24006986

  18. Semi-analytical solutions for flow to a well in an unconfined-fractured aquifer system

    NASA Astrophysics Data System (ADS)

    Sedghi, Mohammad M.; Samani, Nozar

    2015-09-01

    Semi-analytical solutions of flow to a well in an unconfined single porosity aquifer underlain by a fractured double porosity aquifer, both of infinite radial extent, are obtained. The upper aquifer is pumped at a constant rate from a pumping well of infinitesimal radius. The solutions are obtained via Laplace and Hankel transforms and are then numerically inverted to time domain solutions using the de Hoog et al. algorithm and Gaussian quadrature. The results are presented in the form of dimensionless type curves. The solution takes into account the effects of pumping well partial penetration, water table with instantaneous drainage, leakage with storage in the lower aquifer into the upper aquifer, and storativity and hydraulic conductivity of both fractures and matrix blocks. Both spheres and slab-shaped matrix blocks are considered. The effects of the underlying fractured aquifer hydraulic parameters on the dimensionless drawdown produced by the pumping well in the overlying unconfined aquifer are examined. The presented solution can be used to estimate hydraulic parameters of the unconfined and the underlying fractured aquifer by type curve matching techniques or with automated optimization algorithms. Errors arising from ignoring the underlying fractured aquifer in the drawdown distribution in the unconfined aquifer are also investigated.

  19. [Transportation and transformation of 14C-phenanthrene in closed chamber (nutrient solution-lava-plant-air) system].

    PubMed

    Jiang, X; Ou, Z; Ying, P; Yediler, A; Ketrrup, A

    2001-06-01

    The transportation and transformation of 14C-phenanthrene in a closed 'plant-lava-nutrient solution-air' chamber system was studied by using radioactivity technology. The results showed that in this closed chamber system, phenanthrene was degraded fast. The radioactivity of 14C left at 23d in the nutrient solution was only 25% of applied. At the end of experiment (46d), the distribution sequence of 14C activity in the components of closed chamber system was root (38.55%) > volatile organic compounds (VOCs, 17.68%) > lava (14.35%) > CO2 (11.42%) > stem (2%). 14C-activities in plant tissue were combined with the tissue, and existed in the forms of lava-bound(root 4.68%; stem and leaves 0.68%) and polar metabolites (root 23.14%; stem 0.78%). PMID:11758435

  20. Nonlinear stability of periodic traveling wave solutions of systems of viscous conservation laws in the generic case

    NASA Astrophysics Data System (ADS)

    Johnson, Mathew A.; Zumbrun, Kevin

    Extending previous results of Oh-Zumbrun and Johnson-Zumbrun, we show that spectral stability implies linearized and nonlinear stability of spatially periodic traveling wave solutions of viscous systems of conservation laws for systems of generic type, removing a restrictive assumption that wave speed be constant to first order along the manifold of nearby periodic solutions. Key to our analysis is a nonlinear cancellation estimate observed by Johnson and Zumbrun, along with a detailed understanding of the Whitham averaged system. The latter motivates a careful analysis of the Bloch perturbation expansion near zero frequency and suggests factoring out an appropriate translational modulation of the underlying wave, allowing us to derive the sharpened low-frequency estimates needed to close the nonlinear iteration arguments.

  1. [Systems theory solution of the Bieri trilemma. Comments on the comments by E. G. Schmidt on my comments on the body-mind problem in psychosomatic medicine].

    PubMed

    Meyer, A E

    1989-11-01

    E. G. Schmidt criticizes my critique of the wholist-emergentist solution for the mind-body problem. Against my repudiation he proposes an emergentist system theory solution apparently solving the so-called Bieri trilemma. I contend that his solution falsely introduces "psychogenic" causality into the wholist-emergentistic theory. PMID:2587694

  2. Spatial and temporal geochemical trends in the hydrothermal system of Yellowstone National Park: Inferences from river solute fluxes

    USGS Publications Warehouse

    Hurwitz, S.; Lowenstern, J. B.; Heasler, H.

    2007-01-01

    We present and analyze a chemical dataset that includes the concentrations and fluxes of HCO3-, SO42-, Cl-, and F- in the major rivers draining Yellowstone National Park (YNP) for the 2002-2004 water years (1 October 2001 - 30 September 2004). The total (molar) flux in all rivers decreases in the following order, HCO3- > Cl- > SO42- > F-, but each river is characterized by a distinct chemical composition, implying large-scale spatial heterogeneity in the inputs of the various solutes. The data also display non-uniform temporal trends; whereas solute concentrations and fluxes are nearly constant during base-flow conditions, concentrations decrease, solute fluxes increase, and HCO3-/Cl-, and SO42-/Cl- increase during the late-spring high-flow period. HCO3-/SO42- decreases with increasing discharge in the Madison and Falls Rivers, but increases with discharge in the Yellowstone and Snake Rivers. The non-linear relations between solute concentrations and river discharge and the change in anion ratios associated with spring runoff are explained by mixing between two components: (1) a component that is discharged during base-flow conditions and (2) a component associated with snow-melt runoff characterized by higher HCO3-/Cl- and SO42-/Cl-. The fraction of the second component is greater in the Yellowstone and Snake Rivers, which host lakes in their drainage basins and where a large fraction of the solute flux follows thaw of ice cover in the spring months. Although the total river HCO3- flux is larger than the flux of other solutes (HCO3-/Cl- ??? 3), the CO2 equivalent flux is only ??? 1% of the estimated emission of magmatic CO2 soil emissions from Yellowstone. No anomalous solute flux in response to perturbations in the hydrothermal system was observed, possibly because gage locations are too distant from areas of disturbance, or because of the relatively low sampling frequency. In order to detect changes in river hydrothermal solute fluxes, sampling at higher

  3. Integrability aspects and soliton solutions for the inhomogeneous reduced Maxwell-Bloch system in nonlinear optics with symbolic computation

    NASA Astrophysics Data System (ADS)

    Hao, Hui-Qin; Zhang, Jian-Wen

    2015-05-01

    In this paper, we investigate the inhomogeneous reduced Maxwell-Bloch system, which describes the propagation of the intense ultra-short optical pulses through an inhomogeneous two-level dielectric medium. Through symbolic computation, the integrability aspects including the Painlevé integrable condition, Lax pair and infinite conservation laws are derived. By virtue of the Darboux transformation method, one- and two-soliton solutions are generated on the nonvanishing background, including the bright solitons, dark solitons, periodic solutions and some two-soliton solutions. The asymptotic analysis method is performed to verify the elastic interaction between two solitons. Furthermore, by virtue of some figures, the dynamic properties of those solitons are discussed. The results may be useful in the study of the ultrashort pulses propagation in such situations as the model of the two-level dielectric media.

  4. Global existence and boundedness of radial solutions to a two dimensional fully parabolic chemotaxis system with general sensitivity

    NASA Astrophysics Data System (ADS)

    Fujie, Kentarou; Senba, Takasi

    2016-08-01

    This paper deals with positive radially symmetric solutions of the Neumann boundary value problem for the fully parabolic chemotaxis system, {ut=Δu‑∇ṡ(u∇χ(v))in Ω×(0,∞),τvt=Δv‑v+uin Ω×(0,∞), in a ball Ω \\subset {{{R}}2} with general sensitivity function χ (v) satisfying {χ\\prime}>0 and decaying property {χ\\prime}(s)\\to 0 (s\\to ∞ ), parameter τ \\in ≤ft(0,1\\right] and nonnegative radially symmetric initial data. It is shown that if τ \\in ≤ft(0,1\\right] is sufficiently small, then the problem has a unique classical radially symmetric solution, which exists globally and remains uniformly bounded in time. Especially, this result establishes global existence of solutions in the case χ (v)={χ0}log v for all {χ0}>0 , which has been left as an open problem.

  5. Tomographic images of land mines by the elliptic systems method using GPR: efficient solution of the forward problem

    NASA Astrophysics Data System (ADS)

    Gryazin, Yuriy A.; Klibanov, Michael V.; Lucas, Thomas R.

    1999-08-01

    The ultimate goal of the authors is apply inverse problem methods to image land mines using a electromagnetic GPR signal. Specifically, the intention is to use the recently developed Elliptic Systems Method, which has been successfully applied by these authors to the problem of laser imaging of biological tissues. As the first step, however, one should develop a fast and accurate numerical method for the solution of the forward problem to simulate the data for the inverse problem. The main difficulty of the latter consists of the requirement of solving a Helmholtz- like equation for high frequencies which is very time consuming using standard direct solution techniques. A novel accurate and rapid numerical procedure for the solution of this equation is described in this paper.

  6. Rheology and instabilities of thermally responsive polymer solutions in microfluidic systems

    NASA Astrophysics Data System (ADS)

    Stoeber, Boris; Liepmann, Dorian; Muller, Susan

    2004-11-01

    Aqueous solutions of PEO_x-PPO_y-PEOx triblock copolymers undergo a reversible phase change at elevated concentrations and/or temperatures from an isotropic micelle liquid to a soft cubic crystal. The thermo-thickening behavior of these polymer solutions, as well as their shear-thinning properties, have been characterized using cone-and-plate rheometry. Observations of the gel formation process in microchannels under different flow conditions, for example behind a moving air bubble, have been explained by the rheological properties of these polymer solutions. Furthermore, at ambient temperatures close to the gelation temperature shear-induced viscous heating in the flow is sufficient to induce gel formation. This effect has been used to demonstrate thermo-viscous instabilities as well as passive flow control in microfluidic devices.

  7. Optimal Solutions of Multiproduct Batch Chemical Process Using Multiobjective Genetic Algorithm with Expert Decision System

    PubMed Central

    Mokeddem, Diab; Khellaf, Abdelhafid

    2009-01-01

    Optimal design problem are widely known by their multiple performance measures that are often competing with each other. In this paper, an optimal multiproduct batch chemical plant design is presented. The design is firstly formulated as a multiobjective optimization problem, to be solved using the well suited non dominating sorting genetic algorithm (NSGA-II). The NSGA-II have capability to achieve fine tuning of variables in determining a set of non dominating solutions distributed along the Pareto front in a single run of the algorithm. The NSGA-II ability to identify a set of optimal solutions provides the decision-maker DM with a complete picture of the optimal solution space to gain better and appropriate choices. Then an outranking with PROMETHEE II helps the decision-maker to finalize the selection of a best compromise. The effectiveness of NSGA-II method with multiojective optimization problem is illustrated through two carefully referenced examples. PMID:19543537

  8. THERMODYNAMICS AND SOLUBILITY OF (UxNp1-x)O2(am) SOLID SOLUTION IN THE CARBONATE SYSTEM

    SciTech Connect

    Rai, Dhanpat; Hess, Nancy J.; Yui, Mikazu; Felmy, Andrew R.; Moore, Dean A.

    2004-03-15

    ABSTRACT -The formation of a solid solution can significantly affect the solubility of a minor component. The objectives of this study were to determine the nature of U(IV) and Np(IV) solid solutions and their thermodynamic properties. For this purpose, co-precipitates of U(IV) and Np(IV) [(UxNp1-x )O2(am), with values for x of 0.95, 0.85, 0.50, 0.15, and 0.05] were prepared, characterized, and used to determine their solubility as a function of K2CO3 concentrations ranging from 1.0 m to 5.0 m in the presence of 0.01 m Na2S2O4 and 0.01 m KOH, and as a function of KHCO3 concentrations ranging from 0.1 m to 0.8 m in the presence of 0.01 m Na2S2O4. The solubility data show that the equilibrium in these systems is reached in <7 days, the solubility-controlling solids are amorphous, and that we were successful in maintaining U and Np in the tetravalent state. A scanning electron microscope equipped with energy dispersive spectrometry and x-ray absorption spectroscopic analyses of the solids indicated the equilibrated co-precipitates to be solid solutions. A close agreement between the thermodynamic predictions, assuming an ideal solid solution, and the experimental solubilities shows that U(IV) and Np(IV) form an ideal solid solution and that non-ideal solid solution behavior for this system can be ruled out.

  9. An analytical solution for one-dimensional contaminant diffusion through multi-layered system and its applications

    NASA Astrophysics Data System (ADS)

    Chen, Yunmin; Xie, Haijian; Ke, Han; Chen, Renpeng

    2009-09-01

    An analytical solution for one-dimensional contaminant diffusion through multi-layered media is derived regarding the change of the concentration of contaminants at the top boundary with time. The model accounts for the arbitrary initial conditions and the conditions of zero concentration and zero mass flux on the bottom boundary. The average degree of diffusion of the layered system is introduced on the basis of the solution. The results obtained by the presented analytical solutions agree well with those obtained by the numerical methods presented in the literature papers. The application of the analytical solution to the problem of landfill liner design is illustrated by considering a composite liner consisting of geomembrane and compacted clay liner. The results show that the 100-year mass flux of benzene at the bottom of the composite liner is 45 times higher than that of acetone for the same composite liner. The half-life of the contaminant has a great influence on the solute flux of benzene diffused into the underlying aquifer. Results also indicates that an additional 2.9-5.0 m of the conventional (untreated) compacted clay liner under the geomembrane is required to achieve the same level of protection as provided by 0.60 m of the Hexadecyltrimethylammonium (HDTMA)-treated compacted clay liners in conjunction with the geomembrane. Applications of the solution are also presented in the context of a contaminated two-layered media to demonstrate that different boundary and initial conditions can greatly affect the decontamination rate of the problem. The method is relatively simple to apply and can be used for performing equivalency analysis of landfill liners, preliminary design of groundwater remediation system, evaluating experimental results, and verifying more complex numerical models.

  10. Phase equilibria in a system of aqueous arginine with an octane solution of sulfonic acid

    NASA Astrophysics Data System (ADS)

    Kuvaeva, Z. I.; Koval'chuk, I. V.; Vodop'yanova, L. A.; Soldatov, V. S.

    2013-05-01

    The extraction of arginine (Arg) from aqueous salt (0.1 M NaCl) solutions with a sulfo extractant in a wide range of pH values and amino acid concentrations was studied. The 0.1 M solution of dinonylnaphthalenesulfonic acid (HD) in octane was used as an extractant. The degree of extraction was found to be high at pH 0.8-9.0. This can be explained by the effect of additional intermolecular interactions in the extractant phase involving the guanidine group of Arg.

  11. Distribution and determination of Pb, Cd, Bi and Cu in the sea brine system: solution--colloidal particles--biota.

    PubMed

    Bozhkov, Ognyan; Tzvetkova, Christina; Russeva, Elena

    2006-01-01

    The distribution of Pb, Cd, Bi, and Cu in Black Sea brine system (solution--colloidal particles--biota) produced in Burgas and Pomorie salterns is studied. The established distribution of the title elements among the brine components is as follows: Pb--25% in the salt solution, 30%--in colloidal particles, 45%--in biota (Halobacterium salinarium and microalgae Dunaliela salina); Cu--30% in the salt solution, 22%--in colloidal particles, 48%--in biota. Cd and Bi are not detected in biota. They are uniformly distributed (50%: 50%) between the salt solution and colloidal particles. Two procedures for analysis are developed. The first one is designed for determination of the total content of the studied metals in brine. It involves elimination of the biota interference by addition of ethanol, extraction and pre-concentration of the metals with NaDDC into CCl4 followed by FAAS determination. The second procedure intends determination of the elements in the separate components of the brine. It involves separation of the colloidal particles through centrifugation, separation of the studied elements from the resulting solution as dithiocarbamate complexes on a Millipore filter, dissolution of the retained metal species and subsequent FAAS analysis. PMID:16948432

  12. Achieving and Sustaining Automated Health Data Linkages for Learning Systems: Barriers and Solutions

    PubMed Central

    Van Eaton, Erik G.; Devlin, Allison B.; Devine, Emily Beth; Flum, David R.; Tarczy-Hornoch, Peter

    2014-01-01

    Introduction: Delivering more appropriate, safer, and highly effective health care is the goal of a learning health care system. The Agency for Healthcare Research and Quality (AHRQ) funded enhanced registry projects: (1) to create and analyze valid data for comparative effectiveness research (CER); and (2) to enhance the ability to monitor and advance clinical quality improvement (QI). This case report describes barriers and solutions from one state-wide enhanced registry project. Methods: The Comparative Effectiveness Research and Translation Network (CERTAIN) deployed the commercially available Amalga Unified Intelligence System™ (Amalga) as a central data repository to enhance an existing QI registry (the Automation Project). An eight-step implementation process included hospital recruitment, technical electronic health record (EHR) review, hospital-specific interface planning, data ingestion, and validation. Data ownership and security protocols were established, along with formal methods to separate data management for QI purposes and research purposes. Sustainability would come from lowered chart review costs and the hospital’s desire to invest in the infrastructure after trying it. Findings: CERTAIN approached 19 hospitals in Washington State operating within 12 unaffiliated health care systems for the Automation Project. Five of the 19 completed all implementation steps. Four hospitals did not participate due to lack of perceived institutional value. Ten hospitals did not participate because their information technology (IT) departments were oversubscribed (e.g., too busy with Meaningful Use upgrades). One organization representing 22 additional hospitals expressed interest, but was unable to overcome data governance barriers in time. Questions about data use for QI versus research were resolved in a widely adopted project framework. Hospitals restricted data delivery to a subset of patients, introducing substantial technical challenges. Overcoming

  13. The Riemann problem for the Brio system: a solution containing a Dirac mass obtained via a distributional product

    NASA Astrophysics Data System (ADS)

    Sarrico, C. O. R.

    2015-10-01

    The system of conservation laws {u_t} + {( {{{u^2} + {v^2}}/2} )_x} = 0, v t + ( uv - v)x = 0 with the initial conditions u( x, 0) = l 0 + b 0 H( x), v( x, 0) = k 0 + c 0 H( x), where H is the Heaviside function is studied. This strictly hyperbolic system was introduced by M. Brio in 1988 and provides a simplified model for the magnetohydrodynamics equations. Under certain compatibility conditions for the constants l 0, b 0, k 0, c 0, an explicit solution containing a Dirac mass is given and we prove the uniqueness of this solution within a convenient class of distributions which includes Dirac-delta measures. Our concept of solution is defined within the framework of a distributional product, and it is a consistent extension of the concept of a classical solution. This direct method seems considerably simpler than the weak asymptotic method usually used in the study of delta-shocks emergence in nonlinear conservation laws.

  14. The Separatory Cylinder: A Novel Solvent Extraction System for the Study of Chemical Equilibrium in Solution.

    ERIC Educational Resources Information Center

    Cwikel, Dori; And Others

    1986-01-01

    Dicusses the use of the separatory cylinder in student laboratory experiments for investigating equilibrium distribution of a solute between immiscible phases. Describes the procedures for four sets of experiments of this nature. Lists of materials needed and quantities of reagents are provided. (TW)

  15. Semianalytical Solutions for Transport in Aquifer and Fractured Clay Matrix System

    EPA Science Inventory

    A three-dimensional mathematical model that describes transport of contaminant in a horizontal aquifer with simultaneous diffusion into a fractured clay formation is proposed. A group of analytical solutions is derived based on specific initial and boundary conditions as well as ...

  16. Preparation and Analysis of Solid Solutions in the Potassium Perchlorate-Permanganate System.

    ERIC Educational Resources Information Center

    Johnson, Garrett K.

    1979-01-01

    Describes an experiment, designed for and tested in an advanced inorganic laboratory methods course for college seniors and graduate students, that prepares and analyzes several samples in the nearly ideal potassium perchlorate-permanganate solid solution series. The results are accounted for by a theoretical treatment based upon aqueous…

  17. Analytical Solutions for Transport in Aquifer and Fractured Clay Matrix System

    EPA Science Inventory

    A three-dimensional mathematical model that describes transport of contaminant in a horizontal aquifer with simultaneous diffusion into a fractured clay formation is proposed. A group of analytical solutions is derived based on specific initial and boundary conditions as well as ...

  18. Existence of periodic solutions for the Lotka-Volterra type systems

    NASA Astrophysics Data System (ADS)

    Hirano, Norimichi; Rybicki, Sławomir

    In this paper we prove the existence of nonstationary periodic solutions of delay Lotka-Volterra equations. In the proofs we use the S-degree due to Dylawerski et al. [G. Dylawerski, K. Geba, J. Jodel, W. Marzantowicz, An S-equivariant degree and the Fuller index, Ann. Polon. Math. 63 (1991) 243-280].

  19. Future non-linear stability for solutions of the Einstein-Vlasov system of Bianchi types II and VI0

    NASA Astrophysics Data System (ADS)

    Nungesser, Ernesto

    2012-10-01

    In a recent paper [E. Nungesser, "Future non-linear stability for reflection symmetric solutions of the Einstein-Vlasov system of Bianchi types II and VI0," Annales Henri Poincare (2012), 10.1007/s00023-012-0201-0], we have treated the future nonlinear stability for reflection symmetric solutions of the Einstein-Vlasov system of Bianchi types II and VI0. We have been able now to remove the reflection symmetry assumption, thus treating the non-diagonal case. Apart from the increasing complexity, the methods have been essentially the same as in the diagonal case, showing that they are thus quite powerful. Here, the challenge was to put the equations in a form that permits the use of the previous results. We are able to conclude that after a possible basis change, the future of the non-diagonal spacetimes in consideration is asymptotically diagonal.

  20. Binary Mutual Diffusion Coefficients of Polymer/Solvent Systems Using Compressible Regular Solutions Theory and Free Volume Theory

    NASA Astrophysics Data System (ADS)

    Farajnezhad, Arsalan; Asef Afshar, Orang; Asgarpour Khansary, Milad; Shirazian, Saeed

    2016-07-01

    The free volume theory has found practical application for prediction of diffusional behavior of polymer/solvent systems. In this paper, reviewing free volume theory, binary mutual diffusion coefficients in some polymer/solvent systems have been systematically presented through chemical thermodynamic modeling in terms of both activity coefficients and fugacity coefficients models. Here chemical thermodynamic model of compressible regular solution (CRS) was used for evaluation of diffusion coefficients calculations as the pure component properties would be required only. Four binary polymeric solutions of cyclohexane/polyisobutylene, n-pentane/polyisobutylene, toluene/polyisobutylene and chloroform/polyisobutylene were considered. The agreement between calculated data and the experimentally collected data was desirable and no considerable error propagation in approximating mutual diffusion coefficients has been observed.

  1. ILUBCG2-11: Solution of 11-banded nonsymmetric linear equation systems by a preconditioned biconjugate gradient routine

    NASA Astrophysics Data System (ADS)

    Chen, Y.-M.; Koniges, A. E.; Anderson, D. V.

    1989-10-01

    The biconjugate gradient method (BCG) provides an attractive alternative to the usual conjugate gradient algorithms for the solution of sparse systems of linear equations with nonsymmetric and indefinite matrix operators. A preconditioned algorithm is given, whose form resembles the incomplete L-U conjugate gradient scheme (ILUCG2) previously presented. Although the BCG scheme requires the storage of two additional vectors, it converges in a significantly lesser number of iterations (often half), while the number of calculations per iteration remains essentially the same.

  2. Aqueous Biphasic Systems Based on Salting-Out Polyethylene Glycol or Ionic Solutions: Strategies for Actinide or Fission Product Separations

    SciTech Connect

    Rogers, Robin D.; Gutowski, Keith E.; Griffin, Scott T.; Holbrey, John D.

    2004-03-29

    Aqueous biphasic systems can be formed by salting-out (with kosmotropic, waterstructuring salts) water soluble polymers (e.g., polyethylene glycol) or aqueous solutions of a wide range of hydrophilic ionic liquids based on imidazolium, pyridinium, phosphonium and ammonium cations. The use of these novel liquid/liquid biphases for separation of actinides or other fission products associated with nuclear wastes (e.g., pertechnetate salts) has been demonstrated and will be described in this presentation.

  3. Existence of Global Strong Solutions to a Beam-Fluid Interaction System

    NASA Astrophysics Data System (ADS)

    Grandmont, Céline; Hillairet, Matthieu

    2016-06-01

    We study an unsteady nonlinear fluid-structure interaction problem which is a simplified model to describe blood flow through viscoelastic arteries. We consider a Newtonian incompressible two-dimensional flow described by the Navier-Stokes equations set in an unknown domain depending on the displacement of a structure, which itself satisfies a linear viscoelastic beam equation. The fluid and the structure are fully coupled via interface conditions prescribing the continuity of the velocities at the fluid-structure interface and the action-reaction principle. We prove that strong solutions to this problem are global-in-time. We obtain, in particular that contact between the viscoelastic wall and the bottom of the fluid cavity does not occur in finite time. To our knowledge, this is the first occurrence of a no-contact result, and of the existence of strong solutions globally in time, in the frame of interactions between a viscous fluid and a deformable structure.

  4. Solution of the self-adjoint radiative transfer equation on hybrid computer systems

    NASA Astrophysics Data System (ADS)

    Gasilov, V. A.; Kuchugov, P. A.; Olkhovskaya, O. G.; Chetverushkin, B. N.

    2016-06-01

    A new technique for simulating three-dimensional radiative energy transfer for the use in the software designed for the predictive simulation of plasma with high energy density on parallel computers is proposed. A highly scalable algorithm that takes into account the angular dependence of the radiation intensity and is free of the ray effect is developed based on the solution of a second-order equation with a self-adjoint operator. A distinctive feature of this algorithm is a preliminary transformation of rotation to eliminate mixed derivatives with respect to the spatial variables, simplify the structure of the difference operator, and accelerate the convergence of the iterative solution of the equation. It is shown that the proposed method correctly reproduces the limiting cases—isotropic radiation and the directed radiation with a δ-shaped angular distribution.

  5. Dynamic nuclear polarization methods in solids and solutions to explore membrane proteins and membrane systems.

    PubMed

    Cheng, Chi-Yuan; Han, Songi

    2013-01-01

    Membrane proteins regulate vital cellular processes, including signaling, ion transport, and vesicular trafficking. Obtaining experimental access to their structures, conformational fluctuations, orientations, locations, and hydration in membrane environments, as well as the lipid membrane properties, is critical to understanding their functions. Dynamic nuclear polarization (DNP) of frozen solids can dramatically boost the sensitivity of current solid-state nuclear magnetic resonance tools to enhance access to membrane protein structures in native membrane environments. Overhauser DNP in the solution state can map out the local and site-specific hydration dynamics landscape of membrane proteins and lipid membranes, critically complementing the structural and dynamics information obtained by electron paramagnetic resonance spectroscopy. Here, we provide an overview of how DNP methods in solids and solutions can significantly increase our understanding of membrane protein structures, dynamics, functions, and hydration in complex biological membrane environments. PMID:23331309

  6. Investigation on the chemical stability of erythromycin in solutions using an optimization system.

    PubMed

    Brisaert, M; Heylen, M; Plaizier-Vercammen, J

    1996-10-01

    Erythromycin, an antibiotic commonly used topically in the treatment of acne, is unstable in solution. The stability is influenced by the pH and by the presence of water. The influence of the pH on the stability of erythromycin was investigated even with the use of dimethyl isosorbide as co-solvent instead of water. The addition of zinc was attempted to ameliorate erythromycin stability as suggested in the literature. To investigate these three factors and their interactions, an optimization technique was carried out consisting of a 2(3) factorial analysis and a rotative central composite design. The erythromycin solutions were analysed with an HPLC method. The pH and the concentration of dimethyl isosorbide had a significant influence on the stability of erythromycin but the addition of zinc was not a significant factor. Moreover, there was a significant interaction between the pH and dimethyl isosorbide. PMID:8933579

  7. THE SOLAR NEBULA ON FIRE: A SOLUTION TO THE CARBON DEFICIT IN THE INNER SOLAR SYSTEM

    SciTech Connect

    Lee, Jeong-Eun; Bergin, Edwin A.; Nomura, Hideko E-mail: ebergin@umich.edu

    2010-02-10

    Despite a surface dominated by carbon-based life, the bulk composition of the Earth is dramatically carbon poor when compared to the material available at formation. Bulk carbon deficiency extends into the asteroid belt representing a fossil record of the conditions under which planets are born. The initial steps of planet formation involve the growth of primitive sub-micron silicate and carbon grains in the Solar Nebula. We present a solution wherein primordial carbon grains are preferentially destroyed by oxygen atoms ignited by heating due to stellar accretion at radii <5 AU. This solution can account for the bulk carbon deficiency in the Earth and meteorites, the compositional gradient within the asteroid belt, and for growing evidence for similar carbon deficiency in rocks surrounding other stars.

  8. Dynamic Nuclear Polarization Methods in Solids and Solutions to Explore Membrane Proteins and Membrane Systems

    NASA Astrophysics Data System (ADS)

    Cheng, Chi-Yuan; Han, Songi

    2013-04-01

    Membrane proteins regulate vital cellular processes, including signaling, ion transport, and vesicular trafficking. Obtaining experimental access to their structures, conformational fluctuations, orientations, locations, and hydration in membrane environments, as well as the lipid membrane properties, is critical to understanding their functions. Dynamic nuclear polarization (DNP) of frozen solids can dramatically boost the sensitivity of current solid-state nuclear magnetic resonance tools to enhance access to membrane protein structures in native membrane environments. Overhauser DNP in the solution state can map out the local and site-specific hydration dynamics landscape of membrane proteins and lipid membranes, critically complementing the structural and dynamics information obtained by electron paramagnetic resonance spectroscopy. Here, we provide an overview of how DNP methods in solids and solutions can significantly increase our understanding of membrane protein structures, dynamics, functions, and hydration in complex biological membrane environments.

  9. Domains of analyticity for response solutions in strongly dissipative forced systems

    SciTech Connect

    Corsi, Livia E-mail: feola@mat.uniroma1.it; Feola, Roberto E-mail: feola@mat.uniroma1.it; Gentile, Guido E-mail: feola@mat.uniroma1.it

    2013-12-15

    We study the ordinary differential equation εx{sup ¨}+x{sup .}+εg(x)=εf(ωt), where g and f are real-analytic functions, with f quasi-periodic in t with frequency vector ω. If c{sub 0}∈R is such that g(c{sub 0}) equals the average of f and g′(c{sub 0}) ≠ 0, under very mild assumptions on ω there exists a quasi-periodic solution close to c{sub 0} with frequency vector ω. We show that such a solution depends analytically on ε in a domain of the complex plane tangent more than quadratically to the imaginary axis at the origin.

  10. Periodic solutions of a nonautonomous predator-prey system with stage structure and time delays

    NASA Astrophysics Data System (ADS)

    Xu, Rui; Wang, Zhiqiang

    2006-11-01

    A nonautonomous Lotka-Volterra type predator-prey model with stage structure and time delays is investigated. It is assumed in the model that the individuals in each species may belong to one of two classes: the immatures and the matures, the age to maturity is presented by a time delay, and that the immature predators do not feed on prey and do not have the ability to reproduce. By some comparison arguments we first discuss the permanence of the model. By using the continuation theorem of coincidence degree theory, sufficient conditions are derived for the existence of positive periodic solutions to the model. By means of a suitable Lyapunov functional, sufficient conditions are obtained for the uniqueness and global stability of the positive periodic solutions to the model.

  11. An electric impedance based microelectromechanical system flow sensor for ionic solutions

    PubMed Central

    Ayliffe, H Edward; Rabbitt, RD

    2008-01-01

    Microfluidic devices with channel cross sections measuring 4 × 10 μm2 instrumented with gold microelectrodes were used to sense flow rates of ionic solutions on the basis of electric impedance (EI) measured perpendicular to the flow. Negative pressures were applied to access ports of the microdevices to generate flow of saline solutions (physiologic concentrations 0.9%) through the micro-EI recording zone with flow rates between 2.4 and 4.8 μl min−1. The EI spectra (100 Hz–20 MHz) recorded under flow conditions were compared with the no-flow condition. Changes in the magnitude of EI (at 350 Hz) for flow rates as low as 2.4 μl min−1 were statistically significant compared with the no-flow condition. The observed dependence of EI on flow rate is attributed to the relative difference between the rate of migration of charge-balancing electrolyte ions to the electrode surface and the rate of removal of the same ions by forced convection. An electrochemical convection–diffusion model was used to study the observed dependence on flow. Simulations support the conceptual model that passing DC current from the gold electrodes into the ionic solution results in an increase in ionic concentration near the electrode surface (due to the inward migration of counter-balancing ions). When the fluid flow rates increase, these counter-balancing ions are replaced by the bulk solution, thereby lowering the average ionic concentration within the recording zone. This local concentration drop results in an increase in the real part of the impedance. PMID:19672321

  12. Implementation of a block Lanczos algorithm for Eigenproblem solution of gyroscopic systems

    NASA Technical Reports Server (NTRS)

    Gupta, Kajal K.; Lawson, Charles L.

    1987-01-01

    The details of implementation of a general numerical procedure developed for the accurate and economical computation of natural frequencies and associated modes of any elastic structure rotating along an arbitrary axis are described. A block version of the Lanczos algorithm is derived for the solution that fully exploits associated matrix sparsity and employs only real numbers in all relevant computations. It is also capable of determining multiple roots and proves to be most efficient when compared to other, similar, exisiting techniques.

  13. Studies of adsorption equilibria and kinetics in the systems: Aqueous solution of dyes-mesoporous carbons

    NASA Astrophysics Data System (ADS)

    Derylo-Marczewska, A.; Marczewski, A. W.; Winter, Sz.; Sternik, D.

    2010-06-01

    Two carbonaceous materials were synthesized by using the method of impregnation of mesoporous silicas obtained by applying the Pluronic copolymers as pore-creating agents. The isotherms of adsorption of methylene blue and methyl orange from aqueous solutions were measured by the static method. The profiles of adsorbate concentration change in time were obtained from the UV-vis spectra. The adsorption isotherms and kinetic dependence were discussed in the terms of theory of adsorption on heterogeneous surfaces.

  14. [A solution to add digital signatures to medical images according to the DICOM standard: embedded systems].

    PubMed

    Schütze, B; Kroll, M; Filler, T J

    2005-01-01

    Radiology departments often underestimate the importance of protecting medical data during transmission, including the precautions taken to ensure data protection. In teleradiology, transmitted as well as stored patient data have to be signed digitally according to the currently valid regulation (Rontgenverordnung, RoV). The DICOM standard facilitates a digital signature. So far, medical image manufacturers only announced to support this security feature. We introduce a solution that extends the feature of digital signing to older modalities. PMID:15657831

  15. Sustainable Energy Solutions Task 1.0: Networked Monitoring and Control of Small Interconnected Wind Energy Systems

    SciTech Connect

    Janet.twomey@wichita.edu

    2010-04-30

    EXECUTIVE SUMARRY This report presents accomplishments, results, and future work for one task of five in the Wichita State University Sustainable Energy Solutions Project: To develop a scale model laboratory distribution system for research into questions that arise from networked control and monitoring of low-wind energy systems connected to the AC distribution system. The lab models developed under this task are located in the Electric Power Quality Lab in the Engineering Research Building on the Wichita State University campus. The lab system consists of four parts: 1. A doubly-fed induction generator 2. A wind turbine emulator 3. A solar photovoltaic emulator, with battery energy storage 4. Distribution transformers, lines, and other components, and wireless and wired communications and control These lab elements will be interconnected and will function together to form a complete testbed for distributed resource monitoring and control strategies and smart grid applications testing. Development of the lab system will continue beyond this project.

  16. In-line System to Produce High-Purity Acid Solutions.

    PubMed

    Masunaga, Hiroto; Higo, Yuji; Ishii, Mizuo; Maruyama, Noboru; Yamazaki, Shigeo

    2016-01-01

    Herein, we report a new device that generates a high-purity acid solution. It comprises three compartments divided by anion-exchange membranes and filled with ion-exchange resins. Fluorochemical cation-exchange membranes, which tolerate electrochemical wear and permit bulk flow, are inserted between each electrode and the anion-exchange resin. A bipolar boundary is a composite boundary comprising anion and cation exchangers. This device has four bipolar boundaries to separate the location of acid generation from the location where water is electrolyzed. It can tolerate high pressures, resist degradation due to electrolysis at the electrodes, and produce high-purity acid solutions that are free from gases and cationic impurities. The acid solution is generated on the basis of an electrokinetic phenomenon at the surfaces of ion-exchange resins and membranes in an electric field; its concentration can be controlled at rates from 0.01 to 100 μmol/min by adjusting the electrical current applied to the device. PMID:27302592

  17. Solution- and Adsorbed-State Structural Ensembles Predicted for the Statherin-Hydroxyapatite System

    PubMed Central

    Masica, David L.; Gray, Jeffrey J.

    2009-01-01

    Abstract We have developed a multiscale structure prediction technique to study solution- and adsorbed-state ensembles of biomineralization proteins. The algorithm employs a Metropolis Monte Carlo-plus-minimization strategy that varies all torsional and rigid-body protein degrees of freedom. We applied the technique to fold statherin, starting from a fully extended peptide chain in solution, in the presence of hydroxyapatite (HAp) (001), (010), and (100) monoclinic crystals. Blind (unbiased) predictions capture experimentally observed macroscopic and high-resolution structural features and show minimal statherin structural change upon adsorption. The dominant structural difference between solution and adsorbed states is an experimentally observed folding event in statherin's helical binding domain. Whereas predicted statherin conformers vary slightly at three different HAp crystal faces, geometric and chemical similarities of the surfaces allow structurally promiscuous binding. Finally, we compare blind predictions with those obtained from simulation biased to satisfy all previously published solid-state NMR (ssNMR) distance and angle measurements (acquired from HAp-adsorbed statherin). Atomic clashes in these structures suggest a plausible, alternative interpretation of some ssNMR measurements as intermolecular rather than intramolecular. This work demonstrates that a combination of ssNMR and structure prediction could effectively determine high-resolution protein structures at biomineral interfaces. PMID:19383454

  18. Boiling Performance of Antifreeze Solutions in a Saturate Pool Boiling System

    NASA Astrophysics Data System (ADS)

    Matsumura, Kunihito; Kaminaga, Fumito

    Nucleate boiling of binary mixtures is of particular importance in a various industries. The purpose of the present study is to provide experimental data and prediction method for nucleate boiling heat transfer of anti-freeze solutions, Propylene-glycol (PG)/water and Ethylene-glycol (EG)/water. The pool nucleate boiling experiments were carried out under a saturated and atmospheric condition. The platinum wire of 0.3 mm diameter was used as the heating surface. The mole fractions of solutions are varied from 0.85 to 1. It was found that the heat transfer coefficient gradually decreases with increasing fraction of anti-freeze to water. It was also shown that a small addition of propylene-glycol and ethylene-glycol also decreases the CHF value far below that of pure water. It is concluded that the correlation proposed by Fujita for several binary mixtures can well predict the heat transfer coefficients within almost ±5% accuracy for every concentration of present anti-freeze solutions.

  19. Symbolic computation of conservation laws and exact solutions of a coupled variable-coefficient modified Korteweg-de Vries system

    NASA Astrophysics Data System (ADS)

    Adem, Abdullahi Rashid; Khalique, Chaudry Masood

    2016-04-01

    In this paper we study a generalized coupled variable-coefficient modified Korteweg-de Vries (CVCmKdV) system that models a two-layer fluid, which is applied to investigate the atmospheric and oceanic phenomena such as the atmospheric blockings, interactions between the atmosphere and ocean, oceanic circulations and hurricanes. The conservation laws of the CVCmKdV system are derived using the multiplier approach and a new conservation theorem. In addition to this, a similarity reduction and exact solutions with the aid of symbolic computation are computed.

  20. Application of a numerically generated orthogonal coordinate system to the solution of inviscid axisymmetric supersonic flow over blunt bodies

    NASA Technical Reports Server (NTRS)

    Hamilton, H. H., II; Graves, R. A., Jr.

    1980-01-01

    A numerically generated orthogonal coordinate system (with the body surface and shock wave as opposite boundaries) was applied with a time asymptotic method to obtain steady flow solutions for axisymmetric inviscid flow over several blunt bodies including spheres, paraboloids, ellipsoids, hyperboloids, hemisphere cylinders, spherically blunted cones, and a body with a concavity in the stagnation region. Comparisons with experimental data and with the results of other computational methods are discussed. The numerically generated orthogonal coordinate system is described and applications of the method to complex body shapes, particularly those with concave regions, are discussed.

  1. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    SciTech Connect

    A. Rudd and D. Bergey

    2015-08-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs.

  2. Neural-network-based online HJB solution for optimal robust guaranteed cost control of continuous-time uncertain nonlinear systems.

    PubMed

    Liu, Derong; Wang, Ding; Wang, Fei-Yue; Li, Hongliang; Yang, Xiong

    2014-12-01

    In this paper, the infinite horizon optimal robust guaranteed cost control of continuous-time uncertain nonlinear systems is investigated using neural-network-based online solution of Hamilton-Jacobi-Bellman (HJB) equation. By establishing an appropriate bounded function and defining a modified cost function, the optimal robust guaranteed cost control problem is transformed into an optimal control problem. It can be observed that the optimal cost function of the nominal system is nothing but the optimal guaranteed cost of the original uncertain system. A critic neural network is constructed to facilitate the solution of the modified HJB equation corresponding to the nominal system. More importantly, an additional stabilizing term is introduced for helping to verify the stability, which reinforces the updating process of the weight vector and reduces the requirement of an initial stabilizing control. The uniform ultimate boundedness of the closed-loop system is analyzed by using the Lyapunov approach as well. Two simulation examples are provided to verify the effectiveness of the present control approach. PMID:25415951

  3. The relational clinical database: a possible solution to the star wars in registry systems.

    PubMed

    Michels, D K; Zamieroski, M

    1990-12-01

    In summary, having data from other service areas available in a relational clinical database could resolve many of the problems existing in today's registry systems. Uniting sophisticated information systems into a centralized database system could definitely be a corporate asset in managing the bottom line. PMID:10108501

  4. Efficient solutions to hard computational problems by P systems with symport/antiport rules and membrane division.

    PubMed

    Song, Bosheng; Pérez-Jiménez, Mario J; Pan, Linqiang

    2015-04-01

    P systems are computing models inspired by some basic features of biological membranes. In this work, membrane division, which provides a way to obtain an exponential workspace in linear time, is introduced into (cell-like) P systems with communication (symport/antiport) rules, where objects are never modified but they just change their places. The computational efficiency of this kind of P systems is studied. Specifically, we present a (uniform) linear time solution to the NP-complete problem, Subset Sum by using division rules for elementary membranes and communication rules of length at most 3. We further prove that such P system allowing division rules for non-elementary membranes can efficiently solve the PSPACE-complete problem, QSAT in a uniform way. PMID:25802073

  5. Photoreversible micellar solution as a smart drag-reducing fluid for use in district heating/cooling systems.

    PubMed

    Shi, Haifeng; Ge, Wu; Oh, Hyuntaek; Pattison, Sean M; Huggins, Jacob T; Talmon, Yeshayahu; Hart, David J; Raghavan, Srinivasa R; Zakin, Jacques L

    2013-01-01

    A photoresponsive micellar solution is developed as a promising working fluid for district heating/cooling systems (DHCs). It can be reversibly switched between a drag reduction (DR) mode and an efficient heat transfer (EHT) mode by light irradiation. The DR mode is advantageous during fluid transport, and the EHT mode is favored when the fluid passes through heat exchangers. This smart fluid is an aqueous solution of cationic surfactant oleyl bis(2-hydroxyethyl)methyl ammonium chloride (OHAC, 3.4 mM) and the sodium salt of 4-phenylazo benzoic acid (ACA, 2 mM). Initially, ACA is in a trans configuration and the OHAC/ACA solution is viscoelastic and exhibits DR (of up to 80% relative to pure water). At the same time, this solution is not effective for heat transfer. Upon UV irradiation, trans-ACA is converted to cis-ACA, and in turn, the solution is converted to its EHT mode (i.e., it loses its viscoelasticity and DR) but it now has a heat-transfer capability comparable to that of water. Subsequent irradiation with visible light reverts the fluid to its viscoelastic DR mode. The above property changes are connected to photoinduced changes in the nanostructure of the fluid. In the DR mode, the OHAC/trans-ACA molecules assemble into long threadlike micelles that impart viscoelasticity and DR capability to the fluid. Conversely, in the EHT mode the mixture of OHAC and cis-ACA forms much shorter cylindrical micelles that contribute to negligible viscoelasticity and effective heat transfer. These nanostructural changes are confirmed by cryo-transmission electron microscopy (cryo-TEM), and the photoisomerization of trans-ACA and cis-ACA is verified by (1)H NMR. PMID:23210742

  6. Development anmd testing of electrophoresis solutions. Task I.1: Development of optimal buffer system

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Two buffers were explored for testing: low ionic strength electrophoresis buffer with and without density gradient material. It was found that the electrophoresis routine was better tolerated when Ficoll was present. The results of a viability study of primary human fetal kidney (HFK-1) cells at the first passage are shown. Cell strain HFK-1 was used in several experiments at the first and second passage. The HFK consisted mainly of fibroblasts, and HFK-1 has a high epithelioid cell content. The chromosomes of HFK were examined and found to be euploid. The stock medium for cell electrophoresis is described. In this solution density gradient solutes such as sucrose and Ficoll are dissolved to bring the osmolarity to 0.30. Its ionic strength is less than 0.01M, and its conductivity is usually 0.0011 mho/cm. Methods for viability determination included direct microscopic counting of the percent cells attached and spread within 24 hr of plating test cultures or electrophoretically separated fractions. The Cytograf viability assay concept was tested, and shown that blue stained cells scatter less light into the 0.8 to 3.3 deg angular interval than do unstained cells.

  7. Thermal analysis of frozen solutions: multiple glass transitions in amorphous systems.

    PubMed

    Sacha, Gregory A; Nail, Steven L

    2009-09-01

    Frozen aqueous solutions of sucrose exhibit two "glass transition-like" thermal events below the melting endotherm of ice when examined by DSC, but the physical basis of these events has been a source of some disagreement. In this study, a series of sugars, including sucrose, lactose, trehalose, maltose, fructose, galactose, fucose, mannose, and glucose were studied by modulated DSC and freeze-dry microscopy in order to better understand whether sucrose is unique in any way with respect to this behavior, as well as to explore the physical basis, and the pharmaceutical significance of these multiple transitions. Double transitions were found to be a common feature of all sugars examined. The results are consistent with both thermal events being glass transitions in that (1) both events have second-order characteristics that appear in the reversing signals, (2) annealing experiments reveal that enthalpy recovery is associated with each transition, and (3) Lissajous plots indicate that no detectable latent heat of melting is associated with either transition. The data in this study are consistent with the idea that the lower temperature transition arises from a metastable glassy mixture containing more water than that in the maximally freeze-concentrated solute. Freeze-dry microscopy observations show that for all of the sugars examined, it is the higher temperature transition that is associated with structural collapse during freeze-drying. There is no apparent pharmaceutical significance associated with the lower-temperature transition. PMID:19384925

  8. The Core Flight System (cFS) Community: Providing Low Cost Solutions for Small Spacecraft

    NASA Technical Reports Server (NTRS)

    McComas, David; Wilmot, Jonathan; Cudmore, Alan

    2016-01-01

    In February 2015 the NASA Goddard Space Flight Center (GSFC) completed the open source release of the entire Core Flight Software (cFS) suite. After the open source release a multi-NASA center Configuration Control Board (CCB) was established that has managed multiple cFS product releases. The cFS was developed and is being maintained in compliance with the NASA Class B software development process requirements and the open source release includes all Class B artifacts. The cFS is currently running on three operational science spacecraft and is being used on multiple spacecraft and instrument development efforts. While the cFS itself is a viable flight software (FSW) solution, we have discovered that the cFS community is a continuous source of innovation and growth that provides products and tools that serve the entire FSW lifecycle and future mission needs. This paper summarizes the current state of the cFS community, the key FSW technologies being pursued, the development/verification tools and opportunities for the small satellite community to become engaged. The cFS is a proven high quality and cost-effective solution for small satellites with constrained budgets.

  9. Analytic solution for modeling of the ground heat exchanger and groundwater system:

    NASA Astrophysics Data System (ADS)

    Woodbury, A. D.; Olfman, M.

    2009-12-01

    An analytical solution has been developed for the simulation of the effect on the subsurface of operating a geothermal U-Loop type vertical ground heat exchanger. The model results in a solution which allows one to determine a vertical profile of the various thermal properties, including the thermal conductivity. Based on all of the experimental evidence and various assumptions, a hypothesis regarding the cause of the vertical variation in temperature rise is formed: (1) The vertical variation of temperature rise is wholly caused by the vertical variation in thermal conductivity. Thus thermal conductivity is highest where temperature rise is highest, thermal conductivity is lowest where temperature rise is lowest. It follows that the radial heat flux function also has the same pattern as the thermal conductivity so that the most heat transfer occurs where the temperature rise is the highest and the least heat transfer occurs where the temperature rise is the lowestThus a further hypothesis, regarding the nature of the radial heat flux function, is formed: (2) The radial heat flux function takes on the same characteristic shape as the thermal conductivity function. This mathematical model is considered adequate as it predicts the subsurface behaviour observed experimentally and appears to be useful for predictive modelling.

  10. Loss of nitroglycerin from aqueous solution into plastic intravenous delivery systems.

    PubMed

    Yuen, P H; Denman, S L; Sokoloski, T D; Burkman, A M

    1979-09-01

    The mechanism of potential loss of nitroglycerin stored in plastic and glass containers was studied from an equilibrium and kinetic approach. Plastic strips equilibrated with dilute aqueous solutions of neat nitroglycerin showed that the drug was lost by absorption. Drug loss was followed by an electron-capture GLC assay. The same assay of control solutions in glass showed no drug loss in 48 hr at pH 5.7. The kinetics of nitroglycerin absorption and desorption were determined using synthesized 14C-labeled drug. Absorption can be quantified using a diffusion model, where the concentration in the aqueous phase falls with time. Curve fitting yielded an average diffusion coefficient in plastic of 2.05 x 10(-9) cm2/sec and a partition coefficient of 104 (plastic-water) at 30 degrees. Temperature-dependence studies of absorption showed that the diffusion coefficient followed an Arrhenius relationship with an energy requirement of 19.6 kcal/mole, whereas effects on the partition coefficient were negligible. Nitroglycerin desorption from plastic disks under sink conditions into water can be quantified by assuming a diffusion model where the concentration at the surface of a plane sheet remains constant. Nonlinear least-squares curve fitting generated a diffusion coefficient of 1.14 x 10(-9) cm2/sec for the desorption process at 30 degrees. PMID:115988

  11. Conceptual design of a closed loop nutrient solution delivery system for CELSS implementation in a micro-gravity environment

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.; Oleson, Mel W.; Cullingford, Hatice S.

    1989-01-01

    This paper describes the results of a study to develop a conceptual design for an experimental, closed-loop fluid handling system capable of monitoring, controlling, and supplying nutrient solution to higher plants. The Plant Feeder Experiment (PFX) is designed to be flight tested in a micro-gravity (micro-g) environment and was developed under NASA's In-Space Technology Experiments Program (INSTEP). When flown, PFX will provide information on both the generic problems of micro-g fluid handling and the specific problems associated with the delivery of nutrient solution in a micro-g environment. The experimental hardware is designed to fit into two middeck lockers on the Space Shuttle, and incorporates several components that have previously been flight tested.

  12. Solid Solution Effects on the MgAl2O4-MgGa2O4 System

    SciTech Connect

    O'Hara, Kelley; Smith, Jeffrey D; Hemrick, James Gordon

    2009-01-01

    Phase relations between two spinel compounds (MgAl2O4 and MgGa2O4) were studied. Stoichiometric MgAl2O4 was formed in the laboratory through a coprecipitation method. Complete solid solution formation int eh MgAl2O4-MgGa2O4 systems was confirmed through X-ray diffraction analysis. Solid solution between MgAl2O4-MgGa2O4 decreases thermal conductivity at all temperatures up to 900oC. At 200oC with 10 mol% additoin of MgGa2O4 thermal conductivity decreases approximately 25%, and at 900oC there was still an 8% decrease. Additionally, preliminary studies show that porosity between 5% and 10% does not have an appreciable effect on the thermal conductivity in this study.

  13. RELAP5/MOD3 code manual: Code structure, system models, and solution methods. Volume 1

    SciTech Connect

    1995-08-01

    The RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents, and operational transients, such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling, approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I provides modeling theory and associated numerical schemes.

  14. Single cell performance studies on the FE/CR Redox Energy Storage System using mixed reactant solutions at elevated temperature

    NASA Technical Reports Server (NTRS)

    Gahn, R. F.; Hagedorn, N. H.; Ling, J. S.

    1983-01-01

    Experimental studies in a 14.5 sq cm single cell system using mixed reactant solutions at 65 C are described. Systems were tested under isothermal conditions, i.e., reactants and the cell were at the same temperature. Charging and discharging performance were evaluated by measuring watt-hour and coulombic efficiencies, voltage-current relationships, hydrogen evolution and membrane resistivity. Watt-hour efficiencies ranged from 86 percent at 43 ma/sq cm to 75 percent at 129 ma/sq cm with corresponding coulombic efficiencies of 92 percent and 97 percent, respectively. Hydrogen evolution was less than 1 percent of the charge coulumbic capacity during charge-discharge cycling. Bismuth amd bismuth-lead catalyzed chromium electrodes maintained reversible performance and low hydrogen evolution under normal and adverse cycling conditions. Reblending of the anode and cathode solutions was successfully demonstrated to compensate for osmotic volume changes. Improved performance was obtained with mixed reactant systems in comparison to the unmixed reactant systems. Previously announced in STAR as N83-25042

  15. Perfect fluidity of a dissipative system: Analytical solution for the Boltzmann equation in AdS2 Ⓧ S2

    DOE PAGESBeta

    Noronha, Jorge; Denicol, Gabriel S.

    2015-12-30

    In this paper we obtain an analytical solution of the relativistic Boltzmann equation under the relaxation time approximation that describes the out-of-equilibrium dynamics of a radially expanding massless gas. This solution is found by mapping this expanding system in flat spacetime to a static flow in the curved spacetime AdS2 Ⓧ S2. We further derive explicit analytic expressions for the momentum dependence of the single-particle distribution function as well as for the spatial dependence of its moments. We find that this dissipative system has the ability to flow as a perfect fluid even though its entropy density does not matchmore » the equilibrium form. The nonequilibrium contribution to the entropy density is shown to be due to higher-order scalar moments (which possess no hydrodynamical interpretation) of the Boltzmann equation that can remain out of equilibrium but do not couple to the energy-momentum tensor of the system. Furthermore, in this system the slowly moving hydrodynamic degrees of freedom can exhibit true perfect fluidity while being totally decoupled from the fast moving, nonhydrodynamical microscopic degrees of freedom that lead to entropy production.« less

  16. Study of the dose response of the system ferrous ammonium sulfate-sucrose-xylenol orange in acid aqueous solution

    NASA Astrophysics Data System (ADS)

    Juarez-Calderon, J. M.; Negron-Mendoza, A.; Ramos-Bernal, S.

    2014-11-01

    An aqueous solution of ammonium ferrous sulfate-sucrose-xylenol orange in sulfuric acid (FSX) is proposed as a dosimetric system for the processes of gamma irradiation in a range between 0.3 and 6 Gy. This system is based on the indirect oxidation of ferrous ion by an organic compound (sucrose) to ferric ion and on the formation of a color complex of Fe3+ in an acidic medium with xylenol orange (a dye). After gamma radiation, an observable change occurs in the color of the system. Irradiation was executed at three different temperatures (13 °C, 22 °C, and 40 °C). A spectrometric readout method at 585 nm was employed to evaluate the system's dose response. In all of the cases analyzed, the responses had a linear behavior, and a slight effect of irradiation temperature was observed. Post-irradiation response was also evaluated and showed the stability of the solutions 24 h after the irradiation. The results obtained suggest that FSX might be used as a dosimeter for low doses of gamma irradiation because it provides a stable signal, good reproducibility, and an accessible technique for analysis.

  17. Security threats and solutions in distributed, interoperable health information systems using middleware.

    PubMed

    Blobel, B; Holena, M

    1997-01-01

    Increasingly, distributed, interoperable healthcare information systems, which meet the shared care paradigm, work across the boundaries of policy, organisational, and technological domains and are based on middleware concepts. Especially in healthcare with its sensitive personal and medical data, such systems require advanced data security measures. In the paper, a common object-oriented security model for middleware systems and advertisements for implementation are proposed, corresponding the security requirement of both the user and the application environment. PMID:10175374

  18. The aerial relay system: An energy-efficient solution to the airport congestion problem

    NASA Technical Reports Server (NTRS)

    Kyser, A. C.

    1980-01-01

    The ability to transfer airline passengers between aircraft in flight, if adequately developed and integrated into the national air transportation system, could provide significant improvements in transportation-system performance, in terms of airport congestion, fuel consumption, and passenger service. The proposed Aerial Relay System concept, which was developed as a means of exploiting inflight transfer, makes use of large 'cruise liner' aircraft which fly continuously along their routes, docking periodically with short-haul feeder aircraft for exchange of payloads. Preliminary vehicle designs for a representative system are described and the operational feasibility of the concept for the United States in the 1990's is discussed.

  19. On the Maximum Number of Periodical Solutions of a Class of Autonomous Systems

    SciTech Connect

    Raeva, M.

    2008-10-30

    The autonomous systems are investigated on a certain condition, assuming the existence of inner resonances. Nonlinear parts are polynomials of a certain class. The present article is a continuation of the last one, which was published by American Institute of Physics, New York in 2007. We are interested both in the existence and the number of periodical trajectories of the system with initial conditions.

  20. Stability solutions of a dumbbell-like system in an elliptical orbit

    NASA Astrophysics Data System (ADS)

    Souza dos Santos, Denilson Paulo; Brito de Aguiã Morant, Simão António da Rocha e.; Guerman, Anna D.; Burov, Alexander A.

    2015-10-01

    A dumbbell-like system is analyzed, considering two mass points connected with a massless and rigid tether with length variations, and the center of mass described by Keplerian orbits. This kind of system, in a certain type of configuration, is a simple conceptualization of the space elevator. The system motion is obtained with the Lagrangian Formulation in a Central Gravitational Field, and the perturbations of motion are neglected. Laws of control are considered for the angle of systems rotation around the center of mass. Those include uniform rotations or no rotation at all. Stability conditions were obtained for the first case, analyzing its neighborhood and using Floquet Theory. The results shown there are regions of eccentricities were stability is found. Lastly, a dynamic numerical simulator was created, where the implementation of the results could be tested. The dynamic behavior of the system showed regular and chaotic properties.