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Sample records for evaluating neuro-hemodynamic coupling

  1. Evaluation of Coupled Precipitator Two

    SciTech Connect

    Stone, M.E.

    1999-11-08

    The offline testing of the Coupled Precipitator Two (CP-2) has been completed. The tests were conducted and are documented. The tests were conducted at an offline test rack near the Drain Tube Test Stand facility in 672-T.

  2. Evaluation of coupling approaches for thermomechanical simulations

    DOE PAGESBeta

    Novascone, S. R.; Spencer, B. W.; Hales, J. D.; Williamson, R. L.

    2015-08-10

    Many problems of interest, particularly in the nuclear engineering field, involve coupling between the thermal and mechanical response of an engineered system. The strength of the two-way feedback between the thermal and mechanical solution fields can vary significantly depending on the problem. Contact problems exhibit a particularly high degree of two-way feedback between those fields. This paper describes and demonstrates the application of a flexible simulation environment that permits the solution of coupled physics problems using either a tightly coupled approach or a loosely coupled approach. In the tight coupling approach, Newton iterations include the coupling effects between all physics,more » while in the loosely coupled approach, the individual physics models are solved independently, and fixed-point iterations are performed until the coupled system is converged. These approaches are applied to simple demonstration problems and to realistic nuclear engineering applications. The demonstration problems consist of single and multi-domain thermomechanics with and without thermal and mechanical contact. Simulations of a reactor pressure vessel under pressurized thermal shock conditions and a simulation of light water reactor fuel are also presented. Here, problems that include thermal and mechanical contact, such as the contact between the fuel and cladding in the fuel simulation, exhibit much stronger two-way feedback between the thermal and mechanical solutions, and as a result, are better solved using a tight coupling strategy.« less

  3. Evaluation of coupling approaches for thermomechanical simulations

    SciTech Connect

    Novascone, S. R.; Spencer, B. W.; Hales, J. D.; Williamson, R. L.

    2015-08-10

    Many problems of interest, particularly in the nuclear engineering field, involve coupling between the thermal and mechanical response of an engineered system. The strength of the two-way feedback between the thermal and mechanical solution fields can vary significantly depending on the problem. Contact problems exhibit a particularly high degree of two-way feedback between those fields. This paper describes and demonstrates the application of a flexible simulation environment that permits the solution of coupled physics problems using either a tightly coupled approach or a loosely coupled approach. In the tight coupling approach, Newton iterations include the coupling effects between all physics, while in the loosely coupled approach, the individual physics models are solved independently, and fixed-point iterations are performed until the coupled system is converged. These approaches are applied to simple demonstration problems and to realistic nuclear engineering applications. The demonstration problems consist of single and multi-domain thermomechanics with and without thermal and mechanical contact. Simulations of a reactor pressure vessel under pressurized thermal shock conditions and a simulation of light water reactor fuel are also presented. Here, problems that include thermal and mechanical contact, such as the contact between the fuel and cladding in the fuel simulation, exhibit much stronger two-way feedback between the thermal and mechanical solutions, and as a result, are better solved using a tight coupling strategy.

  4. EVALUATION OF AN INDUCTIVELY COUPLED PLASMA, MULTICHANNEL SPECTROMETRIC ANALYSIS SYSTEM

    EPA Science Inventory

    An inductively coupled plasma, multielement atomic emission spectrometric analysis system has been evaluated with respect to the Environmental Protection Agency's need for a rapid method for determination of trace elemental concentrations in water. Data are presented on detection...

  5. Investigation of capacitively coupled ultrasonic transducer system for nondestructive evaluation.

    PubMed

    Zhong, Cheng Huan; Wilcox, Paul D; Croxford, Anthony J

    2013-12-01

    Capacitive coupling offers a simple solution to wirelessly probe ultrasonic transducers. This paper investigates the theory, feasibility, and optimization of such a capacitively coupled transducer system (CCTS) in the context of nondestructive evaluation (NDE) applications. The noncontact interface relies on an electric field formed between four metal plates-two plates are physically connected to the electrodes of a transducer, the other two are in a separate probing unit connected to the transmit/receive channel of the instrumentation. The complete system is modeled as an electric network with the measured impedance of a bonded piezoelectric ceramic disc representing a transducer attached to an arbitrary solid substrate. A transmission line model is developed which is a function of the physical parameters of the capacitively coupled system, such as the permittivity of the material between the plates, the size of the metal plates, and their relative positions. This model provides immediate prediction of electric input impedance, pulse-echo response, and the effect of plate misalignment. The model has been validated experimentally and has enabled optimization of the various parameters. It is shown that placing a tuning inductor and series resistor on the transmitting side of the circuit can significantly improve the system performance in terms of the signal-to-crosstalk ratio. Practically, bulk-wave CCTSs have been built and demonstrated for underwater and through-composite testing. It has been found that electrical conduction in the media between the plates limits their applications. PMID:24297024

  6. Analytic evaluation of the nonadiabatic coupling vector between excited states using equation-of-motion coupled-cluster theory

    NASA Astrophysics Data System (ADS)

    Tajti, Attila; Szalay, Péter G.

    2009-09-01

    Theory and implementation for evaluation of the nonadiabatic coupling vector between excited electronic states described by equation-of-motion excitation energy coupled-cluster singles and doubles (EOMEE-CCSD) method is presented. Problems arising from the non-Hermitian nature of the theory are discussed in detail. The performance of the new approach is demonstrated by the nice agreement of the nonadiabatic coupling curves for LiH obtained at the EOMEE-CCSD and MR-CISD levels. Using the tools developed we also present a computational procedure to evaluate the interstate coupling constants used in vibronic coupling theories. As an application of this part of the implementation we present simulation of the electronic absorption spectrum of the pyrazine molecule within the linear vibronic coupling model.

  7. Couples' Long-Term Evaluations of Their Marriage Encounter Experience.

    ERIC Educational Resources Information Center

    Lester, Mary Ellen; Doherty, William J.

    1983-01-01

    Surveyed 189 couples to see how they felt about their Marriage Encounter experience four years later. Results indicated that about 80 percent of the couples reported a totally positive experience. The most frequently cited positive aspect was the "dialogue." A significant minority of couples experienced negative consequences. (Author/JAC)

  8. Evaluation of Air Coupled Ultrasound for Composite Aerospace Structure

    NASA Astrophysics Data System (ADS)

    Tat, H.; Georgeson, G.; Bossi, R.

    2009-03-01

    Non-contact air coupled ultrasound suffers from the high acoustic impedance mismatch characteristics of air to solid interfaces. Advances in transducer technology, particularly MEMS, have improved the acoustic impedance match at the transmission stage and the signal to noise at the reception stage. Comparisons of through transmission (TTU) scanning of laminate and honeycomb test samples using conventional piezoelectric air coupled transducers, new MEMS air coupled transducers, and standard water coupled inspections have been performed to assess the capability. An additional issue for air coupled UT inspection is the need for a lean implementation for both manufacturing and in-service operations. Concepts and applications utilizing magnetic coupling of transducers have been developed that allows air coupled inspection operations in compact low cost configurations.

  9. COUPLING

    DOEpatents

    Hawke, B.C.

    1963-02-26

    This patent relates to a releasable coupling connecting a control rod to a control rod drive. This remotely operable coupling mechanism can connect two elements which are laterally and angviarly misaligned, and provides a means for sensing the locked condition of the elements. The coupling utilizes a spherical bayonet joint which is locked against rotation by a ball detent lock. (AEC)

  10. PyFREC: Software for Förster electronic coupling evaluation in molecular fragments.

    PubMed

    Kosenkov, Dmytro

    2016-07-15

    Electronic couplings are crucial for understanding exciton dynamics and associated energy transfer in artificial and natural chromophores. The proposed PyFREC (Python FRagment Electronic Coupling) software enables evaluation of electronic couplings based on the Förster model. PyFREC features the decomposition of electronic couplings, obtained through quantum chemical calculations, into the orientation and dipole strength components. Furthermore, the variation method to evaluate energies of coupled electronic excited states and delocalization of electronic excitations is implemented in the software. PyFREC has been tested on the S22 benchmark dataset of non-covalent complexes and water clusters. © 2016 Wiley Periodicals, Inc. PMID:27185273

  11. COUPLING

    DOEpatents

    Frisch, E.; Johnson, C.G.

    1962-05-15

    A detachable coupling arrangement is described which provides for varying the length of the handle of a tool used in relatively narrow channels. The arrangement consists of mating the key and keyhole formations in the cooperating handle sections. (AEC)

  12. Evaluation of nonuniform field exposures with coupling factors

    NASA Astrophysics Data System (ADS)

    Sunohara, Tetsu; Hirata, Akimasa; Laakso, Ilkka; De Santis, Valerio; Onishi, Teruo

    2015-10-01

    In this study, the safety compliance for nonuniform field exposures is discussed using coupling factor concepts. The coupling factor, which is defined in the International Electrotechnical Commission 62311 standard, is extended to consider the effects of harmonics and also to apply to the specific absorption rate (for frequencies up to 30 MHz). The proposed compliance procedure is applied to and demonstrated for a prototype wireless power transfer (WPT) system with induction coupling operating at the fundamental frequency in 140 kHz band. First, measurements confirm that the perturbation of the external magnetic field strength and S11 parameter of a one-loop antenna by a human-equivalent phantom are sufficiently small, suggesting the applicability of the magneto-quasi-static approximation to frequencies up to 30 MHz. Then, the frequency characteristics of the coupling factor are derived for the WPT system. For the prototype system that is not optimized for commercial usage, the maximum allowable transmitting power is relaxed by a factor of 23 with the proposed procedure. The contribution of the harmonics decreased the allowable transmitting power by 39%, indicating their importance for safety compliance.

  13. Evaluation of nonuniform field exposures with coupling factors.

    PubMed

    Sunohara, Tetsu; Hirata, Akimasa; Laakso, Ilkka; De Santis, Valerio; Onishi, Teruo

    2015-10-21

    In this study, the safety compliance for nonuniform field exposures is discussed using coupling factor concepts. The coupling factor, which is defined in the International Electrotechnical Commission 62311 standard, is extended to consider the effects of harmonics and also to apply to the specific absorption rate (for frequencies up to 30 MHz). The proposed compliance procedure is applied to and demonstrated for a prototype wireless power transfer (WPT) system with induction coupling operating at the fundamental frequency in 140 kHz band. First, measurements confirm that the perturbation of the external magnetic field strength and S11 parameter of a one-loop antenna by a human-equivalent phantom are sufficiently small, suggesting the applicability of the magneto-quasi-static approximation to frequencies up to 30 MHz. Then, the frequency characteristics of the coupling factor are derived for the WPT system. For the prototype system that is not optimized for commercial usage, the maximum allowable transmitting power is relaxed by a factor of 23 with the proposed procedure. The contribution of the harmonics decreased the allowable transmitting power by 39%, indicating their importance for safety compliance. PMID:26439390

  14. Coupled Biogeochemical Process Evaluation for Conceptualizing Trichloroethylene Co-Metabolism

    SciTech Connect

    Rick Colwell; Corey Radtke; Mark Delwiche; Deborah Newby; Lynn Petzke; Mark Conrad; Eoin Brodie; Hope Lee; Bob Starr; Dana Dettmers; Ron Crawford; Andrzej Paszczynski; Nick Bernardini; Ravi Paidisetti; Tonia Green

    2006-06-01

    Chlorinated solvent wastes (e.g., trichloroethene or TCE) often occur as diffuse subsurface plumes in complex geological environments where coupled processes must be understood in order to implement remediation strategies. Monitored natural attenuation (MNA) warrants study as a remediation technology because it minimizes worker and environment exposure to the wastes and because it costs less than other technologies. However, to be accepted MNA requires different ?lines of evidence? indicating that the wastes are effectively destroyed. We are studying the coupled biogeochemical processes that dictate the rate of TCE co-metabolism first in the medial zone (TCE concentration: 1,000 to 20,000 ?g/L) of a plume at the Idaho National Laboratory?s Test Area North (TAN) site and then at Paducah or the Savannah River Site. We will use flow-through in situ reactors (FTISR) to investigate the rate of methanotrophic co-metabolism of TCE and the coupling of the responsible biological processes with the dissolved methane flux and groundwater flow velocity. TCE co-metabolic rates at TAN are being assessed and interpreted in the context of enzyme activity, gene expression, and cellular inactivation related to intermediates of TCE co-metabolism. By determining the rate of TCE co-metabolism at different groundwater flow velocities, we will derive key modeling parameters for the computational simulations that describe the attenuation, and thereby refine such models while assessing the contribution of microbial co-metabolism relative to other natural attenuation processes. This research will strengthen our ability to forecast the viability of MNA at DOE and other sites contaminated with chlorinated hydrocarbons.

  15. Coupled Biogeochemical Process Evaluation for Conceptualizing Trichloroethylene Co-Metabolism

    SciTech Connect

    Colwell, Frederick; Radtke, Corey; Newby, Deborah; Delwiche, Mark; Crawf, Ronald L.; Paszczynski, Andrzej; Strap, Janice; Conrad, Mark; Brodic, Eoin; Starr, Robert; Lee, Hope

    2006-04-05

    Chlorinated solvent wastes (e.g., trichloroethene or TCE) often occur as diffuse subsurface plumes in complex geological environments where coupled processes must be understood in order to implement remediation strategies. Monitored natural attenuation (MNA) warrants study as a remediation technology because it minimizes worker and environment exposure to the wastes and because it costs less than other technologies. However, to be accepted MNA requires 'lines of evidence' indicating that the wastes are effectively destroyed. Our research will study the coupled biogeochemical processes that dictate the rate of TCE co-metabolism in contaminated aquifers first at the Idaho National Laboratory and then at Paducah or the Savannah River Site, where natural attenuation of TCE is occurring. We will use flow-through in situ reactors to investigate the rate of methanotrophic co-metabolism of TCE and the coupling of the responsible biological processes with the dissolved methane flux and groundwater flow velocity. We will use new approaches (e.g., stable isotope probing, enzyme activity probes, real-time reverse transcriptase polymerase chain reaction, proteomics) to assay the TCE co-metabolic rates, and interpret these rates in the context of enzyme activity, gene expression, and cellular inactivation related to intermediates of TCE co-metabolism. By determining the rate of TCE co-metabolism at different methane concentrations and groundwater flow velocities, we will derive key modeling parameters for the computational simulations that describe the attenuation, and thereby refine such models while assessing the contribution of microbial relative to other natural attenuation processes. This research will strengthen our ability to forecast the viability of MNA at DOE and other sites that are contaminated with chlorinated hydrocarbons.

  16. Anesthesia and the quantitative evaluation of neurovascular coupling

    PubMed Central

    Masamoto, Kazuto; Kanno, Iwao

    2012-01-01

    Anesthesia has broad actions that include changing neuronal excitability, vascular reactivity, and other baseline physiologies and eventually modifies the neurovascular coupling relationship. Here, we review the effects of anesthesia on the spatial propagation, temporal dynamics, and quantitative relationship between the neural and vascular responses to cortical stimulation. Previous studies have shown that the onset latency of evoked cerebral blood flow (CBF) changes is relatively consistent across anesthesia conditions compared with variations in the time-to-peak. This finding indicates that the mechanism of vasodilation onset is less dependent on anesthesia interference, while vasodilation dynamics are subject to this interference. The quantitative coupling relationship is largely influenced by the type and dosage of anesthesia, including the actions on neural processing, vasoactive signal transmission, and vascular reactivity. The effects of anesthesia on the spatial gap between the neural and vascular response regions are not fully understood and require further attention to elucidate the mechanism of vascular control of CBF supply to the underlying focal and surrounding neural activity. The in-depth understanding of the anesthesia actions on neurovascular elements allows for better decision-making regarding the anesthetics used in specific models for neurovascular experiments and may also help elucidate the signal source issues in hemodynamic-based neuroimaging techniques. PMID:22510601

  17. Air-coupled acoustic thermography for in-situ evaluation

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N. (Inventor); Winfree, William P. (Inventor); Yost, William T. (Inventor)

    2010-01-01

    Acoustic thermography uses a housing configured for thermal, acoustic and infrared radiation shielding. For in-situ applications, the housing has an open side adapted to be sealingly coupled to a surface region of a structure such that an enclosed chamber filled with air is defined. One or more acoustic sources are positioned to direct acoustic waves through the air in the enclosed chamber and towards the surface region. To activate and control each acoustic source, a pulsed signal is applied thereto. An infrared imager focused on the surface region detects a thermal image of the surface region. A data capture device records the thermal image in synchronicity with each pulse of the pulsed signal such that a time series of thermal images is generated. For enhanced sensitivity and/or repeatability, sound and/or vibrations at the surface region can be used in feedback control of the pulsed signal applied to the acoustic sources.

  18. A generalized method for the evaluation of mutual coupling in microstrip arrays

    NASA Astrophysics Data System (ADS)

    Katehi, Pisti B.

    1987-02-01

    An analytical method for the evaluation of mutual coupling in microstrip arrays is discussed. The elements of the array are excited by microstriplines printed on or embedded in the substrate. As an example, the mutual coupling between microstrip dipoles electromagnetically coupled to embedded strip transmission lines is evaluated accurately. The present method is valid in the millimeter range as well as at microwave frequencies and does not have any substrate limitations. Also, it accounts for conductor thickness and surface wave excitation. Comparison with experimental results show excellent agreement.

  19. “Overview and Evaluation of AQMEII Phase 2 Coupled Simulations over North America”

    EPA Science Inventory

    This presentation provides an overview of the second phase of the Air Quality Model Evaluation International Initative (AQMEII). Activities in this phase are focused on the application and evaluation of coupled meteorology-chemistry models to assess how well these models can simu...

  20. Evaluation of a Structured Psychoeducational Intervention with Couples: The Dyadic Relationships Test (DRT).

    ERIC Educational Resources Information Center

    Cusinato, Mario; L'Abate, Luciano

    2003-01-01

    Four cases are presented to illustrate the clinical usefulness of a new, statistically validated, visual-verbal test to evaluate couple relationships at seven different stages of the life cycle. Results from this test can be correlated with dimensions measured with another instrument, allowing to evaluate whether any progress has taken place as a…

  1. Evaluation and coupling of a membraneless nanofluidic device for low-power applications

    NASA Astrophysics Data System (ADS)

    Gurrola, M. P.; Ortiz-Ortega, E.; Farias-Zuñiga, C.; Chávez-Ramírez, A. U.; Ledesma-García, J.; Arriaga, L. G.

    2016-03-01

    This work presents the construction and evaluation of a membraneless nanofluidic fuel cell made with fiberglass using flow-through porous electrodes based on Toray paper, coupled with a microelectronic interface to supply energy to low-power demand applications. The device performance is optimized for different operating conditions related with flow rate, stoichiometry and concentration and employing formic acid as fuel. Evaluation tests were performed with a homemade testing station using a commercial varying resistance.

  2. Experimental Effects of Student Evaluations Coupled with Collaborative Consultation on College Professors' Instructional Skills

    ERIC Educational Resources Information Center

    Knol, Mariska H.; in't Veld, Rachna; Vorst, Harrie C. M.; van Driel, Jan H.; Mellenbergh, Gideon J.

    2013-01-01

    This experimental study concerned the effects of repeated students' evaluations of teaching coupled with collaborative consultation on professors' instructional skills. Twenty-five psychology professors from a Dutch university were randomly assigned to either a control group or an experimental group. During their course, students…

  3. Communication: An efficient algorithm for evaluating the Breit and spin-spin coupling integrals

    NASA Astrophysics Data System (ADS)

    Shiozaki, Toru

    2013-03-01

    We present an efficient algorithm for evaluating a class of two-electron integrals of the form {r}_{12}⊗ {r}_{12}/r_{12}^n over one-electron Gaussian basis functions. The full Breit interaction in four-component relativistic theories beyond the Gaunt term is such an operator with n = 3. Another example is the direct spin-spin coupling term in the quasi-relativistic Breit-Pauli Hamiltonian (n = 5). These integrals have been conventionally evaluated by expensive derivative techniques. Our algorithm is based on tailored Gaussian quadrature, similar to the Rys quadrature for electron repulsion integrals (ERIs), and can utilize the so-called horizontal recurrence relation to reduce the computational cost. The CPU time for computing all six Cartesian components of the Breit or spin-spin coupling integrals is found to be only 3 to 4 times that of the ERI evaluation.

  4. Communication: An efficient algorithm for evaluating the Breit and spin-spin coupling integrals.

    PubMed

    Shiozaki, Toru

    2013-03-21

    We present an efficient algorithm for evaluating a class of two-electron integrals of the form r12⊗r12/r12(n) over one-electron Gaussian basis functions. The full Breit interaction in four-component relativistic theories beyond the Gaunt term is such an operator with n = 3. Another example is the direct spin-spin coupling term in the quasi-relativistic Breit-Pauli Hamiltonian (n = 5). These integrals have been conventionally evaluated by expensive derivative techniques. Our algorithm is based on tailored Gaussian quadrature, similar to the Rys quadrature for electron repulsion integrals (ERIs), and can utilize the so-called horizontal recurrence relation to reduce the computational cost. The CPU time for computing all six Cartesian components of the Breit or spin-spin coupling integrals is found to be only 3 to 4 times that of the ERI evaluation. PMID:23534619

  5. Determination of plutonium in urine: evaluation of electrothermal vaporization inductively coupled plasma mass spectroscopy

    SciTech Connect

    Pietrzak, R.; Kaplan, E.

    1996-11-01

    Mass spectroscopy has the distinct advantage of detecting atoms rather than radioactive decay products for nuclides of low specific activity. Electrothermal vaporization (ETV) is an efficient means of introducing small volumes of prepared samples into an inductively coupled mass spectrometer to achieve the lowest absolute detection limits. The operational characteristics and capabilities of electrothermal vaporization inductively coupled mass spectrometer mass spectroscopy were evaluated. We describe its application as a detection method for determining Pu in urine, in conjunction with a preliminary separation technique to avoid matrix suppression of the signal.

  6. Experimental and Mathematical Evaluation of Dynamic Behaviour of AN Oil-Air Coupling Shock Absorber

    NASA Astrophysics Data System (ADS)

    PING, Y.

    2003-11-01

    The physical mechanism of the actual shock absorber with multi-types of damping and non-linear stiffness through coupling the oil, air, rubber and spring by ingenious devices is systematically investigated. The experimental results of the key-model machine in multi-parameter coupling dynamic test show complex non-linearity dynamic characteristics. Based on this, the non-linear dynamic model for the shock absorber is presented by analysing the internal fluid dynamic phenomenon with respect to the shock absorber. Comparisons with experimental data confirm the validity of the model. Using the model, it is possible to evaluate the importance of different factors for designing the shock absorber.

  7. Development and Evaluation of New Coupling System for Lower Limb Prostheses with Acoustic Alarm System

    PubMed Central

    Eshraghi, Arezoo; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ahmadian, Jalil; Rahmati, Bizhan; Abas, Wan Abu Bakar Wan

    2013-01-01

    Individuals with lower limb amputation need a secure suspension system for their prosthetic devices. A new coupling system was developed that is capable of suspending the prosthesis. The system's safety is ensured through an acoustic alarm system. This article explains how the system works and provides an in vivo evaluation of the device with regard to pistoning during walking. The system was designed to be used with silicone liners and is based on the requirements of prosthetic suspension systems. Mechanical testing was performed using a universal testing machine. The pistoning during walking was measured using a motion analysis system. The new coupling device produced significantly less pistoning compared to a common suspension system (pin/lock). The safety alarm system would buzz if the suspension was going to fail. The new coupling system could securely suspend the prostheses in transtibial amputees and produced less vertical movement than the pin/lock system. PMID:23881340

  8. Evaluation of electrical capacitance tomography sensor based on the coupling of fluid field and electrostatic field

    NASA Astrophysics Data System (ADS)

    Ye, Jiamin; Wang, Haigang; Yang, Wuqiang

    2016-07-01

    Electrical capacitance tomography (ECT) is based on capacitance measurements from electrode pairs mounted outside of a pipe or vessel. The structure of ECT sensors is vital to image quality. In this paper, issues with the number of electrodes and the electrode covering ratio for complex liquid–solids flows in a rotating device are investigated based on a new coupling simulation model. The number of electrodes is increased from 4 to 32 while the electrode covering ratio is changed from 0.1 to 0.9. Using the coupling simulation method, real permittivity distributions and the corresponding capacitance data at 0, 0.5, 1, 2, 3, 5, and 8 s with a rotation speed of 96 rotations per minute (rpm) are collected. Linear back projection (LBP) and Landweber iteration algorithms are used for image reconstruction. The quality of reconstructed images is evaluated by correlation coefficient compared with the real permittivity distributions obtained from the coupling simulation. The sensitivity for each sensor is analyzed and compared with the correlation coefficient. The capacitance data with a range of signal-to-noise ratios (SNRs) of 45, 50, 55 and 60 dB are generated to evaluate the effect of data noise on the performance of ECT sensors. Furthermore, the SNRs of experimental data are analyzed for a stationary pipe with permittivity distribution. Based on the coupling simulation, 16-electrode ECT sensors are recommended to achieve good image quality.

  9. NRC-BNL BENCHMARK PROGRAM ON EVALUATION OF METHODS FOR SEISMIC ANALYSIS OF COUPLED SYSTEMS.

    SciTech Connect

    XU,J.

    1999-08-15

    A NRC-BNL benchmark program for evaluation of state-of-the-art analysis methods and computer programs for seismic analysis of coupled structures with non-classical damping is described. The program includes a series of benchmarking problems designed to investigate various aspects of complexities, applications and limitations associated with methods for analysis of non-classically damped structures. Discussions are provided on the benchmarking process, benchmark structural models, and the evaluation approach, as well as benchmarking ground rules. It is expected that the findings and insights, as well as recommendations from this program will be useful in developing new acceptance criteria and providing guidance for future regulatory activities involving licensing applications of these alternate methods to coupled systems.

  10. Fast Numerical Evaluation of Time-Derivative Nonadiabatic Couplings for Mixed Quantum-Classical Methods.

    PubMed

    Ryabinkin, Ilya G; Nagesh, Jayashree; Izmaylov, Artur F

    2015-11-01

    We have developed a numerical differentiation scheme that eliminates evaluation of overlap determinants in calculating the time-derivative nonadiabatic couplings (TDNACs). Evaluation of these determinants was the bottleneck in previous implementations of mixed quantum-classical methods using numerical differentiation of electronic wave functions in the Slater determinant representation. The central idea of our approach is, first, to reduce the analytic time derivatives of Slater determinants to time derivatives of molecular orbitals and then to apply a finite-difference formula. Benchmark calculations prove the efficiency of the proposed scheme showing impressive several-order-of-magnitude speedups of the TDNAC calculation step for midsize molecules. PMID:26538034

  11. Introductory tests to in vivo evaluation: magnetic coupling influence in motor controller.

    PubMed

    Bock, Eduardo; Andrade, Aron; Dinkhuysen, Jarbas; Arruda, Celso; Fonseca, Jeison; Leme, Juliana; Utiyama, Bruno; Leao, Tarcisio; Uebelhart, Beatriz; Antunes, Pedro; Sugita, Yoichi; Motomura, Tadashi; Nosé, Yukihiko

    2011-01-01

    An implantable centrifugal blood pump has been developed with original features for a ventricle assist device (VAD). This pump is part of a multicenter and international study with objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations were performed followed by prototyping and in vitro tests. Also, previous blood tests for assessment of hemolysis showed mean normalized index of hemolysis (NIH) results of 0.0054 ± 2.46 × 10⁻³ mg/100 L (at 5 L/min and 100 mm Hg). To precede in vivo evaluation, measurements of magnetic coupling interference and enhancements of actuator control were necessary. Methodology was based on the study of two different work situations (1 and 2) studied with two different types of motors (A and B). Situation 1 is when the rotor of pump is closest to the motor and situation 2 its opposite. Torque and mechanical power were collected with a dynamometer (80 g/cm) and then plotted and compared for two situations and both motors. The results showed that motor A has better mechanical behavior and less influence of coupling. Results for situation 1 showed that it is more often under magnetic coupling influence than situation 2. The studies lead to the conclusion that motor A is the best option for in vivo studies as it has less influence of magnetic coupling in both situations. PMID:21841468

  12. Gearbox Reliability Collaborative Analytic Formulation for the Evaluation of Spline Couplings

    SciTech Connect

    Guo, Y.; Keller, J.; Errichello, R.; Halse, C.

    2013-12-01

    Gearboxes in wind turbines have not been achieving their expected design life; however, they commonly meet and exceed the design criteria specified in current standards in the gear, bearing, and wind turbine industry as well as third-party certification criteria. The cost of gearbox replacements and rebuilds, as well as the down time associated with these failures, has elevated the cost of wind energy. The National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) was established by the U.S. Department of Energy in 2006; its key goal is to understand the root causes of premature gearbox failures and improve their reliability using a combined approach of dynamometer testing, field testing, and modeling. As part of the GRC program, this paper investigates the design of the spline coupling often used in modern wind turbine gearboxes to connect the planetary and helical gear stages. Aside from transmitting the driving torque, another common function of the spline coupling is to allow the sun to float between the planets. The amount the sun can float is determined by the spline design and the sun shaft flexibility subject to the operational loads. Current standards address spline coupling design requirements in varying detail. This report provides additional insight beyond these current standards to quickly evaluate spline coupling designs.

  13. Humidity and aggregate content correction factors for air-coupled ultrasonic evaluation of concrete.

    PubMed

    Berriman, J; Purnell, P; Hutchins, D A; Neild, A

    2005-02-01

    This paper describes the use of non-contact ultrasound for the evaluation of concrete. Micromachined capacitance transducers are used to transmit ultrasonic longitudinal chirp signals through concrete samples using air as the coupling medium, and a pulse compression technique is then employed for measurement of time of flight through the sample. The effect on the ultrasonic wave speed of storing concrete samples, made with the same water/cement ratio, at different humidity levels is investigated. It is shown that there is a correlation between humidity and speed of sound, allowing a correction factor for humidity to be derived. A strong positive linear correlation between aggregate content and speed of sound was then observed; there was no obvious correlation between compressive strength and speed of sound. The results from the non-contact system are compared with that from a contact system, and conclusions drawn concerning coupling of energy into the samples. PMID:15567195

  14. Development of polypropylene/wood flour ecocomposites. Evaluation of silane as coupling agent

    NASA Astrophysics Data System (ADS)

    Bouza, R.; Barral, L.; Abad, M. J.; Montero, B.

    2010-06-01

    The effects of Pinus Sylvestris wood flour as filler in polypropylene matrix was evaluated. The mechanical properties and the morphology of different wood flour/polypropylene composites (WPC) were studied. The composites materials were prepared with several amounts of wood flour from 10 to 30% wt. Mechanical properties show that the wood flour incorporation increases the rigidity of the composites. Morphological analysis indicates that agglomerates are formed, with amounts exceeding 30% of wood flour. For the silane—treated composites, the dispersion of the filler into the polypropylene (PP) matrix improved. Shore D hardness of the composites is decreased with the addition of the coupling agent.

  15. Development of polypropylene/wood flour ecocomposites. Evaluation of silane as coupling agent

    SciTech Connect

    Bouza, R.; Barral, L.; Abad, M. J.; Montero, B.

    2010-06-02

    The effects of Pinus Sylvestris wood flour as filler in polypropylene matrix was evaluated. The mechanical properties and the morphology of different wood flour/polypropylene composites (WPC) were studied. The composites materials were prepared with several amounts of wood flour from 10 to 30% wt. Mechanical properties show that the wood flour incorporation increases the rigidity of the composites. Morphological analysis indicates that agglomerates are formed, with amounts exceeding 30% of wood flour. For the silane--treated composites, the dispersion of the filler into the polypropylene (PP) matrix improved. Shore D hardness of the composites is decreased with the addition of the coupling agent.

  16. Coupling Photon Monte Carlo Simulation and CAD Software. Application to X-ray Nondestructive Evaluation

    NASA Astrophysics Data System (ADS)

    Tabary, J.; Glière, A.

    A Monte Carlo radiation transport simulation program, EGS Nova, and a Computer Aided Design software, BRL-CAD, have been coupled within the framework of Sindbad, a Nondestructive Evaluation (NDE) simulation system. In its current status, the program is very valuable in a NDE laboratory context, as it helps simulate the images due to the uncollided and scattered photon fluxes in a single NDE software environment, without having to switch to a Monte Carlo code parameters set. Numerical validations show a good agreement with EGS4 computed and published data. As the program's major drawback is the execution time, computational efficiency improvements are foreseen.

  17. Model-driven evaluation of the production potential for growth-coupled products of Escherichia coli.

    PubMed

    Feist, Adam M; Zielinski, Daniel C; Orth, Jeffrey D; Schellenberger, Jan; Herrgard, Markus J; Palsson, Bernhard Ø

    2010-05-01

    Integrated approaches utilizing in silico analyses will be necessary to successfully advance the field of metabolic engineering. Here, we present an integrated approach through a systematic model-driven evaluation of the production potential for the bacterial production organism Escherichia coli to produce multiple native products from different representative feedstocks through coupling metabolite production to growth rate. Designs were examined for 11 unique central metabolism and amino acid targets from three different substrates under aerobic and anaerobic conditions. Optimal strain designs were reported for designs which possess maximum yield, substrate-specific productivity, and strength of growth-coupling for up to 10 reaction eliminations (knockouts). In total, growth-coupled designs could be identified for 36 out of the total 54 conditions tested, corresponding to eight out of the 11 targets. There were 17 different substrate/target pairs for which over 80% of the theoretical maximum potential could be achieved. The developed method introduces a new concept of objective function tilting for strain design. This study provides specific metabolic interventions (strain designs) for production strains that can be experimentally implemented, characterizes the potential for E. coli to produce native compounds, and outlines a strain design pipeline that can be utilized to design production strains for additional organisms. PMID:19840862

  18. Structural evaluation of Marman V-band coupling and flange with conoseal gasket

    NASA Technical Reports Server (NTRS)

    Oates, J. H.

    1972-01-01

    Results are described of a development test program directed at evaluating the structural capabilities of the Marman V-band coupling and flange with conoseal gasket. The intended end use was for the 75K NERVA flight engine propellant lines. Of major importance in the structural evaluation was the ability to predict stresses throughout the assembly for a variety of loading conditions. Computer finite element analysis was used to predict these stresses but, for the subject configuration, large uncertainties were introduced in modeling the complex geometry and boundary conditions. The purpose of the structural tests was to obtain actual stresses and deflections for correlation with, and updating of the finite element model. Results of the incomplete test program are inconclusive with respect to determining suitability for use on the NERVA engine.

  19. Photorefractive two-beam coupling joint transform correlator: modeling and performance evaluation.

    PubMed

    Nehmetallah, G; Khoury, J; Banerjee, P P

    2016-05-20

    The photorefractive two-beam coupling joint transform correlator combines two features. The first is embedded semi-adaptive optimality, which weighs the correlation against clutter and noise in the input, and the second is the intrinsic dynamic range compression nonlinearity, which improves several metrics simultaneously without metric trade-off. Although the two beam coupling correlator was invented many years ago, its outstanding performance was recognized on only relatively simple images. There was no study about the performance of this correlator on complicated images and using different figures of merit. In this paper, the study is extended to more complicated images. For the first time, to our knowledge, we demonstrate simultaneous improvement in metrics performance without metric trade-off. The performance was evaluated compared to the classical joint transform correlator. A typical experimental result to validate the simulation results was also shown in this work. The best performing operation parameters were identified to guide the experimental work and for future comparison with other well-known optimal correlation filters. PMID:27411127

  20. Annual Application and Evaluation of the Online Coupled WRF‐CMAQ System over North America under AQMEII Phase 2

    EPA Science Inventory

    We present an application of the online coupled WRF-CMAQ modeling system to two annual simulations over North America performed under Phase 2 of the Air Quality Model Evaluation International Initiative (AQMEII). Operational evaluation shows that model performance is comparable t...

  1. An evaluation of a coupled atmosphere-ocean modelling system for regional climate studies: extreme events in the North Atlantic

    NASA Astrophysics Data System (ADS)

    Mooney, Priscilla A.; Mulligan, Frank J.

    2013-04-01

    We investigate the ability of a coupled regional atmosphere-ocean modelling system to simulate two extreme events in the North Atlantic. In this study we use the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST; Warner et al.) modelling system with only the atmosphere and ocean models activated. COAWST couples the atmosphere model (Weather Research and Forecasting model; WRF) to the ocean model (Regional Ocean Modelling System; ROMS) with the Model Coupling Toolkit. Results from the coupled system are compared with atmosphere only simulations of North Atlantic storms to evaluate the performance of the coupled modelling system. Two extreme events (Hurricane Katia and Hurricane Irene) were chosen to assess the level of improvement (or otherwise) arising from coupling WRF with ROMS. These two hurricanes involve different dynamics and present different challenges to the modeling system. This provides a robust assessment of the advantages or disadvantages of coupling WRF with ROMS for regional climate modelling studies of extreme events in the North Atlantic. We examine the ability of the coupled modelling system to simulate these two extreme events by comparing modelled storm tracks, storm intensities, wind speeds and sea surface temperatures with observations in all cases. The effect of domain size, and two different planetary boundary layers used in WRF are also reported.

  2. An evaluation of China's water cycle in the MetUM-GC2 coupled model

    NASA Astrophysics Data System (ADS)

    Rodriguez, Jose; Marzin, Charline

    2015-04-01

    There is a general consensus in climate projections that the global hydrological cycle is likely to experience significant changes in the future, in response to increased concentrations of greenhouse gases. At the regional scale, model simulations show large variations in the predictions of changes in the components of the water cycle. Increasing confidence in regional prediction of the water cycle is at the top of the NWP and climate research agenda, requiring a comprehensive evaluation of the physical processes which may play an important role. Here we present preliminary results of an evaluation of the capacity of the MetUM-GC2 coupled model to reproduce the characteristics of the water cycle in the region of China. Using water budget techniques in the atmospheric and terrestrial branches we test the water cycle components and the model's ability to replicate the climatological annual cycle and its interannual variability. Recent drought and flood events are evaluated and various metrics are employed to compare the role played by the atmospheric general circulation including the boreal summer and winter monsoon regimes and soil moisture feedback in model and observations.

  3. Evaluation of antibacterial effect and mode of Coptidis rhizoma by microcalorimetry coupled with chemometric techniques.

    PubMed

    Kong, Weijun; Wang, Jiabo; Xiao, Xiaohe; Chen, Shilin; Yang, Meihua

    2012-01-01

    In this study, the antibacterial effect and mode of Coptidis rhizoma on Escherichia coli was evaluated by microcalorimetry coupled with chemometric techniques. Using an isothermal microcalorimeter, the metabolic profiles of E. coli growth at 37 °C affected by 15 batches of C. rhizoma were measured. Through principal component analysis (PCA) on nine quantitative thermo-kinetic parameters obtained from the metabolic power-time profiles of E. coli, the antibacterial effects of C. rhizoma from various sources could be easily evaluated by analyzing the change of the two main thermo-kinetic parameters, growth rate constant k(2) and maximum heat-output power P(2)(m), in the second exponential phase of E. coli growth. Then, hierarchical clustering analysis (HCA) was carried out on the two parameters to distinguish those C. rhizoma samples in respect to their antibacterial effects. Clear results were obtained to show that all 15 C. rhizoma samples with different antibacterial effects could be successfully grouped in accordance with their origins. Ranked in decreasing order, the antibacterial mode of C. rhizoma samples that were from Sichuan province had the strongest antibacterial effects, followed by samples from Chongqing city and Hubei province. Our results revealed that the developed microcalorimetry with chemometric techniques had the potential perspective for evaluating the effect and mode of Coptidis rhizoma and other Chinese materia medicas. PMID:22059231

  4. Coupled acoustic-gravity field for dynamic evaluation of ion exchange with a single resin bead.

    PubMed

    Kanazaki, Takahiro; Hirawa, Shungo; Harada, Makoto; Okada, Tetsuo

    2010-06-01

    A coupled acoustic-gravity field is efficient for entrapping a particle at the position determined by its acoustic properties rather than its size. This field has been applied to the dynamic observation of ion-exchange reactions occurring in a single resin bead. The replacement of counterions in an ion-exchange resin induces changes in its acoustic properties, such as density and compressibility. Therefore, we can visually trace the advancement of an ion-exchange reaction as a time change in the levitation position of a resin bead entrapped in the field. Cation-exchange reactions occurring in resin beads with diameters of 40-120 microm are typically completed within 100-200 s. Ion-exchange equilibrium or kinetics is often evaluated with off-line chemical analyses, which require a batch amount of ion exchangers. Measurements with a single resin particle allow us to evaluate ion-exchange dynamics and kinetics of ions including those that are difficult to measure by usual off-line analyses. The diffusion properties of ions in resins have been successfully evaluated from the time change in the levitation positions of resin beads. PMID:20462180

  5. Preliminary Evaluation Of Charge-Coupled Device (CCD) Multispectral Analysis In Ophthalmology

    NASA Astrophysics Data System (ADS)

    Launay, Francoise; Fauconnier, Thierry; Fort, Bernard; Cailloux, Mireille; Bonnin, Paul; Bloch-Michel, Etienne

    1986-05-01

    The work described was originally aimed at providing a new diagnostic technique for the early detection of malignant ocular tumors through their spectral signature. The instrument developed comprises a modified fundus camera, a Charge-coupled device (CCD) camera and a 16 bit microcomputer equipped with floppy disk drives and a 512 x 512X 8-bit display device. The system allows the recording of digitized fundus or iris reflectance pictures in eight spec-tral bands between 500 and 1100 nm. After calibration and preprocessing of the data, a multi-spectral analysis is performed by means of a VAX computer. The image processing methods are described and their ability to characterize pigmented lesions or other ocular anatomical fea-tures through their spectral signature is evaluated.

  6. Khoros, coupled with SIMD processor, provides a standard environment for mine detection algorithm evaluation

    NASA Astrophysics Data System (ADS)

    Long, Daniel T.; Hinnerschitz, Scott E.; Sutha, Surachai; Duvoisin, Herbert A., III; Cloud, Eugene L.; Dubey, Abinash C.

    1995-06-01

    Alternative algorithms for detecting and classifying mines and minelike objects must be evaluated against common image sets to assess performance. The Khoros CantataTM environment provides a standard interface that is both powerful and user friendly. It provides the image algorithmist with an object oriented graphical programming interface (GPI. A Khoros user can import 'toolboxes' of specialized image processing primitives for development of high order algorithms. When Khoros is coupled with a high speed single instruction multiple data (SIMD) algorithms. When Khoros is coupled with a high speed single instruction multiple (SIMD) processor, that operates as a co-processor to a Unix workstation, multiple algorithms and images can be rapidly analyzed at high speeds. The Khoros system and toolboxes with SIMD extensions permit rapid description of the algorithm and allow display and evaluation of the intermediate results. The SIMD toolbox extensions mirror the original serial processor's code results with a SIMD drop in replacement routine which is highly accelerated. This allows an algorithmist to develop identical programs/workspace which run on the host workstation without the use of SIMD coprocessor, but of course with a severe speed performance lost. Since a majority of mine detection componenets are extremely 'CPU intensive', it becomes impractical to process a large number of video frames without SIMD assistance. Development of additional SIMD primitives for customized user toolboxes has been greatly simplified in recent years with the advancement of higher order languages for SIMD processors (e.g.: C + +, Ada). The results is a tool that should greatly enhance the scientific productivity of the mine detection community.

  7. Waterless Coupling of Ultrasound from Planar Contact Transducers to Curved and Irregular Surfaces during Non-destructive Ultrasonic Evaluations

    SciTech Connect

    Denslow, Kayte M.; Diaz, Aaron A.; Jones, Anthony M.; Meyer, Ryan M.; Cinson, Anthony D.; Wells, Mondell D.

    2012-04-30

    The Applied Physics group at the Pacific The Applied Physics group at the Pacific Northwest National Laboratory (PNNL) in Richland, WA has evaluated a method for waterless/liquidless coupling of ultrasonic energy from planar ultrasonic contact transducers to irregular test surfaces for ultrasonic non-destructive evaluation applications. Dry couplant material placed between a planar transducer face and a curved or uneven steel or plastic surface allows for effective sound energy coupling and preserves the integrity of the planar transducer sound field by serving as an acoustic impedance matching layer, providing good surface area contact between geometrically dissimilar surfaces and conforming to rough and unsmooth surfaces. Sound fields radiating from planar ultrasonic contact transducers coupled to curved and uneven surfaces using the dry coupling method were scanned and mapped using a Pinducer receiver connected to a raster scanner. Transducer sound field coverage at several ultrasonic frequencies and several distances from the transducer contact locations were found to be in good agreement with theoretical beam divergence and sound field coverage predictions for planar transducers coupled to simple, planar surfaces. This method is valuable for applications that do not allow for the use of traditional liquid-based ultrasonic couplants due to the sensitivity of the test materials to liquids and for applications that might otherwise require curved transducers or custom coupling wedges. The selection of dry coupling material is reported along with the results of theoretical sound field predictions, the laboratory testing apparatus and the empirical sound field data.

  8. Evaluation of an 18-couple module composed of improved performance SiGe unicouples

    SciTech Connect

    Kelly, C.E.; Klee, P.M.; Nakahara, J.F.; Hartman, R.F.

    1995-12-31

    Radioisotope Thermoelectric Generators (RTGs) have played a major role in providing spacecraft electrical power for interplanetary exploration. Silicon Germanium alloys are the thermoelectric material employed in RTGs. Over the past several years a number of investigations have reported improvements in the figure of merit of these alloys. These improvements are attractive to mission planners because they result in enhanced RTG specific power (watts/lb) and improved efficiency which leads to lower fuel costs. This paper describes the fabrication and testing of an 18-couple module device utilizing unicouples with improved SiGe alloys. The unicouples were fabricated using materials with over a 10% improvement in the 573 to 1,273 K integrated average figure-of-merit over Cassini materials. The p-type material was fabricated by the standard vacuum casting and hot pressing method while the n-type material containing GaP was fabricated by a new method of mechanical alloying and hot isostatic pressing. The unicouples were fabricated in a similar fashion to standard unicouples except that the thermoelectric materials were bonded to the SiMo hot shoe in two thermal cycles due to the disparity of the melting points. A sufficient quantity of unicouples was fabricated to assemble an 18-couple module to evaluate the thermoelectric performance of the improved SiGe materials. The module was brought up to operating temperature following the same heatup rate as previous modules. The module was stabilized at a hot shoe temperature of 1,308 K. Initial performance was compared to the established SiGe database and found to show no improvement thermally or electrically.

  9. Observational Evaluation of Simulated Land-Atmosphere Coupling on the U.S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Phillips, T. J.; Klein, S. A.

    2014-12-01

    In a recent study of observed features of land-atmosphere coupling (LAC) at the ARM Southern Great Plains (ARM SGP) site in northern Oklahoma (Phillips and Klein, 2014 Journal of Geophysical Research), we identified statistically significant interactions between 1997-2008 summertime daily averages of soil moisture (at 10 cm depth) and a number of surface atmospheric variables, such as surface evaporation, relative humidity, and temperature. Here we will report on an evaluation of similar features of LAC simulated by version 5 of the global Community Atmosphere Model (CAM5), coupled to its native CLM4 land model, and downscaled to the vicinity of the ARM SGP site. In these case studies, the CAM5 was initialized from a 6-hourly atmospheric reanalysis for each day of the years 2008 and 2009 (where the CLM4 land state was equilibrated to the atmospheric model state), thus permitting a close comparison of the modeled and observed summer daily average features of the LAC in these years. Correlation coefficients R and "sensitivity indices" I (a measure of the comparative change of an atmospheric variable for a one-standard-deviation change in soil moisture) provided quantitative measures of the respective coupling strengths. Such a comparison of observed versus modeled LAC is complicated by differences in atmospheric forcings of the land; for example, the CAM5's summertime precipitation is too scant, and thus the model's upper soil layer often is drier than observed. The modeled daily average covariations of soil moisture with lower atmospheric variables also display less coherence (lower R values), but sometimes greater "sensitivity" (higher I values) than are observed at the ARM SGP site. Since the observational estimate of LAC may itself be sensitive to soil moisture measurement biases, we also will report on a planned investigation of the dependence of LAC on several alternative choices of soil moisture data sets local to the ARM SGP site. AcknowledgmentsThis work was

  10. Evaluation of optical and chromatic properties under electrical and thermal coupling in solid state lighting systems

    NASA Astrophysics Data System (ADS)

    Fu, Han-Kuei; Peng, Yi-Ping; Wang, Chien-Ping; Chiang, Hsin-Chien; Chen, Tzung-Te; Chen, Chiu-Ling; Chou, Pei-Ting

    2013-09-01

    For energy-saving, high efficiency and low pollution, the lighting of LED systems is important for the future of green energy technology industry. The solid state lighting becomes the replacement of traditional lighting, such as, light bulbs and compact fluorescent lamps. Because of the semiconductor characteristics, the luminous efficiency of LEDs is sensitive to the operating temperature. Besides increasing the luminous efficiency, effective controlling electricity and thermal characteristics in the design of LED lighting products is the key point to achieve the best results. LED modules can be combined with multi-grain process or through a combination of multiple LED chips. Accurate analysis of this LED module for the electrical, thermal characteristics and high reliability is the critical knowledge of modular design. In this report, we studied the electrical and thermal coupling phenomenon in solid state lighting systems to analyze their reliability. By experiments and simulations, we obtained the apparent variation of temperature distribution of LED system due to differences of their forward voltages and thermal resistances. These events may reduce their reliability. Besides, the evaluation of optical and chromatic properties was based on the variation of temperature distribution and current of LED system. This is the key technology to predict the optical and chromatic properties of LED system in use.

  11. Evaluation of coupling protocols to bind beta-glucosidase on magnetic nanoparticles.

    PubMed

    Ricco, Raffaele; Doherty, Cara M; Falcaro, Paolo

    2014-09-01

    Beta-Glucosidase has been chosen as a model biomolecule to establish a general protocol for binding enzymes on both ferromagnetic and superparamagnetic nano-particles for sensing applications. Using EDC (1-(3-dimethyl-aminopropyl)-3-ethylcarbodiimide) or SMCC (Succinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate) as coupling agents, we compared two different methods for the fabrication of enzyme-decorated magnetic nanoparticles. We identified the best conditions for the preparation of a responsive bioactive magnetic system comparing different covalent bio-grafting protocols. The enzymatic test has been performed using beta-Glucosidase. The systems were characterized using scanning electron microscopy, infrared spectroscopy, and the enzyme loading was measured by a glucose assay in the presence of the enzyme-decorated magnetic particles. Although the faster response of ferromagnetic particles to the magnetic field, the assay results suggested that the superparamagnetic particles are more efficient carriers. In fact, the best enzymatic activity was measured on superparamagnetic systems that have the further advantage of preventing aggregation induced by the residual magnetization. Hence, beta-Glucosidase coated magnetic nanospheres could provide an attractive system suitable for the cleavage and the rapid evaluation of glycoside levels in natural products, measuring the liberated glucose without the need for specialised instrumentation. Moreover, the magnetic particles allow the subsequent collection of enzymes for further analysis, such as its use in portable fast screening kits or devices. PMID:25924301

  12. Non-Destructive Evaluation of Grain Structure Using Air-Coupled Ultrasonics

    SciTech Connect

    Belvin, A. D.; Burrell, R. K.; Cole, E.G.

    2009-08-01

    Cast material has a grain structure that is relatively non-uniform. There is a desire to evaluate the grain structure of this material non-destructively. Traditionally, grain size measurement is a destructive process involving the sectioning and metallographic imaging of the material. Generally, this is performed on a representative sample on a periodic basis. Sampling is inefficient and costly. Furthermore, the resulting data may not provide an accurate description of the entire part's average grain size or grain size variation. This project is designed to develop a non-destructive acoustic scanning technique, using Chirp waveforms, to quantify average grain size and grain size variation across the surface of a cast material. A Chirp is a signal in which the frequency increases or decreases over time (frequency modulation). As a Chirp passes through a material, the material's grains reduce the signal (attenuation) by absorbing the signal energy. Geophysics research has shown a direct correlation with Chirp wave attenuation and mean grain size in geological structures. The goal of this project is to demonstrate that Chirp waveform attenuation can be used to measure grain size and grain variation in cast metals (uranium and other materials of interest). An off-axis ultrasonic inspection technique using air-coupled ultrasonics has been developed to determine grain size in cast materials. The technique gives a uniform response across the volume of the component. This technique has been demonstrated to provide generalized trends of grain variation over the samples investigated.

  13. Graphical Analysis of B-737 Airplane Pathloss Data for GPS and Evaluation of Coupling Mitigation Techniques

    NASA Technical Reports Server (NTRS)

    Jafri, Madiha J.; Ely, Jay J.; Vahala, Linda

    2004-01-01

    The use of Portable Electronic Devices (PEDs) onboard commercial airliners is considered to be desirable for many passengers, However, the possibility of Electromagnetic Interference (EMI) caused by these devices may affect flight safety. PEDs may act as transmitters, both intentional and unintentional, and their signals may be detected by the various navigation and communication radios onboard the aircraft. Interference Pathloss (IPL) is defined as the measurement of the radiated field coupling between passenger cabin locations and aircraft communication and navigation receivers, via their antennas. This paper first focuses on IPL measurements for GPS, taken on an out-of-service United Airlines B-737-200. IPL pattern symmetry is verified by analyzing data obtained on the windows of the Port as well as the Starboard side of the aircraft. Further graphical analysis is performed with the door and exit seams sealed with conductive tape in order to better understand the effects of shielding on IPL patterns. Shielding effects are analyzed from window data for VHF and LOC systems. In addition the shielding benefit of applying electrically conductive film to aircraft windows is evaluated for GPS and TCAS systems.

  14. Non-contact evaluation of milk-based products using air-coupled ultrasound

    NASA Astrophysics Data System (ADS)

    Meyer, S.; Hindle, S. A.; Sandoz, J.-P.; Gan, T. H.; Hutchins, D. A.

    2006-07-01

    An air-coupled ultrasonic technique has been developed and used to detect physicochemical changes of liquid beverages within a glass container. This made use of two wide-bandwidth capacitive transducers, combined with pulse-compression techniques. The use of a glass container to house samples enabled visual inspection, helping to verify the results of some of the ultrasonic measurements. The non-contact pulse-compression system was used to evaluate agglomeration processes in milk-based products. It is shown that the amplitude of the signal varied with time after the samples had been treated with lactic acid, thus promoting sample destabilization. Non-contact imaging was also performed to follow destabilization of samples by scanning in various directions across the container. The obtained ultrasonic images were also compared to those from a digital camera. Coagulation with glucono-delta-lactone of skim milk poured into this container could be monitored within a precision of a pH of 0.15. This rapid, non-contact and non-destructive technique has shown itself to be a feasible method for investigating the quality of milk-based beverages, and possibly other food products.

  15. Evaluation of MPLM Design and Mission 6A Coupled Loads Analyses

    NASA Technical Reports Server (NTRS)

    Bookout, Paul S.; Ricks, Ed

    1999-01-01

    Through the development of a space shuttle payload, there are usually several coupled loads analyses (CLA) performed: preliminary design, critical design, final design and verification loads analysis (VLA). A final design CLA is the last analysis conducted prior to model delivery to the shuttle program for the VLA. The finite element models used in the final design CLA and the VLA are test verified dynamic math models. Mission 6A is the first of many flights of the Multi-Purpose Logistics Module (MPLM). The MPLM was developed by Alenia Spazio S.p.A. (an Italian aerospace company) and houses the International Standard Payload Racks (ISPR) for transportation to the space station in the shuttle. Marshall Space Flight Center (MSFC), the payload integrator of the MPLM for Mission 6A, performed the final design CLA using the M6.OZC shuttle data for liftoff and landing conditions using the proper shuttle cargo manifest. Alenia performed the preliminary and critical design CLAs for the development of the MPLM. However, these CLAs did not use the current Mission 6A cargo manifest. An evaluation of the preliminary and critical design performed by Alenia and the final design performed by MSFC is presented.

  16. Synthesis of adriamycin-coupled polyglutaraldehyde microspheres and evaluation of their cytostatic activity

    NASA Technical Reports Server (NTRS)

    Tokes, Z. A.; Rogers, K. E.; Rembaum, A.

    1982-01-01

    Adriamycin was coupled to polyglutaraldehyde microspheres having an average diameter of 4500 A. The coupled microspheres remained stable during incubation with cells. Full cytostatic activity was observed when the coupled adriamycin was tested with murine or human leukemia and murine sarcoma cell lines. A 10-fold increase in sensitivity was obtained with drug-resistant human leukemia cell lines. Repeated use of the coupled microspheres in the cytostatic assays did not decrease their activity, indicating that these complexes can be recycled. The results suggest that coupled adriamycin sufficiently perturbs the plasma membrane to lead to cytostatic activity. It is proposed that this mode of drug delivery provides multiple and repetitious sites for drug-cell interactions. In addition, the drug-polymer complexes may overcome those forms of resistance that are the result of decreased drug binding at the cell surface.

  17. Evaluation and Sensitivity Analysis of An Ensemble-based Coupled Flash Flood and Landslide Modelling System Using Remote Sensing Forcing

    NASA Astrophysics Data System (ADS)

    Zhang, K.; Hong, Y.; Gourley, J. J.; Xue, X.; He, X.

    2015-12-01

    Heavy rainfall-triggered landslides are often associated with flood events and cause additional loss of life and property. It is pertinent to build a robust coupled flash flood and landslide disaster early warning system for disaster preparedness and hazard management based. In this study, we built an ensemble-based coupled flash flood and landslide disaster early warning system, which is aimed for operational use by the US National Weather Service, by integrating the Coupled Routing and Excess STorage (CREST) model and Sacramento Soil Moisture Accounting Model (SAC-SMA) with the physically based SLope-Infiltration-Distributed Equilibrium (SLIDE) landslide prediction model. We further evaluated this ensemble-based prototype warning system by conducting multi-year simulations driven by the Multi-Radar Multi-Sensor (MRMS) rainfall estimates in North Carolina and Oregon. We comprehensively evaluated the predictive capabilities of this system against observed and reported flood and landslides events. We then evaluated the sensitivity of the coupled system to the simulated hydrological processes. Our results show that the system is generally capable of making accurate predictions of flash flood and landslide events in terms of their locations and time of occurrence. The occurrence of predicted landslides show high sensitivity to total infiltration and soil water content, highlighting the importance of accurately simulating the hydrological processes on the accurate forecasting of rainfall triggered landslide events.

  18. Evaluation of a regional assimilation system coupled with the WRF-chem model

    NASA Astrophysics Data System (ADS)

    Liu, Yan-an; Gao, Wei; Huang, Hung-lung; Strabala, Kathleen; Liu, Chaoshun; Shi, Runhe

    2013-09-01

    Air quality has become a social issue that is causing great concern to humankind across the globe, but particularly in developing countries. Even though the Weather Research and Forecasting with Chemistry (WRF-Chem) model has been applied in many regions, the resolution for inputting meteorology field analysis still impacts the accuracy of forecast. This article describes the application of the CIMSS Regional Assimilation System (CRAS) in East China, and its capability to assimilate the direct broadcast (DB) satellite data for obtaining more detailed meteorological information, including cloud top pressure (CTP) and total precipitation water (TPW) from MODIS. Performance evaluation of CRAS is based on qualitative and quantitative analyses. Compared with data collected from ERA-Interim, Radiosonde, and the Tropical Rainfall Measuring Mission (TRMM) precipitation measurements using bias and Root Mean Square Error (RMSE), CRAS has a systematic error due to the impact of topography and other factors; however, the forecast accuracy of all elements in the model center area is higher at various levels. The bias computed with Radiosonde reveals that the temperature and geopotential height of CRAS are better than ERA-Interim at first guess. Moreover, the location of the 24 h accumulated precipitation forecast are highly consistent with the TRMM retrieval precipitation, which means that the performance of CRAS is excellent. In summation, the newly built Vtable can realize the function of inputting the meteorology field from CRAS output into WRF, which couples the CRAS with WRF-Chem. Therefore, this study not only provides for forecast accuracy of CRAS, but also increases the capability of running the WRF-Chem model at higher resolutions in the future.

  19. Evaluating a coupled discrete wavelet transform and support vector regression for daily and monthly streamflow forecasting

    NASA Astrophysics Data System (ADS)

    Liu, Zhiyong; Zhou, Ping; Chen, Gang; Guo, Ledong

    2014-11-01

    This study investigated the performance and potential of a hybrid model that combined the discrete wavelet transform and support vector regression (the DWT-SVR model) for daily and monthly streamflow forecasting. Three key factors of the wavelet decomposition phase (mother wavelet, decomposition level, and edge effect) were proposed to consider for improving the accuracy of the DWT-SVR model. The performance of DWT-SVR models with different combinations of these three factors was compared with the regular SVR model. The effectiveness of these models was evaluated using the root-mean-squared error (RMSE) and Nash-Sutcliffe model efficiency coefficient (NSE). Daily and monthly streamflow data observed at two stations in Indiana, United States, were used to test the forecasting skill of these models. The results demonstrated that the different hybrid models did not always outperform the SVR model for 1-day and 1-month lead time streamflow forecasting. This suggests that it is crucial to consider and compare the three key factors when using the DWT-SVR model (or other machine learning methods coupled with the wavelet transform), rather than choosing them based on personal preferences. We then combined forecasts from multiple candidate DWT-SVR models using a model averaging technique based upon Akaike's information criterion (AIC). This ensemble prediction was superior to the single best DWT-SVR model and regular SVR model for both 1-day and 1-month ahead predictions. With respect to longer lead times (i.e., 2- and 3-day and 2-month), the ensemble predictions using the AIC averaging technique were consistently better than the best DWT-SVR model and SVR model. Therefore, integrating model averaging techniques with the hybrid DWT-SVR model would be a promising approach for daily and monthly streamflow forecasting. Additionally, we strongly recommend considering these three key factors when using wavelet-based SVR models (or other wavelet-based forecasting models).

  20. Evaluation of source model coupled computational fluid dynamics (CFD) simulation of the dispersion of airborne contaminants in a work environment.

    PubMed

    Salim, S M; Viswanathan, Shekar; Ray, Madhumita Bhowmick

    2006-12-01

    Dispersion of airborne contaminants in indoor air was evaluated employing physical measurement, empirical models, and computer simulation methods. Field data collected from a tray of evaporating solvent in the laboratory were compared with computational fluid dynamics (CFD) simulations coupled with evaporation models. The results indicated that mathematical models of evaporation can be coupled with CFD simulations to produce reasonable qualitative predictions of airborne contaminant levels. The airflow pattern within a room is primarily determined by the room layout and the position of the air supply diffusers. Variations in ventilation rate did not alter the airflow pattern, thus generating a characteristic concentration profile of the airborne contaminants. PMID:17050350

  1. Evaluating Land-Atmosphere Coupling Strength Over CONUS Using Satellite-based Remote Sensing

    NASA Astrophysics Data System (ADS)

    Wood, E. F.; Ferguson, C.

    2008-12-01

    Understanding the coupling strength between land and its overlying boundary layer is important to establishing the role of the surface state in boundary layer development and related processes. Much of our current understanding has resulted from model diagnostics carried out by Alan K. Betts using the European Center's (ECMWF) forecast and reanalysis model outputs. Other model based analysis under the GEWEX Land Atmospheric Coupling Experiments (GLACE), lead by Randy Koster, has suggested that models with strong coupling have inferred "hot spots" that imply enhanced predictability of seasonal precipitation. Other analysis (Mitchell, personal communication) suggests that models with strong coupling fail to represent the observed diurnal cycle of precipitation across the central U.S. Dirmeyer et al. in 2006 compared the coupling strength (using Betts" measure that relates surface soil moisture to the lifting condensation level (LCL) pressure) for a number of models from the GLACE experiment, which showed a wide range of strength. This presentation utilizes space-based remote sensing (RS) observations to estimate the strength of warm season land-atmosphere coupling over the continental US. The remote sensing products are derived from the suite of sensors on-board NASA Aqua, including AMSR-E (soil moisture), AIRS (relative humidity, air temperature, skin temperature), MODIS (LAI, NDVI), and CERES (radiation). The relative strength of coupling is quantified in terms of observational diagnostics set forth by the work of Alan Betts, based on his work with the ERA40 model output data set, and Fendall and Eltahir, based on radiosonde data. While the analysis covers the continental US (CONUS), emphasis is placed on the southern Great Plains where dense in-situ measurements enable direct comparison between coupling strengths obtained from ground observations and those from remote sensing, and a region that previous studies by Koster et al. have inferred to be a coupling "hot

  2. Experimental procedure for the evaluation of tooth stiffness in spline coupling including angular misalignment

    NASA Astrophysics Data System (ADS)

    Curà, Francesca; Mura, Andrea

    2013-11-01

    Tooth stiffness is a very important parameter in studying both static and dynamic behaviour of spline couplings and gears. Many works concerning tooth stiffness calculation are available in the literature, but experimental results are very rare, above all considering spline couplings. In this work experimental values of spline coupling tooth stiffness have been obtained by means of a special hexapod measuring device. Experimental results have been compared with the corresponding theoretical and numerical ones. Also the effect of angular misalignments between hub and shaft has been investigated in the experimental planning.

  3. Objective evaluation of interior trim effects on sound quality and noise reduction of a coupled plate cavity system

    NASA Astrophysics Data System (ADS)

    Egab, Laith; Wang, Xu

    2016-03-01

    In this study, the impedance mobility and psychoacoustic analysis methods are combined to develop a structural-acoustic model of a plate-cavity coupling system. The objective is to evaluate the effect of interior trim materials on sound loudness and sharpness of a plate-cavity coupling system. The impedance mobility method is applied to calculate the pressure frequency responses of the interior acoustic field for the plate-cavity coupling system. The sound pressure results calculated by the impedance mobility method are then directly used to calculate the psychoacoustic metrics using psychoacoustic analysis method. A good agreement was found between the experimental and analytical results. The results show that the interior trim has a large influence on the distribution of the sound loudness and sharpness inside the cavity in the middle and high frequency ranges.

  4. A hydrodynamics-reaction kinetics coupled model for evaluating bioreactors derived from CFD simulation.

    PubMed

    Wang, Xu; Ding, Jie; Guo, Wan-Qian; Ren, Nan-Qi

    2010-12-01

    Investigating how a bioreactor functions is a necessary precursor for successful reactor design and operation. Traditional methods used to investigate flow-field cannot meet this challenge accurately and economically. Hydrodynamics model can solve this problem, but to understand a bioreactor in sufficient depth, it is often insufficient. In this paper, a coupled hydrodynamics-reaction kinetics model was formulated from computational fluid dynamics (CFD) code to simulate a gas-liquid-solid three-phase biotreatment system for the first time. The hydrodynamics model is used to formulate prediction of the flow field and the reaction kinetics model then portrays the reaction conversion process. The coupled model is verified and used to simulate the behavior of an expanded granular sludge bed (EGSB) reactor for biohydrogen production. The flow patterns were visualized and analyzed. The coupled model also demonstrates a qualitative relationship between hydrodynamics and biohydrogen production. The advantages and limitations of applying this coupled model are discussed. PMID:20727741

  5. Coupling FLEXPART to the regional scale numerical weather prediction model COSMO: Implementation, evaluation and first results

    NASA Astrophysics Data System (ADS)

    Henne, Stephan; Kaufmann, Pirmin; Schraner, Martin; Brunner, Dominik

    2013-04-01

    The Lagrangian particle dispersion model FLEXPART is a well-known and robust research tool used by many atmospheric scientists worldwide. In its standard version FLEXPART was developed for the use with global or limited area input files from the European Centre for Medium Range Weather Forecast (ECMWF). Further versions exist for input from the NCEP (National Centers for Environmental Prediction) GFS (Global Forecasting System) model and for regional scale input from the MM5 model and its successor WRF. In Europe several national weather services and research groups develop and operate the non-hydrostatic limited-area atmospheric model COSMO (Consortium for Small-scale Modeling). At MeteoSwiss COSMO is operationally run with data assimilation on two grids with approximately 7 km x 7 km and 2 km x 2 km horizontal resolution centered over Switzerland This offers the exceptional opportunity of studying atmospheric transport over complex terrain on an long-term basis. To this end, we have developed a new version of FLEXPART that is offline coupled to COSMO output (FLEXPART-COSMO hereafter) and supports output from multiple COSMO nests. The version features several new developments as compared to the standard version. Most importantly, particles are internally referenced against the native vertical coordinate system used in COSMO and not, as in standard FLEXPART, in a terrain following z-system. This eliminates the need for an additional interpolation step. A new flux deaccumulation scheme was introduced that removes the need for additional preprocessing of the input files. In addition to the existing Emmanuel based convection parameterisation, a convection parameterisation based on the Tiedtke scheme, which is identical to the one implemented in COSMO itself, was introduced. A possibility for offline nesting of a FLEXPART-COSMO run into a FLEXPART-ECMWF run for backward simulations was developed that only requires minor modifications on the FLEXPART-ECMWF version and

  6. Evaluation of the analytical capability of NIR femtosecond laser ablation-inductively coupled plasma mass spectrometry.

    PubMed

    Hirata, Takafumi; Kon, Yoshiaki

    2008-03-01

    A laser ablation-inductively coupled plasma-mass spectrometric (LA-ICPMS) technique utilizing a titanium-sapphire (TiS) femtosecond laser (fs-laser) has been developed for elemental and isotopic analysis. The signal intensity profile, depth of the ablation pit and level of elemental fractionation were investigated in order to evaluate the analytical capability of the present fs-laser ablation-ICPMS technique. The signal intensity profile of (57)Fe, obtained from iron sulfide (FeS(2)), demonstrated that the resulting signal intensity of (57)Fe achieved by the fs-laser ablation was almost 4-times higher than that obtained by ArF excimer laser ablation under a similar energy fluence (5 J/cm(2)). In fs-laser ablation, there is no significant difference in a depth of the ablation pit between glass and zircon material, while in ArF laser ablation, the resulting crater depth on the zircon crystal was almost half the level than that obtained for glass material. Both the thermal-induced and particle size-related elemental fractionations, which have been thought to be main sources of analytical error in the LA-ICPMS analysis, were measured on a Harvard 91500 zircon crystal. The resulting fractionation indexes on the (206)Pb/(238)U (f(Pb/U)) and (238)U/(232)Th (f(U/Th)) ratios obtained by the present fs-laser ablation system were significantly smaller than those obtained by a conventional ArF excimer laser ablation system, demonstrative of smaller elemental fractionation. Using the present fs-laser ablation technique, the time profile of the signal intensity of (56)Fe and the isotopic ratios ((57)Fe/(54)Fe and (56)Fe/(54)Fe) have been measured on a natural pyrite (FeS(2)) sample. Repeatability in signal intensity of (56)Fe achieved by the fs-laser ablation system was significantly better than that obtained by ArF excimer laser ablation. Moreover, the resulting precision in (57)Fe/(54)Fe and (56)Fe/(54)Fe ratio measurements could be improved by the fs-laser ablation system

  7. Evaluation of a coupled dispersion and aerosol process model against measurements near a major road

    NASA Astrophysics Data System (ADS)

    Pohjola, M. A.; Pirjola, L.; Karppinen, A.; Härkönen, J.; Ketzel, M.; Kukkonen, J.

    2007-02-01

    A field measurement campaign was conducted near a major road "Itäväylä" in an urban area in Helsinki in 17-20 February 2003. Aerosol measurements were conducted using a mobile laboratory "Sniffer" at various distances from the road, and at an urban background location. Measurements included particle size distribution in the size range of 7 nm-10 μm (aerodynamic diameter) by the Electrical Low Pressure Impactor (ELPI) and in the size range of 3-50 nm (mobility diameter) by Scanning Mobility Particle Sizer (SMPS), total number concentration of particles larger than 3 nm detected by an ultrafine condensation particle counter (UCPC), temperature, relative humidity, wind speed and direction, driving route of the mobile laboratory, and traffic density on the studied road. In this study, we have compared measured concentration data with the predictions of the road network dispersion model CAR-FMI used in combination with an aerosol process model MONO32. The vehicular exhaust emissions, and atmospheric dispersion and transformation of fine and ultrafine particles was evaluated within the distance scale of 200 m (corresponding to a time scale of a couple of minutes). We computed the temporal evolution of the number concentrations, size distributions and chemical compositions of various particle size classes. The atmospheric dilution rate of particles is obtained from the roadside dispersion model CAR-FMI. Considering the evolution of total number concentration, dilution was shown to be the most important process. The influence of coagulation and condensation on the number concentrations of particle size modes was found to be negligible at this distance scale. Condensation was found to affect the evolution of particle diameter in the two smallest particle modes. The assumed value of the concentration of condensable organic vapour of 1012 molecules cm-3 was shown to be in a disagreement with the measured particle size evolution, while the modelling runs with the

  8. Evaluation of the viability of /sup 111/In-abeled DTPA coupled to fibrinogen

    SciTech Connect

    Layne, W.W.; Hnatowich, D.J.; Doherty, P.W.; Childs, R.L.; Lanteigne, D.; Ansell, J.

    1982-07-01

    In earlier work, DTPA has been covalently coupled to albumin via the cyclic anhydride of DTPA. Using fibrinogen, we have studied the effect of such coupling on protein viability by both an in vitro and an in vivo assay. Clotting time remained identical to that of the native protein whether the anhydride-to-protein molar ratio was 1:1 or 5:1. In vivo studies were done in dogs, with human fibrinogen labeled with /sup 125/I and /sup 111/In. Throughout 130 hr, blood clearances for the two tracers agreed whether with 1:1 or 5:1 coupling. In a dog model with a thrombogenic catheter, the clot-to-blood ratios for the two radiotracers agreed within experimental error. Finally, 1:1-coupled canine fibrinogen, labeled with /sup 111/In, was administered to dogs with a catheter in a jugular vein, and scintigrams at 24 hr clearly showed clotting along the length of the catheter. We conclude that fibrinogen, coupled to DTPA, retains its viability, behaving like radioiodinated fibrinogen in vivo, and /sup 111/In labeled fibrinogen looks promising as a clinical diagnostic agent.

  9. Communication: Spin densities within a unitary group based spin-adapted open-shell coupled-cluster theory: Analytic evaluation of isotropic hyperfine-coupling constants for the combinatoric open-shell coupled-cluster scheme

    SciTech Connect

    Datta, Dipayan Gauss, Jürgen

    2015-07-07

    We report analytical calculations of isotropic hyperfine-coupling constants in radicals using a spin-adapted open-shell coupled-cluster theory, namely, the unitary group based combinatoric open-shell coupled-cluster (COSCC) approach within the singles and doubles approximation. A scheme for the evaluation of the one-particle spin-density matrix required in these calculations is outlined within the spin-free formulation of the COSCC approach. In this scheme, the one-particle spin-density matrix for an open-shell state with spin S and M{sub S} = + S is expressed in terms of the one- and two-particle spin-free (charge) density matrices obtained from the Lagrangian formulation that is used for calculating the analytic first derivatives of the energy. Benchmark calculations are presented for NO, NCO, CH{sub 2}CN, and two conjugated π-radicals, viz., allyl and 1-pyrrolyl in order to demonstrate the performance of the proposed scheme.

  10. Evaluating the Carbon Cycle of a Coupled Atmosphere-Biosphere Model

    SciTech Connect

    Delire, C; Foley, J A; Thompson, S

    2002-08-21

    We investigate how well a coupled biosphere-atmosphere model, CCM3-IBIS, can simulate the functioning of the terrestrial biosphere and the carbon cycling through it. The simulated climate is compared to observations, while the vegetation cover and the carbon cycle are compared to an offline version of the biosphere model IBIS forced with observed climatic variables. The simulated climate presents some local biases that strongly affect the vegetation (e.g., a misrepresentation of the African monsoon). Compared to the offline model, the coupled model simulates well the globally averaged carbon fluxes and vegetation pools. The zonal mean carbon fluxes and the zonal mean seasonal cycle are also well represented except between 0{sup o} and 20{sup o}N due to the misrepresentation of the African monsoon. These results suggest that, despite regional biases in climate and ecosystem simulations, this coupled atmosphere-biosphere model can be used to explore geographic and temporal variations in the global carbon cycle.

  11. Impact Damage Evaluation Method of Friction Disc Based on High-Speed Photography and Tooth-Root Stress Coupling

    NASA Astrophysics Data System (ADS)

    Yin, L.; Shao, Y. M.; Liu, J.; Zheng, H. L.

    2015-07-01

    The stability of friction disc could be seriously affected by the tooth surface damage due to poor working conditions of the wet multi-disc brake in heavy trucks. There are few current works focused on the damage of the friction disc caused by torsion-vibration impacts. Hence, it is necessary to investigate its damage mechanisms and evaluation methods. In this paper, a damage mechanism description and evaluation method of a friction disc based on the high-speed photography and tooth-root stress coupling is proposed. According to the HighSpeed Photography, the collision process between the friction disc and hub is recorded, which can be used to determine the contact position and deformation. Combined with the strain-stress data obtained by the strain gauge at the place of the tooth-root, the impact force and property are studied. In order to obtain the evaluation method, the damage surface morphology data of the friction disc extracted by 3D Super Depth Digital Microscope (VH-Z100R) is compared with the impact force and property. The quantitative relationships between the amount of deformation and collision number are obtained using a fitting analysis method. The experimental results show that the damage of the friction disc can be evaluated by the proposed impact damage evaluation method based on the high-speed photography and tooth-root stress coupling.

  12. The Intercellular Synchronization of Ca2+ Oscillations Evaluates Cx36-Dependent Coupling

    PubMed Central

    Bavamian, Sabine; Pontes, Helena; Cancela, José; Charollais, Anne; Startchik, Sergei; Van De Ville, Dimitri; Meda, Paolo

    2012-01-01

    Connexin36 (Cx36) plays an important role in insulin secretion by controlling the intercellular synchronization of Ca2+ transients induced during stimulation. The lack of drugs acting on Cx36 channels is a major limitation in further unraveling the molecular mechanism underlying this effect. To screen for such drugs, we have developed an assay allowing for a semi-automatic, fluorimetric quantification of Ca2+ transients in large populations of MIN6 cells. Here, we show that (1) compared to control cells, MIN6 cells with reduced Cx36 expression or function showed decreased synchrony of glucose-induced Ca2+ oscillations; (2) glibenclamide, a sulphonylurea which promotes Cx36 junctions and coupling, increased the number of synchronous MIN6 cells, whereas quinine, an antimalarial drug which inhibits Cx36-dependent coupling, decreased this proportion; (3) several drugs were identified that altered the intercellular Ca2+ synchronization, cell coupling and distribution of Cx36; (4) some of them also affected insulin content. The data indicate that the intercellular synchronization of Ca2+ oscillations provides a reliable and non-invasive measurement of Cx36-dependent coupling, which is useful to identify novel drugs affecting the function of β-cells, neurons, and neuron-related cells that express Cx36. PMID:22848521

  13. Development and Evaluation of Novel Coupling Agents for Kenaf-Fiber-Reinforced Unsaturated Polyester Composites

    NASA Astrophysics Data System (ADS)

    Ren, Xiaofeng

    Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a 40% market share of all the thermoset composites. This widespread application is due to many favorable characteristics including low cost, ease of cure at room temperature, ease of molding, a good balance of mechanical, electrical and chemical properties. One of the barriers for the full utilization of the kenaf fiber reinforced UPE composites, however, is the poor interfacial adhesion between the natural fibers and the UPE resins. The good interfacial adhesion between kenaf fibers and UPE matrix is essential for generating the desired properties of kenaf-UPE composites for most of the end applications. Use of a coupling agent is one of the most effective ways of improving the interfacial adhesion. In this study, six novel effective coupling agents were developed and investigated for kenaf-UPE composites: DIH-HEA, MFA, NMA, AESO-DIH, AESO-MDI, and AESO-PMDI. All the coupling agents were able to improve the interfacial adhesion between kanaf and UPE resins. The coupling agents were found to significantly enhance the flexural properties and water resistance of the kenaf-UPE composites. Fourier transform infrared spectroscopy (FTIR) confirmed all the coupling agents were covalently bonded onto kenaf fibers. Scanning electron microscopy (SEM) images of the composites revealed the improved interfacial adhesion between kanaf fibers and UPE resins.

  14. Live Birth is the Correct Outcome for Clinical Trials Evaluating Therapy for the Infertile Couple

    PubMed Central

    Barnhart, Kurt T.

    2014-01-01

    Well-designed and conducted clinical trials are needed to further advance the field for reproductive medicine. However current reporting of outcomes of trials is ambiguous and disparate. In this manuscript it is offed that the preferred outcome for clinical trials in reproductive medicine should be live birth. Multiple births should be listed and it should be specified whether this is multiple births per couple or multiple births per conception. The unit of measure should be women (or couples) and not cycles. The duration of exposure should also be clearly identified (i.e., treatment was one cycle, a pre-specified number of cycles, or a period of time). Pregnancy loss should be specified and the denominator should be those who conceived. While live birth is the primary outcome, complications should be defined and reported including multiple births and other objective markers such as preterm delivery, small-for-gestational age, or stillbirth. PMID:24786740

  15. An experimental evaluation of the fully coupled hysteretic electro-mechanical behaviour of piezoelectric actuators

    NASA Astrophysics Data System (ADS)

    Butcher, Mark; Davino, Daniele; Giustiniani, Alessandro; Masi, Alessandro

    2016-04-01

    Piezoelectrics are the most commonly used of the multifunctional smart materials in industrial applications, because of their relatively low cost and ease of use in electric and electronic oriented applications. Nevertheless, while datasheets usually give just small signal quasi-static parameters, their full potential can only be exploited only if a full characterization is available because the maximum stroke or the higher piezo coupling coefficients are available at different electro-mechanical biases, where often small signal analysis is not valid. In this paper a method to get the quasi-static fully coupled characterization is presented. The method is tested on a commercial piezo actuator but can be extended to similar devices.

  16. Evaluation of bremsstrahlung contribution to photon transport in coupled photon-electron problems

    NASA Astrophysics Data System (ADS)

    Fernández, Jorge E.; Scot, Viviana; Di Giulio, Eugenio; Salvat, Francesc

    2015-11-01

    The most accurate description of the radiation field in x-ray spectrometry requires the modeling of coupled photon-electron transport. Compton scattering and the photoelectric effect actually produce electrons as secondary particles which contribute to the photon field through conversion mechanisms like bremsstrahlung (which produces a continuous photon energy spectrum) and inner-shell impact ionization (ISII) (which gives characteristic lines). The solution of the coupled problem is time consuming because the electrons interact continuously and therefore, the number of electron collisions to be considered is always very high. This complex problem is frequently simplified by neglecting the contributions of the secondary electrons. Recent works (Fernández et al., 2013; Fernández et al., 2014) have shown the possibility to include a separately computed coupled photon-electron contribution like ISII in a photon calculation for improving such a crude approximation while preserving the speed of the pure photon transport model. By means of a similar approach and the Monte Carlo code PENELOPE (coupled photon-electron Monte Carlo), the bremsstrahlung contribution is characterized in this work. The angular distribution of the photons due to bremsstrahlung can be safely considered as isotropic, with the point of emission located at the same place of the photon collision. A new photon kernel describing the bremsstrahlung contribution is introduced: it can be included in photon transport codes (deterministic or Monte Carlo) with a minimal effort. A data library to describe the energy dependence of the bremsstrahlung emission has been generated for all elements Z=1-92 in the energy range 1-150 keV. The bremsstrahlung energy distribution for an arbitrary energy is obtained by interpolating in the database. A comparison between a PENELOPE direct simulation and the interpolated distribution using the data base shows an almost perfect agreement. The use of the data base increases

  17. Laboratory evaluation of a chemical coupling agent to prevent debonding of asphalts from aggregates

    NASA Astrophysics Data System (ADS)

    Divito, J. A.

    1981-08-01

    Debonding of asphalt from mineral aggregates (stripping) was investigated. A silane coupling agent was compared with a well known, commercially available liquid antistrip (amine) in the immersion compression and double punch debonding tests on two Arizona mineral aggregate sources. The silane was used as a mineral aggregate pretreatment while the amine was added to the asphalt. It is indicated that the silane generally performed as well as the liquid antistrip or better.

  18. Evaluation of the Time-Derivative Coupling for Accurate Electronic State Transition Probabilities from Numerical Simulations.

    PubMed

    Meek, Garrett A; Levine, Benjamin G

    2014-07-01

    Spikes in the time-derivative coupling (TDC) near surface crossings make the accurate integration of the time-dependent Schrödinger equation in nonadiabatic molecular dynamics simulations a challenge. To address this issue, we present an approximation to the TDC based on a norm-preserving interpolation (NPI) of the adiabatic electronic wave functions within each time step. We apply NPI and two other schemes for computing the TDC in numerical simulations of the Landau-Zener model, comparing the simulated transfer probabilities to the exact solution. Though NPI does not require the analytical calculation of nonadiabatic coupling matrix elements, it consistently yields unsigned population transfer probability errors of ∼0.001, whereas analytical calculation of the TDC yields errors of 0.0-1.0 depending on the time step, the offset of the maximum in the TDC from the beginning of the time step, and the coupling strength. The approximation of Hammes-Schiffer and Tully yields errors intermediate between NPI and the analytical scheme. PMID:26279558

  19. Experimental and theoretical evaluation of surface plasmon-coupled emission for sensitive fluorescence detection.

    PubMed

    Trnavsky, Michal; Enderlein, Joerg; Ruckstuhl, Thomas; McDonagh, Colette; MacCraith, Brian D

    2008-01-01

    Surface plasmon-coupled emission (SPCE) is a phenomenon whereby the light emitted from a fluorescent molecule can couple into the surface plasmon of an adjacent metal layer, resulting in highly directional emission in the region of the surface plasmon resonance (SPR) angle. In addition to high directionality of emission, SPCE has the added advantage of surface selectivity in that the coupling diminishes with increasing distance from the surface. This effect can be exploited in bioassays whereby a fluorescing background from the sample can be suppressed. We have investigated, both theoretically and experimentally, the SPCE effect for a Cy5-spacer-Ag layer system. Both the angular dependence of emission and the dependence of SPCE emission intensity on Cy5-metal separation were investigated. It is demonstrated that SPCE leads to lower total fluorescence signal than that obtained in the absence of a metal layer. This is the first experimental verification of the reduction in SPCE intensity compared to the metal-free case. Our results are in a good agreement with theoretical models. The validation of the theoretical model provides a basis for optimizing biosensor platform performance, particularly in the context of the advantages offered by SPCE of highly directional emission and surface selectivity. PMID:19021401

  20. Evaluation of Inductively Couple Plasma-time-of-Flight Mass Spectrometry for Laser Ablation Analyses

    SciTech Connect

    S.J. Bajic; D.B. Aeschliman; D.P. Baldwin; R.S. Houk

    2003-09-30

    The purpose of this trip to LECO Corporation was to test the non-matrix matched calibration method and the principal component analysis (PCA) method on a laser ablation-inductively coupled plasma-time of flight mass spectrometry (LA-ICP-TOFMS) system. An LA-ICP-TOFMS system allows for multielement single-shot analysis as well as spatial analysis on small samples, because the TOFMS acquires an entire mass spectrum for all ions extracted simultaneously from the ICP. The TOFMS system differs from the double-focusing mass spectrometer, on which the above methods were developed, by having lower sensitivity and lower mass resolution.

  1. Design Evaluation of Wind Turbine Spline Couplings Using an Analytical Model: Preprint

    SciTech Connect

    Guo, Y.; Keller, J.; Wallen, R.; Errichello, R.; Halse, C.; Lambert, S.

    2015-02-01

    Articulated splines are commonly used in the planetary stage of wind turbine gearboxes for transmitting the driving torque and improving load sharing. Direct measurement of spline loads and performance is extremely challenging because of limited accessibility. This paper presents an analytical model for the analysis of articulated spline coupling designs. For a given torque and shaft misalignment, this analytical model quickly yields insights into relationships between the spline design parameters and resulting loads; bending, contact, and shear stresses; and safety factors considering various heat treatment methods. Comparisons of this analytical model against previously published computational approaches are also presented.

  2. Statistical evaluation of an inductively coupled plasma atomic emission spectrometric method for routine water quality testing

    USGS Publications Warehouse

    Garbarino, J.R.; Jones, B.E.; Stein, G.P.

    1985-01-01

    In an interlaboratory test, inductively coupled plasma atomic emission spectrometry (ICP-AES) was compared with flame atomic absorption spectrometry and molecular absorption spectrophotometry for the determination of 17 major and trace elements in 100 filtered natural water samples. No unacceptable biases were detected. The analysis precision of ICP-AES was found to be equal to or better than alternative methods. Known-addition recovery experiments demonstrated that the ICP-AES determinations are accurate to between plus or minus 2 and plus or minus 10 percent; four-fifths of the tests yielded average recoveries of 95-105 percent, with an average relative standard deviation of about 5 percent.

  3. In vitro evaluation of genotoxic effects under magnetic resonant coupling wireless power transfer.

    PubMed

    Mizuno, Kohei; Shinohara, Naoki; Miyakoshi, Junji

    2015-04-01

    Wireless power transfer (WPT) technology using the resonant coupling phenomenon has been widely studied, but there are very few studies concerning the possible relationship between WPT exposure and human health. In this study, we investigated whether exposure to magnetic resonant coupling WPT has genotoxic effects on WI38VA13 subcloned 2RA human fibroblast cells. WPT exposure was performed using a helical coil-based exposure system designed to transfer power with 85.4% efficiency at a 12.5-MHz resonant frequency. The magnetic field at the positions of the cell culture dishes is approximately twice the reference level for occupational exposure as stated in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines. The specific absorption rate at the positions of the cell culture dishes matches the respective reference levels stated in the ICNIRP guidelines. For assessment of genotoxicity, we studied cell growth, cell cycle distribution, DNA strand breaks using the comet assay, micronucleus formation, and hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation, and did not detect any significant effects between the WPT-exposed cells and control cells. Our results suggest that WPT exposure under the conditions of the ICNIRP guidelines does not cause detectable cellular genotoxicity. PMID:25853218

  4. Evaluation of aerosol properties simulated by the high resolution global coupled chemistry-aerosol-microphysics model C-IFS-GLOMAP

    NASA Astrophysics Data System (ADS)

    Dhomse, Sandip; Mann, Graham; Carslaw, Ken; Flemming, Johannes; Morcrette, Jean-Jacques; Engelen, Richard; Remy, Samuel; Boucher, Olivier; Benduhn, Francois; Hewson, Will; Woodhouse, Matthew

    2016-04-01

    The EU Framework Programme GEMS and MACC consortium projects co-ordinated by the European Centre for Medium-range Weather Forecasts (ECMWF) have developed an operational global forecasting and reanalysis system (Composition-IFS) for atmospheric composition including greenhouse gases, reactive gases and aerosol. The current operational C-IFS system uses a mass-based aerosol model coupled to data assimilation of Aerosol Optical Depth measured by satellite (MODIS) to predict global aerosol properties. During MACC, the GLOMAP-mode aerosol microphysics scheme was added to the system, providing information on aerosol size and number for improved representation of aerosol-radiation and aerosol-cloud interactions, accounting also for simulated global variations in size distribution and internally-mixed particle composition. The IFS-GLOMAP system has recently been upgraded to couple with the sulphur cycle simulated in the online TM5 tropospheric chemistry module for global reactive gases. This C-IFS-GLOMAP system is also being upgraded to use a new "nitrate-extended" version of GLOMAP which realistically treats the size-resolved gas-particle partitioning of semi volatile gases ammonia and nitric acid. In this poster we described C-IFS-GLOMAP and present an evaluation of the global sulphate aerosol distribution simulated in this coupled aerosol-chemistry C-IFS-GLOMAP, comparing to surface observations in Europe, North America and the North Atlantic and contrasting to the fixed timescale sulphate production scheme developed in GEMS. We show that the coupling to the TM5 sulphur chemistry improves the seasonal cycle of sulphate aerosol, for example addressing a persistent wintertime sulphate high bias in northern Europe. The improved skill in simulated sulphate aerosol seasonal cycle is a pre-requisite to realistically characterise nitrate aerosol since biases in sulphate affect the amount of free ammonia available to form ammonium nitrate.

  5. Evaluation of precursor evaporation in Si nanoparticle synthesis by inductively coupled thermal plasmas

    NASA Astrophysics Data System (ADS)

    Colombo, V.; Ghedini, E.; Gherardi, M.; Sanibondi, P.

    2013-06-01

    The evaporation of a micro-sized silicon solid precursor in a laboratory scale inductively coupled thermal plasma system for nanoparticle synthesis is investigated numerically using a customized version of the commercial CFD code ANSYS FLUENT©. Two turbulence models—the standard k-ɛ and the Reynolds stress model—and two different models for the computation of vapour production from the heated precursor—evaporation at boiling point and vaporization driven by vapour concentration gradients—are compared. The choice of the turbulence model can considerably influence the estimation of vapour production because plasma temperature reduction by plasma-particle heat exchange is increased when the flow in the torch region is predicted to be laminar, whereas the choice of the model for particle evaporation may be critical when the plasma temperature is decreased by plasma-particle heat exchange to values close to the boiling point of the material treated.

  6. Wing motion transformation to evaluate aerodynamic coupling in flapping wing flight.

    PubMed

    Faruque, Imraan A; Humbert, J Sean

    2014-12-21

    Whether the remarkable flight performance of insects is because the animals leverage inherent physics at this scale or because they employ specialized neural feedback mechanisms is an active research question. In this study, an empirically derived aerodynamics model is used with a transformation involving a delay and a rotation to identify a class of kinematics that provide favorable roll-yaw coupling. The transformation is also used to transform both synthetic and experimentally measured wing motions onto the manifold representing proverse yaw and to quantify the degree to which freely flying insects make use of passive aerodynamic mechanisms to provide proverse roll-yaw turn coordination. The transformation indicates that recorded insect kinematics do act to provide proverse yaw for a variety of maneuvers. This finding suggests that passive aerodynamic mechanisms can act to reduce the neural feedback demands of an insect׳s flight control strategy. PMID:25128237

  7. Evaluation of FOXFET biased ac-coupled silicon strip detector prototypes for CDF SVX upgrade

    SciTech Connect

    Laakso, M. Research Inst. for High Energy Physics , Helsinki )

    1992-03-01

    Silicon microstrip detectors for high-precision charged particle position measurements have been used in nuclear and particle physics for years. The detectors have evolved from simple surface barrier strip detectors with metal strips to highly complicated double-sided AC-coupled junction detectors. The feature of AC-coupling the readout electrodes from the diode strips necessitates the manufacture of a separate biasing structure for the strips, which comprises a common bias line together with a means for preventing the signal from one strip from spreading to its neighbors through the bias line. The obvious solution to this is to bias the strips through individual high value resistors. These resistors can be integrated on the detector wafer by depositing a layer of resistive polycrystalline silicon and patterning it to form the individual resistors. To circumvent the extra processing step required for polysilicon resistor processing and the rather difficult tuning of the process to obtain uniform and high enough resistance values throughout the large detector area, alternative methods for strip biasing have been devised. These include the usage of electron accumulation layer resistance for N{sup +}{minus} strips or the usage of the phenomenon known as the punch-through effect for P{sup +}{minus} strips. In this paper we present measurement results about the operation and radiation resistance of detectors with a punch-through effect based biasing structure known as a Field OXide Field-Effect Transistor (FOXFET), and present a model describing the FOXFET behavior. The studied detectors were prototypes for detectors to be used in the CDF silicon vertex detector upgrade.

  8. Evaluation of promising algal strains for sustainable exploitation coupled with CO2 fixation.

    PubMed

    Singh, Shailendra Kumar; Rahman, Akhlaqur; Dixit, Kritika; Nath, Adi; Sundaram, Shanthy

    2016-01-01

    The photosynthetic activity of three microalgae, Chlamydomonas reinhardtii, Chlorella AU1, Scenedesmus AU1, and six cyanobacteria, Spirulina platensis, Anabaena cylindrica, Oscillatoria AU1, Nostoc muscurum, Synechococcus AU1, Synechocystis sp. PCC6803, was investigated. Strains S. platensis, Scenedesmus AU1 sp. and Chlorella AU1 sp. showed the highest fluorescence quenching than other strains tested. Thus, these were selected for CO2 mitigation analysis in a designed tubular photobioreactor system at 0.06%, 6%, 12%, 18% and 24% CO2 concentrations. Spirulina showed maximum biomass productivity of 1.03 g L(-1) d(-1) with the highest CO2 fixation rate of 0.678 g [Formula: see text] L(-1) d(-1) at 6% CO2 concentration. The maximum protein content (66.63%) was also achieved in Spirulina sp. at 6% CO2 concentration. Thus, Spirulina could be utilized as a source of protein supplement coupled with CO2 fixation. Maximum carbohydrate proportion (51.71%) was noted with Scenedesmus AU1 sp. at 12% CO2. Scenedesmus AU1 sp. also accumulated the maximum lipid content (25.07%) at 6% CO2 concentration, which was further analysed for biodiesel production. The extracted Scenedesmus oil was mainly rich in short chain fatty acids (C-16 : 0, C-18:1, C-18:2, C-18:3) which is an ideal combination for efficient biodiesel. Thus, this is vital in helping to choose Scenedesmus as a biodiesel feedstock, coupled with CO2 fixation. PMID:26215134

  9. Toward a microscopic-macroscopic coupled evaluation of the stability of a landslide dam during overtopping

    NASA Astrophysics Data System (ADS)

    Feng, Qingfeng; Liu, Detian; Fu, Xudong

    2016-04-01

    We explore the failure process of a landslide dam during overtopping, using a microscopic-macroscopic coupled simulation method. The numerical simulation contains two parts: the FVM (finite volume method) calculation for macroscopic external and internal erosion and the LBM (lattice Boltzmann Method)-DEM (discrete element method) calculation for microscopic shear failure. The FVM module provides the boundary condition (e.g., water discharge, confining pressure) and internal condition (e.g., porosity, gradation of soil particles) of each sub-region of a landslide dam. The LBM-DEM module calculates the shearing process of soil particles within each sub-region. The location and size of shear zone is identified in each sub-region and then integrated into shear zones across sub-regions. The shear zones changing during the overtopping process are captured and analyzed. We assume that, if some shear zones form into an area with strong concentration and connectivity at the macroscopic scale, the dam will be unstable and is undergoing the failure process. Two real cases of landslide dam in the "May 12, 2008" Wenchuan Earthquake hit region are analyzed. The potential applicability of the present method is demonstrated.

  10. Evaluation of a coupled event-driven phenology and evapotranspiration model for croplands in the United States northern Great Plains

    NASA Astrophysics Data System (ADS)

    Kovalskyy, V.; Henebry, G. M.; Roy, D. P.; Adusei, B.; Hansen, M.; Senay, G.; Mocko, D. M.

    2013-06-01

    A new model coupling scheme with remote sensing data assimilation was developed for estimation of daily actual evapotranspiration (ET). The scheme consists of the VegET, a model to estimate ET from meteorological and water balance data, and an Event Driven Phenology Model (EDPM), an empirical crop specific model trained on multiple years of flux tower data transformed into six types of environmental forcings that are called "events" to emphasize their temporally discrete character, which has advantages for modeling multiple contingent influences. The EDPM in prognostic mode supplies seasonal trajectories of normalized difference vegetation index (NDVI); whereas in diagnostic mode, it can adjust the NDVI prediction with assimilated remotely sensed observations. The scheme was deployed within the croplands of the Northern Great Plains. The evaluation used 2007-2009 land surface forcing data from the North American Land Data Assimilation System and crop maps derived from remotely sensed data of NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). We compared the NDVI produced by the EDPM with NDVI data derived from the MODIS nadir bidirectional reflectance distribution function adjusted reflectance product. The EDPM performance in prognostic mode yielded a coefficient of determination (r2) of 0.8 ± 0.15and the root mean square error (RMSE) of 0.1 ± 0.035 across the entire study area. Retrospective correction of canopy attributes using assimilated MODIS NDVI values improved EDPM NDVI estimates, bringing the errors down to the average level of 0.1. The ET estimates produced by the coupled scheme were compared with the MODIS evapotranspiration product and with ET from NASA's Mosaic land surface model. The expected r2 = 0.7 ± 0.15 and RMSE = 11.2 ± 4 mm per 8 days achieved in earlier point-based validations were met in this study by the coupling scheme functioning in both prognostic and retrospective modes. Coupled model performance was diminished at the

  11. Closed-Form Evaluation of Mutual Coupling in a Planar Array of Circular Apertures

    NASA Technical Reports Server (NTRS)

    Bailey, M. C.

    1996-01-01

    The integral expression for the mutual admittance between circular apertures in a planar array is evaluated in closed form. Very good accuracy is realized when compared with values that were obtained by numerical integration. Utilization of this closed-form expression, for all element pairs that are separated by more than one element spacing, yields extremely accurate results and significantly reduces the computation time that is required to analyze the performance of a large electronically scanning antenna array.

  12. Evaluating Observing Requirements for ENSO Prediction: Experiments with an Intermediate Coupled Model.

    NASA Astrophysics Data System (ADS)

    Morss, Rebecca E.; Battisti, David S.

    2004-08-01

    The Tropical Atmosphere Ocean (TAO) array of moored buoys in the tropical Pacific Ocean is a major source of data for understanding and predicting the El Niño Southern Oscillation (ENSO). Despite the importance of the TAO array, limited work has been performed to date on the number and locations of observations required to predict ENSO effectively. To address this issue, this study performs a series of observing system simulation experiments (OSSEs) with a linearized intermediate coupled ENSO model, stochastically forced. ENSO forecasts are simulated for a number of observing network configurations, and forecast skill averaged over 1000 years of simulated ENSO events is compared.The experiments demonstrate that an OSSE framework can be used with a linear, stochastically forced ENSO model to provide useful information about requirements for ENSO prediction. To the extent that the simplified model dynamics represent ENSO dynamics accurately, the experiments also suggest which types of observations in which regions are most important for ENSO prediction. The results indicate that, using this model and experimental setup, subsurface ocean observations are relatively unimportant for ENSO prediction when good information about sea surface temperature (SST) is available; adding subsurface observations primarily improves forecasts initialized in late summer. For short lead-time (1 2 month) forecasts, observations within approximately 3° of the equator are most important for skillful forecasts, while for longer lead-time forecasts, forecast skill is increased by including information at higher latitudes. For forecasts longer than a few months, the most important region for observations is the eastern equatorial Pacific, south of the equator; a secondary region of importance is the western equatorial Pacific. These regions correspond to those where the leading singular vector for the ENSO model has a large amplitude. In a continuation of this study, these results will be

  13. Evaluation of down scaling predicted precipitation in a coupled modeling system

    SciTech Connect

    Costigan, K. R.; Tomkins, C. D.; Springer, E. P.; Winter, C. L.; Stalker, J. R.; Langley, D. L.

    2001-01-01

    With limited supplies and increasing demands for water resources, especially in arid and semi-arid regions, it is becoming increasingly important to understand the workings of the hydrologic cycle within river basins. A thorough understanding of the typical precipitation and runoff and the nature of the their variability is vital for planning the best use of these water resources. In the long term, all aspects of the hydrologic cycle affect the availability of water and it is therefore important to explore the entire cycle in order to understand the potential effects of increased water use and of changes in the regional climate. To simulate water resources, we are coupling a series of existing and previously tested models that address the multitude of physical processes and temporal and spatial scales that are important (Bossert, et al., 1999). The modeling system (Figure 1) includes the Regional Atmospheric Modeling System (RAMS) (Pielke et al., 1992), which simulates regional climate and provides meteorological variables and precipitation to the Los Alamos Distributed Hydrologic System (LADHS), a land-surface hydrology model. The Finite Element Heat and Mass (FEHM) model (Zyvoloski et al, 1997) is being added to the system to include ground water in the simulations. This modeling system is being applied to the upper Rio Grande Basin of Colorado and New Mexico. The headwaters of the Rio Grande are located in the San Juan Mountains of southwestern Colorado and the upper portions of the river are fed primarily by snowmelt from winter storms. In contrast, the lower portions of the river accumulate runoff from thunderstorms of tho summer monsoon season.

  14. Evaluation of a numerical simulation model for a system coupling atmospheric gas, surface water and unsaturated or saturated porous medium.

    PubMed

    Hibi, Yoshihiko; Tomigashi, Akira; Hirose, Masafumi

    2015-12-01

    Numerical simulations that couple flow in a surface fluid with that in a porous medium are useful for examining problems of pollution that involve interactions among the atmosphere, surface water and groundwater, including, for example, saltwater intrusion along coasts. We previously developed a numerical simulation method for simulating a coupled atmospheric gas, surface water, and groundwater system (called the ASG method) that employs a saturation equation for flow in a porous medium; this equation allows both the void fraction of water in the surface system and water saturation in the porous medium to be solved simultaneously. It remained necessary, however, to evaluate how global pressure, including gas pressure, water pressure, and capillary pressure, should be specified at the boundary between the surface and the porous medium. Therefore, in this study, we derived a new equation for global pressure and integrated it into the ASG method. We then simulated water saturation in a porous medium and the void fraction of water in a surface system by the ASG method and reproduced fairly well the results of two column experiments. Next, we simulated water saturation in a porous medium (sand) with a bank, by using both the ASG method and a modified Picard (MP) method. We found only a slight difference in water saturation between the ASG and MP simulations. This result confirmed that the derived equation for global pressure was valid for a porous medium, and that the global pressure value could thus be used with the saturation equation for porous media. Finally, we used the ASG method to simulate a system coupling atmosphere, surface water, and a porous medium (110m wide and 50m high) with a trapezoidal bank. The ASG method was able to simulate the complex flow of fluids in this system and the interaction between the porous medium and the surface water or the atmosphere. PMID:26583741

  15. Evaluation of a numerical simulation model for a system coupling atmospheric gas, surface water and unsaturated or saturated porous medium

    NASA Astrophysics Data System (ADS)

    Hibi, Yoshihiko; Tomigashi, Akira; Hirose, Masafumi

    2015-12-01

    Numerical simulations that couple flow in a surface fluid with that in a porous medium are useful for examining problems of pollution that involve interactions among the atmosphere, surface water and groundwater, including, for example, saltwater intrusion along coasts. We previously developed a numerical simulation method for simulating a coupled atmospheric gas, surface water, and groundwater system (called the ASG method) that employs a saturation equation for flow in a porous medium; this equation allows both the void fraction of water in the surface system and water saturation in the porous medium to be solved simultaneously. It remained necessary, however, to evaluate how global pressure, including gas pressure, water pressure, and capillary pressure, should be specified at the boundary between the surface and the porous medium. Therefore, in this study, we derived a new equation for global pressure and integrated it into the ASG method. We then simulated water saturation in a porous medium and the void fraction of water in a surface system by the ASG method and reproduced fairly well the results of two column experiments. Next, we simulated water saturation in a porous medium (sand) with a bank, by using both the ASG method and a modified Picard (MP) method. We found only a slight difference in water saturation between the ASG and MP simulations. This result confirmed that the derived equation for global pressure was valid for a porous medium, and that the global pressure value could thus be used with the saturation equation for porous media. Finally, we used the ASG method to simulate a system coupling atmosphere, surface water, and a porous medium (110 m wide and 50 m high) with a trapezoidal bank. The ASG method was able to simulate the complex flow of fluids in this system and the interaction between the porous medium and the surface water or the atmosphere.

  16. Evaluation of 1100 couples with recurrent pregnancy loss using conventional cytogenetic, PGD, and PGS: hype or hope.

    PubMed

    Farahmand, Kamelia; Kalantari, Hamid; Fakhri, Mostafa; Fazeli, Abolhasan Shahzadeh; Moradi, Shabnam Zari; Almadani, Navid; Hashemi, Mehrdad; Gourabi, Hamid; Mohseni-Meybodi, Anahita

    2016-06-01

    Recurrent pregnancy loss (RPL) is an important clinical problem, mostly resulting from chromosomal or genetic defects, while in 30-60% of cases, it is idiopathic. The aim of this study is to evaluate the frequency and types of chromosomal abnormalities, also pre-implantation genetic diagnosis (PGD) and pre-implantation genetic screening (PGS) outcomes among Iranian couples with RPL. This retrospective study was conducted on 1100 Iranian couples (2200 individuals) with RPL referred to Royan Institute between 2008 and 2014. Karyotyping had been performed using standard cytogenetic techniques. PGD results of RPL patients with abnormal karyotypes and PGS results of RPL patients with normal karyotypes were also analyzed. The frequency of chromosomal abnormalities in these patients was 4.95%. Women demonstrated more abnormalities (6.82%) in comparison to men (3.09%). The successful rate of pregnancy after PGD and PGS was 52 and 18.64%, respectively. The observation of 4.95% chromosomal abnormalities among the patients with RPL could support this hypothesis that there is a direct relationship between chromosomal abnormalities and RPL. More than half of the patients who underwent PGD had successful pregnancy; therefore, this approach can improve the success rate of pregnancy in them. The results of PGS cycles showed that this technique could increase the live birth rate in RPL patients. PMID:26854690

  17. Analytical evaluation of a surface integral expressing the coupling between interior and exterior volumes in a FE-IE approach

    NASA Technical Reports Server (NTRS)

    Zuffada, C.; Cwik, T.; Jamnejad, V.

    1993-01-01

    Recently an approach which combines the finite element technique and an integral equation to determine the fields scattered by inhomogeneous bodies of complicated shape has been proposed. Basically, a mathematical surface which encloses the scatterers is introduced, thus dividing the space into an interior and an exterior volume, in which the finite element technique and an integral equation for EM scattering, respectively, are applied. The integral equation is set up for the tangential components of the fields at the surface, while the interior volume the unknowns are the total fields. Continuity of the tangential fields at the boundary, as required by Maxwell's equations, is imposed, thus coupling the two methods to obtain a consistent solution. The coupling term is expressed by a surface integral formed by the dot product of a FE basis function and an IE testing function, or viceversa. By choosing the boundary to be a surface of revolution and by making a convenient selection of IE basis (testing) functions, it is possible to evaluate the integrals analytically on surfaces such as curved triangles, curved quadrilaterals and curved pentagons. We will illustrate the salient steps involved in setting up and carrying out these integrals and discuss what class of basis (testing) functions and analytic surfaces of revolution they are applicable to. Analytic calculations offer the advantage of better accuracy than purely numerical ones, and, when combined with them, often shed light on issues of numerical convergence and limiting values. Furthermore, they may reduce computation time and storage requirements.

  18. Evaluating the one-way coupling of WRF-Hydro for flood forecasting

    NASA Astrophysics Data System (ADS)

    Yucel, Ismail; Onen, Alper; Yilmaz, Koray; Gochis, David

    2016-04-01

    A fully-distributed, multi-physics, multi-scale hydrologic and hydraulic modeling system, WRF-Hydro, is used to assess the potential for skillful flood forecasting based on precipitation inputs derived from the Weather Research and Forecasting (WRF) model and the EUMETSAT Multi-sensor Precipitation Estimates (MPEs). Similar to past studies it was found that WRF model precipitation forecast errors related to model initial conditions are reduced when the three dimensional atmospheric data assimilation (3DVAR) scheme in the WRF model simulations is used. A comparative evaluation of the impact of MPE versus WRF precipitation estimates, both with and without data assimilation, in driving WRF-Hydro simulated streamflow is then made. The ten rainfall-runoff events that occurred in the Black Sea Region were used for testing and evaluation. With the availability of streamflow data across rainfall-runoff events, the cal- ibration is only performed on the Bartin sub-basin using two events and the calibrated parameters are then transferred to other neighboring three ungauged sub-basins in the study area. The rest of the events from all sub-basins are then used to evaluate the performance of the WRF-Hydro system with the cali- brated parameters. Following model calibration, the WRF-Hydro system was capable of skillfully repro- ducing observed flood hydrographs in terms of the volume of the runoff produced and the overall shape of the hydrograph. Streamflow simulation skill was significantly improved for those WRF model simula- tions where storm precipitation was accurately depicted with respect to timing, location and amount. Accurate streamflow simulations were more evident in WRF model simulations where the 3DVAR scheme was used compared to when it was not used. Because of substantial dry bias feature of MPE, as compared with surface rain gauges, streamflow derived using this precipitation product is in general very poor. Overall, root mean squared errors for runoff were

  19. Evaluating Global Streamflow Simulations by a Physically-based Routing Model Coupled with the Community Land Model

    SciTech Connect

    Li, Hongyi; Leung, Lai-Yung R.; Getirana, Augusto; Huang, Maoyi; Wu, Huan; Xu, Yubin; Guo, Jiali; Voisin, Nathalie

    2015-04-15

    Accurately simulating hydrological processes such as streamflow is important in land surface modeling because they can influence other land surface processes, such as carbon cycle dynamics, through various interaction pathways. This study aims to evaluate the global application of a recently developed Model for Scale Adaptive River Transport (MOSART)coupled with theCommunity Land Model, version 4 (CLM4). To support the global implementation of MOSART, a comprehensive global hydrography dataset has been derived at multiple resolutions from different sources. The simulated runoff fields are first evaluated against the composite runoff map from theGlobal RunoffData Centre (GRDC). The simulated streamflow is then shown to reproduce reasonably well the observed daily andmonthly streamflow at over 1600 of the world’smajor river stations in terms of annual, seasonal, and daily flow statistics. The impacts of model structure complexity are evaluated, and results show that the spatial and temporal variability of river velocity simulated byMOSART is necessary for capturing streamflow seasonality and annual maximum flood. Other sources of the simulation bias include uncertainties in the atmospheric forcing, as revealed by simulations driven by four different climate datasets, and human influences, based on a classification framework that quantifies the impact levels of large dams on the streamflow worldwide.

  20. Evaluation of liposome populations using a sucrose density gradient centrifugation approach coupled to a continuous flow system.

    PubMed

    Sánchez-López, V; Fernández-Romero, J M; Gómez-Hens, A

    2009-07-10

    A method for the evaluation of liposome size populations using sucrose density gradient centrifugation coupled with a continuous flow system is presented. Liposomes, prepared using different methods (rapid solvent evaporation, rehydration, and detergent removal) and modified by assaying several procedures (shaking, sonication and extrusion) were evaluated according to the type of liposome, size and polydispersity. The preparation of liposomes was carried out in the presence of the fluorophor cresyl violet. Extracts of the liposomes were homogenised and centrifuged at 20,073 x g at 4 degrees C for 30 min using sucrose density gradient centrifugation programmes, which provide efficient liposome separation in different sizes. The results of the separation procedure were tested by aspiration of the extracts into a continuous flow system in which the liposomes were disrupted by the continuous mixing with a Triton X-100 solution, prior to their translation to the detector. The luminescence provided by the liberation of the encapsulated fluorophor indicates the distribution of liposomes in each density gradient stage. Three zones were obtained: zone alpha, containing giant unilamellar and multivesicular vesicles, zone beta, with large and medium size liposomes, and zone gamma, which contained small size liposomes. The precision of the separation zones obtained, expressed as RSD%, was lower than 5.6% in all instances. The method provides a relative rapid way to evaluate the liposome polydispersity and size after using conventional methods of synthesis and mechanical modifications. PMID:19481634

  1. Experimental Non-Contact Evaluation of Delamination in CFRP Composite Plates by Laser Air-Coupled Detection Ultrasonic System

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Joon; Lee, Joon-Hyun; Byun, Joon-Hyung

    The objective of this research is to develop non-contact and real time inspection technique based on laser generated ultrasound for evaluating near-surface delamination in Carbon/Epoxy composite fabricated from automated fiber placement system. In this study, A hybrid laser generation/air-coupled detection ultrasonic system for detection and visualization of delamination in composite plates with simulated delamination of the area of 20 mm × 20 mm between the first and the second layer. Optical fiberized Nd:YAG pulse laser (532 nm, 32 mJ) with linear slit array is used to generate ultrasonic guided wave in unidirectional CFRP specimen (24 plies, 2.85 mm thickness). The characteristic of time domain waveform and frequency spectrum of guided wave is discussed. Two- dimensional images are obtained from these characteristics. The convergence of received signal using the pitch-catch and the scattering-reflection technique is discussed.

  2. Coupled cluster evaluation of the frequency dispersion of the first and second hyperpolarizabilities of water, methanol, and dimethyl ether.

    PubMed

    Beaujean, Pierre; Champagne, Benoît

    2016-07-28

    The static and dynamic first (β‖) and second (γ‖) hyperpolarizabilities of water, methanol, and dimethyl ether have been evaluated within the response function approach using a hierarchy of coupled cluster levels of approximation and doubly augmented correlation consistent atomic basis sets. For the three compounds, the electronic β‖ and γ‖ values calculated at the CCSD and CC3 levels are in good agreement with gas phase electric field-induced second harmonic generation (EFISHG) measurements. In addition, for dimethyl ether, the frequency dispersion of both properties follows closely recent experimental values [V. W. Couling and D. P. Shelton, J. Chem. Phys. 143, 224307 (2015)] demonstrating the reliability of these methods and levels of approximation. This also suggests that the vibrational contributions to the EFISHG responses of these molecules are small. PMID:27475365

  3. Coupled cluster evaluation of the frequency dispersion of the first and second hyperpolarizabilities of water, methanol, and dimethyl ether

    NASA Astrophysics Data System (ADS)

    Beaujean, Pierre; Champagne, Benoît

    2016-07-01

    The static and dynamic first (β‖) and second (γ‖) hyperpolarizabilities of water, methanol, and dimethyl ether have been evaluated within the response function approach using a hierarchy of coupled cluster levels of approximation and doubly augmented correlation consistent atomic basis sets. For the three compounds, the electronic β‖ and γ‖ values calculated at the CCSD and CC3 levels are in good agreement with gas phase electric field-induced second harmonic generation (EFISHG) measurements. In addition, for dimethyl ether, the frequency dispersion of both properties follows closely recent experimental values [V. W. Couling and D. P. Shelton, J. Chem. Phys. 143, 224307 (2015)] demonstrating the reliability of these methods and levels of approximation. This also suggests that the vibrational contributions to the EFISHG responses of these molecules are small.

  4. Annual application and evaluation of the online coupled WRF-CMAQ system over North America under AQMEII phase 2

    NASA Astrophysics Data System (ADS)

    Hogrefe, Christian; Pouliot, George; Wong, David; Torian, Alfreida; Roselle, Shawn; Pleim, Jonathan; Mathur, Rohit

    2015-08-01

    We present an application of the online coupled Weather Research and Forecasting-Community Multiscale Air Quality (WRF-CMAQ) modeling system to two annual simulations over North America performed under Phase 2 of the Air Quality Model Evaluation International Initiative (AQMEII). Operational evaluation shows that model performance is comparable to earlier annual applications of the uncoupled WRF/CMAQ modeling system Results also indicate that factors such as changes in the underlying emissions inventory and chemical boundary conditions likely exert a larger influence on overall model performance than feedback effects. A comparison of the simulated Aerosol Optical Depth (AOD) against observations reveals a tendency toward underprediction in all seasons despite a general overprediction of PM2.5 during wintertime. Summertime sensitivity simulations without feedback effects are used to quantify the average impact of the simulated direct feedback effect on temperature, PBL heights, ozone and PM2.5 concentrations. Model results for 2006 and 2010 are analyzed to compare modeled changes between these years to those seen in observations. The results for summertime average daily maximum 8-h ozone showed that the model tends to underestimate the observed decrease in concentrations. The results for total and speciated PM2.5 vary between seasons, networks and species, but the WRF-CMAQ simulations do capture the substantial decreases in observed PM2.5 concentrations in summer and fall. These 2010-2006 PM2.5 decreases result in simulated increases of summer mean clear-sky shortwave radiation between 5 and 10 W/m2. The WRF-CMAQ configuration without direct feedback effects simulates smaller changes in summertime PM2.5 concentrations, indicating that the direct feedback effect enhances the air quality benefits arising from emission controls and that coupled modeling systems are necessary to quantify such feedback effects.

  5. Using ARM Observations to Evaluate Model Predictions of Land-Atmosphere Coupling on the U.S. Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Phillips, T. J.; Klein, S. A.; Ma, H. Y.

    2015-12-01

    Statistically significant interactions between summertime soil moisture and a number of atmospheric surface and boundary-layer variables have been observed at the U.S. Southern Great Plains Central Facility (SGP CF) site that is maintained by the Department of Energy's Atmospheric Radiation Measurement (ARM) program in northern Oklahoma (Phillips and Klein, 2014 JGR). The observed land-atmosphere coupling (LAC) strength was assessed by means of correlation coefficients R and "sensitivity indices" I (a measure of the comparative change in an atmospheric variable for a one-standard-deviation change in soil moisture). In the current study, we evaluate similar features of LAC in global predictions generated by version 5.1 of the Community Atmosphere Model (CAM5.1), when coupled to the CLM4 land model and downscaled to the ARM SGP site. Each day's prediction was made after initializing the CAM5 atmosphere with ERA Interim reanalysis state variables, while other needed variables were obtained from a nudging simulation. In addition, the CLM4 daily initial conditions were determined by running the land model offline using observed surface net radiation, precipitation, and wind as forcings. Different aspects of LAC in the CAM5 will be compared with those found in the ARM observations during the summers of 2003-2011, when 3 independent measurements of soil moisture are available to provide an estimate of the inherent uncertainties in the LAC strengths determined from the ARM observations. This evaluation may uncover some unrealistic aspects of LAC in the CAM5 model that point toward potential deficiencies in its land or atmospheric model parameterizations. AcknowledgmentsThis work was funded by the U.S. Department of Energy Office of Science and was performed at the Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. Evaluating the coupled vegetation-fire model, LPJ-GUESS-SPITFIRE, against observed tropical forest biomass

    NASA Astrophysics Data System (ADS)

    Spessa, Allan; Forrest, Matthew; Werner, Christian; Steinkamp, Joerg; Hickler, Thomas

    2013-04-01

    disturbance such as fire. SPITFIRE (SPread and InTensity of FIRe and Emissions) mechanistically simulates the number of fires, area burnt, fire intensity, crown fires, fire-induced plant mortality, and emissions of carbon, trace gases and aerosols from biomass burning. Originally developed as an embedded model within LPJ-DGVM, SPITFIRE has since been coupled to LPJ-GUESS. However, neither LPJ-DGVM-SPITFIRE nor LPJ-GUESS-SPITFIRE has been fully benchmarked, especially in terms of how well each model simulates vegetation patterns and biomass in areas where fire is known to be important. This information is crucial if we are to have confidence in the models in forecasting fire, emissions from biomass burning and fire-climate impacts on ecosystems. Here we report on the benchmarking of the LPJ-GUESS-SPITFIRE model. We benchmarked LPJ-GUESS-SPITFIRE driven by a combination of daily reanalysis climate data (Sheffield 2012), monthly GFEDv3 burnt area data (1997-2009) (van der Werf et al. 2010) and long-term annual fire statistics (1901 to 2000) (Mouillot and Field 2005) against new Lidar-based biomass data for tropical forests and savannas (Saatchi et al. 2011; Baccini et al., 2012). Our new work has focused on revising the way GUESS simulates tree allometry, light penetration through the tree canopy and sapling recruitment, and how GUESS-SPITFIRE simulates fire-induced mortality, all based on recent literature, as well as a more explicit accounting of land cover change (JRC's GLC 2009). We present how these combined changes result in a much improved simulation of tree carbon across the tropics, including the Americas, Africa, Asia and Australia. Our results are compared with respect to more empirical-based approaches to calculating emissions from biomass burning. We discuss our findings in terms of improved forecasting of fire, emissions from biomass burning and fire-climate impacts on ecosystems.

  7. Characterization and evaluation of Aspergillus oryzae lactase coupled to a regenerable support

    SciTech Connect

    Friend, B.A.; Shahani, K.M.

    1982-03-01

    A derivative of crosslinked Sepharose, p-(N-acetyl-L-tyrosine azo) benzamidoethyl-CL-Sepharose 4B, was synthesized and used for the selective immobilization of thermostable lactase from Aspergillus oryzae. Preparations of soluble and immobilized lactase were evaluated under initial velocity conditions in a batch process. Immobilization had no significant effect on the pH optimum at 50 degrees C or kinetic parameters at pH 4.5 or pH 6.5 and 50 degrees C. At pH 4.5, the soluble enzyme possessed maximum activity at 60 degrees C and the immobilized at 55 degrees C; at pH 6.5 both showed maximum activity at 55 degrees C. The activation energy, entropy, and enthalpy decreased significantly with immobilization at pH 4.5 but not at pH 6.5. When the immobilized enzyme was placed in a packed-bed reactor, the effect of temperature on activity was altered as reflected by a marked decrease in the thermodynamic parameters of activation at both pH levels. Upon immobilization there was also a dramatic increase in the apparent thermal stability of the lactase, and the mean half-life at 50 degrees C was increased from 7.2 to 13 days at pH 4.5 and from 3.8 to 16 days at pH 6.5. (Refs. 45).

  8. Final Progress Report: Coupled Biogeochemical Process Evaluation for Conceptualizing Trichloroethylene Cometabolism

    SciTech Connect

    Crawford, Ronald L; Paszczynski, Andrzej J

    2010-02-19

    spectrometry and genomic analyses using RT-PCR to characterize these enzyme systems. UI’s specific objectives were to develop the proteomics and genomic tools to assess the presence of the methane monooxygenase (MMO) proteins in the aquifers under study and relate this to the enumeration of methanotrophic microorganisms. We targeted the identification of both sMMO and pMMO. We believe that the copper level in the TAN aquifer is most likely suppressing the expression of sMMO and mediates the higher levels of pMMO expression. Hence our investigations included the identification of both forms of MMOs, and we expected a higher concentration of pMMO proteins in TAN samples. The amounts of these proteins present were correlated with numbers of methanotrophs determined by us and other members of the research team using PCR-based methods. In summary, to accomplish our objectives we applied environmental proteomics techniques to monitor proteins that are involved in the co-metabolic degradation of trichloroethylene (TCE) in groundwater of the INL TAN site on Department of Energy ands of near Idaho Falls, ID USA. To acquire peptides sequences information we used an ultra performance chromatography (UPLC) system coupled with QToF Premiere nano-electrospray tandem quadropole-time of flight mass spectrometer. Our goal was to identify signature peptides of methane monooxygenases (MMOs) within methanotrophic bacteria that are active in cometabolic degradation of TCE. We developed a new method for extracting total proteins from environmental planktonic and/or biofilm samples that involve a new time course cell lysis and protein extraction method in combination with chromatographic separation of peptide and tandem mass spectrometry sequencing. The techniques resulted in successful extraction and identification of MMO-based peptides from both pure cultures and TAN site samples. The work confirmed the importance of mathonotrophs in the co-metabolic removal of TCE from the TAN site aquifer.

  9. Evaluating storm-scale groundwater recharge dynamics with coupled weather radar data and unsaturated zone modeling

    NASA Astrophysics Data System (ADS)

    Nasta, P.; Gates, J. B.; Lock, N.; Houston, A. L.

    2013-12-01

    generation until late winter, even when intense convective storms took place. For this reason, about 86% of all precipitation events produce insignificant recharge contributions. Recharge responses to individual storms were nonlinear and did not cluster well with either storm amount or storm classification type. For example, ~7% of rainfall events fall near the 1:1 rainfall/recharge line and these events represent about 37% of cumulative recharge, and individual storms accounted for up to 4% of their annual totals. However, recharge events in late winter are mainly triggered by stratiform precipitation whereas in spring they are generally generated by convective storms. This novel approach to assessing storm-scale recharge may be relevant to several current challenges in the characterization of groundwater recharge processes, including the evaluation of their spatiotemporal distributions and the impacts of climate change on groundwater.

  10. Evaluating the influence of process parameters on soluble microbial products formation using response surface methodology coupled with grey relational analysis.

    PubMed

    Xu, Juan; Sheng, Guo-Ping; Luo, Hong-Wei; Fang, Fang; Li, Wen-Wei; Zeng, Raymond J; Tong, Zhong-Hua; Yu, Han-Qing

    2011-01-01

    Soluble microbial products (SMPs) present a major part of residual chemical oxygen demand (COD) in the effluents from biological wastewater treatment systems, and the SMP formation is greatly influenced by a variety of process parameters. In this study, response surface methodology (RSM) coupled with grey relational analysis (GRA) method was used to evaluate the effects of substrate concentration, temperature, NH(4)(+)-N concentration and aeration rate on the SMP production in batch activated sludge reactors. Carbohydrates were found to be the major component of SMP, and the influential priorities of these factors were: temperature>substrate concentration > aeration rate > NH(4)(+)-N concentration. On the basis of the RSM results, the interactive effects of these factors on the SMP formation were evaluated, and the optimal operating conditions for a minimum SMP production in such a batch activated sludge system also were identified. These results provide useful information about how to control the SMP formation of activated sludge and ensure the bioreactor high-quality effluent. PMID:20832838

  11. Computational evaluations of charge coupling and hydrogen bonding in the active site of a family 7 cellobiohydrolase.

    PubMed

    Granum, David M; Vyas, Shubham; Sambasivarao, Somisetti V; Maupin, C Mark

    2014-01-16

    Solution pH and the pKa values of ionizable residues are critical factors known to influence enzyme catalysis, structural stability, and dynamical fluctuations. Presented here is an exhaustive computational study utilizing long time constant pH molecular dynamics, pH replica exchange simulations, and kinetic modeling to evaluate pH-dependent conformations, charge dynamics, residue pKa values, and the catalytic activity-pH profile for cellobiohydrolase Cel7B from Melanocarpus albomyces . The predicted pKa values support the role of Glu212 as the catalytic nucleophile and Glu217 as the acid-base residue. The presence of a charge-correlated active site and an extensive hydrogen bonding network is found to be critical in enabling favorable residue orientations for catalysis and shuttling excess protons around the active site. Clusters of amino acids are identified that act in concert to effectively modulate the optimal pH for catalysis while elevating the overall catalytic rate with respect to a noncoupled system. The work presented here demonstrates the complex and critical role of coupled ionizable residues to the proper functioning of cellobiohydrolase Cel7B, functionally related glycosyl hydrolases, and enzymes in general. The simulations also support the use of the CpHMD for the accurate prediction of residue pKa values and to evaluate the impact of pH on protein structure and charge dynamics. PMID:24359013

  12. Explicitly-coupled cloud physics and radiation parameterizations and subsequent evaluation in WRF high-resolution convective forecasts

    NASA Astrophysics Data System (ADS)

    Thompson, Gregory; Tewari, Mukul; Ikeda, Kyoko; Tessendorf, Sarah; Weeks, Courtney; Otkin, Jason; Kong, Fanyou

    2016-02-01

    The impacts of various assumptions of cloud properties represented within a numerical weather prediction model's radiation scheme are demonstrated. In one approach, the model assumed the radiative effective radii of cloud water, cloud ice, and snow were represented by values assigned a priori, whereas a second, "coupled" approach utilized known cloud particle assumptions in the microphysics scheme that evolved during the simulations to diagnose the radii explicitly. This led to differences in simulated infrared (IR) brightness temperatures, radiative fluxes through clouds, and resulting surface temperatures that ultimately affect model-predicted diurnally-driven convection. The combined approach of evaluating simulated versus observed IR brightness temperatures, radiation reaching the ground, and surface temperature forecasts revealed the root model biases better than evaluating any single variable. This study found that the Weather Research and Forecasting (WRF) model predicted less overall clouds than was observed, particularly in the mid-troposphere, but that properly connecting the assumptions of particle sizes in the microphysics scheme to the radiation scheme resulted in sensible cloud-radiation indirect effects and modest improvements in simulated IR brightness temperature, amount of solar radiation reaching the ground, and surface temperature.

  13. Evaluating Coupled Human-Hydrologic Systems in High Altitude Regions: A Case Study of the Arun Watershed, Eastern Nepal

    NASA Astrophysics Data System (ADS)

    Voss, K.; Bookhagen, B.; Tague, C.; Lopez-Carr, D.

    2014-12-01

    The Himalaya exhibit dynamic ecological, hydrological, and climatic extremes that magnify the variability and extent of natural hazards, resulting in destruction to both physical and human landscapes. Coupled with poverty, these factors intensify local communities' vulnerability to climate change. This study highlights the Arun watershed in eastern Nepal as a case study to evaluate how local communities in high altitude regions are managing their water for domestic and agricultural needs while coping with extreme events, such as floods and landslides. Remotely-sensed precipitation, snowpack and glacial extent data from the past decade are combined with preliminary results from extensive field-based community surveys in the Arun watershed. The analysis of remotely-sensed data will describe seasonal trends in water availability, glacial lake growth, and the spatial variation of these trends within the basin. These hydrologic changes will be linked to the human survey analysis, which will provide an understanding of locals' perceptions of water challenges and the current water management strategies within the basin. Particular attention will be given to a comparison between the eastern and western tributaries of the Arun River, where the catchments are mainly rain-fed (eastern) versus glacial-fed (western). This contrast will highlight how different hydrologic scenarios evidenced from remote-sensing data motivate diverse human water management responses as defined in field surveys. A particular focus will be given to management decisions related to agriculture expansion and hydropower development. This synthesis of remote-sensing and social research methodologies provides a valuable perspective on coupled human-hydrologic systems.

  14. Evaluation of an operational ocean configuration at 1/12° on the Indonesian seas: Physical/Biogeochemical coupling

    NASA Astrophysics Data System (ADS)

    Gutknecht, Elodie; Reffray, Guillaume; Gehlen, Marion

    2015-04-01

    In the framework of the INDESO (Infrastructure Development of Space Oceanography) project, an operational ocean forecasting center has been developed to monitor the state of the Indonesian seas in terms of circulation, biogeochemistry and fisheries. The forecasting system combines a suite of numerical models connecting physical and biogeochemical parameters to population dynamics of large marine predators. Developed by Mercator Ocean and CLS, the physical/biogeochemical coupled component (INDO12BIO configuration) covers a large region extending from the western Pacific Ocean to the Eastern Indian Ocean at 1/12° resolution. The OPA/NEMO physical ocean model and the PISCES biogeochemical model are coupled in mode "on-line" without degradation in space and time. The operational global ocean forecasting system (1/4°) operated by Mercator Ocean provides the physical forcing while climatological open boundary conditions are prescribed for the biogeochemistry. This poster describes the performances of the INDO12BIO configuration. They are assessed by the evaluation of a reference hindcast simulation covering the last 8 years (2007-2014). Confrontations to satellite, in-situ and climatological observations are commented. Diagnostics are performed on chlorophyll-a, primary production, nutrients and oxygen. The model catches the main characteristics of the biogeochemical tracers in space and time. The seasonal cycle of chlorophyll-a and primary production is in phase with satellite-based products. The northern and southern parts of the archipelago present a distinct seasonal cycle, with higher chlorophyll biomass and production rates in the southern (northern) part during SE (NW) monsoon. Nutrient and oxygen concentrations are correctly reproduced in terms of horizontal and vertical distributions. The biogeochemical content of water masses entering in the archipelago as well as the water mass transformation across the archipelago conserves realistic vertical distribution

  15. Airway occlusion pressure and diaphragm global electromyogram analysis for evaluation of inspiratory muscle drive and neuromechanical coupling in cattle.

    PubMed

    Desmecht, D J; Linden, A S; Rollin, F A; Lekeux, P M

    1994-06-01

    Although healthy and diseased bovine respiratory tracts have been intensively studied during the last years, to the authors' knowledge, there have been no attempts to objectively examine the inspiratory drive from the brain to the nerves and muscles and its transformation in pressure. Such technique would be useful in assessing the possibility of altered ventilatory drive or inspiratory muscle fatigue in the context of an animal with ventilatory failure. The relation among ventilation, airway opening occlusion pressure generated 100 milliseconds after onset of inspiration (Pawo100ms) and 6 indexes describing diaphragmatic electromyographic activity (EMGdi) recorded via implanted fishhooks was evaluated during free and impeded CO2 rebreathing in 6 young bulls. The best significant linear correlations (r > 0.8) with inspiratory center afferent stimulation, as judged by end-tidal CO2 concentration in expired air, were found for Pawo100ms, peak moving time average or variance EMGdi, and mean integrated EMGdi, whatever had been the respiratory impedance. However, with an inspiratory load, Pawo100ms responses systematically had greater increase for a given change in the driving EMGdi, implying dependence of the former not only on neural input, but also on configurational factors that determine inspiratory muscle excitation-pressure generation couplings. The reproducibility of EMGdi absolute values and changes was satisfactory up to 10 hours, but could not be repeated from one day to the other. It was concluded that, provided the constancy of the electrical coupling of the recording system to the tissue being studied is ensured, specific EMGdi and Pawo100ms values correlate reliably with amount of CO2 during free and loaded breathing.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7944009

  16. Evaluating the coupling effects of climate aridity and vegetation restoration on soil erosion over the Loess Plateau in China.

    PubMed

    Zhang, Baoqing; He, Chansheng; Burnham, Morey; Zhang, Lanhui

    2016-01-01

    In this study, the coupling effects of climate aridity and vegetation restoration on runoff and sediment yield over the Loess Plateau were examined and characterized. To take into consideration the complexity of drought, as well as the varied strengths and weaknesses of different drought measures, two drought indices are selected to identify and evaluate drought variability. The Normalized Difference Vegetation Index (NDVI) data were obtained to monitor and express spatiotemporal variations in vegetation cover. The results show that most regions of the Loess Plateau experienced increasingly severe droughts over the past 40years, and these regions comprise the major source of the Yellow River sediment. Climatic drying initially occurred in the 1990s, and became statistically significant in 2000s. The increasingly severe droughts could negatively impact surface and groundwater supplies as well as soil water storage, but may also minimize surface runoff yield, which is one of the major causes of soil erosion on the Loess Plateau. Vegetation cover on the Loess Plateau was significantly improved after the implementation of "Grain for Green" project, which were helpful for controlling severe soil erosion. With the impacts of the construction of check dams, terraces and large reservoirs, runoff and sediment yield over the Loess Plateau initially exhibited downward trends between 1970 and 1990. After 1990, with the effects of the climate warming and drying, a second sharp reduction in runoff and sediment yield occurred. The coupling effects of climate aridity and vegetation restoration have led to a third significant decrease in runoff and sediment yield over the Loess Plateau after 2000. PMID:26379259

  17. Islet-selectivity of G-protein coupled receptor ligands evaluated for PET imaging of pancreatic {beta}-cell mass

    SciTech Connect

    Cline, Gary W.; Zhao, Xiaojian; Jakowski, Amy B.; Soeller, Walter C.; Treadway, Judith L.

    2011-09-02

    Highlights: {yields} We screened G-protein coupled receptors for imaging pancreatic. {yields} Database mining and immunohistochemistry identified GPCRs enriched in {beta}-cells. {yields} In vitro and in vivo assays were used to determine exocrine vs endocrine specificity. {yields} GPCR candidates for imaging of {beta}-cell mass are Prokineticin-1R, mGluR5, and GLP-1R. -- Abstract: A critical unmet need exists for methods to quantitatively measure endogenous pancreatic {beta}-cell mass (BCM) for the clinical evaluation of therapies to prevent or reverse loss of BCM and diabetes progression. Our objective was to identify G-protein coupled receptors (GPCRs) that are expressed with a high degree of specificity to islet {beta}-cells for receptor-targeted imaging of BCM. GPCRs enriched in pancreatic islets relative to pancreas acinar and hepatic tissue were identified using a database screen. Islet-specific expression was confirmed by human pancreas immunohistochemistry (IHC). In vitro selectivity assessment was determined from the binding and uptake of radiolabeled ligands to the rat insulinoma INS-1 832/13 cell line and isolated rat islets relative to the exocrine pancreas cell-type, PANC-1. Tail-vein injections of radioligands into rats were used to determine favorable image criteria of in vivo biodistribution to the pancreas relative to other internal organs (i.e., liver, spleen, stomach, and lungs). Database and IHC screening identified four candidate receptors for further in vitro and in vivo evaluation for PET imaging of BCM: prokineticin-1 receptor (PK-1R), metabotropic glutamate receptor type-5 (mGluR5), neuropeptide Y-2 receptor (NPY-2R), and glucagon-like peptide 1 receptor (GLP-1R). In vitro specificity ratios gave the following receptor rank order: PK-1R > GLP-1R > NPY-2R > mGluR5. The biodistribution rank order of selectivity to the pancreas was found to be PK-1R > VMAT2 {approx} GLP-1R > mGluR5. Favorable islet selectivity and biodistribution

  18. TU-F-17A-03: A 4D Lung Phantom for Coupled Registration/Segmentation Evaluation

    SciTech Connect

    Markel, D; El Naqa, I; Levesque, I

    2014-06-15

    Purpose: Coupling the processes of segmentation and registration (regmentation) is a recent development that allows improved efficiency and accuracy for both steps and may improve the clinical feasibility of online adaptive radiotherapy. Presented is a multimodality animal tissue model designed specifically to provide a ground truth to simultaneously evaluate segmentation and registration errors during respiratory motion. Methods: Tumor surrogates were constructed from vacuum sealed hydrated natural sea sponges with catheters used for the injection of PET radiotracer. These contained two compartments allowing for two concentrations of radiotracer mimicking both tumor and background signals. The lungs were inflated to different volumes using an air pump and flow valve and scanned using PET/CT and MRI. Anatomical landmarks were used to evaluate the registration accuracy using an automated bifurcation tracking pipeline for reproducibility. The bifurcation tracking accuracy was assessed using virtual deformations of 2.6 cm, 5.2 cm and 7.8 cm of a CT scan of a corresponding human thorax. Bifurcations were detected in the deformed dataset and compared to known deformation coordinates for 76 points. Results: The bifurcation tracking accuracy was found to have a mean error of −0.94, 0.79 and −0.57 voxels in the left-right, anterior-posterior and inferior-superior axes using a 1×1×5 mm3 resolution after the CT volume was deformed 7.8 cm. The tumor surrogates provided a segmentation ground truth after being registered to the phantom image. Conclusion: A swine lung model in conjunction with vacuum sealed sponges and a bifurcation tracking algorithm is presented that is MRI, PET and CT compatible and anatomically and kinetically realistic. Corresponding software for tracking anatomical landmarks within the phantom shows sub-voxel accuracy. Vacuum sealed sponges provide realistic tumor surrogate with a known boundary. A ground truth with minimal uncertainty is thus

  19. Evaluation of the mineral profile of textile materials using inductively coupled plasma optical emission spectrometry and chemometrics.

    PubMed

    Menezes, E A; Carapelli, R; Bianchi, S R; Souza, S N P; Matos, W O; Pereira-Filho, E R; Nogueira, A R A

    2010-10-15

    The content of Al, Ba, Ca, Cr, Cu, Fe, Ni, P, Zn, Cd and Pb was determined in textile material samples after microwave-assisted decomposition in a cavity oven and extraction with an artificial sweat solution. Radial viewing inductively coupled plasma optical emission spectrometry (ICP OES) was the main detection technique, but Cd and Pb were determined by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) to increase the sensitivity. Principal components analysis (PCA) was applied to the data sets to characterize the samples with respect to their geographic origin and color difference. The PCA for Brazilian single-color samples showed separation, with one group consisting of blue and green textiles and another with all the other materials evaluated. The geographic origin study showed a clear separation between Brazilian and Chinese textiles. The metals amount extracted with sweat extractable solution were lower than limits values pointed by the International Testing and Certification System for Textiles, Oko Tex Standard 100, in the all considered classes. Recoveries varied from 85 to 112% for additions ranging from 3.0 to 25 mg kg(-1) for Ca and from 0.3 to 7.0 mg kg(-1) for all other analytes through the microwave-assisted decomposition procedure. PMID:20599322

  20. Quality control evaluation of nutraceutical products from Ginkgo biloba using liquid chromatography coupled to high resolution mass spectrometry.

    PubMed

    López-Gutiérrez, Noelia; Romero-González, Roberto; Martínez Vidal, José Luis; Garrido Frenich, Antonia

    2016-03-20

    Analysis of 11 commercial nutraceutical products obtained from ginkgo has been performed using ultra-high performance liquid chromatography coupled to single-stage Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-MS). The main phytochemicals present in these samples were detected and quantified, utilizing a database containing 65 compounds. Phytochemicals were extracted using a mixture of an aqueous solution of methanol:water (80:20, v/v) in two sequential solid-liquid extractions. Adequate validation parameters were obtained. The validated compounds exhibited suitable linearity with determination coefficients (R(2)) higher than 0.99, and intra and inter-day precision were lower than 17 and 22%, respectively. Limits of detection (LODs) and quantification (LOQs) were calculated, ranging from 2 to 10 μg L(-1), except for myricetin (LOD, 150 μg L(-1) and LOQ, 300 μg L(-1)). Results indicate that the amount of terpenoids greatly varies among samples, ranging from 1133 (C7) to 12706 mg kg(-1) (C11). This emphasizes the importance of improve quality control in ginkgo-based products. Moreover, retrospective analysis allowed the detection of some undesirable substances as ginkgolic acid in the samples evaluated. PMID:26808064

  1. Novel 9′-substituted-noscapines: Synthesis with Suzuki cross-coupling, structure elucidation and biological evaluation

    PubMed Central

    Porcù, Elena; Sipos, Attila; Basso, Giuseppe; Hamel, Ernest; Bai, Ruoli; Stempfer, Verena; Udvardy, Antal; Bényei, Attila Cs.; Schmidhammer, Helmut; Antus, Sàndor; Viola, Giampietro

    2014-01-01

    Tubulin is a major molecular target for anticancer drugs. The dynamic process of microtubule assembly and disassembly can be blocked by various agents that bind to distinct sites on tubulin, usually its β-subunit. Among the antimitotic agents that perturb microtubule dynamics, noscapinoids represent an emerging class of agents. In particular, 9′-bromonoscapine (EM011) has been identified as a potent noscapine analog. Here we present high yielding, efficient synthetic methods based on Suzuki coupling of 9′-alkyl and 9′-arylnoscapines and an evaluation of their antiproliferative properties. Our results showed that 9′-alkyl and 9′-aryl derivatives inhibit proliferation of human cancer cells. The most active compounds were the 9′-methyl and the 9′-phenyl derivatives, which showed similar cytotoxic potency in comparison to the 9′-brominated derivative. Interestingly these newly synthesized derivatives did not induce cell death in normal human lymphocytes, suggesting that the compounds may be selective against cancer cells. All of these derivatives, except 9′-(2-methoxyphenyl)-noscapine, efficiently induced a cell cycle arrest in the G2/M phase of the cell cycle in HeLa and Jurkat cells. Furthermore, we showed that the most active compounds in HeLa cells induced apoptosis following the mitochondrial pathway with the activation of both caspase-9 and caspase-3. In addition, these compounds significantly reduced the expression of the antiapoptotic proteins Mcl-1 and Bcl-2. PMID:25050880

  2. The evaluation of a biphasic osteochondral implant coupled with an electrospun membrane in a large animal model.

    PubMed

    Ho, Saey Tuan Barnabas; Hutmacher, Dietmar Werner; Ekaputra, Andrew Krishna; Hitendra, Doshi; Hui, James Hoi

    2010-04-01

    Conventional clinical therapies are unable to resolve osteochondral defects adequately; hence, tissue engineering solutions are sought to address the challenge. A biphasic implant that was seeded with mesenchymal stem cells (MSCs) and coupled with an electrospun membrane was evaluated as an alternative. This dual phase construct comprised of a polycaprolactone (PCL) cartilage scaffold and a PCL-tricalcium phosphate osseous matrix. Autologous MSCs were seeded into the entire implant via fibrin and the construct was inserted into critically sized osteochondral defects located at the medial condyle and patellar groove of pigs. The defect was resurfaced with a PCL-collagen electrospun mesh, which served as a substitute for periosteal flap in preventing cell leakage. Controls without either implanted MSCs or resurfacing membrane were included. After 6 months, cartilaginous repair was observed with a low occurrence of fibrocartilage at the medial condyle. Osteochondral repair was promoted and host cartilage degeneration was arrested as shown by superior glycosaminoglycan maintenance. This positive morphological outcome was supported by a higher relative Young's modulus, which indicated functional cartilage restoration. Bone ingrowth and remodeling occurred in all groups, with a higher degree of mineralization in the experimental group. Tissue repair was compromised in the absence of the implanted cells or the resurfacing membrane. Moreover, healing was inferior at the patellar groove when compared with the medial condyle and this was attributed to the native biomechanical features. PMID:19863255

  3. Do the Effects of a Relationship Education Program Vary for Different Types of Couples? Exploratory Subgroup Analysis in the Supporting Healthy Marriage Evaluation. OPRE Report 2014-22

    ERIC Educational Resources Information Center

    Gubits, Daniel; Lowenstein, Amy E.; Harris, Jorgen; Hsueh, JoAnn

    2014-01-01

    The Supporting Healthy Marriage (SHM) evaluation was launched in 2003 to test the effectiveness of a skills-based relationship education program designed to help low-and modest-income married couples strengthen their relationships and to support more stable and more nurturing home environments and more positive outcomes for parents and their…

  4. Evaluation of operational online-coupled regional air quality models over Europe and North America in the context of AQMEII phase 2. Part II: Particulate Matter

    EPA Science Inventory

    The second phase of the Air Quality Model Evaluation International Initiative (AQMEII) brought together seventeen modeling groups from Europe and North America, running eight operational online-coupled air quality models over Europe and North America on common emissions and bound...

  5. Evaluation of operational online-coupled regional air quality models over Europe and North America in the context of AQMEII phase 2. Part 1: Ozone”

    EPA Science Inventory

    The second phase of the Air Quality Model Evaluation International Initiative (AQMEII) brought together sixteen modeling groups from Europe and North America, running eight operational online-coupled air quality models over Europe and North America on common emissions and boundar...

  6. Application of online-coupled WRF/Chem-MADRID in East Asia: Model evaluation and climatic effects of anthropogenic aerosols

    NASA Astrophysics Data System (ADS)

    Liu, Xu-Yan; Zhang, Yang; Zhang, Qiang; He, Ke-Bin

    2016-01-01

    The online-coupled Weather Research and Forecasting model with Chemistry with the Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (referred to as WRF/Chem-MADRID) is applied to simulate meteorological fields, air quality, and the direct and indirect effects of anthropogenic aerosols over East Asia in four months (January, April, July, and October) in 2008. Model evaluation against available surface and satellite measurements shows that despite some model biases, WRF/Chem-MADRID is able to reproduce reasonably well the spatial and seasonal variations of most meteorological fields and chemical concentrations. Large model biases for chemical concentrations are attributed to uncertainties in emissions and their spatial and vertical allocations, simulated meteorological fields, imperfectness of model representations of aerosol formation processes, uncertainties in the observations based on air pollution index, and the use of a coarse grid resolution. The results show that anthropogenic aerosols can reduce net shortwave flux at the surface by up to 40.5-57.2 W m-2, Temperature at 2-m by up to 0.5-0.8 °C, NO2 photolytic rates by up to 0.06-0.1 min-1 and the planetary boundary layer height by up to 83.6-130.4 m. Anthropogenic aerosols contribute to the number concentrations of aerosols by up to 6.2-8.6 × 104 cm-3 and the surface cloud concentration nuclei at a supersaturation of 0.5% by up to 1.0-1.6 × 104 cm-3. They increase the column cloud droplet number concentrations by up to 3.6-11.7 × 108 cm-2 and cloud optical thickness by up to 19.8-33.2. However, anthropogenic aerosols decrease daily precipitation in most areas by up to 3.9-18.6 mm during the 4 months. These results indicate the importance of anthropogenic aerosols in modulating regional climate changes in East Asia through aerosol direct and indirect effects, as well as the need to further improve the performance of online-coupled models.

  7. Relativistic four-component calculations of indirect nuclear spin-spin couplings with efficient evaluation of the exchange-correlation response kernel

    SciTech Connect

    Křístková, Anežka; Malkin, Vladimir G.; Komorovsky, Stanislav; Repisky, Michal; Malkina, Olga L.

    2015-03-21

    In this work, we report on the development and implementation of a new scheme for efficient calculation of indirect nuclear spin-spin couplings in the framework of four-component matrix Dirac-Kohn-Sham approach termed matrix Dirac-Kohn-Sham restricted magnetic balance resolution of identity for J and K, which takes advantage of the previous restricted magnetic balance formalism and the density fitting approach for the rapid evaluation of density functional theory exchange-correlation response kernels. The new approach is aimed to speedup the bottleneck in the solution of the coupled perturbed equations: evaluation of the matrix elements of the kernel of the exchange-correlation potential. The performance of the new scheme has been tested on a representative set of indirect nuclear spin-spin couplings. The obtained results have been compared with the corresponding results of the reference method with traditional evaluation of the exchange-correlation kernel, i.e., without employing the fitted electron densities. Overall good agreement between both methods was observed, though the new approach tends to give values by about 4%-5% higher than the reference method. On the average, the solution of the coupled perturbed equations with the new scheme is about 8.5 times faster compared to the reference method.

  8. Decadal predictions with the HiGEM high resolution global coupled climate model: description and basic evaluation

    NASA Astrophysics Data System (ADS)

    Shaffrey, L. C.; Hodson, D.; Robson, J.; Stevens, D. P.; Hawkins, E.; Polo, I.; Stevens, I.; Sutton, R. T.; Lister, G.; Iwi, A.; Smith, D.; Stephens, A.

    2016-04-01

    This paper describes the development and basic evaluation of decadal predictions produced using the HiGEM coupled climate model. HiGEM is a higher resolution version of the HadGEM1 Met Office Unified Model. The horizontal resolution in HiGEM has been increased to 1.25° × 0.83° in longitude and latitude for the atmosphere, and 1/3° × 1/3° globally for the ocean. The HiGEM decadal predictions are initialised using an anomaly assimilation scheme that relaxes anomalies of ocean temperature and salinity to observed anomalies. 10 year hindcasts are produced for 10 start dates (1960, 1965,..., 2000, 2005). To determine the relative contributions to prediction skill from initial conditions and external forcing, the HiGEM decadal predictions are compared to uninitialised HiGEM transient experiments. The HiGEM decadal predictions have substantial skill for predictions of annual mean surface air temperature and 100 m upper ocean temperature. For lead times up to 10 years, anomaly correlations (ACC) over large areas of the North Atlantic Ocean, the Western Pacific Ocean and the Indian Ocean exceed values of 0.6. Initialisation of the HiGEM decadal predictions significantly increases skill over regions of the Atlantic Ocean, the Maritime Continent and regions of the subtropical North and South Pacific Ocean. In particular, HiGEM produces skillful predictions of the North Atlantic subpolar gyre for up to 4 years lead time (with ACC > 0.7), which are significantly larger than the uninitialised HiGEM transient experiments.

  9. [PAHs concentrations in aquatic products and food safety evaluation in the coupled mangrove planting-aquaculture ecological system].

    PubMed

    Chen, Guan-Qiu; Li, Yao-Chu; Huang, Jin-Mu; Nan, Yan; Lin, Mao-Hong

    2012-06-01

    In order to know about the PAHs concentration in aquatic products from mangrove planting-aquaculture ecological system and to make sure of food quality and food safety, HPLC was used to determine concentrations of 13 polycyclic aromatic hydrocarbons (PAHs) in the Tilapia mossambica, Mugil cephalu and Concha ostreae from coupled mangrove planting-aquaculture ponds, food safety in aquatic products was also evaluated. The 13 PAHs were Fluorene (Flu), Phenanthrene (Phe), Anthracene (Ant), Fluoranthene (Fla), Pyrene (Pyr), Benz[a] anthraces (BaA), Chrysene (Chr), Benzo[b] fluoranthene (BbF), Benzo[k] fluoranthene (BkF), Benzo[a] Pyrene (BaP), Dibenzo [a, h] anthercene (DahA), Benzo [g, h, i] perylene (BghiP) and Indeno [1,2,3-c, d] pyrene (InP). Concentrations of PAHs were the highest in Concha ostreae which were in the range of 89.79-98.49 microg x kg(-1) dry weight, while those were in the range of 25.97-34.64 microg x kg(-1) in Mugil cephalu and 12.31-14.41 microg x kg(-1) in Tilapia mossambica. The content of fat affected the levels of PAHs content in different aquatic products. The individual composition of PAHs was characterized by 3 rings in samples with the range of 41.58% - 83.35%. Comparing with other areas, PAHs pollution of aquatic products in the studied area was in the mild level. Values of the total BaP(eq) concentration ranged from 0.0689 microg x kg(-1) to 1.0373 microg x kg(-1), which were lower than the maximum level set by European Union. PMID:22946164

  10. Evaluating the Performance of a Coupled Distributed Hydrologic - Hydraulic Model for Flash Flood Modeling Using Multiple Precipitation Data Sources

    NASA Astrophysics Data System (ADS)

    Nguyen, P.; Sorooshian, S.; Hsu, K.; AghaKouchak, A.; Sanders, B. F.

    2013-12-01

    Flash floods are considered one of the most hazardous natural disasters, which kills thousands of people and causes billions of US dollar economic damages annually world-wide. Forecasting flash floods to provide accurate warnings in a timely manner is still challenging. At the Center for Hydrometeorology and Remote Sensing (CHRS) at the University of California, Irvine, we have been developing a coupled high resolution distributed hydrologic-hydraulic system for flash flood modeling which has been successfully tested for some selected areas in the U.S. and has potential to be implemented in global scale. The system employs the National Weather Service's distributed hydrologic model (HL-RDHM) as a rainfall-runoff generator, and a high-resolution hydraulic model (BreZo) for simulating the channel and flood-plain flows realistically. In this research, we evaluate the system for flash flood warning using multiple precipitation sources (gauge, radar and satellite and forecast). A flash flood event occurring on June 11, 2010 in the Upper Little Missouri River watershed in Arkansas is used as a case study. The catchment was delineated into 123 sub-catchments based on the 10m Digital Elevation Model (DEM) topography data from USGS. From HL-RDHM surface runoff, 123 hydrographs can be derived and connected as inputs to BreZo. The system was calibrated using NEXRAD Stage IV radar-based rainfall by tuning the roughness parameter in BreZo to best match the USGS discharge observation at the catchment outlet. The results show good agreement with the USGS gauge flow measurement (Nash-Sutcliffe coefficient = 0.91) when using Stage IV data. The system is under investigation with satellite-based precipitation data, rain gauge and Global Forecast System (GFS) data and will be reported in the presentation.

  11. Evaluation of 3D radio-frequency electromagnetic fields for any matching and coupling conditions by the use of basis functions

    NASA Astrophysics Data System (ADS)

    Tiberi, Gianluigi; Fontana, Nunzia; Monorchio, Agostino; Stara, Riccardo; Retico, Alessandra; Tosetti, Michela

    2015-12-01

    A procedure for evaluating radio-frequency electromagnetic fields in anatomical human models for any matching and coupling conditions is introduced. The procedure resorts to the extraction of basis functions: such basis functions, which represent the fields produced by each individual port without any residual coupling, are derived through an algebraic procedure which uses the S parameter matrix and the fields calculated in one (only) full-wave simulation. The basis functions are then used as building-blocks for calculating the fields for any other S parameter matrix. The proposed approach can be used both for volume coil driven in quadrature and for parallel transmission configuration.

  12. Evaluation of a 512-Channel Faraday-Strip Array Detector Coupled to an Inductively Coupled Plasma Mattauch-Herzog Mass Spectrograph

    SciTech Connect

    Schilling, G. D.; Ray, Steven J.; Rubinshtein, Arnon A.; Felton, Jermey; Sperline, Roger P.; Denton, Bonner M.; Barinaga, Charles J.; Koppenaal, David W.; Hieftje, Gary M.

    2009-07-01

    A 512-channel Faraday-strip array detector has been developed and fitted to a Mattauch-Herzog geometry mass spectrograph for the simultaneous acquisition of multiple mass-to-charge values. Several advantages are realized by using simultaneous detection methods, including higher duty cycles, removal of correlated noise, and multianalyte transient analyses independent of spectral skew. The new 512-channel version offers narrower, more closely spaced pixels, providing improved spectral peak sampling and resolution. In addition, the electronics in the amplification stage of the new detector array incorporate a sample-and-hold feature that enables truly simultaneous interrogation of all 512 channels. While sensitivity and linear dynamic range remain impressive for this Faraday-based detector system, limits of detection and isotope ratio data have suffered slightly from leaky p-n junctions produced during the manufacture of the semiconductor-based amplification and readout stages. This paper describes the new 512-channel detector array, the current dominant noise sources, and the figures of merit for the device as pertaining to inductively coupled plasma ionization.

  13. EVALUATION OF A MULTICHANNEL INDUCTIVELY COUPLED PLASMA-OPTICAL EMISSION SPECTROMETER MODIFIED TO MINIMIZE AND CORRECT SCATTERED LIGHT EFFECTS

    EPA Science Inventory

    In a study of an inductively coupled plasma optical emission spectrometer, data from an early commercially available instrument are compared with data from the same instrument after modifications to correct observed inadequacies were made. Results show negligible changes in power...

  14. Fire severity estimated from remote sensing data to evaluate the Coupled Atmosphere-Wildland Fire-Environment (CAWFE) model

    NASA Astrophysics Data System (ADS)

    Oliva, P.; Coen, J.; Schroeder, W.

    2013-12-01

    Fire severity defined as the degree of damage originated from fire on soils and vegetation immediately after the fire, is affected by weather conditions (i.e. wind, air humidity), terrain characteristics (i.e. slope, aspect) and fuel properties (i.e. tree density, fuel moisture content). In this study we evaluated the relationships between fire severity estimated from Earth Observing Advance Land Imager (EO-ALI) images and the heat fluxes produced by the Coupled Atmosphere-Wildland Fire-Environment (CAWFE) model (Coen 2013). We present the results for a large fire occurred in New Mexico in June 2012 which burned 44,330 acres. The EO-ALI sensor (30 m spatial resolution) has nine spectral bands, six of them were designed to mimic Landsat bands and the three additional bands cover 443, 867.5 and 1250 nm. We used a physically-based approach to estimate fire severity developed by De Santis et al. (2009). This method classifies the satellite image into Geophysical Composite burned index (GeoCBI) values, which represent the fire severity within the fire-affected area, using radiative transfer model simulated spectra as reference. This method has been used to characterize fire severity levels using Landsat images and validated with field data (R2 > 0.85). Based on those results we expected a better performance of EO-ALI images due to its improved spectral resolution. On the other hand, CAWFE is composed of two parts: a numerical weather prediction model and a fire behavior module that represents the growth of a wildland fire in response to factors such as wind, terrain, and fuels, and includes the fire's impact on the atmosphere. To perform the evaluation we selected a stratified random sample by fire severity level. The values of maximum heat flux (sensible, latent), and total heat flux showed a higher correlation with the higher levels of fire severity (GeoCBI: 2.8-3) than with the medium levels of fire severity (GeoCBI: 2.3-2.8). However, the total heat flux proved to

  15. Evaluating Diurnal Variations of Summer Precipitation over the Asian Monsoon Region based on TRMM Satellite Data and Coupled model outputs

    NASA Astrophysics Data System (ADS)

    Mao, J.; Wu, G.

    2013-12-01

    Climatological characteristics of diurnal variations in summer precipitation over the entire Asian monsoon region are comprehensively investigated based on the Tropical Rainfall Measuring Mission (TRMM) satellite data during 1998-2008. The amplitude and phase of diurnal precipitation show a distinct geographical pattern. Significant diurnal variations occur over most of continental and coastal areas including the Maritime Continent, with the relative amplitude exceeding 40%, indicating that the precipitation peak is 1.4 times the 24-h mean. Although the diurnal variations of summer precipitation over the continental areas are characterized by an afternoon peak (1500-1800 Local Solar Time (LST)), over the central Indochina Peninsula and central and southern Indian Peninsula the diurnal phase is delayed to after 2100 LST, suggesting the diurnal behaviors over these areas different from the general continental areas. The weak diurnal variations with relative amplitudes less than 40% exist mainly over oceanic areas in the western Pacific and most of Indian Ocean, with the rainfall peak mainly occurring from midnight to early morning (0000-0600 LST), indicating a typical oceanic regime characterized by an early morning peak. However, apparent exceptions occur over the South China Sea (SCS), Bay of Bengal (BOB), and eastern Arabian Sea, with the rainfall peak occurring in daytime (0900-1500 LST). Prominent meridional propagations of the diurnal phase exist in South Asia and East Asia. The diurnal precipitation variations are also evaluated using the simulated outputs from several coupled general circulation models (CGCMs) participating in CMIP3 (such as CNRM-CM3 and MRI-GCGM2.3.2) and CMIP5 (FGOALS-g2). As compared with those from TRMM data, current state-of-the-art CGCMs still have significant problems in simulating the diurnal variability of the Asian summer monsoon. Although most models can capture the amplitude and phase of the diurnal rainfall cycle over continental

  16. Systematic evaluation of matrix effects in hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry.

    PubMed

    Periat, Aurélie; Kohler, Isabelle; Thomas, Aurélien; Nicoli, Raul; Boccard, Julien; Veuthey, Jean-Luc; Schappler, Julie; Guillarme, Davy

    2016-03-25

    Reversed phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) is the gold standard technique in bioanalysis. However, hydrophilic interaction chromatography (HILIC) could represent a viable alternative to RPLC for the analysis of polar and/or ionizable compounds, as it often provides higher MS sensitivity and alternative selectivity. Nevertheless, this technique can be also prone to matrix effects (ME). ME are one of the major issues in quantitative LC-MS bioanalysis. To ensure acceptable method performance (i.e., trueness and precision), a careful evaluation and minimization of ME is required. In the present study, the incidence of ME in HILIC-MS/MS and RPLC-MS/MS was compared for plasma and urine samples using two representative sets of 38 pharmaceutical compounds and 40 doping agents, respectively. The optimal generic chromatographic conditions in terms of selectivity with respect to interfering compounds were established in both chromatographic modes by testing three different stationary phases in each mode with different mobile phase pH. A second step involved the assessment of ME in RPLC and HILIC under the best generic conditions, using the post-extraction addition method. Biological samples were prepared using two different sample pre-treatments, i.e., a non-selective sample clean-up procedure (protein precipitation and simple dilution for plasma and urine samples, respectively) and a selective sample preparation, i.e., solid phase extraction for both matrices. The non-selective pretreatments led to significantly less ME in RPLC vs. HILIC conditions regardless of the matrix. On the contrary, HILIC appeared as a valuable alternative to RPLC for plasma and urine samples treated by a selective sample preparation. Indeed, in the case of selective sample preparation, the compounds influenced by ME were different in HILIC and RPLC, and lower and similar ME occurrence was generally observed in RPLC vs. HILIC for urine and plasma samples

  17. [Coupling coordination evaluation method between eco-environment quality and economic development level in contiguous special poverty-stricken areas of China].

    PubMed

    Wang, Yan-hui; Li, Jing-yi

    2015-05-01

    It is one of the important strategies in the new period of national poverty alleviation and development to maintain the basic balance between the ecological environment and economic development, and to promote the coordinated sustainable development of economy and ecological environment. Taking six contiguous special poverty-stricken areas as the study areas, a coupling coordination evaluation method between eco-environment quality and economic development level in contiguous special poverty-stricken areas was explored in this paper. The region' s ecological poverty index system was proposed based on the natural attribute of ecological environment, and the ecological environment quality evaluation method was built up by using AHP weighting method, followed by the design of the coupling coordination evaluation method between the ecological environment indices and the county economic poverty comprehensive indices. The coupling coordination degrees were calculated and their spatial representation differentiations were analyzed respectively at district, province, city, and county scales. Results showed that approximately half of the counties in the study areas achieved the harmoniously coordinated development. However, the ecological environmental quality and the economic development in most counties could not be synchronized, where mountains, rivers and other geographic features existed roughly as a dividing line of the coordinated development types. The phenomena of dislocation between the ecological environment and economic development in state-level poor counties were more serious than those of local poor counties. PMID:26571673

  18. Evaluating the effects of charged oligopeptide motifs coupled with RGD on osteogenic differentiation of mesenchymal stem cells.

    PubMed

    Cao, Feng-Yi; Yin, Wei-Na; Fan, Jin-Xuan; Tao, Li; Qin, Si-Yong; Zhuo, Ren-Xi; Zhang, Xian-Zheng

    2015-04-01

    Mesenchymal stem cells, due to their multilineage differentiation potential, have emerged as a promising cell candidate for cell-based therapy. In recent years, biomaterials were artificially synthesized to control the differentiation of mesenchymal stem cells. In this study, a series of charged or neutral oligopeptide motifs coupled with RGD were synthesized and used for surface modification using quartz substrates as model. Cell behaviors on the modified surfaces with different charged oligopeptide motifs were studied. It was found that these different charged oligopeptide motifs coupled with RGD were biocompatible for cell proliferation and adhesion. Moreover, it was demonstrated that the positively charged oligopeptide motif could inhibit osteogenic differentiation, while the negatively charged and neutral oligopeptide motifs could enhance osteogenic differentiation in the presence of RGD. This work may bring us enlightenment that different charged oligopeptide motifs coupled with RGD may be used for biomaterial surface modification for different stem cell-based therapies. PMID:25748883

  19. Evaluation of the influence of the main plasma density parameters on antenna coupling and radio frequency potentials with TOPICA code

    NASA Astrophysics Data System (ADS)

    Milanesio, D.; Maggiora, R.

    2013-04-01

    The successful design of an ion cyclotron antenna mainly relies on the capability of accurately predicting its behavior both in terms of input parameters, and therefore power coupled to plasma, and radiated fields. All these features essentially depend on the antenna itself (its geometry, the matching and tuning systems) and, obviously, on the faced loading. In this paper a number of plasma profiles is analysed with the help of the TOPICA code, a predictive tool for the design and optimization of radio frequency (RF) launchers in front of a plasma, in order to understand which plasma parameters have the most significant influence on the coupling performances of a typical IC antenna.

  20. Synthesis of heterocyclic triads by Pd-catalyzed cross-couplings and evaluation of their cell-specific toxicity profile.

    PubMed

    Salamoun, Joseph; Anderson, Shelby; Burnett, James C; Gussio, Rick; Wipf, Peter

    2014-04-01

    Two complementary approaches for the preparation of linked 5-membered heterocycles were developed. The Pd-catalyzed Suzuki-Miyaura cross-coupling with halogenated furan, thiophene, and selenophene led to higher overall yields, but C,H-bond activation was a more efficient strategy for the coupling at C(2) of oxazoles. Potency and selectivity of the final hydroxymethyl products in renal (A498), lung (NCI-H226), kidney (CAKI-1), and breast (MDA-MB-468, MCF7) carcinoma cell lines were determined. PMID:24641272

  1. Synthesis of Heterocyclic Triads by Pd-Catalyzed Cross-Couplings and Evaluation of Their Cell-Specific Toxicity Profile

    PubMed Central

    2015-01-01

    Two complementary approaches for the preparation of linked 5-membered heterocycles were developed. The Pd-catalyzed Suzuki–Miyaura cross-coupling with halogenated furan, thiophene, and selenophene led to higher overall yields, but C,H-bond activation was a more efficient strategy for the coupling at C(2) of oxazoles. Potency and selectivity of the final hydroxymethyl products in renal (A498), lung (NCI-H226), kidney (CAKI-1), and breast (MDA-MB-468, MCF7) carcinoma cell lines were determined. PMID:24641272

  2. Coupled Cluster Evaluation of the Stability of Atmospheric Acid-Base Clusters with up to 10 Molecules.

    PubMed

    Myllys, Nanna; Elm, Jonas; Halonen, Roope; Kurtén, Theo; Vehkamäki, Hanna

    2016-02-01

    We investigate the utilization of the domain local pair natural orbital coupled cluster (DLPNO-CCSD(T)) method for calculating binding energies of atmospherical molecular clusters. Applied to small complexes of atmospherical relevance we find that the DLPNO method significantly reduces the scatter in the binding energy, which is commonly present in DFT calculations. For medium sized clusters consisting of sulfuric acid and bases the DLPNO method yields a systematic underestimation of the binding energy compared to canonical coupled cluster results. The errors in the DFT binding energies appear to be more random, while the systematic nature of the DLPNO results allows the establishment of a scaling factor, to better mimic the canonical coupled cluster calculations. Based on the trends identified for the small and medium sized systems, we further extend the application of the DLPNO method to large acid - base clusters consisting of up to 10 molecules, which have previously been out of reach with accurate coupled cluster methods. Using the Atmospheric Cluster Dynamics Code (ACDC) we compare the sulfuric acid dimer formation based on the new DLPNO binding energies with previously published RI-CC2/aug-cc-pV(T+d)Z results. We also compare the simulated sulfuric acid dimer concentration as a function of the base concentration with measurement data from the CLOUD chamber and flow tube experiments. The DLPNO method, even after scaling, underpredicts the dimer concentration significantly. Reasons for this are discussed. PMID:26771121

  3. Towards Fully Coupled Atmosphere-Hydrology Model Systems: Recent Developments and Performance Evaluation For Different Climate Regions

    NASA Astrophysics Data System (ADS)

    Kunstmann, Harald; Fersch, Benjamin; Rummler, Thomas; Wagner, Sven; Arnault, Joel; Senatore, Alfonso; Gochis, David

    2015-04-01

    Limitations in the adequate representation of terrestrial hydrologic processes controlling the land-atmosphere coupling are assumed to be a significant factor currently limiting prediction skills of regional atmospheric models. The necessity for more comprehensive process descriptions accounting for the interdependencies between water- and energy fluxes at the compartmental interfaces are driving recent developments in hydrometeorological modeling towards more sophisticated treatment of terrestrial hydrologic processes. It is particularly the lateral surface and subsurface water fluxes that are neglected in standard regional atmospheric models. Current developments in enhanced lateral hydrological process descriptions in the WRF model system will be presented. Based on WRF and WRF-Hydro, new modules and concepts for integrating the saturated zone by a 2-dim groundwater scheme and coupling approaches to the unsaturated zone will be presented. The fully coupled model system allows to model the complete regional water cycle, from the top of the atmosphere, via the boundary layer, the land surface, the unsaturated zone and the saturated zone till the flow in the river beds. With this increasing complexity, that also allows to describe the complex interaction of the regional water cycle on different spatial and temporal scales, the reliability and predictability of model simulations can only be shown, if performance is tested for a variety of hydrological variables for different climatological environments. We will show results of fully coupled simulations for the regions of sempiternal humid Southern Bavaria/Germany (rivers Isar and Ammer) and semiarid to subhumid Westafrica (river Sissilli). In both regions, in addition to streamflow measurements, also the validation of heat fluxes is possible via Eddy-Covariance stations within hydrometeorological testbeds. In the German Isar/Ammer region, e.g., we apply the extended WRF-Hydro modeling system in 3km atmospheric- grid

  4. Coupling meteorological and hydrological models to evaluate the uncertainty in runoff forecasting: the case study of Maggiore Lake basin

    NASA Astrophysics Data System (ADS)

    Ceppi, A.; Ravazzani, G.; Rabuffetti, D.; Mancini, M.

    2009-04-01

    observed data to run the control simulations were supplied by ARPA-Piemonte. The study is focused on Maggiore Lake basin, an alpine basin between North-West of Italy and Southern Switzerland; results and statistical testing of the re-analyses shown in this presentation, are subdivided for each of three smaller sub-basins: Toce, Ticino and Maggia, in order to demonstrate the research progress on coupling meteorological and hydrological models in particular orographic features. It is presented how the meteorological forecasts are efficient into hydrological forecasting system, how the ensemble predictions are powerful to evaluate the uncertainty of the QPF which affects the QDF and the whole hydro-meteorological alert system for a mountain catchment. Further, in order to control the quality of the hydrological predictions in the short and medium term, statistical methods are used to calculate how the skill scores can be applied for hydrological applications and how the ensemble forecasts can help the users for decision making in management situations. Two significant events are analysed in order to compare the behaviour of the model driven by different weather scenarios: one convective in June that has yielded a high peak flow and one light stratiform in November that has been studied for the snow melt temperature which has affected the liquid precipitation and therefore the forecasted runoff. It is shown how the entire rainfall, the liquid precipitation and the runoff change in function of an areal the sub-basin scale, in order to understand where the errors are more frequently encountered.

  5. Theoretical and numerical evaluation of polarimeter using counter-circularly-polarized-probing-laser under the coupling between Faraday and Cotton-Mouton effect

    NASA Astrophysics Data System (ADS)

    Imazawa, Ryota; Kawano, Yasunori; Itami, Kiyoshi

    2016-04-01

    This study evaluated an effect of an coupling between the Faraday and Cotton-Mouton effect to a measurement signal of the Dodel-Kunz method which uses counter-circular-polarized probing-laser for measuring the Faraday effect. When the coupling is small (the Faraday effect is dominant and the characteristic eigenmodes are approximately circularly polarized), the measurement signal can be algebraically expressed and it is shown that the finite effect of the coupling is still significant. When the Faraday effect is not dominant, a numerical calculation is necessary. The numerical calculation under an ITER-like condition (Bt = 5.3 T, Ip = 15 MA, a = 2 m, ne = 1020 m-3 and λ = 119 μm) showed that difference between the pure Faraday rotation and the measurement signal of the Dodel-Kunz method was an order of one degree, which exceeds allowable error of ITER poloidal polarimeter. In conclusion, similar to other polarimeter techniques, the Dodel-Kunz method is not free from the coupling between the Faraday and Cotton-Mouton effect.

  6. Evaluation of a new Gulf of St. Lawrence coupled environmental prediction system based on the GEM atmospheric model and on the NEMO-CICE ocean-ice model

    NASA Astrophysics Data System (ADS)

    Pellerin, Pierre; Roy, François; Dick, Sarah; Smith, Greg; Dupont, Fred; Pilon, Mark; Senneville, Simon; Chanut, Jerome

    2015-04-01

    The Canadian operational Gulf of St. Lawrence (GSL) coupled environmental forecast system has been updated with a new ocean-ice component (NEMO-CICE) and coupling methodology. The use of NEMO-CICE will facilitate future advances toward an increase in resolution and the introduction of new scientific developments. Indeed NEMO and CICE are supported by a large scientific community and are based on more efficient computing technologies than the current system. An ensemble of hindcasts over previous years demonstrate that recent developments in the NEMO-CICE model make it possible to meet the high quality standards of the ocean model by Saucier et al. (2009) used in the previous operational system in terms of the tides, circulation and water mass properties. We present results from these hindcasts as well as from an experimental run for the winter of 2014 and compare them with the operational system. The experimental run includes a pseudo-analysis cycle producing daily initial ice-ocean conditions and their subsequent coupled atmosphere-ice-ocean 48 hr forecasts. We first examine extreme weather event cases, and then present results from a subjective evaluation as well as objective skill scores for SST analyses and for ice, surface air temperature and wind forecasts. The importance of the two-way coupling will also be assessed.

  7. Evaluation and development of hydrological parameterisations for the atmosphere, ocean and land surface coupled model developed by the UK Environmental Prediction (UKEP) Prototype project

    NASA Astrophysics Data System (ADS)

    Martinez-de la Torre, Alberto; Blyth, Eleanor; Ashton, Heather; Lewis, Huw

    2016-04-01

    The UKEP project brings together atmosphere, ocean and land surface models and scientist to build a coupled prediction system for the UK at 1.5 km scale. JULES (Joint UK Land-Environment Simulator) is the land surface model that generates runoff and simulates soil hydrology within the coupled prediction system. Here we present an evaluation of JULES performance at producing river flow for 13 selected catchments in Great Britain, where we use daily river flow observations at the catchment outlets. The evaluation is based on the Nush-Sutcliffe metric and bias. Results suggest that the inclusion of a new linear topographic slope dependency in the S0 parameter of the PDM (Probability Distributed Model, scheme that generates saturation excess runoff at the land surface when the soil water storage reaches S0), improves results for all catchments, constraining the surface runoff production for flatter catchments during rainy episodes. The new hydrological configuration developed offline using the JULES model has been implemented in the coupled prediction system for an intense winter storm case study. We found significant changes in accumulated runoff and total column soil moisture, and results consistent with the offline experiments with an increase in surface runoff on the high slopes of Scotland.

  8. Fabrication and Evaluation of Thin-Film Spiral-Antenna-Coupled VOx Microbolometer by Metal-Organic Decomposition

    NASA Astrophysics Data System (ADS)

    Son, Le Ngoc; Tachiki, Takashi; Uchida, Takashi

    2013-04-01

    A VOx microbolometer coupled with thin-film spiral antenna was fabricated on a fused-quartz substrate by metal-organic decomposition (MOD). The size of the bolometer was 1 ×52 µm2, and the antenna was designed for operating at 75-110 GHz. The DC sensitivity and responsivity of the bolometer were 540 W-1 and 124 V/W at the bias current of 0.5 mA under the irradiation of a 94 GHz electromagnetic wave, respectively. These values were over one order higher than those of the Bi microbolometer, which is conventionally utilized as a detector in terahertz and infrared regions. The antenna-coupled VOx microbolometer with a high responsivity was realized by MOD.

  9. Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem model

    NASA Astrophysics Data System (ADS)

    Bash, J. O.; Cooter, E. J.; Dennis, R. L.; Walker, J. T.; Pleim, J. E.

    2013-03-01

    Atmospheric ammonia (NH3) is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurements indicate that the air-surface exchange of NH3 is bidirectional. However, the effects of bidirectional exchange, soil biogeochemistry and human activity are not parameterized in air quality models. The US Environmental Protection Agency's (EPA) Community Multiscale Air-Quality (CMAQ) model with bidirectional NH3 exchange has been coupled with the United States Department of Agriculture's (USDA) Environmental Policy Integrated Climate (EPIC) agroecosystem model. The coupled CMAQ-EPIC model relies on EPIC fertilization timing, rate and composition while CMAQ models the soil ammonium (NH4+) pool by conserving the ammonium mass due to fertilization, evasion, deposition, and nitrification processes. This mechanistically coupled modeling system reduced the biases and error in NHx (NH3 + NH4+) wet deposition and in ambient aerosol concentrations in an annual 2002 Continental US (CONUS) domain simulation when compared to a 2002 annual simulation of CMAQ without bidirectional exchange. Fertilizer emissions estimated in CMAQ 5.0 with bidirectional exchange exhibits markedly different seasonal dynamics than the US EPA's National Emissions Inventory (NEI), with lower emissions in the spring and fall and higher emissions in July.

  10. Evaluation of the temporal profiles and the analytical features of a laser ablation - Pulsed glow discharge coupling for optical emission spectrometry

    NASA Astrophysics Data System (ADS)

    González de Vega, Claudia; Bordel, Nerea; Pereiro, Rosario; Sanz-Medel, Alfredo

    2016-07-01

    The coupling of a glow discharge (GD) in pulsed mode (PGD) as secondary source for excitation/ionization of the material provided by laser ablation (LA) has been investigated using optical emission spectrometry (OES). The variation of the laser pulse delay with respect to the GD pulse allows to producing the ablation process during prepeak, plateau or afterglow GD regions. Emission properties of the LA-PGD plasma in each temporal region of the GD pulse have been evaluated for analytical lines of different elements. Resonant atomic lines have shown higher emission intensity in the prepeak region compared to non-resonant lines. Non-resonant lines showed higher enhancement of the emission intensity in the afterglow region. Moreover, the coupled LA-PGD system offered better linear correlation coefficients using a set of glass standards for calibration as well as lower detection limits (by at least a factor of two) when compared to laser induced breakdown spectroscopy.

  11. Evaluation of nitrogen nuclear hyperfine and quadrupole coupling parameters for the proximal imidazole in myoglobin-azide, -cyanide, and -mercaptoethanol complexes by electron spin echo envelope modulation spectroscopy.

    PubMed

    Magliozzo, R S; Peisach, J

    1993-08-24

    Electron spin echo envelope modulation (ESEEM) spectroscopy and computer simulation of spectra has been used to evaluate the nitrogen nuclear hyperfine and quadrupole coupling parameters for the proximal imidazole nitrogen directly coordinated to iron in three low-spin heme complexes, myoglobin-azide, -cyanide, and -mercaptoethanol (MbN3, MbCN, and MbRS). The variability in the weak electron-nuclear coupling parameters reveals the electronic flexibility within the heme group that depends on properties of the exogenous ligands. For example, the isotropic component of the nitrogen nuclear hyperfine coupling ranges from 4.4 MHz for MbN3 to 2.2 MHz for both MbCN and MbRS. The weaker coupling in MbCN and MbRS is taken as evidence for delocalization of unpaired electron spin from iron into the exogenous anionic ligands. The value of e2Qq, the nuclear quadrupole coupling constant for the axial imidazole nitrogen in MbCN and MbRS, was 2.5 MHz but was significantly larger, 3.2 MHz, in MbN3. This large value is considered evidence for a weakened sigma bond between the proximal imidazole and ferric iron in this form, and for a feature contributing to the origin of the high spin-low spin equilibrium exhibited by MbN3 [Beetlestone, J., & George, P. (1964) Biochemistry 5, 707-714]. The ESEEM results have allowed a correlation to be made between the orientation of the g tensor axes, the orientation of the p-pi orbital of the proximal imidazole nitrogen, and sigma- and pi-bonding features of the axial ligands. Furthermore, the proximal imidazole is suggested to act as a pi-acceptor in low-spin heme complexes in order to support strong sigma electron donation from the lone pair orbital to iron. An evaluation of the nitrogen nuclear hyperfine coupling parameters for the porphyrin pyrrole sites in MbRS reveals a large inequivalence in isotropic components consistent with an orientation of rhombic axes (and g tensor axes) that eclipses the Fe-Npyrrole vector directions. PMID:8395204

  12. Using Coupled Hydrologic and Agro-economic Models to Evaluate the Impact of Agricultural Activity on Streamflows

    NASA Astrophysics Data System (ADS)

    Brugger, D. R.; Maneta, M. P.

    2014-12-01

    Irrigation substantially alters the timing and magnitude of surface water flows, and continued agricultural intensification to keep up with demand means perpetual stress on surface water resources. A critical challenge is to manage irrigation in a way that balances ecosystem health with sustaining agricultural economies. Coupled hydrologic-agroeconomic models are promising tools for meeting this challenge: the models can quantify 1) how water withdrawal for irrigation impacts streamflows, 2) how these impacts propagate through a surface water system, 3) how the amount of water available for irrigation changes the allocation of resources (e.g. land, water) to available crops, and 4) the impact of water availability on agricultural economies. However, these models can be very data intensive, which limits their applicability. We present a parsimonious coupled hydrologic-agroeconomic model that uses the Positive Mathematical Programming (PMP) method, extensively used in agricultural resource economics, and calibrates to data on allotment of agricultural inputs, available from sources such as the USDA's National Agricultural Statistics Service. PMP assumes that farmers allocate resources to maximize net revenues, justifying the use of optimality conditions to constrain the parameters of the agroeconomic model. We improve the standard PMP model by 1) having the calibrated model reproduce not only the observed input allotment but also the observed yield, and 2) using the ensemble Kalman filter equations to solve the mathematical programming problem recursively, which permits refinement of the model calibration as new observations become available. We demonstrate the proposed agroeconomic model by coupling it to HEC-HMS, a hydrologic model capable of simulating regional natural and man-made water distribution networks, to investigate the sensitivity of streamflows to the allocation of agricultural inputs (land and water) in response to changes in climatic and economic

  13. Miniaturization Design Method and Performance Evaluation of Prototype Permanent-Magnet Synchronous Motor Optimally Designed by Thermomagnetic Field Coupling Analysis

    NASA Astrophysics Data System (ADS)

    Iwasaki, Norihisa; Kitamura, Hideki; Kitamura, Masashi; Nakatsugawa, Junnosuke; Enomoto, Yuji

    This paper reports the results of the miniaturization design of a permanent-magnet synchronous motor, for which an optimal design technique based on thermomagnetic field coupling analysis is used. We derived the optimal solutions for various motor flatness ratios and determined the relationship between the motor size and the flatness ratio. For motors with different flatness ratios, we calculated the speed-torque characteristics by considering the voltage, temperature rise, and demagnetization limits and compared them. Moreover, we manufactured and tested the smallest designed motor. The measured temperature rises demonstrated the high accuracy of the proposed miniaturization design.

  14. Radiation shielding evaluation of the BNCT treatment room at THOR: a TORT-coupled MCNP Monte Carlo simulation study.

    PubMed

    Chen, A Y; Liu, Y-W H; Sheu, R J

    2008-01-01

    This study investigates the radiation shielding design of the treatment room for boron neutron capture therapy at Tsing Hua Open-pool Reactor using "TORT-coupled MCNP" method. With this method, the computational efficiency is improved significantly by two to three orders of magnitude compared to the analog Monte Carlo MCNP calculation. This makes the calculation feasible using a single CPU in less than 1 day. Further optimization of the photon weight windows leads to additional 50-75% improvement in the overall computational efficiency. PMID:17825572

  15. Development of a 3D finite element model evaluating air-coupled ultrasonic measurements of nonlinear Rayleigh waves

    NASA Astrophysics Data System (ADS)

    Uhrig, Matthias P.; Kim, Jin-Yeon; Jacobs, Laurence J.

    2016-02-01

    This research presents a 3D numerical finite element (FE) model which, previously developed, precisely simulates non-contact, air-coupled measurements of nonlinear Rayleigh wave propagation. The commercial FE-solver ABAQUS is used to perform the simulations. First, frequency dependent pressure wave attenuation is investigated numerically to reconstruct the sound pressure distribution along the active surface of the non-contact receiver. Second, constitutive law and excitation source properties are optimized to match nonlinear ultrasonic experimental data. Finally, the FE-model data are fit with analytical solutions showing a good agreement and thus, indicating the significance of the study performed.

  16. An evaluation of 20th century climate for the Southeastern United States as simulated by Coupled Model Intercomparison Project Phase 5 (CMIP5) global climate models

    USGS Publications Warehouse

    David E. Rupp

    2016-01-01

    The 20th century climate for the Southeastern United States and surrounding areas as simulated by global climate models used in the Coupled Model Intercomparison Project Phase 5 (CMIP5) was evaluated. A suite of statistics that characterize various aspects of the regional climate was calculated from both model simulations and observation-based datasets. CMIP5 global climate models were ranked by their ability to reproduce the observed climate. Differences in the performance of the models between regions of the United States (the Southeastern and Northwestern United States) warrant a regional-scale assessment of CMIP5 models.

  17. An evaluation of a coupled microstructural approach for the analysis of functionally graded composites via the finite-element method

    NASA Technical Reports Server (NTRS)

    Pindera, Marek-Jerzy; Dunn, Patrick

    1995-01-01

    A comparison is presented between the predictions of the finite-element analysis and a recently developed higher-order theory for functionally graded materials subjected to a thorough-thickness temperature gradient. In contrast to existing micromechanical theories that utilize classical (i.e., uncoupled) homogenization schemes to calculate micro-level and macro-level stress and displacement fields in materials with uniform or nonuniform fiber spacing (i.e., functionally graded materials), the new theory explicitly couples the microstructural details with the macrostructure of the composite. Previous thermo-elastic analysis has demonstrated that such coupling is necessary when: the temperature gradient is large with respect to the dimension of the reinforcement; the characteristic dimension of the reinforcement is large relative to the global dimensions of the composite and the number of reinforcing fibers or inclusions is small. In these circumstances, the standard micromechanical analyses based on the concept of the representative volume element used to determine average composite properties produce questionable results. The comparison between the predictions of the finite-element method and the higher-order theory presented herein establish the theory's accuracy in predicting thermal and stress fields within composites with a finite number of fibers in the thickness direction subjected to a thorough-thickness thermal gradient.

  18. Quantitative evaluation of positive ϕ angle propensity in flexible regions of proteins from three-bond J couplings.

    PubMed

    Lee, Jung Ho; Ying, Jinfa; Bax, Ad

    2016-02-17

    (3)JHNHα and (3)JC'C' couplings can be readily measured in isotopically enriched proteins and were shown to contain precise information on the backbone torsion angles, ϕ, sampled in disordered regions of proteins. However, quantitative interpretation of these couplings required the population of conformers with positive ϕ angles to be very small. Here, we demonstrate that this restriction can be removed by measurement of (3)JC'Hα values. Even though the functional forms of the (3)JC'Hα and (3)JHNHα Karplus equations are the same, large differences in their coefficients enable accurate determination of the fraction of time that positive ϕ angles are sampled. A four-dimensional triple resonance HACANH[C'] E.COSY experiment is introduced to simultaneously measure (3)JC'Hα and (3)JHNC' in the typically very congested spectra of disordered proteins. High resolution in these spectra is obtained by non-uniform sampling (in the 0.1-0.5% range). Application to the intrinsically disordered protein α-synuclein shows that while most residues have close-to-zero positive ϕ angle populations, up to 16% positive ϕ population is observed for Asn residues. Positive ϕ angle populations determined with the new approach agree closely with consensus values from protein coil libraries and prior analysis of a large set of other NMR parameters. The combination of (3)JHNC' and (3)JC'C' provides information about the amplitude of ϕ angle dynamics. PMID:26415896

  19. Evaluation of Nodal Reactor Physics Methods for Quasi-Static and Time-Dependent Coupled Neutronic Thermal - Analysis of Pressurized Water Reactor Transients

    NASA Astrophysics Data System (ADS)

    Feltus, Madeline Anne

    1990-01-01

    This thesis examines coupled time-dependent thermal -hydraulic (T/H) and neutronics solution methods for Pressurized Water Reactor (PWR) transient analysis. The degree of equivalence is evaluated between the typical quasi-static approach and a newly-developed iterative tandem method. Four specific PWR transients that exhibit a wide range of Reactor Coolant System (RCS) T/H response were investigated: (1) a Station Blackout Anticipated Transient Without Scram (ATWS), (2) a Loss of Feedwater ATWS, (3) a Total Loss of RCS Flow with Scram, and (4) a Main Steam Line Break (MSLB). Rather than using simplified RCS and core models, the theory and method in this thesis were applied practically by using realistic models for an actual four-loop Westinghouse PWR plant. The time-dependent STAR kinetics code, based on the QUANDRY Analytic Nodal Method, and the RETRAN and MCPWR T/H systems codes were used to develop a new, fully coupled, tandem STAR/MCPWRQ methodology that runs tandemly on an enhanced 386/387 IBM PC architecture. MCPWRQ uses externally calculated power input rather than point kinetics power level results. The tandem method was compared to quasi -static STAR and time-dependent STAR 2-D and 3-D kinetics results. The new STAR/MCPWRQ method uses RETRAN time-dependent T/H and point kinetics power input as a first estimate. STAR and MCPWRQ are used tandemly to couple STAR 3-D, time-dependent core power results with the MCPWRQ RCS T/H phenomena. This thesis shows that: (a) quasi-static and point kinetics methods are not able to describe severe PWR transient phenomena adequately; and (b) fully coupled, 3-D, time -dependent, tandem (or possibly parallel) analysis methods should be used for PWR reactor transients instead. By tandemly coupling the RCS response in terms of updated core inlet conditions with 3-D time-dependent core kinetics response, the core power response and T/H conditions are forced to be self-consistent during the entire transient. The transient analyses

  20. Build an Ensemble-based Remote-Sensing Driven Coupled Flash Flood and Landslide Warning System and Its Evaluation Across the United States

    NASA Astrophysics Data System (ADS)

    Zhang, K.; Hong, Y.; Gourley, J. J.; Vergara, H. J.; Xue, X.; Lu, N.; Wooten, R.

    2014-12-01

    Flooding and flash flooding are the most costly weather-related natural hazards in the United States and world. Heavy rainfall-triggered landslides are often associated with flash flood events and cause additional loss of life and property. Therefore, it is important to understand the linkage and interaction between flash flood events and landslides. It is also pertinent to build a robust coupled flash flood and landslide disaster early warning system for disaster preparedness and hazard management. In this study, we built a coupled flash flood and landslide disaster early warning system, which is aimed for operational use by the US National Weather Service, based on an existing ensemble framework by extending the model ensemble and coupling a set of distributed hydrologic models, the Coupled Routing and Excess STorage (CREST) model and the SACramento Soil Moisture Accounting (SAC-SMA) model, with two physically based landslide prediction models, the SLope-Infiltration-Distributed Equilibrium (SLIDE) model and the Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability (TRIGRS) model. We tested this prototype warning system by conducting multi-year simulations driven by the Multi-Radar Multi-Sensor (MRMS) rainfall estimates at selected basins across the United States. We then comprehensively evaluated the predictive capabilities of this system against observed and reported flood and landslides events. Our results show that the system is generally capable of making accurate predictions of flash flood and landslide events in terms of their locations and time of occurrence. The recently developed ensemble framework also enables us to quantify the uncertainty of the predictions and the probabilities of anticipated disaster events.

  1. Toward reducing systematic errors in NWP - cross-evaluation of common physics from 6h-regional to 6d-global to 6mon-coupled applications

    NASA Astrophysics Data System (ADS)

    Benjamin, S.

    2015-12-01

    An integrated evaluation system against gridded data and observations is being applied against global models (FIM, GFS) and regional models (WRF-ARW applications for RAP/HRRR). An overview will be presented on wind, relative humidity, and temperature model errors as measured against rawinsonde and aircraft observations in common at 12h forecast duration for global and regional models. Systematic errors common to both applications will be presented. A common problem with deficient cloud cover has been evident in both 6h (3km HRRR-WRF-ARW) regional forecasts and 6-month coupled-global (FIM-HYCOM) forecasts, allowing improvements in a common deep/shallow convection scheme (Grell-Freitas) with subgrid-scale clouds to be evaluated across time scales.

  2. Gear Spline Coupling Program

    Energy Science and Technology Software Center (ESTSC)

    2013-08-29

    An analytical model is developed to evaluate the design of a spline coupling. For a given torque and shaft misalignment, the model calculates the number of teeth in contact, tooth loads, stiffnesses, stresses, and safety factors. The analytic model provides essential spline coupling design and modeling information and could be easily integrated into gearbox design and simulation tools.

  3. An application for tunes and coupling evaluation from turn-by-turn data at the Fermilab Booster

    SciTech Connect

    Marsh, W.; Alexahin, Y.; Gianfelice-Wendt, E.; /Fermilab

    2011-03-01

    A console application using the phasing of Turn-by-Turn signals from the different BPMs has been tested at the Fermilab Booster. This technique allows the on-line detection of the beam tunes during the fast Booster ramp in conditions where other algorithms were unsuccessful. The application has been recently expanded to include the computation of the linear coupling coefficients. Algorithm and measurement results are presented. Although improved by the phased sum technique the automatic identification of the tunes is not always successful. This makes the use of the on-line application difficult. Ideas for further improvements are under investigation. Measurements have indicated that the effect of the skew quadrupoles is by a factor 3 weaker than expected from the nominal optics. A calibration of the skew quadrupole circuits using the TBT data is planned.

  4. Development and evaluation of high resolution quadrupole mass analyzer and an inductively coupled plasma-Mach disk

    SciTech Connect

    Amad, Ma'an Hazem

    1999-12-10

    By definition a plasma is an electrically conducting gaseous mixture containing a significant concentration of cations and electrons. The Inductively Coupled Plasma (ICP) is an electrodeless discharge in a gas at atmospheric pressure. This discharge is an excellent one for vaporizing, atomizing, and ionizing elements. The early development of the ICP began in 1942 by Babat and then by Reed in the early 1960s. This was then followed by the pioneering work of Fassel and coworkers in the late 1960s. Commercial ICP spectrometers were introduced in the mid 1970s. A major breakthrough in the area of ICP took place in the early 1980s when the ICP was shown to be an excellent ion source for mass spectrometry.

  5. Study of laser heated propulsion devices. Part 1: Evaluation of laser devices, fuels and energy coupling mechanisms

    NASA Technical Reports Server (NTRS)

    Hofer, O. C.

    1982-01-01

    Closed cycle, CW waveform and short wavelength laser devices are desirable characteristics for laser propulsion. The choice of specific wavelengths for hydrogen fuel affects the operational conditions under which a laser supported absorption (LSA) wave is initiated and maintained. The mechanisms of initiating and maintaining LSA waves depend on the wavelength of the laser. Consequently, the shape and size of the hot core plasma is also dependent on wavelength and pressure. Detailed modeling of these mechanisms must be performed before their actual significance can be ascertained. Inverse bremsstrahlung absorption mechanism is the dominant mechanism for coupling energy into the plasma, but other mechanisms which are wavelength dependent can dictate the LSA wave plasma initiation and maintenance conditions. Multiphoton mechanisms become important at visible or shorter wavelengths. These are important mechanisms in creating the initial H2 gas breakdown and supplying the precursor electrons required to sustain the plasma.

  6. Diverse reactivity in microwave-promoted catalyst-free coupling of substituted anilines with ethyl trifluoropyruvate and biological evaluation.

    PubMed

    Zhang, Chen; Zhuang, Dao-Min; Li, Jia; Chen, Si-Yuan; Du, Xiao-Long; Wang, Jian-Yong; Li, Jing-Yun; Jiang, Biao; Yao, Jian-Hua

    2013-09-14

    Diverse reactivity by coupling of substituted anilines with ethyl trifluoropyruvate was developed under microwave irradiation without catalysts to generate 3-trifluoromethyl-3-hydroxy oxindoles, aromatic hydroxy trifluoromethyl esters, and 1,2-dicarbonyl compounds in a fast and efficient manner. The plausible mechanism for obtaining different products was proposed. Furthermore, the anti-HIV activity of aromatic hydroxy trifluoromethyl esters was first reported. The best inhibitory activity against wild-type HIV-1 IIIB was exemplified by trifluoromethyloxindole 3q with an IC50 = 5.8 μM, which also displayed potential activity against Y181C mutant virus with an IC50 = 7.5 μM. More significantly, the activities of oxindoles 3q and 3r to inhibit K103N/Y181C double mutant HIV-1 reverse transcriptase (RT) are probably similar to that of the second-generation nonnucleoside inhibitor HBY 097 by docking calculation. PMID:23863885

  7. Using the coupled wake boundary layer model to evaluate the effect of turbulence intensity on wind farm performance

    NASA Astrophysics Data System (ADS)

    Stevens, Richard J. A. M.; Gayme, Dennice; Meneveau, Charles

    2015-06-01

    We use the recently introduced coupled wake boundary layer (CWBL) model to predict the effect of turbulence intensity on the performance of a wind farm. The CWBL model combines a standard wake model with a “top-down” approach to get improved predictions for the power output compared to a stand-alone wake model. Here we compare the CWBL model results for different turbulence intensities with the Horns Rev field measurements by Hansen et al., Wind Energy 15, 183196 (2012). We show that the main trends as function of the turbulence intensity are captured very well by the model and discuss differences between the field measurements and model results based on comparisons with LES results from Wu and Porté-Agel, Renewable Energy 75, 945-955 (2015).

  8. Statistical Safety Evaluation of BWR Turbine Trip Scenario Using Coupled Neutron Kinetics and Thermal Hydraulics Analysis Code SKETCH-INS/TRACE5.0

    NASA Astrophysics Data System (ADS)

    Ichikawa, Ryoko; Masuhara, Yasuhiro; Kasahara, Fumio

    The Best Estimate Plus Uncertainty (BEPU) method has been prepared for the regulatory cross-check analysis at Japan Nuclear Energy Safety Organization (JNES) on base of the three-dimensional neutron-kinetics/thermal- hydraulics coupled code SKETCH-INS/TRACE5.0. In the preparation, TRACE5.0 is verified against the large-scale thermal-hydraulic tests carried out with NUPEC facility. These tests were focused on the pressure drop of steam-liquid two phase flow and void fraction distribution. From the comparison of the experimental data with other codes (RELAP5/MOD3.3 and TRAC-BF1), TRACE5.0 was judged better than other codes. It was confirmed that TRACE5.0 has high reliability for thermal hydraulics behavior and are used as a best-estimate code for the statistical safety evaluation. Next, the coupled code SKETCH-INS/TRACE5.0 was applied to turbine trip tests performed at the Peach Bottom-2 BWR4 Plant. The turbine trip event shows the rapid power peak due to the voids collapse with the pressure increase. The analyzed peak value of core power is better simulated than the previous version SKETCH-INS/TRAC-BF1. And the statistical safety evaluation using SKETCH-INS/TRACE5.0 was applied to the loss of load transient for examining the influence of the choice of sampling method.

  9. Coupled modeling of a directly heated tubular solar receiver for supercritical carbon dioxide Brayton cycle: Optical and thermal-fluid evaluation

    DOE PAGESBeta

    Ortega, Jesus; Khivsara, Sagar; Christian, Joshua; Ho, Clifford; Yellowhair, Julius; Dutta, Pradip

    2016-05-30

    In single phase performance and appealing thermo-physical properties supercritical carbon dioxide (s-CO2) make a good heat transfer fluid candidate for concentrating solar power (CSP) technologies. The development of a solar receiver capable of delivering s-CO2 at outlet temperatures ~973 K is required in order to merge CSP and s-CO2 Brayton cycle technologies. A coupled optical and thermal-fluid modeling effort for a tubular receiver is undertaken to evaluate the direct tubular s-CO2 receiver’s thermal performance when exposed to a concentrated solar power input of ~0.3–0.5 MW. Ray tracing, using SolTrace, is performed to determine the heat flux profiles on the receivermore » and computational fluid dynamics (CFD) determines the thermal performance of the receiver under the specified heating conditions. Moreover, an in-house MATLAB code is developed to couple SolTrace and ANSYS Fluent. CFD modeling is performed using ANSYS Fluent to predict the thermal performance of the receiver by evaluating radiation and convection heat loss mechanisms. Understanding the effects of variation in heliostat aiming strategy and flow configurations on the thermal performance of the receiver was achieved through parametric analyses. Finally, a receiver thermal efficiency ~85% was predicted and the surface temperatures were observed to be within the allowable limit for the materials under consideration.« less

  10. Small wind turbine performance evaluation using field test data and a coupled aero-electro-mechanical model

    NASA Astrophysics Data System (ADS)

    Wallace, Brian D.

    A series of field tests and theoretical analyses were performed on various wind turbine rotor designs at two Penn State residential-scale wind-electric facilities. This work involved the prediction and experimental measurement of the electrical and aerodynamic performance of three wind turbines; a 3 kW rated Whisper 175, 2.4 kW rated Skystream 3.7, and the Penn State designed Carolus wind turbine. Both the Skystream and Whisper 175 wind turbines are OEM blades which were originally installed at the facilities. The Carolus rotor is a carbon-fiber composite 2-bladed machine, designed and assembled at Penn State, with the intent of replacing the Whisper 175 rotor at the off-grid system. Rotor aerodynamic performance is modeled using WT_Perf, a National Renewable Energy Laboratory developed Blade Element Momentum theory based performance prediction code. Steady-state power curves are predicted by coupling experimentally determined electrical characteristics with the aerodynamic performance of the rotor simulated with WT_Perf. A dynamometer test stand is used to establish the electromechanical efficiencies of the wind-electric system generator. Through the coupling of WT_Perf and dynamometer test results, an aero-electro-mechanical analysis procedure is developed and provides accurate predictions of wind system performance. The analysis of three different wind turbines gives a comprehensive assessment of the capability of the field test facilities and the accuracy of aero-electro-mechanical analysis procedures. Results from this study show that the Carolus and Whisper 175 rotors are running at higher tip-speed ratios than are optimum for power production. The aero-electro-mechanical analysis predicted the high operating tip-speed ratios of the rotors and was accurate at predicting output power for the systems. It is shown that the wind turbines operate at high tip-speeds because of a miss-match between the aerodynamic drive torque and the operating torque of the wind

  11. First step toward near-infrared continuous glucose monitoring: in vivo evaluation of antibody coupled biomaterials.

    PubMed

    Gellynck, Karolien; Kodeck, Valérie; Van De Walle, Elke; Kersemans, Ken; De Vos, Filip; Declercq, Heidi; Dubruel, Peter; Vlaminck, Lieven; Cornelissen, Maria

    2015-04-01

    Continuous glucose monitoring (CGM) is crucial in diabetic care. Long-term CGM systems however require an accurate sensor as well as a suitable measuring environment. Since large intravenous sensors are not feasible, measuring inside the interstitial fluid is considered the best alternative. This option, unfortunately, has the drawback of a lag time with blood glucose values. A good strategy to circumvent this is to enhance tissue integration and enrich the peri-implant vasculature. Implants of different optically transparent biomaterials (poly(methyl-methacrylate) [PMMA] and poly(dimethylsiloxane) [PDMS]) - enabling glucose monitoring in the near-infrared (NIR) spectrum - were surface-treated and subsequently implanted in goats at various implantation sites for up to 3 months. The overall in vivo biocompatibility, tissue integration, and vascularization at close proximity of the surfaces of these materials were assessed. Histological screening showed similar tissue reactions independent of the implantation site. No significant inflammation reaction was observed. Tissue integration and vascularization correlated, to some extent, with the biomaterial composition. A modification strategy, in which a vascular endothelial-cadherin antibody was coupled to the biomaterials surface through a dopamine layer, showed significantly enhanced vascularization 3 months after subcutaneous implantation. Our results suggest that the developed strategy enables the creation of tissue interactive NIR transparent packaging materials, opening the possibility of continuous glucose monitoring. PMID:25304314

  12. Antioxidant inhibition of skin inflammation induced by reactive oxidants: evaluation of the redox couple dihydrolipoate/lipoate.

    PubMed

    Fuchs, J; Milbradt, R

    1994-01-01

    Reactive oxygen species play an important role in mediating skin inflammation, and antioxidants may provide protection. We investigated the anti-inflammatory activity of natural antioxidants, such as superoxide dismutase, catalase, trolox (a water-soluble tocopherol analog) and the redox couple dihydrolipoate/lipoate in skin. Furthermore we compared the anti-inflammatory potency of natural R and racemic dihydrolipoate, as well as R and S lipoate. Skin inflammation in hairless mice was induced by intradermal injection of the hydrogen peroxide producing enzyme glucose oxidase (GOD) or by topical application of the prooxidant drug anthralin. Intradermal injection of the antioxidants inhibited skin inflammation caused by GOD (catalase, dihydrolipoate) and anthralin (trolox, superoxide dismutase, dihydrolipoate). There was no statistically significant difference between the anti-inflammatory activity of the natural R and racemic dihydrolipoate. R or S lipoate did not inhibit skin inflammation when injected intradermally. In feeding experiments, however, R lipoate significantly inhibited GOD-mediated skin inflammation, while S lipoate was only marginally protective. We conclude that (1) several natural antioxidants such as catalase, superoxide dismutase and dihydrolipoate have anti-inflammatory properties in dermatitis induced by reactive oxidants, (2) lipoate (oxidized dihydrolipoate) has skin anti-inflammatory activity when administered orally and (3) naturally occurring R lipoate is a more potent anti-inflammatory agent than the non-physiological S lipoate. PMID:8054210

  13. Evaluation of a coupled model for numerical simulation of a multiphase flow system in a porous medium and a surface fluid.

    PubMed

    Hibi, Yoshihiko; Tomigashi, Akira

    2015-09-01

    Numerical simulations that couple flow in a surface fluid with that in a porous medium are useful for examining problems of pollution that involve interactions among atmosphere, water, and groundwater, including saltwater intrusion along coasts. Coupled numerical simulations of such problems must consider both vertical flow between the surface fluid and the porous medium and complicated boundary conditions at their interface. In this study, a numerical simulation method coupling Navier-Stokes equations for surface fluid flow and Darcy equations for flow in a porous medium was developed. Then, the basic ability of the coupled model to reproduce (1) the drawdown of a surface fluid observed in square-pillar experiments, using pillars filled with only fluid or with fluid and a porous medium and (2) the migration of saltwater (salt concentration 0.5%) in the porous medium using the pillar filled with fluid and a porous medium was evaluated. Simulations that assumed slippery walls reproduced well the results with drawdowns of 10-30 cm when the pillars were filled with packed sand, gas, and water. Moreover, in the simulation of saltwater infiltration by the method developed in this study, velocity was precisely reproduced because the experimental salt concentration in the porous medium after saltwater infiltration was similar to that obtained in the simulation. Furthermore, conditions across the boundary between the porous medium and the surface fluid were satisfied in these numerical simulations of square-pillar experiments in which vertical flow predominated. Similarly, the velocity obtained by the simulation for a system coupling flow in surface fluid with that in a porous medium when horizontal flow predominated satisfied the conditions across the boundary. Finally, it was confirmed that the present simulation method was able to simulate a practical-scale surface fluid and porous medium system. All of these numerical simulations, however, required a great deal of

  14. Cluster Randomized Controlled Trial Evaluation of a Gender Equity and Family Planning Intervention for Married Men and Couples in Rural India

    PubMed Central

    Raj, Anita; Ghule, Mohan; Ritter, Julie; Battala, Madhusudana; Gajanan, Velhal; Nair, Saritha; Dasgupta, Anindita; Silverman, Jay G.; Balaiah, Donta; Saggurti, Niranjan

    2016-01-01

    Background Despite ongoing recommendations to increase male engagement and gender-equity (GE) counseling in family planning (FP) services, few such programs have been implemented and rigorously evaluated. This study evaluates the impact of CHARM, a three-session GE+FP counseling intervention delivered by male health care providers to married men, alone (sessions 1&2) and with their wives (session 3) in India. Methods and Findings A two-armed cluster randomized controlled trial was conducted with young married couples (N = 1081 couples) recruited from 50 geographic clusters (25 clusters randomized to CHARM and a control condition, respectively) in rural Maharashtra, India. Couples were surveyed on demographics, contraceptive behaviors, and intimate partner violence (IPV) attitudes and behaviors at baseline and 9 &18-month follow-ups, with pregnancy testing at baseline and 18-month follow-up. Outcome effects on contraceptive use and incident pregnancy, and secondarily, on contraceptive communication and men’s IPV attitudes and behaviors, were assessed using logistic generalized linear mixed models. Most men recruited from CHARM communities (91.3%) received at least one CHARM intervention session; 52.5% received the couple’s session with their wife. Findings document that women from the CHARM condition, relative to controls, were more likely to report contraceptive communication at 9-month follow-up (AOR = 1.77, p = 0.04) and modern contraceptive use at 9 and 18-month follow-ups (AORs = 1.57–1.58, p = 0.05), and they were less likely to report sexual IPV at 18-month follow-up (AOR = 0.48, p = 0.01). Men in the CHARM condition were less likely than those in the control clusters to report attitudes accepting of sexual IPV at 9-month (AOR = 0.64, p = 0.03) and 18-month (AOR = 0.51, p = 0.004) follow-up, and attitudes accepting of physical IPV at 18-month follow-up (AOR = 0.64, p = 0.02). No significant effect on pregnancy was seen. Conclusions Findings demonstrate

  15. Evaluation of Mixed-mode Integral Invariant for Polymer Material Trough The Couple Experimental-Numerical Process

    NASA Astrophysics Data System (ADS)

    Meite, M.; Pop, O.; Dubois, F.; Absi, J.

    2010-06-01

    Usually the element of real structures is subject of the mixed mode loadings. This fact can be explained by the elements geometry and the loading orientations. In this case the propagation of the eventual cracks is characterised by the mixed mode kinematics. In order to characterize the fracture process in mixed mode it’s necessary to separate the fracture process in order to evaluate the influence of each mode. Our study is limited to plane configurations. The mixed mode is considered as an association of opening and shear modes. The mixed mode fracture is evaluated trough the experimental tests using the SEN specimen for different mixed mode ratios. The fracture process separation is operated by the invariant integral Mθ. Moreover, our study regroups an experimental and a numerical approaches.

  16. Coupling LC MS-MS analysis of estrogens with E-Screen bioassay in the evaluation of agricultural wastewater

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solid phase extracted agricultural wastewater samples were evaluated by E-Screen and LC-MSMS. Detection limits for natural estrogens by LC-MSMS were ~1 pg/ul on column (original sample 2 ng/ l) while the E-Screen limits were 0.3 fg/ul E2 equivalents (E2Eq) on cells (original sample [20 pg/l]). Th...

  17. Coupling climate and hydrological models to evaluate the impact of climate change on run of the river hydropower schemes from UK study sites

    NASA Astrophysics Data System (ADS)

    Pasten-Zapata, Ernesto; Jones, Julie; Moggridge, Helen

    2015-04-01

    As climate change is expected to generate variations on the Earth's precipitation and temperature, the water cycle will also experience changes. Consequently, water users will have to be prepared for possible changes in future water availability. The main objective of this research is to evaluate the impacts of climate change on river regimes and the implications to the operation and feasibility of run of the river hydropower schemes by analyzing four UK study sites. Run of the river schemes are selected for analysis due to their higher dependence to the available river flow volumes when compared to storage hydropower schemes that can rely on previously accumulated water volumes (linked to poster in session HS5.3). Global Climate Models (GCMs) represent the main tool to assess future climate change. In this research, Regional Climate Models (RCMs), which dynamically downscale GCM outputs providing higher resolutions, are used as starting point to evaluate climate change within the study catchments. RCM daily temperature and precipitation will be downscaled to an appropriate scale for impact studies and bias corrected using different statistical methods: linear scaling, local intensity scaling, power transformation, variance scaling and delta change correction. The downscaled variables will then be coupled to hydrological models that have been previously calibrated and validated against observed daily river flow data. The coupled hydrological and climate models will then be used to simulate historic river flows that are compared to daily observed values in order to evaluate the model accuracy. As this research will employ several different RCMs (from the EURO-CORDEX simulations), downscaling and bias correction methodologies, greenhouse emission scenarios and hydrological models, the uncertainty of each element will be estimated. According to their uncertainty magnitude, a prediction of the best downscaling approach (or approaches) is expected to be obtained. The

  18. Evaluation of ELISA coupled with Western blot as a surveillance tool for Trichinella infection in wild boar (Sus scrofa).

    PubMed

    Cuttell, Leigh; Gómez-Morales, Maria Angeles; Cookson, Beth; Adams, Peter J; Reid, Simon A; Vanderlinde, Paul B; Jackson, Louise A; Gray, C; Traub, Rebecca J

    2014-01-31

    Trichinella surveillance in wildlife relies on muscle digestion of large samples which are logistically difficult to store and transport in remote and tropical regions as well as labour-intensive to process. Serological methods such as enzyme-linked immunosorbent assays (ELISAs) offer rapid, cost-effective alternatives for surveillance but should be paired with additional tests because of the high false-positive rates encountered in wildlife. We investigated the utility of ELISAs coupled with Western blot (WB) in providing evidence of Trichinella exposure or infection in wild boar. Serum samples were collected from 673 wild boar from a high- and low-risk region for Trichinella introduction within mainland Australia, which is considered Trichinella-free. Sera were examined using both an 'in-house' and a commercially available indirect-ELISA that used excretory-secretory (E/S) antigens. Cut-off values for positive results were determined using sera from the low-risk population. All wild boar from the high-risk region (352) and 139/321 (43.3%) of the wild boar from the low-risk region were tested by artificial digestion. Testing by Western blot using E/S antigens, and a Trichinella-specific real-time PCR was also carried out on all ELISA-positive samples. The two ELISAs correctly classified all positive controls as well as one naturally infected wild boar from Gabba Island in the Torres Strait. In both the high- and low-risk populations, the ELISA results showed substantial agreement (k-value=0.66) that increased to very good (k-value=0.82) when WB-positive only samples were compared. The results of testing sera collected from the Australian mainland showed the Trichinella seroprevalence was 3.5% (95% C.I. 0.0-8.0) and 2.3% (95% C.I. 0.0-5.6) using the in-house and commercial ELISA coupled with WB respectively. These estimates were significantly higher (P<0.05) than the artificial digestion estimate of 0.0% (95% C.I. 0.0-1.1). Real-time PCR testing of muscle from

  19. Storm and fair-weather driven sediment-transport within Poverty Bay, New Zealand, evaluated using coupled numerical models

    NASA Astrophysics Data System (ADS)

    Bever, Aaron J.; Harris, Courtney K.

    2014-09-01

    The Waipaoa River Sedimentary System in New Zealand, a focus site of the MARGINS Source-to-Sink program, contains both a terrestrial and marine component. Poverty Bay serves as the interface between the fluvial and oceanic portions of this dispersal system. This study used a three-dimensional hydrodynamic and sediment-transport numerical model, the Regional Ocean Modeling System (ROMS), coupled to the Simulated WAves Nearshore (SWAN) wave model to investigate sediment-transport dynamics within Poverty Bay and the mechanisms by which sediment travels from the Waipaoa River to the continental shelf. Two sets of model calculations were analyzed; the first represented a winter storm season, January-September, 2006; and the second an approximately 40 year recurrence interval storm that occurred on 21-23 October 2005. Model results indicated that hydrodynamics and sediment-transport pathways within Poverty Bay differed during wet storms that included river runoff and locally generated waves, compared to dry storms driven by oceanic swell. During wet storms the model estimated significant deposition within Poverty Bay, although much of the discharged sediment was exported from the Bay during the discharge pulse. Later resuspension events generated by Southern Ocean swell reworked and modified the initial deposit, providing subsequent pulses of sediment from the Bay to the continental shelf. In this manner, transit through Poverty Bay modified the input fluvial signal, so that the sediment characteristics and timing of export to the continental shelf differed from the Waipaoa River discharge. Sensitivity studies showed that feedback mechanisms between sediment-transport, currents, and waves were important within the model calculations.

  20. Evaluation of number concentration quantification by single-particle inductively coupled plasma mass spectrometry: microsecond vs. millisecond dwell times.

    PubMed

    Abad-Álvaro, Isabel; Peña-Vázquez, Elena; Bolea, Eduardo; Bermejo-Barrera, Pilar; Castillo, Juan R; Laborda, Francisco

    2016-07-01

    The quality of the quantitative information in single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS) depends directly on the number concentration of the nanoparticles in the sample analyzed, which is proportional to the flux of nanoparticles through the plasma. Particle number concentrations must be selected in accordance with the data acquisition frequency, to control the precision from counting statistics and the bias, which is produced by the occurrence of multiple-particle events recorded as single-particle events. With quadrupole mass spectrometers, the frequency of data acquisition is directly controlled by the dwell time. The effect of dwell times from milli- to microseconds (10 ms, 5 ms, 100 μs, and 50 μs) on the quality of the quantitative data has been studied. Working with dwell times in the millisecond range, precision figures about 5 % were achieved, whereas using microsecond dwell times, the suitable fluxes of nanoparticles are higher and precision was reduced down to 1 %; this was independent of the dwell time selected. Moreover, due to the lower occurrence of multiple-nanoparticle events, linear ranges are wider when dwell times equal to or shorter than 100 μs are used. A calculation tool is provided to determine the optimal concentration for any instrument or experimental conditions selected. On the other hand, the use of dwell times in the microsecond range reduces significantly the contribution of the background and/or the presence of dissolved species, in comparison with the use of millisecond dwell times. Although the use of dwell times equal to or shorter than 100 μs offers improved performance working in single-particle mode, the use of conventional dwell times (3-10 ms) should not be discarded, once their limitations are known. PMID:27086011

  1. Evaluation of Coupled Perturbed and Density Functional Methods of Computing the Parity-Violating Energy Difference between Enantiomers

    NASA Astrophysics Data System (ADS)

    MacDermott, A. J.; Hyde, G. O.; Cohen, A. J.

    2009-03-01

    We present new coupled-perturbed Hartree-Fock (CPHF) and density functional theory (DFT) computations of the parity-violating energy difference (PVED) between enantiomers for H2O2 and H2S2. Our DFT PVED computations are the first for H2S2 and the first with the new HCTH and OLYP functionals. Like other “second generation” PVED computations, our results are an order of magnitude larger than the original “first generation” uncoupled-perturbed Hartree-Fock computations of Mason and Tranter. We offer an explanation for the dramatically larger size in terms of cancellation of contributions of opposing signs, which also explains the basis set sensitivity of the PVED, and its conformational hypersensitivity (addressed in the following paper). This paper also serves as a review of the different types of “second generation” PVED computations: we set our work in context, comparing our results with those of four other groups, and noting the good agreement between results obtained by very different methods. DFT PVEDs tend to be somewhat inflated compared to the CPHF values, but this is not a problem when only sign and order of magnitude are required. Our results with the new OLYP functional are less inflated than those with other functionals, and OLYP is also more efficient computationally. We therefore conclude that DFT computation offers a promising approach for low-cost extension to larger biosystems, especially polymers. The following two papers extend to terrestrial and extra-terrestrial amino acids respectively, and later work will extend to polymers.

  2. Evaluation of the metal uptake of several algae strains in a multicomponent matrix utilizing inductively coupled plasma emission spectrometry

    SciTech Connect

    Mahan, C.A.; Majidi, V.; Holcombe, J.A.

    1989-03-15

    Three freshwater heat-killed, lyophilized blue-green algae strains have been characterized as to their ability to accumulate heavy metals with a focus on the utilization of these algae as an analytical preconcentration technique. This study examines the metal uptake in several multicomponent mixtures by using inductively coupled plasma optical emission spectrometry (ICP-OES). Six milligrams of a pure strain of algae was added to 20-mL aliquots of buffered (pH 5.5-6.5) multielement solutions containing 0.1, 0.5, 1.0, 2.0, and 4.0 mg/L of K, Mg, Ca, Fe, Sr, Co, Cu, Mn, Ni, V, Zn, As, Cd, Mo, Pb, and Se. All three algae strains exhibit relatively high adsorption affinities for Fe, Pb, and Cu, with uptake between 70 and 98% at the 4 ppm concentration level. Biosorption occurs for essentially every element with the relative affinities decreasing in the order Pb greater than Fe greater than Cu greater than Cd greater than Zn greater than Mn greater than Mo greater than Sr greater than Ni greater than V greater than Se greater than As greater than Co for Chlorella pyrenoidosa at the 4 mg/L concentration level. Although some minor differences were seen, the other algae strains (Stichococcus bacillaris and Chlamydomonas reinharti) displayed similar adsorption behavior over the concentration range studied, indicating similar cell wall binding sites. Langmuirian isotherms exhibited a minimum of two slopes over the concentration range of 0.1-4.0 mg/L, indicating the probable existence of at least two adsorption mechanisms.

  3. Climate-related Indicators and Data Provenance: Evaluating Coupled Boundary Objects for Science, Innovation, and Decision-Making

    NASA Astrophysics Data System (ADS)

    Wiggins, A.; Young, A.; Brody, C.; Gerst, M.; Kenney, M. A.; Lamoureux, A.; Rice, A.; Wolfinger, F.

    2015-12-01

    Boundary object theory focuses on the role of artifacts, such as indicator images, in translation and communication across the boundaries of social groups. We use this framework for understanding how data can communicate across contexts to answer the question: Can coupling climate-related indicators with data provenance support scientific innovation and science translation? To address this question we conducted a study to understand the features and capabilities necessary for indicators and data provenance for scientific uses, using the recently online-released U.S. Global Change Research Program (USGCRP) Indicators and Global Change Information System (GCIS) as linked boundary objects. We conducted semi-structured interviews with professional researchers in which we asked the researchers to explore and describe what they observed that was useful or frustrating for a subset of the USGCRP Indicators, related GCIS content, and other similar indicator and metadata websites. Participants found these sites' navigation and the labeling and description of their assets frustrating and confusing, but were able to clearly articulate the metadata and provenance information they needed to both understand and trust the indicators. In addition to identifying desired features that are likely to be specific to this audience (e.g., references or citations for indicators), scientists wanted clear, easier-to-access provenance information of the type usually recommended for documenting research data. Notably, they felt the information would be best presented in a fashion accessible to a broader audience, as those with more technical expertise should be able to infer additional contextual details given the provenance information that they had identified as key. Such results are useful for the improvement of indicator systems, such as the prototype released by USGCRP. We note in particular that the consistency of responses across the multi-disciplinary sample, which included scholars in

  4. Evaluate the urban effect on summer convective precipitation by coupling a urban canopy model with a Regional Climate Model

    NASA Astrophysics Data System (ADS)

    Liu, Z.; Liu, S.; Xue, Y.; Oleson, K. W.

    2013-12-01

    One of the most significant urbanization in the world occurred in Great Beijing Area of China during the past several decades. The land use and land cover changes modifies the land surface physical characteristics, including the anthropogenic heat and thermo-dynamic conduction. All of those play important roles in the urban regional climate changes. We developed a single layer urban canopy module based on the Community Land Surface Model Urban Module (CLMU). We have made further improvements in the urban module: the energy balances on the five surface conditions are considered separately: building roof, sun side and shade side wall, pervious and impervious land surface. Over each surface, a method to calculate sky view factor (SVF) is developed based on the physically process while most urban models simply provide an empirical value; A new scheme for calculating the latent heat flux is applied on both wall and impervious land; anthropogenic heat is considered in terms of industrial production, domestic wastes, vehicle and air condition. All of these developments improve the accuracy of surface energy balance processing in urban area. The urban effect on summer convective precipitation under the unstable atmospheric condition in the Great Beijing Area was investigated by simulating a heavy rainfall event in July 21st 2012. In this storm, strong meso-scale convective complexes (MCC) brought precipitation of averagely 164 mm within 6 hours, which is the record of past 60 years in the region. Numerical simulating experiment was set up by coupling MCLMU with WRF. Several condition/blank control cases were also set up. The horizontal resolution in all simulations was 2 km. While all of the control results drastically underestimate the urban precipitation, the result of WRF-MCLMU is much closer to the observation though still underestimated. More sensitive experiments gave a preliminary conclusion of how the urban canopy physics processing affects the local precipitation

  5. Evaluation of a direct injection nebulizer interface for flow injection analysis and high performance liquid chromatography with inductively coupled plasma-atomic emission spectroscopic detection

    SciTech Connect

    LaFreniere, K.E.

    1986-06-01

    A direct injection nebulizer (DIN) was designed, developed, and evaluated to determine its potential utilization as an effective interface for flow injection analysis (FIA) and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma-atomic emission spectroscopic detection. The analytical figures of merit for the DIN when used as an interface for FIA-ICP-AES were found to be comparable to or better than those obtained with conventional pneumatic nebulization in terms of limits of detection (LODs), reproducibility, linearity, and interelement effects. Stable plasma operation was maintained for the DIN sample introduction of a variety of pure organic solvents, including acetonitrile, methanol, methylisobutylketone, and pyridine. The HPLC-DIN-ICP-AES facility was specifically applied for the speciation of inorganic and organometallic species contained in synthetic mixtures, vanilla extracts, and a variety of energy-related materials, such as shale oil process water, coal extracts, shale oil, crude oil, and an SRC II. Suggestions for future research are also considered. 227 refs., 44 figs., 15 tabs.

  6. Evaluation of a direct injection nebulizer interface for flow injection analysis and high performance liquid chromatography with inductively coupled plasma-atomic emission spectroscopic detection

    SciTech Connect

    LaFreniere, K.E.

    1986-01-01

    A direct injection nebulizer (DIN) was designed, developed and evaluated to determine its potential utilization as an effective interface for flow injection analysis (FIA) and high performance liquid chromatography (HPLC) coupled with inductively coupled plasma-atomic emission spectroscopic detection. The analytical figures of merit for the DIN when used as an interface for FIA-ICP-AES were found to be comparable to or better than those obtained with conventional pneumatic nebulization in terms of limits of detection (LODs), reproducibility, linearity, and interelement effects. In the HPLC mode, the LODDs were found to be comparable to those obtained by continuous-flow sample introduction into the ICP, or inferior by up to only a factor of four. Stable plasma operation was maintained for the DIN sample introduction of a variety of pure organic solvents, including acetonitrile, methanol, methyl-isobutylketone, and pyridine. The HPLC-DIN-ICP-AES facility was specifically applied for the speciation of inorganic and organo-metallic species contained in synthetic mixtures, vanilla extracts and a variety of energy-related materials, such as shale oil process water, coal extracts, shale oil, crude oil, and an SRC II. Suggestions for future research are also considered.

  7. Analytic first derivatives for a spin-adapted open-shell coupled cluster theory: Evaluation of first-order electrical properties

    SciTech Connect

    Datta, Dipayan Gauss, Jürgen

    2014-09-14

    An analytic scheme is presented for the evaluation of first derivatives of the energy for a unitary group based spin-adapted coupled cluster (CC) theory, namely, the combinatoric open-shell CC (COSCC) approach within the singles and doubles approximation. The widely used Lagrange multiplier approach is employed for the derivation of an analytical expression for the first derivative of the energy, which in combination with the well-established density-matrix formulation, is used for the computation of first-order electrical properties. Derivations of the spin-adapted lambda equations for determining the Lagrange multipliers and the expressions for the spin-free effective density matrices for the COSCC approach are presented. Orbital-relaxation effects due to the electric-field perturbation are treated via the Z-vector technique. We present calculations of the dipole moments for a number of doublet radicals in their ground states using restricted open-shell Hartree-Fock (ROHF) and quasi-restricted HF (QRHF) orbitals in order to demonstrate the applicability of our analytic scheme for computing energy derivatives. We also report calculations of the chlorine electric-field gradients and nuclear quadrupole-coupling constants for the CCl, CH{sub 2}Cl, ClO{sub 2}, and SiCl radicals.

  8. Development and evaluation of HIS-RIS-modality-PACS coupling: remote operation of PACS display terminal from HIS terminal in outpatient clinics

    NASA Astrophysics Data System (ADS)

    Kondoh, Hiroshi; Takeshi, Washiashi; Sasagaki, Michihiro; Nakamura, Hironobu; Inamura, Kiyonari; Matsumura, Yasushi; Takeda, Hiroshi

    1998-07-01

    Purpose: To evaluate the clinical acceptability of personal computer (PC)-based PACS in daily practice of HIS-RIS- Modality-PACS coupling. Materials And Methods: We are developing a hospital-wide PC-based PACS which uses HIS/RIS network. PACS servers are connecting to HIS-RIS network and store images on hard disks and magneto-optical disk (MOD) juke-boxes from 8 FCRs and 3 CT scanners. We developed the remote control software of PACS terminal from HIS terminal for physicians' easy operation in the out-patent clinics. We investigated the network workloads and display time in the daily work. Clinicians' opinion was recorded on a 5-point scale for image quality, response, and function. Result: The network workload is under the limitation and display time is within twenty-six seconds. The quality was acceptable in 54%. The response was acceptable in 25%. The function of PACS was acceptable in 40%. Conclusion: PC-based HIS/RIS/PACS coupling has possibility of acceptance.

  9. Evaluation of the magnetic coupling degree and performance of an axial-axial flux compound-structure permanent-magnet synchronous machine used for hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Zheng, Ping; Zhao, Jing; Wu, Qian; Fan, Weiguang; Shen, Lin; Li, Lina; Liu, Ranran

    2008-04-01

    A novel axial-axial flux compound-structure permanent-magnet synchronous machine (CS-PMSM), which is a hybrid electric vehicle (HEV) power train concept, is integrated by two axial flux disk machines. As the two machines share a common rotor [a magnet rotor with permanent magnets (PMs) on both sides], there may be magnetic coupling between them. Three-dimensional (3D) finite-element method (FEM) calculation shows that the two machines have little magnetic coupling if they have the same pole number and consistent magnetization direction of the two layers of PMs on the common rotor. The performance of the CS-PMSM is evaluated on criteria such as power, power per unit volume and mass, torque, and torque ripple. The power and torque equations of this type of machine are deduced and verified with 3D FEM. After the optimization of diameter ratio and pole number, the power and power per unit active volume and mass are high. The torque ripple is much reduced due to the optimization of the pole arc embrace and magnet skewing angle.

  10. Coupling spectroscopic and chromatographic techniques for evaluation of the depositional history of hydrocarbons in a subtropical estuary.

    PubMed

    Martins, César C; Doumer, Marta E; Gallice, Wellington C; Dauner, Ana Lúcia L; Cabral, Ana Caroline; Cardoso, Fernanda D; Dolci, Natiely N; Camargo, Luana M; Ferreira, Paulo A L; Figueira, Rubens C L; Mangrich, Antonio S

    2015-10-01

    Spectroscopic and chromatographic techniques can be used together to evaluate hydrocarbon inputs to coastal environments such as the Paranaguá estuarine system (PES), located in the SW Atlantic, Brazil. Historical inputs of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed using two sediment cores from the PES. The AHs were related to the presence of biogenic organic matter and degraded oil residues. The PAHs were associated with mixed sources. The highest hydrocarbon concentrations were related to oil spills, while relatively low levels could be attributed to the decrease in oil usage during the global oil crisis. The results of electron paramagnetic resonance were in agreement with the absolute AHs and PAHs concentrations measured by chromatographic techniques, while near-infrared spectroscopy results were consistent with unresolved complex mixture (UCM)/total n-alkanes ratios. These findings suggest that the use of a combination of techniques can increase the accuracy of assessment of contamination in sediments. PMID:26210796

  11. Evaluation of material parameters using contra-directional single incident beam two-beam coupling in Fe:LiNbO3

    NASA Astrophysics Data System (ADS)

    Saleh, M. A.; Evans, D. R.; Allen, A. S.; Bunning, T. J.; Guha, S.

    2002-03-01

    By fitting the experimental results to a theoretical analysis of two-beam coupling including diffraction effects [1], the photorefractive gain as well the dark current irradiance has been evaluated. Crystals with a transparent conductive coating were used to reduce grating writing instabilities; instabilities as well as multiple reflection effects were also eliminated by AR (anti-reflection) coating the crystal surfaces [2]. [1] G. Cook, D. C. Jones, C. J. Finnan, L. L. Taylor, T. W. Vere, and J. P. Duignan, Materials Research Society Symposium Proceedings 597 (2000) 263-274. [2] D. R. Evans, S. A. Basun, M. A. Saleh, T. P. Pottenger, G. Cook, T. J. Bunning, and S. Guha, "Elimination of Photorefractive Grating Writing Instabilities in Iron-doped Lithium Niobate," Submitted to IEEE J. Quantum Electronics. Dec. 2001.

  12. Development and evaluation of materials for thermochemical heat storage based on the CaO/CaCO3 reaction couple

    NASA Astrophysics Data System (ADS)

    Sakellariou, Kyriaki G.; Tsongidis, Nikolaos I.; Karagiannakis, George; Konstandopoulos, Athanasios G.; Baciu, Diana; Charalambopoulou, Georgia; Steriotis, Theodore; Stubos, Athanasios; Arlt, Wolfgang

    2016-05-01

    The current work relates to the development of synthetic calcium oxide (CaO) based compositions as candidate materials for energy storage under a cyclic carbonation/decarbonation reaction scheme. Although under such a cyclic scheme the energy density of natural lime based CaO is high (˜ 3MJ/kg), the particular materials suffer from notable cycle-to-cycle deactivation. To this direction, pure CaO and CaO/Al2O3 composites have been prepared and preliminarily evaluated under the suggested cyclic carbonation/decarbonation scheme in the temperature range of 600-800°C. For the composite materials, Ca/Al molar ratios were in the range between 95/5 and 52/48 and upon calcination the formation of mixed Ca/Al phases was verified. The preliminary evaluation of materials studied was conducted under 3 carbonation/decarbonation cycles and the loss of activity for the case of natural CaO was obvious. Synthetic materials with superior stability/capture c.f. natural CaO were further subjected to multi-cyclic carbonation/decarbonation, via which the positive effect of alumina addition was made evident. Selected compositions exhibited adequately high CO2 capture capacity and stable performance during multi-cyclic operation. Moreover, this study contains preliminary experiments referring to proof-of-principle validation of a concept based on the utilization of a CaO-based honeycomb reactor/heat exchanger preliminary design. In particular, cordierite monolithic structures were coated with natural CaO and in total 11 cycles were conducted. Upon operation, clear signs of heat dissipation by the imposed flow in the duration of the exothermic reaction step were identified.

  13. Evaluation of the Event Driven Phenology Model Coupled with the VegET Evapotranspiration Model Through Comparisons with Reference Datasets in a Spatially Explicit Manner

    NASA Technical Reports Server (NTRS)

    Kovalskyy, V.; Henebry, G. M.; Adusei, B.; Hansen, M.; Roy, D. P.; Senay, G.; Mocko, D. M.

    2011-01-01

    A new model coupling scheme with remote sensing data assimilation was developed for estimation of daily actual evapotranspiration (ET). The scheme represents a mix of the VegET, a physically based model to estimate ET from a water balance, and an event driven phenology model (EDPM), where the EDPM is an empirically derived crop specific model capable of producing seasonal trajectories of canopy attributes. In this experiment, the scheme was deployed in a spatially explicit manner within the croplands of the Northern Great Plains. The evaluation was carried out using 2007-2009 land surface forcing data from the North American Land Data Assimilation System (NLDAS) and crop maps derived from remotely sensed data of NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). We compared the canopy parameters produced by the phenology model with normalized difference vegetation index (NDVI) data derived from the MODIS nadir bi-directional reflectance distribution function (BRDF) adjusted reflectance (NBAR) product. The expectations of the EDPM performance in prognostic mode were met, producing determination coefficient (r2) of 0.8 +/-.0.15. Model estimates of NDVI yielded root mean square error (RMSE) of 0.1 +/-.0.035 for the entire study area. Retrospective correction of canopy dynamics with MODIS NDVI brought the errors down to just below 10% of observed data range. The ET estimates produced by the coupled scheme were compared with ones from the MODIS land product suite. The expected r2=0.7 +/-.15 and RMSE = 11.2 +/-.4 mm per 8 days were met and even exceeded by the coupling scheme0 functioning in both prognostic and retrospective modes. Minor setbacks of the EDPM and VegET performance (r2 about 0.5 and additional 30 % of RMSR) were found on the peripheries of the study area and attributed to the insufficient EDPM training and to spatially varying accuracy of crop maps. Overall the experiment provided sufficient evidence of soundness and robustness of the EDPM and

  14. Coupling data from U-series and 10Be CRN to evaluate soil steady-state in the Betic Cordillera

    NASA Astrophysics Data System (ADS)

    Schoonejans, Jerome; Vanacker, Veerle; Opfergelt, Sophie; Granet, Mathieu; Chabaux, François

    2015-04-01

    from first simulations of the U-series disequilibrium model rather suggest that soil production rates are of the same order of magnitude in the Sierra Estancias and Cabrera. In the Sierra Filabres, the U-series disequilibrium in the depth profile do not respect the hypotheses of the model therefore no rates of soil production could be constrain for this profile. Thanks to the coupling of the two isotopic datasets the long term soil development will be explored in two profiles. This study highlights that comparison and combination of analytical techniques is useful to further unravel the mechanisms of chemical and physical weathering in such dynamic environments. Bellin, N., Vanacker, V., and Kubik, P. W., 2014, Denudation rates and tectonic geomorphology of the Spanish Betic Cordillera: Earth and Planetary Science Letters, v. 390, p. 19-30.

  15. Evaluation of mycotoxins and their metabolites in human breast milk using liquid chromatography coupled to high resolution mass spectrometry.

    PubMed

    Rubert, Josep; León, Nuria; Sáez, Carmen; Martins, Claudia P B; Godula, Michal; Yusà, Vicent; Mañes, Jordi; Soriano, José Miguel; Soler, Carla

    2014-04-11

    Humans can be exposed to mycotoxins through the food chain. Mycotoxins are mainly found as contaminants in food and could be subsequently excreted via biological fluids such as urine or human breast milk in native or metabolised form. Since breast milk is usually supposed as the only food for new-borns, the occurrence of mycotoxins in thirty-five human milk samples was evaluated by a newly developed method based on QuEChERS extraction and UHPLC-HRMS detection. The method described here allows the detection of target mycotoxins in order to determine the quality of this initial feeding. The method has been fully validated, with recoveries ranging from 64% to 93% and relative standard deviations (RSD, %) being lower than 20%. Using the method described, non-metabolised mycotoxins such as ZEA, NEO, NIV, ENA, ENA1, ENB, ENB1 and metabolites, such as ZEA metabolites, HT-2, DOM and T-2 triol were detected in human milk samples. Results obtained help to estimate the exposure of mothers and infants to mycotoxins. Moreover, to the best of our knowledge, this is the first work describing the simultaneous detection, quantification and screening of mycotoxins and their metabolites in human mature milk. PMID:24745736

  16. Bioequivalence evaluation of two roxithromycin formulations in healthy human volunteers by high performance liquid cromatography coupled to tandem mass spectrometry.

    PubMed

    Motta, M; Ribeiro, W; Ifa, D R; Moares, M E; Moraes, M O; Corrado, A P; De Nucci, G

    1999-01-01

    The bioequivalence of two different formulations containing roxithromycin (SPE-712-1). Oral suspension 300 mg/15 mL as test formulation and Rotram, tablets 300 mg as reference formulation, both by Schering Plough S.A., Brazil) was evaluated in 24 healthy volunteers of both sexes (12 male and 12 female). The study was conducted open with randomized two-period crossover design and a 14-day washout period. Each subject received 300 mg of each roxithromycin formulation. Plasma samples were obtained over a 72-hour interval and roxithromycin concentrations were analyzed by combined LC-MS/MS with positive ion electrospray ionization using selected ion monitoring method. From the plasma roxithromycin concentration vs time curves the following pharmacokinetic parameters were obtained: AUC(0-72 h), AUC(0-infinity), Cmax, t1/2 ratios and tmax individual differences. The 90% for confidence interval (CI) of geometric mean SPE-712-L/Rotram individual percent ratio were 105.0-128.3% for AUC(0-72 h), and 78.4-96.9 for Cmax. Although this 90% CI were marginally outside the interval proposed by the Food and Drug Administration, the probability assessed by the two-one sided West for ratios was included in the 0.8-1.25 interval, as we concluded that SPE-712-L oral suspension formulation was bioequivalent to Rotram tablet formulation for the extent and rate of absorption. PMID:10797866

  17. Quality evaluation of Semen Cassiae (Cassia obtusifolia L.) by using ultra-high performance liquid chromatography coupled with mass spectrometry.

    PubMed

    Zhang, Wei-Dong; Wang, Ying; Wang, Qing; Yang, Wan-Jun; Gu, Yi; Wang, Rong; Song, Xiao-Mei; Wang, Xiao-Juan

    2012-08-01

    A sensitive and reliable ultra-high performance liquid chromatography-electrospray ionization-tandem mass spectrometry has been developed and partially validated to evaluate the quality of Semen Cassiae (Cassia obtusifolia L.) through simultaneous determination of 11 anthraquinones and two naphtha-γ-pyrone compounds. The analysis was achieved on a Poroshell 120 EC-C(18) column (100 mm × 2.1 mm, 2.7 μm; Agilent, Palo Alto, CA, USA) with gradient elution using a mobile phase that consisted of acetonitrile-water (30 mM ammonium acetate) at a flow rate of 0.4 mL/min. For quantitative analysis, all calibration curves showed perfect linear regression (r(2) > 0.99) within the testing range. This method was also validated with respect to precision and accuracy, and was successfully applied to quantify the 13 components in nine batches of Semen Cassiae samples from different areas. The performance of developed method was compared with that of conventional high-performance liquid chromatography method. The significant advantages of the former include high-speed chromatographic separation, four times faster than high-performance liquid chromatography with conventional columns, and great enhancement in sensitivity. This developed method provided a new basis for overall assessment on quality of Semen Cassiae. PMID:22753381

  18. Evaluation of microwave and ultrasound extraction procedures for arsenic speciation in bivalve mollusks by liquid chromatography-inductively coupled plasma-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Santos, Clarissa M. M.; Nunes, Matheus A. G.; Barbosa, Isa S.; Santos, Gabriel L.; Peso-Aguiar, Marlene C.; Korn, Maria G. A.; Flores, Erico M. M.; Dressler, Valderi L.

    2013-08-01

    Liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) was used for arsenic speciation analysis in tissues of bivalve mollusks (Anomalocardia brasiliana sp. and Macoma constricta sp.). Microwave and ultrasound radiation, combined with different extraction conditions (solvent, sample amount, time, and temperature), were evaluated for As-species extraction from the mollusks' tissues. Accuracy, extraction efficiency, and the stability of As species were evaluated by analyzing certified reference materials (DORM-2, dogfish muscle; BCR-627, tuna fish tissue; and SRM 1566b, oyster tissue) and analyte recovery tests. The best conditions were found to be microwave-assisted extraction using 200 mg of samples and water at 80 °C for 6 min. The agreement of As-species concentration in samples ranged from 97% to 102%. Arsenobetaine (AsB) was the main species present in bivalve mollusk tissues, while monomethylarsonic acid (MMA) and arsenate (As(V)) were below the limit of quantification (0.001 and 0.003 μg g- 1, respectively). Two unidentified As species also were detected and quantified. The sum of the As-species concentration was in agreement (90 to 104%), with the total As content determined by ICP-MS after sample digestion.

  19. Evaluation of intergranular exchange coupling and magnetic domain size in CoCrPt-SiOX thin films with perpendicular anisotropy

    NASA Astrophysics Data System (ADS)

    Papusoi, C.; Desai, M.; Acharya, R.

    2015-06-01

    A method to evaluate the intergranular exchange coupling constant JEX in thin films with perpendicular anisotropy, based on first order reversal curve (FORC) diagrams, is proposed. For a 7.5 nm thick CoCrPt-SiOx magnetic (MAG) layer, JEX can be decreased from 1.1 to 0.26 erg cm-2 by using an adjacent CoCr-TiOx layer (isolation enhancement layer or IEL), enabling its application for high-density magnetic recording. The minimum value of JEX is attained for an IEL thickness of ~1.5 nm, which is low enough to preserve the HCP crystallographic structure of the MAG layer, with the c-axis perpendicular to film plane. The extracted values of JEX are used to evaluate the magnetic domain size of MAG layer using the checkerboard and the stripe domain models. Magnetic force microscopy observations indicate that domain size approaches the value predicted by the checkerboard model when JEX ≈ 0.8 erg cm-2, while for JEX > 0.8 erg cm-2 the actual domain size lies between the values indicated by the two models.

  20. Helix coupling

    DOEpatents

    Ginell, W.S.

    1982-03-17

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the U sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  1. Helix coupling

    DOEpatents

    Ginell, William S.

    1989-04-25

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the "U" sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  2. Authentication of Kalix (N.E. Sweden) vendace caviar using inductively coupled plasma-based analytical techniques: evaluation of different approaches.

    PubMed

    Rodushkin, I; Bergman, T; Douglas, G; Engström, E; Sörlin, D; Baxter, D C

    2007-02-01

    Different analytical approaches for origin differentiation between vendace and whitefish caviars from brackish- and freshwaters were tested using inductively coupled plasma double focusing sector field mass spectrometry (ICP-SFMS) and multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). These approaches involve identifying differences in elemental concentrations or sample-specific isotopic composition (Sr and Os) variations. Concentrations of 72 elements were determined by ICP-SFMS following microwave-assisted digestion in vendace and whitefish caviar samples from Sweden (from both brackish and freshwater), Finland and USA, as well as in unprocessed vendace roe and salt used in caviar production. This data set allows identification of elements whose contents in caviar can be affected by salt addition as well as by contamination during production and packaging. Long-term method reproducibility was assessed for all analytes based on replicate caviar preparations/analyses and variations in element concentrations in caviar from different harvests were evaluated. The greatest utility for differentiation was demonstrated for elements with varying concentrations between brackish and freshwaters (e.g. As, Br, Sr). Elemental ratios, specifically Sr/Ca, Sr/Mg and Sr/Ba, are especially useful for authentication of vendace caviar processed from brackish water roe, due to the significant differences between caviar from different sources, limited between-harvest variations and relatively high concentrations in samples, allowing precise determination by modern analytical instrumentation. Variations in the 87Sr/86Sr ratio for vendace caviar from different harvests (on the order of 0.05-0.1%) is at least 10-fold less than differences between caviar processed from brackish and freshwater roe. Hence, Sr isotope ratio measurements (either by ICP-SFMS or by MC-ICP-MS) have great potential for origin differentiation. On the contrary, it was impossible to

  3. Exploring Potential Chemical Transformation by Chemical Profiling Approach for Rapidly Evaluating Chemical Consistency between Sun-Dried and Sulfur-Fumigated Radix Paeoniae Alba Using Ultraperformance Liquid Chromatography Coupled with Time-of-Flight Mass Spectrometry

    PubMed Central

    Zhang, Jida; Cai, Hao; Cao, Gang; Liu, Xiao; Wen, Chengping; Fan, Yongsheng

    2013-01-01

    Ultraperformance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-QTOF/MS) based on a chemical profiling method was applied to rapidly evaluate the chemical consistency between sun-dried and sulfur-fumigated Radix Paeoniae Alba. By virtue of the high resolution, high speed of UPLC, and the accurate mass measurement of TOFMS coupled with reliable MarkerLynx software, five newly assigned monoterpene glycoside sulfonates were found and identified in sulfur-fumigated Radix Paeoniae Alba samples. This method could be applied for rapid quality evaluation of different kinds of sulfur-fumigated Radix Paeoniae Alba among commercial samples. PMID:24381637

  4. An evaluation of uncertainty in the aerosol optical properties as represented by satellites and an ensemble of chemistry-climate coupled models over Europe

    NASA Astrophysics Data System (ADS)

    Palacios-Peña, Laura; Baró, Rocío; Jiménez-Guerrero, Pedro

    2016-04-01

    The changes in Earth's climate are produced by forcing agents such as greenhouse gases, clouds and atmospheric aerosols. The latter modify the Earth's radiative budget due to their optical, microphysical and chemical properties, and are considered to be the most uncertain forcing agent. There are two main approaches to the study of aerosols: (1) ground-based and remote sensing observations and (2) atmospheric modelling. With the aim of characterizing the uncertainties associated with these approaches, and estimating the radiative forcing caused by aerosols, the main objective of this work is to assess the representation of aerosol optical properties by different remote sensing sensors and online-coupled chemistry-climate models and to determine whether the inclusion of aerosol radiative feedbacks in this type of models improves the modelling outputs over Europe. Two case studies have been selected under the framework of the EuMetChem COST Action ES1004, when important aerosol episodes during 2010 over Europe took place: a Russian wildfires episode and a Saharan desert dust outbreak covering most of Europe. Model data comes from an ensemble of regional air quality-climate simulations performed by the working group 2 of EuMetChem, that investigates the importance of different processes and feedbacks in on-line coupled chemistry-climate models. These simulations are run for three different configurations for each model, differing in the inclusion (or not) of aerosol-radiation and aerosol-cloud interactions. The remote sensing data comes from three different sensors, MODIS (Moderate Resolution Imaging Spectroradiometer), OMI (Ozone Monitoring Instrument) and SeaWIFS (Sea-viewing Wide Field-of-view Sensor). The evaluation has been performed by using classical statistical metrics, comparing modelled and remotely sensed data versus a ground-based instrument network (AERONET). The evaluated variables are aerosol optical depth (AOD) and the Angström exponent (AE) at

  5. Optical coupling

    NASA Astrophysics Data System (ADS)

    Bock, J. J.; Gundersen, J.; Lee, A. T.; Richards, P. L.; Wollack, E.

    2009-03-01

    This paper describes contributions to the CMBpol Technology Study Workshop concerning optical coupling structures. These are structures in or near the focal plane which convert the free space wave to a superconducting microstrip on a SI wafer, or to the waveguide input to a HEMT receiver. In addition to an introduction and conclusions by the editor, this paper includes independent contributions by Bock on 'Planar Antenna-Coupled Bolometers for CMB Polarimetry', by Gunderson and Wollack on 'Millimeter-Wave Platlet Feeds', and by Lee on 'Multi-band Dual-Polarization Lens-coupled Planar Antennas for Bolometric CMB polarimetry.'

  6. Microwave-assisted cross-coupling and hydrogenation chemistry by using heterogeneous transition-metal catalysts: an evaluation of the role of selective catalyst heating.

    PubMed

    Irfan, Muhammed; Fuchs, Michael; Glasnov, Toma N; Kappe, C Oliver

    2009-11-01

    The concept of specific microwave effects in solid/liquid catalytic processes resulting from the selective heating of a microwave-absorbing heterogeneous transition-metal catalyst by using 2.45 GHz microwave irradiation was evaluated. As model transformations Ni/C-, Cu/C-, Pd/C-, and Pd/Al2O3-catalyzed carbon-carbon/carbon-heteroatom cross-couplings and hydrogenation reactions were investigated. To probe the existence of specific microwave effects by means of selective catalyst heating in these transformations, control experiments comparing microwave dielectric heating and conventional thermal heating at the same reaction temperature were performed. Although the supported metal catalysts were experimentally found to be strongly microwave absorbing, for all chemistry examples investigated herein no differences in reaction rate or selectivity between microwave and conventional heating experiments under carefully controlled conditions were observed. This was true also for reactions that use low-absorbing or microwave transparent solvents, and was independent of the microwave absorbtivity of the catalyst support material. In the case of hydrogenation reactions, the stirring speed was found to be a critical factor on the mass transfer between gas and liquid phase, influencing the rate of the hydrogenation in both microwave and conventionally heated experiments. PMID:19774573

  7. Nonadiabatic couplings from the Kohn-Sham derivative matrix: Formulation by time-dependent density-functional theory and evaluation in the pseudopotential framework

    SciTech Connect

    Hu, Chunping; Sugino, Osamu; Hirai, Hirotoshi; Tateyama, Yoshitaka

    2010-12-15

    We study the time-dependent density-functional theory formulation of nonadiabatic couplings (NAC's) to settle problems regarding practical calculations. NAC's have so far been rigorously formulated on the basis of the density response scheme and expressed using the nuclear derivative of the Hamiltonian, {partial_derivative}H/{partial_derivative}R, whereby causing the pseudopotential problem. When rewritten using the nuclear derivative operator, {partial_derivative}/{partial_derivative}R, or the d operator, the formula is found free of the problem and thus provides a working numerical scheme. The d-operator-based formulation also allows us to lay a foundation on the empirical Slater transition-state method and to show an improved way of using the auxiliary excited-state wave-function ansatz, both of which have been utilized in previous works. Evaluation of NAC near either the Jahn-Teller or the Renner-Teller intersection in various molecular systems shows that the values of NAC are much improved over previous calculations when the d-operator formula is implemented in the pseudopotential framework.

  8. Coupled modeling of a directly heated tubular solar receiver for supercritical carbon dioxide Brayton cycle: Structural and creep-fatigue evaluation

    DOE PAGESBeta

    Ortega, Jesus; Khivsara, Sagar; Christian, Joshua; Ho, Clifford; Dutta, Pradip

    2016-06-06

    A supercritical carbon dioxide (sCO2) Brayton cycle is an emerging high energy-density cycle undergoing extensive research due to the appealing thermo-physical properties of sCO2 and single phase operation. Development of a solar receiver capable of delivering sCO2 at 20 MPa and 700 °C is required for implementation of the high efficiency (~50%) solar powered sCO2 Brayton cycle. In this work, extensive candidate materials are review along with tube size optimization using the ASME Boiler and Pressure Vessel Code. Moreover, temperature and pressure distribution obtained from the thermal-fluid modeling (presented in a complementary publication) are used to evaluate the thermal andmore » mechanical stresses along with detailed creep-fatigue analysis of the tubes. For resulting body stresses were used to approximate the lifetime performance of the receiver tubes. A cyclic loading analysis is performed by coupling the Strain-Life approach and the Larson-Miller creep model. The structural integrity of the receiver was examined and it was found that the stresses can be withstood by specific tubes, determined by a parametric geometric analysis. The creep-fatigue analysis display the damage accumulation due to cycling and the permanent deformation on the tubes showed that the tubes can operate for the full lifetime of the receiver.« less

  9. Evaluation of different extraction procedures for determination of organic Mercury species in petroleum by high performance liquid chromatography coupled with cold vapor atomic fluorescence spectrometry.

    PubMed

    Yun, Zhaojun; He, Bin; Wang, Zhenhua; Wang, Thanh; Jiang, Guibin

    2013-03-15

    An extraction procedure for extracting organic mercury species including methylmercury (MeHg) and ethylmercury (EtHg) from petroleum samples was developed. Three extraction methods (shaking, ultrasonic and microwave assisted extraction) using different extraction solvents (TMAH, KOH/CH3OH, HCl and acidic CuSO4/KBr) were investigated by comparing the extraction efficiency of the organic mercury species. Microwave assisted extraction at 60 W for 5 min using TMAH (tetramethylammonium hydroxide, 25%, m/v) provided the most satisfactory extraction efficiency for MeHg and EtHg in petroleum at 86.7% ± 3.4% and 70.6% ± 5.9%, respectively. Speciation analysis of mercury was done by on-line coupling of high performance liquid chromatography with cold vapor generation atomic fluorescence spectrometry (HPLC-CV-AFS). The proposed method was successfully applied to analyze several crude oil and light oil samples. The concentrations of MeHg ranged from under detection limit to 0.515 ng g(-1), whereas EtHg was not detected in the samples. This method can be a very useful tool in evaluating the risk of mercury emissions from petroleum. PMID:23598095

  10. Reconfigured, close-coupled reconfigured, and Wyodak coal integrated two-stage coal liquefaction process materials from the Wilsonville facility: Chemical and toxicological evaluation

    SciTech Connect

    Wright, C.W.

    1987-03-01

    This document reports the results of the chemical analysis and toxicological testing of process materials sampled during the operation of the Advanced Coal Liquefaction Research and Development Facility (Wilsonville, AL) in the reconfigured, integrated (RITSL run No. 247), the close-coupled, reconfigured, integrated (CCRITSL run No. 249), and the Wyodak coal integrated (ITSL run No. 246) two-stage liquefaction operating modes. Chemical methods of analysis included proton nuclear magnetic resonance spectroscopy, adsorption column chromatography, high resolution gas chromatography, gas chromatography/mass spectrometry, and low-voltage probe-inlet mass spectrometry. Toxicological evaluation of the process materials included a histidine reversion assay for microbial mutagenicity, an initiation/promotion assay for tumorigenicity in mouse skin, and an aquatic toxicity assay using Daphnia magna. The results of these analyses and tests are compared to the previously reported results derived from the Illinois No. 6 coal ITSL and nonintegrated two-stage liquefaction (NTSL) process materials from the Wilsonville facility. 21 refs., 13 figs., 21 tabs.

  11. Binary chromatographic fingerprinting for quality evaluation of Radix Ophiopogonis by high-performance liquid chromatography coupled with ultraviolet and evaporative light-scattering detectors.

    PubMed

    Liu, Li; Lu, Yun; Shao, Qing; Cheng, Yi-Yu; Qu, Hai-Bin

    2007-11-01

    Radix Ophiopogonis is a widely used traditional Chinese medicine. The quality of Radix Ophiopogonis available in the market varies, and some confusing or fake herbs exist. In order to improve the quality control of Radix Ophiopogonis, a novel fingerprinting method was established using HPLC coupled with UV and evaporative light-scattering detectors (ELSDs). Extraction with methanol and liquid-liquid extraction with water-saturated n-butanol were employed for the preparation of the sample solution. Chromatographic separation was performed on a Lichrospher C(18) column (250x4.6 mm id, 5.0 microm particle size) with a linear gradient elution program. UV detection at 280 nm and evaporative light-scattering detection were utilized to obtain two subfingerprinting chromatograms. A novel protocol for data processing was proposed, in order to identify and remove redundant data obtained by the two detectors, and balance the weight of the two subfingerprints on the similarity values. The method was validated and applied to quality evaluation of 16 samples of Radix Ophiopogonis and related herbs. PMID:17874416

  12. Evaluation and improvement in the accuracy of a charge-coupled-device-based pyrometer for temperature field measurements of continuous casting billets

    NASA Astrophysics Data System (ADS)

    Bai, Haicheng; Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei

    2013-06-01

    This paper presents a radiometric high-temperature field measurement model based on a charge-coupled-device (CCD). According to the model, an intelligent CCD pyrometer with a digital signal processor as the core is developed and its non-uniformity correction algorithm for reducing the differences in accuracy between individual pixel sensors is established. By means of self-adaptive adjustment for the light-integration time, the dynamic range of the CCD is extended and its accuracy in low-temperature range is improved. The non-uniformity correction algorithm effectively reduces the accuracy differences between different pixel sensors. The performance of the system is evaluated through a blackbody furnace and an integrating sphere, the results of which show that the dynamic range of 400 K is obtained and the accuracy in low temperature range is increased by 7 times compared with the traditional method based on the fixed light-integration time. In addition, the differences of accuracy between the on-axis pixel and the most peripheral pixels are decreased from 19.1 K to 2.8 K. Therefore, this CCD pyrometer ensures that the measuring results of all pixels tend to be equal-accuracy distribution across the entire measuring ranges. This pyrometric system has been successfully applied to the temperature field measurements in continuous casting billets.

  13. Re-evaluation of interferences of doubly charged ions of heavy rare earth elements on Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Yang, Yue-Heng; Wu, Fu-Yuan; Xie, Lie-Wen; Chu, Zhu-Yin; Yang, Jin-Hui

    2014-07-01

    We re-evaluate the interference of doubly charged heavy rare earth elements during Sr isotopic analysis using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). A series of mixed solutions of standard reference material SRM 987, rare earth elements, and Sr separated from rock reference materials are measured to assess the influence of isobaric interferences on the MC-ICP-MS analysis of Sr isotopes. After sample dissolution, conventional cation-exchange chromatography is employed for Sr purification of rock reference materials prior to MC-ICP-MS measurement. It has been demonstrated that if the natural abundances of Er and Yb are used to correct for doubly charged ion interferences on Sr, an overcorrection results. In contrast, the use of measured doubly charged ion ratios results in an accurate and precise correction of isobaric interference. This finding is confirmed by analytical results for several certified reference materials from mafic (basaltic) to felsic (granitic) silicate rocks. It is noteworthy that, because Er is more prone to doubly charged ion formation, it dominates over Yb doubly charged ions as an interference source.

  14. Proton-Coupled Electron Transfer in a Series of Ruthenium-Linked Tyrosines with Internal Bases: Evaluation of a Tunneling Model for Experimental Temperature-Dependent Kinetics.

    PubMed

    Markle, Todd F; Zhang, Ming-Tian; Santoni, Marie-Pierre; Johannissen, Linus O; Hammarström, Leif

    2016-09-01

    Photoinitiated proton-coupled electron transfer (PCET) kinetics has been investigated in a series of four modified tyrosines linked to a ruthenium photosensitizer in acetonitrile, with each tyrosine bearing an internal hydrogen bond to a covalently linked pyridine or benzimidazole base. After correcting for differences in driving force, it is found that the intrinsic PCET rate constant still varies by 2 orders of magnitude. The differences in rates, as well as the magnitude of the kinetic isotope effect (KIE = kH/kD), both generally correlate with DFT calculated proton donor-acceptor distances. An Arrhenius analysis of temperature dependent data shows that the difference in reactivity arises primarily from differences in activation energies. We use this kinetic data to evaluate a commonly employed theoretical model for proton tunneling which includes a harmonic distribution of proton donor-acceptor distances due to vibrational motions of the molecule. Applying this model to the experimental data yields the conclusion that donor-acceptor compression is more facile in the compounds with shorter PT distance; however, this is contrary to independent calculations for the same compounds. This discrepancy is likely because the assumption in the model of Morse-shaped proton potential energy surfaces is inappropriate for (strongly) hydrogen-bonded systems. These results question the general applicability of this model. The results also suggest that a correlation of rate vs proton tunneling distance for the series of compounds is complicated by a concomitant variation of other relevant parameters. PMID:27490689

  15. Evaluation of Dietary Supplement Contamination by Xenobiotic and Essential Elements Using Microwave-Enhanced Sample Digestion and Inductively Coupled Plasma-Mass Spectrometry.

    PubMed

    Zinn, Gregory M; Rahman, G M Mizanur; Faber, Scott; Wolle, Mesay Mulugeta; Pamuku, Matt; Kingston, H M Skip

    2016-01-01

    Dietary supplements were analyzed by evaluating the elemental content in six widely consumed products manufactured by four well-known companies. The elements included the neurotoxic and carcinogenic elements cadmium, mercury, aluminum, lead, arsenic, and antimony, as well as the essential elements zinc, selenium, chromium, iron, and copper, which were often not listed as ingredients on the product labels. Contamination from either xenobiotic or essential elements was found in all samples analyzed. The samples were prepared using US Environmental Protection Agency (EPA) Method 3052, microwave-enhanced digestion. The resulting digests were analyzed by Inductively Coupled Plasma-Mass Spectrometry based on EPA Method 6020B. The analytical protocols were validated by analyzing a multivitamin standard reference material, the National Institute of Standards and Technology Standard Reference Material 3280. The application of EPA standard methods demonstrated their utility in making accurate and precise measurements in complex matrices with multiple ingredients and excipients. In the future, the use of these methods could provide a uniform quality assurance protocol that can be implemented along with other industry guidelines to improve the production of dietary supplements. PMID:25730528

  16. An evaluation of microwave-assisted fusion and microwave-assisted acid digestion methods for determining elemental impurities in carbon nanostructures using inductively coupled plasma optical emission spectrometry.

    PubMed

    Patole, Shashikant P; Simões, Filipa; Yapici, Tahir F; Warsama, Bashir H; Anjum, Dalaver H; Costa, Pedro M F J

    2016-02-01

    It is common for as-prepared carbon nanotube (CNT) and graphene samples to contain remnants of the transition metals used to catalyze their growth; contamination may also leave other trace elemental impurities in the samples. Although a full quantification of impurities in as-prepared samples of carbon nanostructures is difficult, particularly when trace elements are intercalated or encapsulated within a protective layer of graphitic carbon, reliable information is essential for reasons such as quantifying the adulteration of physico-chemical properties of the materials and for evaluating environmental issues. Here, we introduce a microwave-based fusion method to degrade single- and double-walled CNTs and graphene nanoplatelets into a fusion flux thereby thoroughly leaching all metallic impurities. Subsequent dissolution of the fusion product in diluted hydrochloric and nitric acid allowed us to identify their trace elemental impurities using inductively coupled plasma optical emission spectrometry. Comparisons of the results from the proposed microwave-assisted fusion method against those of a more classical microwave-assisted acid digestion approach suggest complementarity between the two that ultimately could lead to a more reliable and less costly determination of trace elemental impurities in carbon nanostructured materials. PMID:26653428

  17. Evaluation.

    ERIC Educational Resources Information Center

    McAnany, Emile G.; And Others

    1980-01-01

    Two lead articles set the theme for this issue devoted to evaluation as Emile G. McAnany examines the usefulness of evaluation and Robert C. Hornik addresses four widely accepted myths about evaluation. Additional articles include a report of a field evaluation done by the Accion Cultural Popular (ACPO); a study of the impact of that evaluation by…

  18. Evaluation of Nickel and Chromium Ion Release During Fixed Orthodontic Treatment Using Inductively Coupled Plasma-Mass Spectrometer: An In Vivo Study

    PubMed Central

    Nayak, Rabindra S; Khanna, Bharti; Pasha, Azam; Vinay, K; Narayan, Anjali; Chaitra, K

    2015-01-01

    Background: Fixed orthodontic appliances with the use of stainless steel brackets and archwires made of nitinol have a corrosive potential in the oral environment. Nickel and chromium ions released from these appliances act as allergens apart from being cytotoxic, mutagenic and carcinogenic in smaller quantities in the range of nanograms. This study was done to evaluate the release of nickel and chromium ions from orthodontic appliances in the oral cavity using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Materials and Methods: Saliva samples from 30 orthodontic patients undergoing treatment with 0.022″ MBT mechanotherapy were collected prior to commencement of treatment, after initial aligning wires and after 10-12 months of treatment. Salivary nickel and chromium ion concentration was measured in parts per billion (ppb) using ICP-MS. Results: Mean, standard deviation and range were computed for the concentrations of ions obtained. Results analyzed using ANOVA indicated a statistically significant increase of 10.35 ppb in nickel ion concentration and 33.53 ppb in chromium ion concentration after initial alignment. The ionic concentration at the end of 10-12 months of treatment showed a statistically significant increase in of 17.92 ppb for chromium and a statistically insignificant decrease in nickel ion concentration by 1.58 ppb. Pearson’s correlation coefficient showed a positive correlation for an increase in nickel concentration after aligning, but not at the end of 10-12 months. A positive correlation was seen for an increase in chromium ion concentration at both time intervals. Conclusion: Nickel and chromium ion concentration in saliva even though below the recommended daily allowance should not be ignored in light of the new knowledge regarding effects of these ions at the molecular level and the allergic potential. Careful and detailed medical history of allergy is essential. Nickel free alternatives should form an essential part of an

  19. Quantitative analysis of trace elements in environmental powders with laser ablation inductively coupled mass spectrometry using non-sample-corresponding reference materials for signal evaluation

    NASA Astrophysics Data System (ADS)

    Bauer, Gerald; Limbeck, Andreas

    2015-11-01

    Laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) is an attractive alternative to traditional procedures for the analysis of environmental samples (i.e., conventional liquid measurement after sample digestion). However, for accurate quantification, certified reference materials (CRM) are necessary which match the composition of the sample and include all elements of interest at the required concentration levels. The limited availability of appropriate CRMs hampers therefore substantial application. In this work, an LA-ICP-MS procedure allowing for accurate determination of trace element contents in powdered environmental samples is presented. For LA-ICP-MS analysis, the samples are mixed with an internal standard (silver oxide) and a binder (sodium tetra borate) and subsequently pressed to pellets. Quantification is accomplished using a calibration function determined using CRMs with varying matrix composition and analyte content, pre-treated and measured in the same way as the samples. With this approach, matrix-induced ablation differences resulting from varying physical/chemical properties of the individual CRMs could be compensated. Furthermore, ICP-related matrix-effects could be minimized using collision/reaction cell technology. Applicability of the procedure has been demonstrated by assessment of Cd, Cu, Ni, and Zn in four different environmental CRMs (NIST SRM1648a (urban particulate matter), NIST SRM2709 (San Joaquin Soil), BCR144 (sewage sludge), and BCR723 (road dust)). Signal evaluation was performed by alternative use of three CRMs for calculation of the calibration function whereas the remaining fourth CRM acted as unknown sample, resulting in a good agreement between measured and certified values for all elements and reference materials.

  20. Cell-based bioreporter assay coupled to HPLC micro-fractionation in the evaluation of antimicrobial properties of the basidiomycete fungus Pycnoporus cinnabarinus.

    PubMed

    Järvinen, Päivi; Nybond, Susanna; Marcourt, Laurence; Ferreira Queiroz, Emerson; Wolfender, Jean-Luc; Mettälä, Aila; Karp, Matti; Vuorela, Heikki; Vuorela, Pia; Hatakka, Annele; Tammela, Päivi

    2016-06-01

    Context Identification of bioactive components from complex natural product extracts can be a tedious process that aggravates the use of natural products in drug discovery campaigns. Objective This study presents a new approach for screening antimicrobial potential of natural product extracts by employing a bioreporter assay amenable to HPLC-based activity profiling. Materials and methods A library of 116 crude extracts was prepared from fungal culture filtrates by liquid-liquid extraction with ethyl acetate, lyophilised, and screened against Escherichia coli using TLC bioautography. Active extracts were studied further with a broth microdilution assay, which was, however, too insensitive for identifying the active microfractions after HPLC separation. Therefore, an assay based on bioluminescent E. coli K-12 (pTetLux1) strain was coupled with HPLC micro-fractionation. Results Preliminary screening yielded six fungal extracts with potential antimicrobial activity. A crude extract from a culture filtrate of the wood-rotting fungus, Pycnoporus cinnabarinus (Jacq.) P. Karst. (Polyporaceae), was selected for evaluating the functionality of the bioreporter assay in HPLC-based activity profiling. In the bioreporter assay, the IC50 value for the crude extract was 0.10 mg/mL. By integrating the bioreporter assay with HPLC micro-fractionation, the antimicrobial activity was linked to LC-UV peak of a compound in the chromatogram of the extract. This compound was isolated and identified as a fungal pigment phlebiarubrone. Discussion and conclusion HPLC-based activity profiling using the bioreporter-based approach is a valuable tool for identifying antimicrobial compound(s) from complex crude extracts, and offers improved sensitivity and speed compared with traditional antimicrobial assays, such as the turbidimetric measurement. PMID:26808592

  1. Toward a chemical reanalysis in a coupled chemistry-climate model: An evaluation of MOPITT CO assimilation and its impact on tropospheric composition

    NASA Astrophysics Data System (ADS)

    Gaubert, B.; Arellano, A. F.; Barré, J.; Worden, H. M.; Emmons, L. K.; Tilmes, S.; Buchholz, R. R.; Vitt, F.; Raeder, K.; Collins, N.; Anderson, J. L.; Wiedinmyer, C.; Martinez Alonso, S.; Edwards, D. P.; Andreae, M. O.; Hannigan, J. W.; Petri, C.; Strong, K.; Jones, N.

    2016-06-01

    We examine in detail a 1 year global reanalysis of carbon monoxide (CO) that is based on joint assimilation of conventional meteorological observations and Measurement of Pollution in The Troposphere (MOPITT) multispectral CO retrievals in the Community Earth System Model (CESM). Our focus is to assess the impact to the chemical system when CO distribution is constrained in a coupled full chemistry-climate model like CESM. To do this, we first evaluate the joint reanalysis (MOPITT Reanalysis) against four sets of independent observations and compare its performance against a reanalysis with no MOPITT assimilation (Control Run). We then investigate the CO burden and chemical response with the aid of tagged sectoral CO tracers. We estimate the total tropospheric CO burden in 2002 (from ensemble mean and spread) to be 371 ± 12% Tg for MOPITT Reanalysis and 291 ± 9% Tg for Control Run. Our multispecies analysis of this difference suggests that (a) direct emissions of CO and hydrocarbons are too low in the inventory used in this study and (b) chemical oxidation, transport, and deposition processes are not accurately and consistently represented in the model. Increases in CO led to net reduction of OH and subsequent longer lifetime of CH4 (Control Run: 8.7 years versus MOPITT Reanalysis: 9.3 years). Yet at the same time, this increase led to 5-10% enhancement of Northern Hemisphere O3 and overall photochemical activity via HOx recycling. Such nonlinear effects further complicate the attribution to uncertainties in direct emissions alone. This has implications to chemistry-climate modeling and inversion studies of longer-lived species.

  2. Prosthesis coupling

    NASA Technical Reports Server (NTRS)

    Reswick, J. B.; Mooney, V.; Bright, C. W.; Owens, L. J. (Inventor)

    1979-01-01

    A coupling for use in an apparatus for connecting a prosthesis to the bone of a stump of an amputated limb is described which permits a bio-compatible carbon sleeve forming a part of the prosthesis connector to float so as to prevent disturbing the skin seal around the carbon sleeve. The coupling includes a flexible member interposed between a socket that is inserted within an intermedullary cavity of the bone and the sleeve. A lock pin is carried by the prosthesis and has a stem portion which is adapted to be coaxially disposed and slideably within the tubular female socket for securing the prosthesis to the stump. The skin around the percutaneous carbon sleeve is able to move as a result of the flexing coupling so as to reduce stresses caused by changes in the stump shape and/or movement between the bone and the flesh portion of the stump.

  3. FLEXIBLE COUPLING

    DOEpatents

    Babelay, E.F.

    1962-02-13

    A flexible shaft coupling for operation at speeds in excess of 14,000 rpm is designed which requires no lubrication. A driving sleeve member and a driven sleeve member are placed in concentric spaced relationship. A torque force is transmitted to the driven member from the driving member through a plurality of nylon balls symmetrically disposed between the spaced sleeves. The balls extend into races and recesses within the respective sleeve members. The sleeve members have a suitable clearance therebetween and the balls have a suitable radial clearance during operation of the coupling to provide a relatively loose coupling. These clearances accommodate for both parallel and/or angular misalignments and avoid metal-tometal contact between the sleeve members during operation. Thus, no lubrication is needed, and a minimum of vibrations is transmitted between the sleeve members. (AEC)

  4. Interlaboratory evaluation of a standardized inductively coupled plasma mass spectrometry method for the determination of trace beryllium in air filter samples.

    PubMed

    Ashley, Kevin; Brisson, Michael J; Howe, Alan M; Bartley, David L

    2009-12-01

    A collaborative interlaboratory evaluation of a newly standardized inductively coupled plasma mass spectrometry (ICP-MS) method for determining trace beryllium in workplace air samples was carried out toward fulfillment of method validation requirements for ASTM International voluntary consensus standard test methods. The interlaboratory study (ILS) was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Uncertainty was also estimated in accordance with ASTM D7440, which applies the International Organization for Standardization Guide to the Expression of Uncertainty in Measurement to air quality measurements. Performance evaluation materials (PEMs) used consisted of 37 mm diameter mixed cellulose ester filters that were spiked with beryllium at levels of 0.025 (low loading), 0.5 (medium loading), and 10 (high loading) microg Be/filter; these spiked filters were prepared by a contract laboratory. Participating laboratories were recruited from a pool of over 50 invitees; ultimately, 20 laboratories from Europe, North America, and Asia submitted ILS results. Triplicates of each PEM (blanks plus the three different loading levels) were conveyed to each volunteer laboratory, along with a copy of the draft standard test method that each participant was asked to follow; spiking levels were unknown to the participants. The laboratories were requested to prepare the PEMs by one of three sample preparation procedures (hotplate or microwave digestion or hotblock extraction) that were described in the draft standard. Participants were then asked to analyze aliquots of the prepared samples by ICP-MS and to report their data in units of mu g Be/filter sample. Interlaboratory precision estimates from participating laboratories, computed in accordance with ASTM E691, were 0.165, 0.108, and 0.151 (relative standard deviation) for the PEMs spiked at 0.025, 0

  5. Evaluation of a tunable bandpass reaction cell inductively coupled plasma mass spectrometer for the determination of selenium in serum and urine

    NASA Astrophysics Data System (ADS)

    Nixon, David E.; Neubauer, Kenneth R.; Eckdahl, Steven J.; Butz, John A.; Burritt, Mary F.

    2003-01-01

    A Dynamic Reaction Cell™ inductively coupled plasma mass spectrometer (DRC-ICP-MS) was evaluated for the determination of selenium in serum and urine. Reaction cell conditions were evaluated for the suppression of Ar 2+ dimer at m/ z 78 and 80 using methane as the reaction gas. A diluent containing 10% ethanol, 1% nitric acid, 0.5% Triton X-100 with gallium and yttrium internal standards was used to dilute urine and serum samples. Instrument response calibration was achieved by using aqueous acidic standards spiked into a urine matrix. Slopes for aqueous inorganic selenium, seleno- DL-cystine, seleno- DL-methionine and trimethylselenonium iodide spiked into urine and serum matrices were nearly identical. In general, reagent blank readings and detection limits were significantly lower in the DRC mode (reaction cell pressurized) than the standard mode (cell vented). Average results for the analysis of National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1598 bovine serum (attained over 13 days) are: 43.8±3.6 μg Se/l. Reference concentration is 43.6±3.6 μg Se/l. For NIST SRM 2670 Normal Urine the DRC-ICP-MS results are 30.7±4.6 μg Se/l with a certified concentration of 30±8 μg Se/l. For NIST SRM 2670 Elevated Urine the DRC-ICP-MS results are 463±35 μg Se/l with a certified concentration of 460±30 μg Se/l. The DRC-ICP-MS results for selenium determinations in urine and serum survey samples from the Institut National de Sante Publique du Quebec were compared with the reference concentrations and results produced by conventional ICP-MS. While conventional ICP-MS gave acceptable results for survey samples, DRC-ICP-MS gave excellent results for both urine and sera. Closer correlation was observed for DRC-ICP-MS results with target concentrations than with conventional ICP-MS.

  6. Module coupling and predictability

    NASA Astrophysics Data System (ADS)

    Knopf, B.; Held, H.

    2003-04-01

    Successive coupling of several nonlinear submodules seems to be the implicit master strategy of the current world-wide modelling endeavour. The process of coupling is investigated by using different methods of examining low order coupled atmosphere-ocean systems. As a first step, a coupled atmosphere-ocean system, based on the Lorenz84 atmosphere is considered, operated in a forced versus the truly coupled mode. In [1] it is shown that forcing cannot emulate the fully coupled system, yet quite the contrary, generates time series of intermittently high predictability ("locking"). Standard linear stability analysis is incapable to explain the locking phenomenon. While regions of linear asymptotic stability can be evaluated, it turns out that this criterion is too conservative and does not explain the standard locking situation, as the trajectory periodically leaves the region of stability during a locking phase. We therefore propose that the locking phenomenon needs to be analysed in the framework of non-linear dynamics. Preliminary analysis of the statistic of locking-periods displays a similarity to type III intermittency. Bifurcation diagrams obtained from the continuation software AUTO indicate a rich phase space structure which makes the interpretation of the locking phenomenon intricate. Systematic variation of coupling constants appears to be a promising task as the key effects could be followed into parameter regimes of more transparent phase space structure. begin{thebibliography}{0} bibitem{Wittenberg98}A. T. Wittenberg, J. L. Anderson. Dynamical implications of prescribing part of a coupled system: Results from a low order model. Nonlinear Processes in Geophysics, 5: 167-179, 1998.

  7. Evaluation of photoinduced change in refractive index of a polymer film doped with an azobenzene liquid crystal by means of a prism-coupling method

    SciTech Connect

    Kurihara, Hideo; Shishido, Atsushi; Ikeda, Tomiki

    2005-10-15

    The photoinduced change in refractive index of poly(methyl methacrylate) films doped with an azobenzene liquid crystal was measured by the prism-coupling method. Upon irradiation of the film with a high-pressure mercury lamp at 366 nm, the coupling angles shifted and then recovered to the initial position by turning off the light. The change in refractive index was found to be 2x10{sup -3}, which is attributed to the reversible photoisomerization of the azobenzene moieties.

  8. One-way coupling of an integrated assessment model and a water resources model: evaluation and implications of future changes over the US Midwest

    NASA Astrophysics Data System (ADS)

    Voisin, N.; Liu, L.; Hejazi, M.; Tesfa, T.; Li, H.; Huang, M.; Liu, Y.; Leung, L. R.

    2013-11-01

    An integrated model is being developed to advance our understanding of the interactions between human activities, terrestrial system and water cycle, and to evaluate how system interactions will be affected by a changing climate at the regional scale. As a first step towards that goal, a global integrated assessment model, which includes a water-demand model driven by socioeconomics at regional and global scales, is coupled in a one-way fashion with a land surface hydrology-routing-water resources management model. To reconcile the scale differences between the models, a spatial and temporal disaggregation approach is developed to downscale the annual regional water demand simulations into a daily time step and subbasin representation. The model demonstrates reasonable ability to represent the historical flow regulation and water supply over the US Midwest (Missouri, Upper Mississippi, and Ohio river basins). Implications for future flow regulation, water supply, and supply deficit are investigated using climate change projections with the B1 and A2 emission scenarios, which affect both natural flow and water demand. Although natural flow is projected to increase under climate change in both the B1 and A2 scenarios, there is larger uncertainty in the changes of the regulated flow. Over the Ohio and Upper Mississippi river basins, changes in flow regulation are driven by the change in natural flow due to the limited storage capacity. However, both changes in flow and demand have effects on the Missouri River Basin summer regulated flow. Changes in demand are driven by socioeconomic factors, energy and food demands, global markets and prices with rainfed crop demand handled directly by the land surface modeling component. Even though most of the changes in supply deficit (unmet demand) and the actual supply (met demand) are driven primarily by the change in natural flow over the entire region, the integrated framework shows that supply deficit over the Missouri River

  9. Evaluation of a Minimally Invasive Cell Sampling Device Coupled with Assessment of Trefoil Factor 3 Expression for Diagnosing Barrett's Esophagus: A Multi-Center Case–Control Study

    PubMed Central

    Ross-Innes, Caryn S.; Debiram-Beecham, Irene; O'Donovan, Maria; Walker, Elaine; Varghese, Sibu; Lao-Sirieix, Pierre; Lovat, Laurence; Griffin, Michael; Ragunath, Krish; Haidry, Rehan; Sami, Sarmed S.; Kaye, Philip; Novelli, Marco; Disep, Babett; Ostler, Richard; Aigret, Benoit; North, Bernard V.; Bhandari, Pradeep; Haycock, Adam; Morris, Danielle; Attwood, Stephen; Dhar, Anjan; Rees, Colin; Rutter, Matthew D. D.; Sasieni, Peter D.; Fitzgerald, Rebecca C.

    2015-01-01

    Background Barrett's esophagus (BE) is a commonly undiagnosed condition that predisposes to esophageal adenocarcinoma. Routine endoscopic screening for BE is not recommended because of the burden this would impose on the health care system. The objective of this study was to determine whether a novel approach using a minimally invasive cell sampling device, the Cytosponge, coupled with immunohistochemical staining for the biomarker Trefoil Factor 3 (TFF3), could be used to identify patients who warrant endoscopy to diagnose BE. Methods and Findings A case–control study was performed across 11 UK hospitals between July 2011 and December 2013. In total, 1,110 individuals comprising 463 controls with dyspepsia and reflux symptoms and 647 BE cases swallowed a Cytosponge prior to endoscopy. The primary outcome measures were to evaluate the safety, acceptability, and accuracy of the Cytosponge-TFF3 test compared with endoscopy and biopsy. In all, 1,042 (93.9%) patients successfully swallowed the Cytosponge, and no serious adverse events were attributed to the device. The Cytosponge was rated favorably, using a visual analogue scale, compared with endoscopy (p < 0.001), and patients who were not sedated for endoscopy were more likely to rate the Cytosponge higher than endoscopy (Mann-Whitney test, p < 0.001). The overall sensitivity of the test was 79.9% (95% CI 76.4%–83.0%), increasing to 87.2% (95% CI 83.0%–90.6%) for patients with ≥3 cm of circumferential BE, known to confer a higher cancer risk. The sensitivity increased to 89.7% (95% CI 82.3%–94.8%) in 107 patients who swallowed the device twice during the study course. There was no loss of sensitivity in patients with dysplasia. The specificity for diagnosing BE was 92.4% (95% CI 89.5%–94.7%). The case–control design of the study means that the results are not generalizable to a primary care population. Another limitation is that the acceptability data were limited to a single measure. Conclusions The

  10. Evaluation of a real-time BeO ceramic fiber-coupled luminescence dosimetry system for dose verification of high dose rate brachytherapy

    SciTech Connect

    Santos, Alexandre M. Caraça; Mohammadi, Mohammad; Shahraam, Afshar V.

    2015-11-15

    Purpose: The authors evaluate the capability of a beryllium oxide (BeO) ceramic fiber-coupled luminescence dosimeter, named radioluminescence/optically stimulated luminescence (RL/OSL) BeO FOD, for dosimetric verification of high dose rate (HDR) treatments. The RL/OSL BeO FOD is capable of RL and OSL measurements. Methods: The RL/OSL BeO FOD is able to be inserted in 6F proguide needles, used in interstitial HDR treatments. Using a custom built Perspex phantom, 6F proguide needles could be submerged in a water tank at 1 cm separations from each other. A second background fiber was required to correct for the stem effect. The stem effect, dose linearity, reproducibility, depth-dose curves, and angular and temperature dependency of the RL/OSL BeO FOD were characterised using an Ir-192 source. The RL/OSL BeO FOD was also applied to the commissioning of a 10 mm horizontal Leipzig applicator. Results: Both the RL and OSL were found to be reproducible and their percentage depth-dose curves to be in good agreement with those predicted via TG-43. A combined uncertainty of 7.9% and 10.1% (k = 1) was estimated for the RL and OSL, respectively. For the 10 mm horizontal Leipzig applicator, measured percentage depth doses were within 5% agreement of the published reference calculations. The output at the 3 mm prescription depth for a 1 Gy delivery was verified to be 0.99 ± 0.08 Gy and 1.01 ± 0.10 Gy by the RL and OSL, respectively. Conclusions: The use of the second background fiber under the current setup means that the two fibers cannot fit into a single 6F needle. Hence, use of the RL is currently not adequate for the purpose of in vivo brachytherapy dosimetry. While not real-time, the OSL is shown to be adequate for in vivo brachytherapy dosimetry.

  11. Comprehensive evaluation of multi-year real-time air quality forecasting using an online-coupled meteorology-chemistry model over southeastern United States

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Hong, Chaopeng; Yahya, Khairunnisa; Li, Qi; Zhang, Qiang; He, Kebin

    2016-08-01

    An online-coupled meteorology-chemistry model, WRF/Chem-MADRID, has been deployed for real time air quality forecast (RT-AQF) in southeastern U.S. since 2009. A comprehensive evaluation of multi-year RT-AQF shows overall good performance for temperature and relative humidity at 2-m (T2, RH2), downward surface shortwave radiation (SWDOWN) and longwave radiation (LWDOWN), and cloud fraction (CF), ozone (O3) and fine particles (PM2.5) at surface, tropospheric ozone residuals (TOR) in O3 seasons (May-September), and column NO2 in winters (December-February). Moderate-to-large biases exist in wind speed at 10-m (WS10), precipitation (Precip), cloud optical depth (COT), ammonium (NH4+), sulfate (SO42-), and nitrate (NO3-) from the IMPROVE and SEARCH networks, organic carbon (OC) at IMPROVE, and elemental carbon (EC) and OC at SEARCH, aerosol optical depth (AOD) and column carbon monoxide (CO), sulfur dioxide (SO2), and formaldehyde (HCHO) in both O3 and winter seasons, column nitrogen dioxide (NO2) in O3 seasons, and TOR in winters. These biases indicate uncertainties in the boundary layer and cloud process treatments (e.g., surface roughness, microphysics cumulus parameterization), emissions (e.g., O3 and PM precursors, biogenic, mobile, and wildfire emissions), upper boundary conditions for all major gases and PM2.5 species, and chemistry and aerosol treatments (e.g., winter photochemistry, aerosol thermodynamics). The model shows overall good skills in reproducing the observed multi-year trends and inter-seasonal variability in meteorological and radiative variables such as T2, WS10, Precip, SWDOWN, and LWDOWN, and relatively well in reproducing the observed trends in surface O3 and PM2.5, but relatively poor in reproducing the observed column abundances of CO, NO2, SO2, HCHO, TOR, and AOD. The sensitivity simulations using satellite-constrained boundary conditions for O3 and CO show substantial improvement for both spatial distribution and domain-mean performance

  12. Gay and lesbian couples in Italy: comparisons with heterosexual couples.

    PubMed

    Antonelli, Paolo; Dèttore, Davide; Lasagni, Irene; Snyder, Douglas K; Balderrama-Durbin, Christina

    2014-12-01

    Assessing couple relationships across diverse languages and cultures has important implications for both clinical intervention and prevention. This is especially true for nontraditional relationships potentially subject to various expressions of negative societal evaluation or bias. Few empirically validated measures of relationship functioning have been developed for cross-cultural applications, and none have been examined for their psychometric sufficiency for evaluating same-sex couples across different languages and cultures. The current study examined the psychometric properties of an Italian translation of the Marital Satisfaction Inventory - Revised (MSI-R), a 150-item 13-scale measure of couple relationship functioning, for its use in assessing the intimate relationships of gay and lesbian couples in Italy. Results for these couples were compared to data from heterosexual married and unmarried cohabiting couples from the same geographical region, as well as to previously published data for gay, lesbian, and unmarried heterosexual couples from the United States. Findings suggest that, despite unique societal pressures confronting Italian same-sex couples, these relationships appear resilient and fare well both overall and in specific domains of functioning compared to heterosexual couples both in Italy and the United States. PMID:24867576

  13. Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF–CMAQ: model description, development, evaluation and regional analysis

    SciTech Connect

    Yu, S.; Mathur, R.; Pleim, J.; Wong, D.; Gilliam, R.; Alapaty, K.; Zhao, C.; Liu, X.

    2014-01-01

    This study implemented first, second and glaciation aerosol indirect effects (AIE) on resolved clouds in the two-way coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF–CMAQ) modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQ-predicted aerosol distributions and WRF meteorological conditions. The performance of the newly developed WRF–CMAQ model, with alternate Community Atmospheric Model (CAM) and Rapid Radiative Transfer Model for GCMs (RRTMG) radiation schemes, was evaluated with observations from the Clouds and the See http://ceres.larc.nasa.gov/. Earth's Radiant Energy System (CERES) satellite and surface monitoring networks (AQS, IMPROVE, CASTNET, STN, and PRISM) over the continental US (CONUS) (12 km resolution) and eastern Texas (4 km resolution) during August and September of 2006. The results at the Air Quality System (AQS) surface sites show that in August, the normalized mean bias (NMB) values for PM2.5 over the eastern US (EUS) and the western US (WUS) are 5.3% (-0.1%) and 0.4% (-5.2%) for WRF–CMAQ/CAM (WRF–CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF–CMAQ/CAM (WRF–CMAQ/RRTMG) consistently underestimated the observed SO42- by -23.0% (-27.7%), -12.5% (-18.9%) and -7.9% (-14.8%) over the EUS at the Clean Air Status Trends Network (CASTNET), Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciated Trends Network (STN) sites, respectively. Both configurations (WRF–CMAQ/CAM, WRF–CMAQ/RRTMG) overestimated the observed mean organic carbon (OC), elemental carbon (EC) and and total carbon (TC) concentrations over the EUS in August at the IMPROVE sites. Both configurations generally underestimated the cloud field (shortwave cloud forcing, SWCF) over the CONUS in August due to the

  14. Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF-CMAQ: model description, development, evaluation and regional analysis

    NASA Astrophysics Data System (ADS)

    Yu, S.; Mathur, R.; Pleim, J.; Wong, D.; Gilliam, R.; Alapaty, K.; Zhao, C.; Liu, X.

    2014-10-01

    This study implemented first, second and glaciation aerosol indirect effects (AIE) on resolved clouds in the two-way coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF-CMAQ) modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQ-predicted aerosol distributions and WRF meteorological conditions. The performance of the newly developed WRF-CMAQ model, with alternate Community Atmospheric Model (CAM) and Rapid Radiative Transfer Model for GCMs (RRTMG) radiation schemes, was evaluated with observations from the Clouds and the See http://ceres.larc.nasa.gov/. Earth's Radiant Energy System (CERES) satellite and surface monitoring networks (AQS, IMPROVE, CASTNET, STN, and PRISM) over the continental US (CONUS) (12 km resolution) and eastern Texas (4 km resolution) during August and September of 2006. The results at the Air Quality System (AQS) surface sites show that in August, the normalized mean bias (NMB) values for PM2.5 over the eastern US (EUS) and the western US (WUS) are 5.3% (-0.1%) and 0.4% (-5.2%) for WRF-CMAQ/CAM (WRF-CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF-CMAQ/CAM (WRF-CMAQ/RRTMG) consistently underestimated the observed SO42- by -23.0% (-27.7%), -12.5% (-18.9%) and -7.9% (-14.8%) over the EUS at the Clean Air Status Trends Network (CASTNET), Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciated Trends Network (STN) sites, respectively. Both configurations (WRF-CMAQ/CAM, WRF-CMAQ/RRTMG) overestimated the observed mean organic carbon (OC), elemental carbon (EC) and and total carbon (TC) concentrations over the EUS in August at the IMPROVE sites. Both configurations generally underestimated the cloud field (shortwave cloud forcing, SWCF) over the CONUS in August due to the fact that the AIE on the subgrid convective clouds was not

  15. Tubular Coupling

    NASA Technical Reports Server (NTRS)

    Rosenbaum, Bernard J. (Inventor)

    2000-01-01

    A system for coupling a vascular overflow graft or cannula to a heart pump. A pump pipe outlet is provided with an external tapered surface which receives the end of a compressible connula. An annular compression ring with a tapered internal bore surface is arranged about the cannula with the tapered internal surface in a facing relationship to the external tapered surface. The angle of inclination of the tapered surfaces is converging such that the spacing between the tapered surfaces decreases from one end of the external tapered surface to the other end thereby providing a clamping action of the tapered surface on a cannula which increases as a function of the length of cannula segment between the tapered surfaces. The annular compression ring is disposed within a tubular locking nut which threadedly couples to the pump and provides a compression force for urging the annular ring onto the cannula between the tapered surfaces. The nut has a threaded connection to the pump body. The threaded coupling to the pump body provides a compression force for the annular ring. The annular ring has an annular enclosure space in which excess cannula material from the compression between the tapered surfaces to "bunch up" in the space and serve as an enlarged annular ring segment to assist holding the cannula in place. The clamped cannula provides a seamless joint connection to the pump pipe outlet where the clamping force is uniformly applied to the cannula because of self alignment of the tapered surfaces. The nut can be easily disconnected to replace the pump if necessary.

  16. Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF-CMAQ: model description, development, evaluation and regional analysis

    EPA Science Inventory

    This study implemented first, second and glaciations aerosol indirect effects (AIE) on resolved clouds in the two-way coupled WRF-CMAQ modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQ predicted aerosol distribu...

  17. Evaluation of the two-way coupled WRF-CMAQ modeling system to the 2011 DISCOVER-AQ campaign at 12-km, 4-km and 1-km resolutions

    EPA Science Inventory

    At the 12th Annual CMAS Conference initial results from the application of the coupled WRF-CMAQ modeling system to the 2011 Baltimore-Washington D.C. DISCOVER-AQ campaign were presented, with the focus on updates and new methods applied to the WRF modeling for fine-scale applicat...

  18. Coupling of the simultaneous heat and water model with a distributed hydrological model and evaluation of the combined model in a cold region watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To represent the effects of frozen soil on hydrology in cold regions, a new physically based distributed hydrological model has been developed by coupling the simultaneous heat and water model (SHAW) with the geomorphology based distributed hydrological model (GBHM), under the framework of the water...

  19. Evaluation of sample preparation methods for the detection of total metal content using inductively coupled plasma optical emission spectrometry (ICP-OES) in wastewater and sludge

    NASA Astrophysics Data System (ADS)

    Dimpe, K. M.; Ngila, J. C.; Mabuba, N.; Nomngongo, P. N.

    Heavy metal contamination exists in aqueous wastes and sludge of many industrial discharges and domestic wastewater, among other sources. Determination of metals in the wastewater and sludge requires sample pre-treatment prior to analysis because of certain challenges such as the complexity of the physical state of the sample, which may lead to wrong readings in the measurement. This is particularly the case with low analyte concentration to be detected by the instrument. The purpose of this work was to assess and validate the different sample preparation methods namely, hot plate and microwave-assisted digestion procedures for extraction of metal ions in wastewater and sludge samples prior to their inductively coupled plasma optical emission spectrometric (ICP-OES) determination. For the extraction of As, Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn, three acid mixtures, that is, HNO3/H2O2, HNO3/HClO4/H2O2 and aqua regia + H2O2, were evaluated. Influent wastewater spiked with the SRM (CWW-TM-B) was used for the optimization of acid mixtures affecting the extraction procedure. After sample digestion, the filtration capabilities of cellulose-acetate filter paper and the acrodisc syringe filter with the pore size of 0.45 μm were compared. In terms of performance, acrodisc syringe filter in terms of the improved recoveries obtained, was found to be the best filtration method compared to the filter paper. Based on the analytical results obtained, microwave-assisted digestion (MAD) using aqua regia + H2O2 mixture was found to be the most suitable method for extraction of heavy metals and major elements in all the sample matrices. Therefore, MAD using aqua regia + H2O2 mixture was used for further investigations. The precision of the developed MAD method expressed in terms of relative standard deviations (% RSD) for different metals was found to be <5%. The limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.12% to 2.18 μg L-1 and 0.61% to 3.43 μg L-1

  20. Thermoacoustic couple

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-10-04

    An apparatus and method for determining acoustic power density level and its direction in a fluid using a single sensor are disclosed. The preferred embodiment of the apparatus, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.

  1. Dark coupling

    SciTech Connect

    Gavela, M.B.; Hernández, D.; Honorez, L. Lopez; Mena, O.; Rigolin, S. E-mail: d.hernandez@uam.es E-mail: omena@ific.uv.es

    2009-07-01

    The two dark sectors of the universe—dark matter and dark energy—may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit ''phantom crossing'' and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed.

  2. Evaluation of the Coupling of a Full-Dimensional Multiphase Model with a Vertical Equilibrium Model for the Simulation of Underground Gas Storage

    NASA Astrophysics Data System (ADS)

    Becker, B.; Helmig, R.; Flemisch, B.; Guo, B.; Celia, M. A.

    2015-12-01

    Modeling underground gas storage requires simulations on a large domain over the whole time of plant operation and beyond, including local features such as fault zones and a representation of the transient saline front. The boundary conditions and resulting pressure reversal are affected by external fluctuations in energy demand and supply (e.g. power to gas) over a wide range of time scales. In addition, often a large number of simulation runs need to be conducted to quantify parameter uncertainty (e.g. Monte Carlo simulation). Within acceptable computational time this cannot be achieved by full three-dimensional multiphase multicomponent models due to limited computational resources. In contrast to that, less computational resources are required by numerous simplified mathematical models. One class of these models is based on the assumption of vertical equilibrium. However, this assumption may be invalid in the area around the well during injection and extraction of gas and at the tip of the plume and in general only holds after a certain timescale in the rest of the domain. In addition, simplified models do not provide the accuracy desired for some parts of interest in the domain, like fault zones, the displacement front or geological heterogeneity especially around the injection zone. The individual benefits of simplified models such as a vertically integrated model and more complex and thus more accurate models such as a full-dimensional multiphase model are combined by coupling both model types in one domain. The boundary between the models is adapted during the simulation to capture transient processes. Stability, applicability and efficiency of the coupled model for different injection scenarios and domain features will be analyzed and discussed. Physically/mathematically motivated coupling criteria to govern the movement of the boundaries between the models will be presented and compared. It will be shown how the coupled model maintains a high degree of

  3. Evaluation of a regional air-quality model with bi-directional NH3 exchange coupled to an agro-ecosystem model

    NASA Astrophysics Data System (ADS)

    Bash, J. O.; Cooter, E. J.; Dennis, R. L.; Walker, J. T.; Pleim, J. E.

    2012-08-01

    Atmospheric ammonia (NH3) is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurements indicate that the air-surface exchange of NH3 is bi-directional. However, the effects of bi-directional exchange, soil biogeochemistry and human activity are not parameterized in air quality models. The US Environmental Protection Agency (EPA)'s Community Multiscale Air-Quality (CMAQ) model with bi-directional NH3 exchange has been coupled with the United States Department of Agriculture (USDA)'s Environmental Policy Integrated Climate (EPIC) agro-ecosystem model's nitrogen geochemistry algorithms. CMAQ with bi-directional NH3 exchange coupled to EPIC connects agricultural cropping management practices to emissions and atmospheric concentrations of reduced nitrogen and models the biogeochemical feedback on NH3 air-surface exchange. This coupled modeling system reduced the biases and error in NHx (NH3 + NH4+) wet deposition and in ambient aerosol concentrations in an annual 2002 Continental US (CONUS) domain simulation when compared to a 2002 annual simulation of CMAQ without bi-directional exchange. Fertilizer emissions estimated in CMAQ 5.0 with bi-directional exchange exhibits markedly different seasonal dynamics than the US EPA's National Emissions Inventory (NEI), with lower emissions in the spring and fall and higher emissions in July.

  4. Evaluation of UV/TiO(2) and UV/ZnO photocatalytic systems coupled to a biological process for the treatment of bleaching pulp mill effluent.

    PubMed

    Botía, Diana C; Rodríguez, Manuel S; Sarria, Víctor M

    2012-10-01

    This paper presents an exploratory study of pulp mill bleaching effluent treatment by a biological-photocatalytic coupled system. A fungus, Trametes pubescens, immobilized on polyurethane foam was used to inoculate the biological pre-treatment system. The pretreated effluent was then exposed to a photocatalytic treatment in which two catalysts (TiO(2) and ZnO) and two supports (aluminum foil and Luffa cylindrica) were tested. Catalyst characterization was carried out by means of X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). Information about crystalline structure, chemical composition, morphology, homogeneity and distribution on the support surface area was obtained. The overall biological-photocatalytic coupled system achieved degradation of 96% of initial total organic carbon (TOC), 97% of 2-chlorophenol (2-CP), 90% of 2,4-dichlorophenol (2,4-CP) and 99% of 2,4,6-trichlorophenol (2,4,6-TCP). This approach of synergistic coupling of T. pubescens and a semiconductor photocatalyst appears to be a viable alternative for the treatment of these non-biodegradable effluents. PMID:22818977

  5. Low-loss coupling to dielectric resonators

    NASA Technical Reports Server (NTRS)

    Hearn, C. P.; Bradshaw, E. S.; Trew, R. J.; Hefner, B. B., Jr.

    1991-01-01

    A compilation is presented of experimental observations and arguments concerning the use of dielectric resonators in applications requiring both tight coupling (beta greater than 10) and high unloaded Q, such as low loss bandpass filters. The microstrip coupled dielectric resonator is the primary focus, but an alternative coupling technique is discussed and comparatively evaluated. It is concluded that coupling factors as large as 65 are achievable.

  6. Evaluation of the Event Driven Phenology Model Coupled to the VegET Evapotranspiration Model Using Spatially Explicit Comparisons with Independent Reference Data

    NASA Astrophysics Data System (ADS)

    Kovalskyy, V.; Henebry, G. M.; Roy, D. P.; Senay, G. B.

    2011-12-01

    Vegetation growing cycles have a profound influence on regional evapotranspiration regimes. The recently developed Event Driven Phenology Model (EDPM) is an empirical crop-specific phenology model with data assimilation capabilities. Deployed in prognostic mode, the EDPM uses weather forcing data to produce daily estimates of phenology coefficients; and in diagnostic mode a one-dimensional Kalman filter is used to adjust EDPM estimates with satellite normalized difference vegetation index (NDVI) retrievals. In this study the EDPM is coupled to the VegET model that uses the Penman-Monteith equation to calculate reference ET and a water balance model for water stress coefficients to derive daily actual evapotranspiration. The coupled models were run for the croplands of the U.S. Northern Great Plains for three annual growing seasons to derive 8-day total actual evapotranspiration (ETa) estimates at 0.05° spatial resolution. The models were driven by North American Land Data Assimilation System (NLDAS) weather forcing and parameterized using annual MODIS cropland cover maps. Regional validation of the modeled NDVI and ETa were undertaken by comparison with MODIS NDVI and MODIS ETa products respectively. The modeled NDVI had a median coefficient of determination (r2) of 0.83 and a root mean square error (RMSE) of 0.15 within study area. With the EDPM deployed in both prognostic and diagnostic modes, the modeled ETa had r2 of 0.75 and RMSE of about 25% of season average ETa per observation period. With small computational effort these results yield comparable accuracy to those from computationally complex models of ETa which require more parameterization. The performance of the coupling scheme demonstrates that the modeling approach is a promising avenue for regional application studies.

  7. Design, construction and evaluation of a 12.2 GHz, 4.0 kW-CW coupled-cavity traveling wave tube

    NASA Technical Reports Server (NTRS)

    Ayers, W. R.; Harman, W. A.

    1973-01-01

    An analytical and experimental program to study design techniques and to utilize these techniques to optimize the performance of an X-band 4 kW, CW traveling wave tube ultimately intended for satellite-borne television broadcast transmitters is described. The design is based on the coupled-cavity slow-wave circuit with velocity resynchronization to maximize the conversion efficiency. The design incorporates a collector which is demountable from the tube. This was done to facilitate multistage depressed collector experiments employing a NASA designed axisymmetric, electrostatic collector for linear beam microwave tubes after shipment of the tubes to NASA.

  8. Evaluation of the Role of G Protein-Coupled Receptor Kinase 3 in Desensitization of Mouse Odorant Receptors in a Mammalian Cell Line and in Olfactory Sensory Neurons

    PubMed Central

    Kato, Aya; Reisert, Johannes; Ihara, Sayoko; Yoshikawa, Keiichi

    2014-01-01

    Thousands of odors are sensed and discriminated by G protein-coupled odorant receptors (ORs) expressed in olfactory sensory neurons (OSNs). G protein-coupled receptor kinases (GRKs) may have a role in desensitization of ORs. However, whether ORs are susceptible to agonist-dependent desensitization and whether GRKs affect odorant responsiveness of OSNs are currently unknown. Here we show that GRK3 attenuated the agonist responsiveness of a specific mouse odorant receptor for eugenol (mOR-EG) upon agonist pretreatment in HEK293 cells, but GRK3 did not affect the response amplitude or the recovery kinetics upon repeated agonist stimulation. We performed electrophysiological recordings of single OSNs which expressed mOR-EG and green fluorescent protein (GFP) in the presence or absence of GRK3. The kinetics and amplitude of agonist responsiveness of individual GFP-labeled mOR-EG neurons were not significantly affected by the absence of GRK3. These results indicate that the role of GRK3 in attenuating ORs responsiveness in OSNs may have been overestimated. PMID:25313015

  9. Evaluation of Laser Ablation Inductively Coupled Plasma Mass Spectrometry for the Quantitative Determination of Lead in Different Parts of Archeological Human Teeth

    PubMed Central

    Bellis, David J.; Parsons, Patrick J.; Jones, Joseph; Amarasiriwardena, Dula

    2011-01-01

    The lead content of teeth or tooth-parts has been used as a biomarker of cumulative lead exposure in clinical, epidemiological, environmental, and archaeological studies. Through the application of laser ablation inductively coupled plasma mass spectrometry, a pilot study of the micrometer-scale distribution and quantification of lead was conducted for two human teeth obtained from an archeological burial site in Manhattan, New York, USA. Lead was highly localized within each tooth, with accumulation in circumpulpal dentine and cementum. The maximum localized lead content in circumpulpal dentine was remarkably high, almost 2000 μg g-1, compared to the mean enamel and dentine content of about 5 μg g-1. The maximum lead content in cementum was approximately 700 μg g-1. The large quantity of cementum found in the teeth suggested that the subjects had hypercementosis (excess cementum formation) of the root, a condition reported to have been prevalent among African-American slave populations. The distribution of lead in these human teeth was remarkably similar to the distribution that we previously reported in the teeth of present-day lead-dosed goats. The data shown demonstrate the feasibility of using laser ablation inductively coupled plasma mass spectrometry to examine lead exposure in archaeological studies. PMID:22467976

  10. Highly efficient perturbative + variational strategy based on orthogonal valence bond theory for the evaluation of magnetic coupling constants. Application to the trinuclear Cu(ii) site of multicopper oxidases.

    PubMed

    Tenti, Lorenzo; Maynau, Daniel; Angeli, Celestino; Calzado, Carmen J

    2016-07-21

    A new strategy based on orthogonal valence-bond analysis of the wave function combined with intermediate Hamiltonian theory has been applied to the evaluation of the magnetic coupling constants in two AF systems. This approach provides both a quantitative estimate of the J value and a detailed analysis of the main physical mechanisms controlling the coupling, using a combined perturbative + variational scheme. The procedure requires a selection of the dominant excitations to be treated variationally. Two methods have been employed: a brute-force selection, using a logic similar to that of the CIPSI approach, or entanglement measures, which identify the most interacting orbitals in the system. Once a reduced set of excitations (about 300 determinants) is established, the interaction matrix is dressed at the second-order of perturbation by the remaining excitations of the CI space. The diagonalization of the dressed matrix provides J values in good agreement with experimental ones, at a very low-cost. This approach demonstrates the key role of d → d* excitations in the quantitative description of the magnetic coupling, as well as the importance of using an extended active space, including the bridging ligand orbitals, for the binuclear model of the intermediates of multicopper oxidases. The method is a promising tool for dealing with complex systems containing several active centers, as an alternative to both pure variational and DFT approaches. PMID:27336417