The Conceptual Landscape of iSchools: Examining Current Research Interests of Faculty Members

ERIC Educational Resources Information Center

Holmberg, Kim

2013-01-01

Introduction: This study describes the intellectual landscape of iSchools and examines how the various iSchools map on to these research areas. Method: The primary focus of the data collection process was on faculty members' current research interests as described by the individuals themselves. A co-word analysis of all iSchool faculty…

Finite element methods and Navier-Stokes equations

NASA Astrophysics Data System (ADS)

Cuvelier, C.; Segal, A.; van Steenhoven, A. A.

This book is devoted to two and three-dimensional FEM analysis of the Navier-Stokes (NS) equations describing one flow of a viscous incompressible fluid. Three different approaches to the NS equations are described: a direct method, a penalty method, and a method that constructs discrete solenoidal vector fields. Subjects of current research which are important from the industrial/technological viewpoint are considered, including capillary-free boundaries, nonisothermal flows, turbulence, and non-Newtonian fluids.

Current Knowledge and Projection on Assessing the Effectiveness of Training.

ERIC Educational Resources Information Center

Orlansky, Jesse

This discussion of methods used to assess the effectiveness of training for U.S. Army personnel identifies various types of training, describes methods currently used, and suggests ways of improving the assessment process. The methodology and results of assessments of effectiveness, including the costs associated with the level of performance, are…

Temperature compensated and self-calibrated current sensor using reference current

DOEpatents

Yakymyshyn, Christopher Paul [Seminole, FL; Brubaker, Michael Allen [Loveland, CO; Yakymyshyn, Pamela Jane [Seminole, FL

2008-01-22

A method is described to provide temperature compensation and self-calibration of a current sensor based on a plurality of magnetic field sensors positioned around a current carrying conductor. A reference electrical current carried by a conductor positioned within the sensing window of the current sensor is used to correct variations in the output signal due to temperature variations and aging.

Defining the methodological challenges and opportunities for an effective science of sociotechnical systems and safety.

PubMed

Waterson, Patrick; Robertson, Michelle M; Cooke, Nancy J; Militello, Laura; Roth, Emilie; Stanton, Neville A

2015-01-01

An important part of the application of sociotechnical systems theory (STS) is the development of methods, tools and techniques to assess human factors and ergonomics workplace requirements. We focus in this paper on describing and evaluating current STS methods for workplace safety, as well as outlining a set of six case studies covering the application of these methods to a range of safety contexts. We also describe an evaluation of the methods in terms of ratings of their ability to address a set of theoretical and practical questions (e.g. the degree to which methods capture static/dynamic aspects of tasks and interactions between system levels). The outcomes from the evaluation highlight a set of gaps relating to the coverage and applicability of current methods for STS and safety (e.g. coverage of external influences on system functioning; method usability). The final sections of the paper describe a set of future challenges, as well as some practical suggestions for tackling these. We provide an up-to-date review of STS methods, a set of case studies illustrating their use and an evaluation of their strengths and weaknesses. The paper concludes with a 'roadmap' for future work.

Monotonicity based imaging method for time-domain eddy current problems

NASA Astrophysics Data System (ADS)

Su, Z.; Ventre, S.; Udpa, L.; Tamburrino, A.

2017-12-01

Eddy current imaging is an example of inverse problem in nondestructive evaluation for detecting anomalies in conducting materials. This paper introduces the concept of time constants and associated natural modes in eddy current imaging. The monotonicity of time constants is then described and applied to develop a non-iterative imaging method. The proposed imaging method has a low computational cost which makes it suitable for real-time operations. Full 3D numerical examples prove the effectiveness of the method in realistic scenarios. This paper is dedicated to Professor Guglielmo Rubinacci on the occasion of his 65th Birthday.

An Immersed Boundary Method for Solving the Compressible Navier-Stokes Equations with Fluid Structure Interaction

NASA Technical Reports Server (NTRS)

Brehm, Christoph; Barad, Michael F.; Kiris, Cetin C.

2016-01-01

An immersed boundary method for the compressible Navier-Stokes equation and the additional infrastructure that is needed to solve moving boundary problems and fully coupled fluid-structure interaction is described. All the methods described in this paper were implemented in NASA's LAVA solver framework. The underlying immersed boundary method is based on the locally stabilized immersed boundary method that was previously introduced by the authors. In the present paper this method is extended to account for all aspects that are involved for fluid structure interaction simulations, such as fast geometry queries and stencil computations, the treatment of freshly cleared cells, and the coupling of the computational fluid dynamics solver with a linear structural finite element method. The current approach is validated for moving boundary problems with prescribed body motion and fully coupled fluid structure interaction problems in 2D and 3D. As part of the validation procedure, results from the second AIAA aeroelastic prediction workshop are also presented. The current paper is regarded as a proof of concept study, while more advanced methods for fluid structure interaction are currently being investigated, such as geometric and material nonlinearities, and advanced coupling approaches.

Apparatus and method for magnetically unloading a rotor bearing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanders, Seth Robert

An apparatus and method for unloading a rotor bearing is described. The apparatus includes an electromagnet for levitating the rotor. In one embodiment, a sensor of the magnetic field near the electromagnet is used to control the current to levitate the rotor. In another embodiment, a method is provided that includes rotating the rotor, increasing the current to levitate the rotor and decrease the gap between electromagnet and rotor, and then reducing the current to levitate the rotor with a minimal amount of electric power to the electromagnet.

The current status of 3D imaging in dental practice.

PubMed

McNamara, Clare; House, Kate; Davies, Rebecca; Barker, Chris S; Chawla, Ourvinder; Sandy, Jonathan R; Ireland, Anthony J

2011-12-01

This article aims to describe the current status of 3-dimensional (3D) imaging in dental practice. Advances in this field have made 3D imaging far more accessible in all dental fields. This paper describes methods of imaging dental hard and soft tissues and their clinical uses. In addition, the potential advantages and disadvantages of various systems are discussed, as well as expected future developments.

What is the lifetime risk of developing cancer?: the effect of adjusting for multiple primaries

PubMed Central

Sasieni, P D; Shelton, J; Ormiston-Smith, N; Thomson, C S; Silcocks, P B

2011-01-01

Background: The ‘lifetime risk' of cancer is generally estimated by combining current incidence rates with current all-cause mortality (‘current probability' method) rather than by describing the experience of a birth cohort. As individuals may get more than one type of cancer, what is generally estimated is the average (mean) number of cancers over a lifetime. This is not the same as the probability of getting cancer. Methods: We describe a method for estimating lifetime risk that corrects for the inclusion of multiple primary cancers in the incidence rates routinely published by cancer registries. The new method applies cancer incidence rates to the estimated probability of being alive without a previous cancer. The new method is illustrated using data from the Scottish Cancer Registry and is compared with ‘gold-standard' estimates that use (unpublished) data on first primaries. Results: The effect of this correction is to make the estimated ‘lifetime risk' smaller. The new estimates are extremely similar to those obtained using incidence based on first primaries. The usual ‘current probability' method considerably overestimates the lifetime risk of all cancers combined, although the correction for any single cancer site is minimal. Conclusion: Estimation of the lifetime risk of cancer should either be based on first primaries or should use the new method. PMID:21772332

Non-destructive control of graphite electrodes with use of current displacement effect

NASA Astrophysics Data System (ADS)

Myatezh, A. V.; Malozyomov, B. V.; Smirnov, M. A.

2017-10-01

The work is devoted to methods of nondestructive diagnostics and their use for solving the problem of diagnosing various defects in solid surface of graphite electrodes used in steelmaking furnaces. Various non-destructive control methods of materials are analyzed. In the article, methods of eddy-current defectoscopy of graphite electrodes are considered. Rationalization of the sensitivity increase of the method and localization of damage is described. Imitating modeling of electromagnetic processes was executed; results were made and conclusions were drawn.

Improvement of calculation method for electrical parameters of short network of ore-thermal furnaces

NASA Astrophysics Data System (ADS)

Aliferov, A. I.; Bikeev, R. A.; Goreva, L. P.

2017-10-01

The paper describes a new calculation method for active and inductive resistance of split interleaved current leads packages in ore-thermal electric furnaces. The method is developed on basis of regression analysis of dependencies of active and inductive resistances of the packages on their geometrical parameters, mutual disposition and interleaving pattern. These multi-parametric calculations have been performed with ANSYS software. The proposed method allows solving split current lead electrical parameters minimization and balancing problems for ore-thermal furnaces.

Method of targeted delivery of laser beam to isolated retinal rods by fiber optics.

PubMed

Sim, Nigel; Bessarab, Dmitri; Jones, C Michael; Krivitsky, Leonid

2011-11-01

A method of controllable light delivery to retinal rod cells using an optical fiber is described. Photo-induced current of the living rod cells was measured with the suction electrode technique. The approach was tested with measurements relating the spatial distribution of the light intensity to photo-induced current. In addition, the ion current responses of rod cells to polarized light at two different orientation geometries of the cells were studied.

The NLM Indexing Initiative.

PubMed Central

Aronson, A. R.; Bodenreider, O.; Chang, H. F.; Humphrey, S. M.; Mork, J. G.; Nelson, S. J.; Rindflesch, T. C.; Wilbur, W. J.

2000-01-01

The objective of NLM's Indexing Initiative (IND) is to investigate methods whereby automated indexing methods partially or completely substitute for current indexing practices. The project will be considered a success if methods can be designed and implemented that result in retrieval performance that is equal to or better than the retrieval performance of systems based principally on humanly assigned index terms. We describe the current state of the project and discuss our plans for the future. PMID:11079836

Scanning tunneling spectroscopy under large current flow through the sample.

PubMed

Maldonado, A; Guillamón, I; Suderow, H; Vieira, S

2011-07-01

We describe a method to make scanning tunneling microscopy/spectroscopy imaging at very low temperatures while driving a constant electric current up to some tens of mA through the sample. It gives a new local probe, which we term current driven scanning tunneling microscopy/spectroscopy. We show spectroscopic and topographic measurements under the application of a current in superconducting Al and NbSe(2) at 100 mK. Perspective of applications of this local imaging method includes local vortex motion experiments, and Doppler shift local density of states studies.

Service and Methods Demonstration - Annual Report

DOT National Transportation Integrated Search

1975-11-01

This report contains a description of the Service and Methods Demonstration Program. Transit demonstration projects undertaken in previous years are reviewed. Recently completed and current demonstration projects are described and project results fro...

AC/DC current ratio in a current superimposition variable flux reluctance machine

NASA Astrophysics Data System (ADS)

Kohara, Akira; Hirata, Katsuhiro; Niguchi, Noboru; Takahara, Kazuaki

2018-05-01

We have proposed a current superimposition variable flux reluctance machine for traction motors. The torque-speed characteristics of this machine can be controlled by increasing or decreasing the DC current. In this paper, we discuss an AC/DC current ratio in the current superimposition variable flux reluctance machine. The structure and control method are described, and the characteristics are computed using FEA in several AC/DC ratios.

Exploitation of SAR data for measurement of ocean currents and wave velocities

NASA Technical Reports Server (NTRS)

Shuchman, R. A.; Lyzenga, D. R.; Klooster, A., Jr.

1981-01-01

Methods of extracting information on ocean currents and wave orbital velocities from SAR data by an analysis of the Doppler frequency content of the data are discussed. The theory and data analysis methods are discussed, and results are presented for both aircraft and satellite (SEASAT) data sets. A method of measuring the phase velocity of a gravity wave field is also described. This method uses the shift in position of the wave crests on two images generated from the same data set using two separate Doppler bands. Results of the current measurements are pesented for 11 aircraft data sets and 4 SEASAT data sets.

78 FR 22540 - Notice of Public Meeting/Webinar: EPA Method Development Update on Drinking Water Testing Methods...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-16

...: EPA Method Development Update on Drinking Water Testing Methods for Contaminant Candidate List... Division will describe methods currently in development for many CCL contaminants, with an expectation that several of these methods will support future cycles of the Unregulated Contaminant Monitoring Rule (UCMR...

Emerging nondestructive inspection methods for aging aircraft

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beattie, A; Dahlke, L; Gieske, J

This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with amore » discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.« less

Analytical procedures for water-soluble vitamins in foods and dietary supplements: a review.

PubMed

Blake, Christopher J

2007-09-01

Water-soluble vitamins include the B-group vitamins and vitamin C. In order to correctly monitor water-soluble vitamin content in fortified foods for compliance monitoring as well as to establish accurate data banks, an accurate and precise analytical method is a prerequisite. For many years microbiological assays have been used for analysis of B vitamins. However they are no longer considered to be the gold standard in vitamins analysis as many studies have shown up their deficiencies. This review describes the current status of analytical methods, including microbiological assays and spectrophotometric, biosensor and chromatographic techniques. In particular it describes the current status of the official methods and highlights some new developments in chromatographic procedures and detection methods. An overview is made of multivitamin extractions and analyses for foods and supplements.

A review on the solution of Grad-Shafranov equation in the cylindrical coordinates based on the Chebyshev collocation technique

NASA Astrophysics Data System (ADS)

Amerian, Z.; Salem, M. K.; Salar Elahi, A.; Ghoranneviss, M.

2017-03-01

Equilibrium reconstruction consists of identifying, from experimental measurements, a distribution of the plasma current density that satisfies the pressure balance constraint. Numerous methods exist to solve the Grad-Shafranov equation, describing the equilibrium of plasma confined by an axisymmetric magnetic field. In this paper, we have proposed a new numerical solution to the Grad-Shafranov equation (an axisymmetric, magnetic field transformed in cylindrical coordinates solved with the Chebyshev collocation method) when the source term (current density function) on the right-hand side is linear. The Chebyshev collocation method is a method for computing highly accurate numerical solutions of differential equations. We describe a circular cross-section of the tokamak and present numerical result of magnetic surfaces on the IR-T1 tokamak and then compare the results with an analytical solution.

Automatic method of measuring silicon-controlled-rectifier holding current

NASA Technical Reports Server (NTRS)

Maslowski, E. A.

1972-01-01

Development of automated silicon controlled rectifier circuit for measuring minimum anode current required to maintain rectifiers in conducting state is discussed. Components of circuit are described and principles of operation are explained. Illustration of circuit is provided.

Defining the methodological challenges and opportunities for an effective science of sociotechnical systems and safety

PubMed Central

Waterson, Patrick; Robertson, Michelle M.; Cooke, Nancy J.; Militello, Laura; Roth, Emilie; Stanton, Neville A.

2015-01-01

An important part of the application of sociotechnical systems theory (STS) is the development of methods, tools and techniques to assess human factors and ergonomics workplace requirements. We focus in this paper on describing and evaluating current STS methods for workplace safety, as well as outlining a set of six case studies covering the application of these methods to a range of safety contexts. We also describe an evaluation of the methods in terms of ratings of their ability to address a set of theoretical and practical questions (e.g. the degree to which methods capture static/dynamic aspects of tasks and interactions between system levels). The outcomes from the evaluation highlight a set of gaps relating to the coverage and applicability of current methods for STS and safety (e.g. coverage of external influences on system functioning; method usability). The final sections of the paper describe a set of future challenges, as well as some practical suggestions for tackling these. Practitioner Summary: We provide an up-to-date review of STS methods, a set of case studies illustrating their use and an evaluation of their strengths and weaknesses. The paper concludes with a ‘roadmap’ for future work. PMID:25832121

Methods for stable recording of short-circuit current in a Na+-transporting epithelium.

PubMed

Gondzik, Veronika; Awayda, Mouhamed S

2011-07-01

Epithelial Na(+) transport as measured by a variety of techniques, including the short-circuit current technique, has been described to exhibit a "rundown" phenomenon. This phenomenon manifests as time-dependent decrease of current and resistance and precludes the ability to carry out prolonged experiments aimed at examining the regulation of this transport. We developed methods for prolonged stable recordings of epithelial Na(+) transport using modifications of the short-circuit current technique and commercial Ussing-type chambers. We utilize the polarized MDCK cell line expressing the epithelial Na(+) channel (ENaC) to describe these methods. Briefly, existing commercial chambers were modified to allow continuous flow of Ringer solution and precise control of such flow. Chamber manifolds and associated plumbing were modified to allow precise temperature clamp preventing temperature oscillations. Recording electrodes were modified to eliminate the use of KCl and prevent membrane depolarization from KCl leakage. Solutions utilized standard bicarbonate-based buffers, but all gasses were prehydrated to clamp buffer osmolarity. We demonstrate that these modifications result in measurements of current and resistance that are stable for at least 2 h. We further demonstrate that drifts in osmolarity similar to those obtained before prior to our modifications can lead to a decrease of current and resistance similar to those attributed to rundown.

The role of finite-difference methods in design and analysis for supersonic cruise

NASA Technical Reports Server (NTRS)

Townsend, J. C.

1976-01-01

Finite-difference methods for analysis of steady, inviscid supersonic flows are described, and their present state of development is assessed with particular attention to their applicability to vehicles designed for efficient cruise flight. Current work is described which will allow greater geometric latitude, improve treatment of embedded shock waves, and relax the requirement that the axial velocity must be supersonic.

78 FR 35072 - Proposed Revisions to Reliability Assurance Program

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-11

... current staff review methods and practices based on lessons learned from NRC reviews of design... following methods (unless this document describes a different method for submitting comments on a specific... possesses and is publicly-available, by the following methods: Federal Rulemaking Web site: Go to http://www...

Current Directions in Mediation Analysis

PubMed Central

MacKinnon, David P.; Fairchild, Amanda J.

2010-01-01

Mediating variables continue to play an important role in psychological theory and research. A mediating variable transmits the effect of an antecedent variable on to a dependent variable, thereby providing more detailed understanding of relations among variables. Methods to assess mediation have been an active area of research for the last two decades. This paper describes the current state of methods to investigate mediating variables. PMID:20157637

Oscillatory nonohomic current drive for maintaining a plasma current

DOEpatents

Fisch, N.J.

1984-01-01

Apparatus and methods are described for maintaining a plasma current with an oscillatory nonohmic current drive. Each cycle of operation has a generation period in which current driving energy is applied to the plasma, and a relaxation period in which current driving energy is removed. Plasma parameters, such as plasma temperature or plasma average ionic charge state, are modified during the generation period so as to oscillate plasma resistivity in synchronism with the application of current driving energy. The invention improves overall current drive efficiencies.

Quantum Monte Carlo methods for nuclear physics

DOE PAGES

Carlson, Joseph A.; Gandolfi, Stefano; Pederiva, Francesco; ...

2014-10-19

Quantum Monte Carlo methods have proved very valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states, moments and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. We review the nuclear interactions and currents, and describe the continuum Quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit, and three-bodymore » interactions. We present a variety of results including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. We also describe low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars. A coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.« less

Targeted methods for quantitative analysis of protein glycosylation

PubMed Central

Goldman, Radoslav; Sanda, Miloslav

2018-01-01

Quantification of proteins by LC-MS/MS-MRM has become a standard method with broad projected clinical applicability. MRM quantification of protein modifications is, however, far less utilized, especially in the case of glycoproteins. This review summarizes current methods for quantitative analysis of protein glycosylation with a focus on MRM methods. We describe advantages of this quantitative approach, analytical parameters that need to be optimized to achieve reliable measurements, and point out the limitations. Differences between major classes of N- and O-glycopeptides are described and class-specific glycopeptide assays are demonstrated. PMID:25522218

Shoreline Activities.

ERIC Educational Resources Information Center

Stout, Prentice K.

1980-01-01

Described is a method of photographically recording the seasonal movements of the beach, and the equipment and details used in this method. Included is a method for determining current speed and instruction for construction of a tin can viewing box to be used in underwater sea form observations. (Author/DS)

Landslide and Land Subsidence Hazards to Pipelines

USGS Publications Warehouse

Baum, Rex L.; Galloway, Devin L.; Harp, Edwin L.

2008-01-01

Landslides and land subsidence pose serious hazards to pipelines throughout the world. Many existing pipeline corridors and more and more new pipelines cross terrain that is affected by either landslides, land subsidence, or both. Consequently the pipeline industry recognizes a need for increased awareness of methods for identifying and evaluating landslide and subsidence hazard for pipeline corridors. This report was prepared in cooperation with the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration, and Pipeline Research Council International through a cooperative research and development agreement (CRADA) with DGH Consulting, Inc., to address the need for up-to-date information about current methods to identify and assess these hazards. Chapters in this report (1) describe methods for evaluating landslide hazard on a regional basis, (2) describe the various types of land subsidence hazard in the United States and available methods for identifying and quantifying subsidence, and (3) summarize current methods for investigating individual landslides. In addition to the descriptions, this report provides information about the relative costs, limitations and reliability of various methods.

Hierarchical equations of motion method applied to nonequilibrium heat transport in model molecular junctions: Transient heat current and high-order moments of the current operator

NASA Astrophysics Data System (ADS)

Song, Linze; Shi, Qiang

2017-02-01

We present a theoretical approach to study nonequilibrium quantum heat transport in molecular junctions described by a spin-boson type model. Based on the Feynman-Vernon path integral influence functional formalism, expressions for the average value and high-order moments of the heat current operators are derived, which are further obtained directly from the auxiliary density operators (ADOs) in the hierarchical equations of motion (HEOM) method. Distribution of the heat current is then derived from the high-order moments. As the HEOM method is nonperturbative and capable of treating non-Markovian system-environment interactions, the method can be applied to various problems of nonequilibrium quantum heat transport beyond the weak coupling regime.

Quasilinear theory of plasma turbulence. Origins, ideas, and evolution of the method

NASA Astrophysics Data System (ADS)

Bakunin, O. G.

2018-01-01

The quasilinear method of describing weak plasma turbulence is one of the most important elements of current plasma physics research. Today, this method is not only a tool for solving individual problems but a full-fledged theory of general physical interest. The author's objective is to show how the early ideas of describing the wave-particle interactions in a plasma have evolved as a result of the rapid expansion of the research interests of turbulence and turbulent transport theorists.

MONOMIALS AND BASIN CYLINDERS FOR NETWORK DYNAMICS.

PubMed

Austin, Daniel; Dinwoodie, Ian H

We describe methods to identify cylinder sets inside a basin of attraction for Boolean dynamics of biological networks. Such sets are used for designing regulatory interventions that make the system evolve towards a chosen attractor, for example initiating apoptosis in a cancer cell. We describe two algebraic methods for identifying cylinders inside a basin of attraction, one based on the Groebner fan that finds monomials that define cylinders and the other on primary decomposition. Both methods are applied to current examples of gene networks.

MONOMIALS AND BASIN CYLINDERS FOR NETWORK DYNAMICS

PubMed Central

AUSTIN, DANIEL; DINWOODIE, IAN H

2014-01-01

We describe methods to identify cylinder sets inside a basin of attraction for Boolean dynamics of biological networks. Such sets are used for designing regulatory interventions that make the system evolve towards a chosen attractor, for example initiating apoptosis in a cancer cell. We describe two algebraic methods for identifying cylinders inside a basin of attraction, one based on the Groebner fan that finds monomials that define cylinders and the other on primary decomposition. Both methods are applied to current examples of gene networks. PMID:25620893

Method and apparatus for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiuchi, T.; Yasuoka, A.

1988-05-24

A method of controlling the solenoid current of a solenoid valve which controls suction air in an internal combustion engine, is described comprising the steps of: calculating a solenoid current control value as a function of engine operating conditions; detecting an engine coolant temperature corresponding to the solenoid temperature; determining a temperature correction value in accordance with the solenoid temperature; and calculating a driving signal for controlling the operation of the solenoid as a function of the solenoid current control value and the temperature correction value.

Optimal lattice-structured materials

DOE PAGES

Messner, Mark C.

2016-07-09

This paper describes a method for optimizing the mesostructure of lattice-structured materials. These materials are periodic arrays of slender members resembling efficient, lightweight macroscale structures like bridges and frame buildings. Current additive manufacturing technologies can assemble lattice structures with length scales ranging from nanometers to millimeters. Previous work demonstrates that lattice materials have excellent stiffness- and strength-to-weight scaling, outperforming natural materials. However, there are currently no methods for producing optimal mesostructures that consider the full space of possible 3D lattice topologies. The inverse homogenization approach for optimizing the periodic structure of lattice materials requires a parameterized, homogenized material model describingmore » the response of an arbitrary structure. This work develops such a model, starting with a method for describing the long-wavelength, macroscale deformation of an arbitrary lattice. The work combines the homogenized model with a parameterized description of the total design space to generate a parameterized model. Finally, the work describes an optimization method capable of producing optimal mesostructures. Several examples demonstrate the optimization method. One of these examples produces an elastically isotropic, maximally stiff structure, here called the isotruss, that arguably outperforms the anisotropic octet truss topology.« less

Temperature compensated and self-calibrated current sensor using reference magnetic field

DOEpatents

Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

2007-10-09

A method is described to provide temperature compensation and self-calibration of a current sensor based on a plurality of magnetic field sensors positioned around a current carrying conductor. A reference magnetic field generated within the current sensor housing is detected by the magnetic field sensors and is used to correct variations in the output signal due to temperature variations and aging.

Temperature compensated current sensor using reference magnetic field

DOEpatents

Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

2007-10-09

A method is described to provide temperature compensation and self-calibration of a current sensor based on a plurality of magnetic field sensors positioned around a current carrying conductor. A reference magnetic field generated within the current sensor housing is detected by a separate but identical magnetic field sensor and is used to correct variations in the output signal due to temperature variations and aging.

A commercially viable virtual reality knee arthroscopy training system.

PubMed

McCarthy, A D; Hollands, R J

1998-01-01

Arthroscopy is a minimally invasive form of surgery used to inspect joints. It is complex to learn yet current training methods appear inadequate, thus negating the potential benefits to the patient. This paper describes the development and initial assessment of a cost-effective virtual reality based system for training surgeons in arthroscopy of the knee. The system runs on a P.C. Initial assessments by surgeons have been positive and current developments in deformable models are described.

Direct current electrical potential measurement of the growth of small cracks

NASA Technical Reports Server (NTRS)

Gangloff, Richard P.; Slavik, Donald C.; Piascik, Robert S.; Van Stone, Robert H.

1992-01-01

The analytical and experimental aspects of the direct-current electrical potential difference (dcEPD) method for continuous monitoring of the growth kinetics of short (50 to 500 microns) fatigue cracks are reviewed, and successful applications of the deEPD method to study fatigue crack propagation in a variety of metallic alloys exposed to various environments are described. Particular attention is given to the principle of the dcEPD method, the analytical electrical potential calibration relationships, and the experimental procedures and equipment.

Temperature compensated and self-calibrated current sensor

DOEpatents

Yakymyshyn, Christopher Paul; Brubaker, Michael Allen; Yakymyshyn, Pamela Jane

2007-09-25

A method is described to provide temperature compensation and reduction of drift due to aging for a current sensor based on a plurality of magnetic field sensors positioned around a current carrying conductor. The offset voltage signal generated by each magnetic field sensor is used to correct variations in the output signal due to temperature variations and aging.

A Short-Circuit Method for Networks.

ERIC Educational Resources Information Center

Ong, P. P.

1983-01-01

Describes a method of network analysis that allows avoidance of Kirchoff's Laws (providing the network is symmetrical) by reduction to simple series/parallel resistances. The method can be extended to symmetrical alternating current, capacitance or inductance if corresponding theorems are used. Symmetric cubic network serves as an example. (JM)

A Current View of Learning Disabilities.

ERIC Educational Resources Information Center

Feagans, Lynne

1983-01-01

The issue of defining learning disability is considered. Important recent trends in research are reviewed with regard to: intellectual skills, academic retardation, neurological and behavioral dysfunction, and cognitive and interactive processes. Current intervention methods are also briefly described. Available from: Journal of Pediatrics, C.V.…

Financing Academic Departments of Psychiatry

ERIC Educational Resources Information Center

Liptzin, Benjamin; Meyer, Roger E.

2011-01-01

Objective: The authors describe the many financial challenges facing academic departments of psychiatry and the resulting opportunities that may arise. Method: The authors review the history of financial challenges, the current economic situation, and what may lie ahead for academic departments of psychiatry. Results: The current environment has…

How current ginning processes affect fiber length uniformity index

USDA-ARS?s Scientific Manuscript database

There is a need to develop cotton ginning methods that improve fiber characteristics that are compatible with the newer and more efficient spinning technologies. A literature search produced recent studies that described how current ginning processes affect HVI fiber length uniformity index. Resul...

Methods for describing the electromagnetic properties of silver and gold nanoparticles.

PubMed

Zhao, Jing; Pinchuk, Anatoliy O; McMahon, Jeffrey M; Li, Shuzhou; Ausman, Logan K; Atkinson, Ariel L; Schatz, George C

2008-12-01

This Account provides an overview of the methods that are currently being used to study the electromagnetics of silver and gold nanoparticles, with an emphasis on the determination of extinction and surface-enhanced Raman scattering (SERS) spectra. These methods have proven to be immensely useful in recent years for interpreting a wide range of nanoscience experiments and providing the capability to describe optical properties of particles up to several hundred nanometers in dimension, including arbitrary particle structures and complex dielectric environments (adsorbed layers of molecules, nearby metal films, and other particles). While some of the methods date back to Mie's celebrated work a century ago, others are still at the forefront of algorithm development in computational electromagnetics. This Account gives a qualitative description of the physical and mathematical basis behind the most commonly used methods, including both analytical and numerical methods, as well as representative results of applications that are relevant to current experiments. The analytical methods that we discuss are either derived from Mie theory for spheres or from the quasistatic (Gans) model as applied to spheres and spheroids. In this discussion, we describe the use of Mie theory to determine electromagnetic contributions to SERS enhancements that include for retarded dipole emission effects, and the use of the quasistatic approximation for spheroidal particles interacting with dye adsorbate layers. The numerical methods include the discrete dipole approximation (DDA), the finite difference time domain (FDTD) method, and the finite element method (FEM) based on Whitney forms. We discuss applications such as using DDA to describe the interaction of two gold disks to define electromagnetic hot spots, FDTD for light interacting with metal wires that go from particle-like plasmonic response to the film-like transmission as wire dimension is varied, and FEM studies of electromagnetic fields near cubic particles.

The current status and portability of our sequence handling software.

PubMed Central

Staden, R

1986-01-01

I describe the current status of our sequence analysis software. The package contains a comprehensive suite of programs for managing large shotgun sequencing projects, a program containing 61 functions for analysing single sequences and a program for comparing pairs of sequences for similarity. The programs that have been described before have been improved by the addition of new functions and by being made very much easier to use. The major interactive programs have 125 pages of online help available from within them. Several new programs are described including screen editing of aligned gel readings for shotgun sequencing projects; a method to highlight errors in aligned gel readings, new methods for searching for putative signals in sequences. We use the programs on a VAX computer but the whole package has been rewritten to make it easy to transport it to other machines. I believe the programs will now run on any machine with a FORTRAN77 compiler and sufficient memory. We are currently putting the programs onto an IBM PC XT/AT and another micro running under UNIX. PMID:3511446

Review of Railgun Modeling Techniques: The Computation of Railgun Force and Other Key Factors

NASA Astrophysics Data System (ADS)

Eckert, Nathan James

Currently, railgun force modeling either uses the simple "railgun force equation" or finite element methods. It is proposed here that a middle ground exists that does not require the solution of partial differential equations, is more readily implemented than finite element methods, and is more accurate than the traditional force equation. To develop this method, it is necessary to examine the core railgun factors: power supply mechanisms, the distribution of current in the rails and in the projectile which slides between them (called the armature), the magnetic field created by the current flowing through these rails, the inductance gradient (a key factor in simplifying railgun analysis, referred to as L'), the resultant Lorentz force, and the heating which accompanies this action. Common power supply technologies are investigated, and the shape of their current pulses are modeled. The main causes of current concentration are described, and a rudimentary method for computing current distribution in solid rails and a rectangular armature is shown to have promising accuracy with respect to outside finite element results. The magnetic field is modeled with two methods using the Biot-Savart law, and generally good agreement is obtained with respect to finite element methods (5.8% error on average). To get this agreement, a factor of 2 is added to the original formulation after seeing a reliable offset with FEM results. Three inductance gradient calculations are assessed, and though all agree with FEM results, the Kerrisk method and a regression analysis method developed by Murugan et al. (referred to as the LRM here) perform the best. Six railgun force computation methods are investigated, including the traditional railgun force equation, an equation produced by Waindok and Piekielny, and four methods inspired by the work of Xu et al. Overall, good agreement between the models and outside data is found, but each model's accuracy varies significantly between comparisons. Lastly, an approximation of the temperature profile in railgun rails originally presented by McCorkle and Bahder is replicated. In total, this work describes railgun technology and moderately complex railgun modeling methods, but is inconclusive about the presence of a middle-ground modeling method.

The morphology of flare phenomena, magnetic fields, and electric currents in active regions. I - Introduction and methods

NASA Technical Reports Server (NTRS)

Canfield, Richard C.; De La Beaujardiere, J.-F.; Fan, Yuhong; Leka, K. D.; Mcclymont, A. N.; Metcalf, Thomas R.; Mickey, Donald L.; Wuelser, Jean-Pierre; Lites, Bruce W.

1993-01-01

Electric current systems in solar active regions and their spatial relationship to sites of electron precipitation and high-pressure in flares were studied with the purpose of providing observational evidence for or against the flare models commonly discussed in the literature. The paper describes the instrumentation, the data used, and the data analysis methods, as well as improvements made upon earlier studies. Several flare models are overviewed, and the predictions yielded by each model for the relationships of flares to the vertical current systems are discussed.

A multiclass multiresidue LC-MS/MS method for analysis of veterinary drugs in bovine kidney

USDA-ARS?s Scientific Manuscript database

The increased efficiency permitted by multiclass, multiresidue methods has made such approaches very attractive to laboratories involved in monitoring veterinary drug residues in animal tissues. In this current work, evaluation of a multiclass multiresidue LC-MS/MS method in bovine kidney is describ...

Using Replication Projects in Teaching Research Methods

ERIC Educational Resources Information Center

Standing, Lionel G.; Grenier, Manuel; Lane, Erica A.; Roberts, Meigan S.; Sykes, Sarah J.

2014-01-01

It is suggested that replication projects may be valuable in teaching research methods, and also address the current need in psychology for more independent verification of published studies. Their use in an undergraduate methods course is described, involving student teams who performed direct replications of four well-known experiments, yielding…

Improved Sampling Method Reduces Isokinetic Sampling Errors.

ERIC Educational Resources Information Center

Karels, Gale G.

The particulate sampling system currently in use by the Bay Area Air Pollution Control District, San Francisco, California is described in this presentation for the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971. The method represents a practical, inexpensive tool that can…

Topological data analysis as a morphometric method: using persistent homology to demarcate a leaf morphospace

USDA-ARS?s Scientific Manuscript database

Current morphometric methods that comprehensively measure shape cannot compare the disparate leaf shapes found in flowering plants and are sensitive to processing artifacts. Here we describe a persistent homology approach to measuring shape. Persistent homology is a topological method (concerned wit...

Stable superconducting magnet. [high current levels below critical temperature

NASA Technical Reports Server (NTRS)

Boom, R. W. (Inventor)

1967-01-01

Operation of a superconducting magnet is considered. A method is described for; (1) obtaining a relatively high current in a superconducting magnet positioned in a bath of a gas refrigerant; (2) operating a superconducting magnet at a relatively high current level without training; and (3) operating a superconducting magnet containing a plurality of turns of a niobium zirconium wire at a relatively high current level without training.

The Stigma of Families with Mental Illness

ERIC Educational Resources Information Center

Larson, Jon E.; Corrigan, Patrick

2008-01-01

Objective: This article describes family stigma, which is defined as the prejudice and discrimination experienced by individuals through associations with their relatives. Methods: The authors describe family stigma and present current research related to mental illness stigma experienced by family members. Research indicates this type of stigma…

The construction of airfoil pressure models by the plate method: Achievements, current research, technology development and potential applications

NASA Technical Reports Server (NTRS)

Lawing, P. L.

1985-01-01

A method of constructing airfoils by inscribing pressure channels on the face of opposing plates, bonding them together to form one plate with integral channels, and contour machining this plate to form an airfoil model is described. The research and development program to develop the bonding technology is described as well as the construction and testing of an airfoil model. Sample aerodynamic data sets are presented and discussed. Also, work currently under way to produce thin airfoils with camber is presented. Samples of the aft section of a 6 percent airfoil with complete pressure instrumentation including the trailing edge are pictured and described. This technique is particularly useful in fabricating models for transonic cryogenic testing, but it should find application in a wide ange of model construction projects, as well as the fabrication of fuel injectors, space hardware, and other applications requiring advanced bonding technology and intricate fluid passages.

An overview of tests for animal tissues in feeds applied in response to public health concerns regarding bovine spongiform encephalopathy.

PubMed

Gizzi, G; van Raamsdonk, L W D; Baeten, V; Murray, I; Berben, G; Brambilla, G; von Holst, C

2003-04-01

Enforcing the ban on meat-and-bone meal in feed for farmed animals, and especially ruminants, is considered an important measure to prevent the spread of bovine spongiform encephalopathy. The authors describe current analytical methods for the detection and identification of animal tissues in feed. In addition, recently approved requirements, such as the ban of intra-species recycling (practice of feeding an animal species with proteins derived from the bodies, or parts of bodies, of the same species) are described. In principle, four different approaches are currently applied, i.e. microscopic analysis, polymerase chain reaction, immunoassay analysis and near infrared spectroscopy or microscopy. The principal performance characteristics of these methods are presented and compared, and their specific advantages and disadvantages described. Special emphasis is also placed on the impact of rendering conditions, particularly high temperatures and on the use of molecular biology techniques.

Beliefs about the Role of Parenting in Feeding and Childhood Obesity among Mothers of Lower Socioeconomic Status

PubMed Central

Kalinowski, Alison; Krause, Kylene; Berdejo, Carla; Harrell, Kristina; Rosenblum, Katherine; Lumeng, Julie C.

2010-01-01

Objective To examine beliefs about the role of parenting in feeding and childhood obesity among mothers of lower socioeconomic status. Methods Individual semi-structured audio-taped interview with 91 mothers of preschool-aged children (49% of mothers obese, 21% of children obese) in the Midwestern United States. Participant comments were transcribed and common themes identified using the constant comparative method and NVivo software. Results Mothers often described their parents’ feeding style as authoritarian or neglectful, and their own current style as comparatively indulgent and better. Mothers described parents of overweight children as inept or neglectful, but never described their own parenting as such. Conclusions and Implications Encouraging mothers to reflect on how they were fed as children, how it may impact their current parenting, and how the relationship between mothering and child obesity is complex are important nutrition education opportunities. PMID:21724469

Remote sensing of ocean currents

NASA Technical Reports Server (NTRS)

Goldstein, R. M.; Zebker, H. A.; Barnett, T. P.

1989-01-01

A method of remotely measuring near-surface ocean currents with a synthetic aperture radar (SAR) is described. The apparatus consists of a single SAR transmitter and two receiving antennas. The phase difference between SAR image scenes obtained from the antennas forms an interferogram that is directly proportional to the surface current. The first field test of this technique against conventional measurements gives estimates of mean currents accurate to order 20 percent, that is, root-mean-square errors of 5 to 10 centimeters per second in mean flows of 27 to 56 centimeters per second. If the full potential of the method could be realized with spacecraft, then it might be possible to routinely monitor the surface currents of the world's oceans.

Prospects for pharmacologic inhibition of hepatic glucose production.

PubMed

Kurukulasuriya, R; Link, J T; Madar, D J; Pei, Z; Rohde, J J; Richards, S J; Souers, A J; Szczepankiewicz, B G

2003-01-01

Type 2 diabetes is a widespread disease where effective pharmacologic therapies can have a profound beneficial public health impact. Increased hepatic glucose production (HGP) is observed in diabetics and its moderation by currently available agents provides therapeutic benefits. This review describes the challenges associated with the discovery of small molecules that inhibit HGP. Gluconeogenesis, glycogenolysis, liver architecture, and hepatocyte composition are described to provide background information on hepatic function. Current methods of target validation for drug discovery, HGP measurement, diabetes animal models, as well as current drug therapies are covered. In the accompanying review article the new drug targets being probed to produce the next generation of therapies are described. Significant pharmaceutical and academic efforts to pharmacologically inhibit HGP has the opportunity to provide new therapeutics for type 2 diabetics.

Mode-Stirred Method Implementation for HIRF Susceptibility Testing and Results Comparison with Anechoic Method

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.; Ely, Jay J.; Koppen, Sandra V.

2001-01-01

This paper describes the implementation of mode-stirred method for susceptibility testing according to the current DO-160D standard. Test results on an Engine Data Processor using the implemented procedure and the comparisons with the standard anechoic test results are presented. The comparison experimentally shows that the susceptibility thresholds found in mode-stirred method are consistently higher than anechoic. This is consistent with the recent statistical analysis finding by NIST that the current calibration procedure overstates field strength by a fixed amount. Once the test results are adjusted for this value, the comparisons with the anechoic results are excellent. The results also show that test method has excellent chamber to chamber repeatability. Several areas for improvements to the current procedure are also identified and implemented.

DC-Compensated Current Transformer.

PubMed

Ripka, Pavel; Draxler, Karel; Styblíková, Renata

2016-01-20

Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component.

Aerogel sorbents

DOEpatents

Begag, Redouane; Rhine, Wendell E.; Dong, Wenting

2018-04-03

The current invention describes methods and compositions of various sorbents based on aerogels of various silanes and their use as sorbent for carbon dioxide. Methods further provide for optimizing the compositions to increase the stability of the sorbents for prolonged use as carbon dioxide capture matrices.

Aerogel sorbents

DOEpatents

Begag, Redouane; Rhine, Wendell E; Dong, Wenting

2016-04-05

The current invention describes methods and compositions of various sorbents based on aerogels of various silanes and their use as sorbent for carbon dioxide. Methods further provide for optimizing the compositions to increase the stability of the sorbents for prolonged use as carbon dioxide capture matrices.

Teaching about Death to Undergraduates.

ERIC Educational Resources Information Center

Pine, Vanderlyn R.; And Others

Development, implementation, and teaching of a college-level course on dying and death are described. The authors review their own experiences in becoming involved with death education and describe teaching methods, problems, and content of their current course in dying and death at the State University of New York, College at New Paltz. Because…

Methods and Forms of Rehabilitation of Visually Impaired Persons.

ERIC Educational Resources Information Center

Bell, S.

1990-01-01

The paper describes rehabilitation services provided by the Royal National Institute for the Blind (United Kingdom), focusing specifically on its Employment Rehabilitation Centers. Current vocational rehabilitation policy of the Institute is described, and a study in progress to determine the Institute's role in future programs is discussed.…

Auger electron spectroscopy at high spatial resolution and nA primary beam currents

NASA Technical Reports Server (NTRS)

Todd, G.; Poppa, H.; Moorhead, D.; Bales, M.

1975-01-01

An experimental Auger microprobe system is described which incorporates a field-emission electron gun and total beam currents in the nanoampere range. The distinguishing characteristics of this system include a large multistation UHV specimen chamber, pulse counting and fully digital Auger signal-processing techniques, and digital referencing methods to eliminate the effects of beam instabilities. Some preliminary results obtained with this system are described, and it is concluded that field-emission electron sources can be used for high-resolution Auger electron spectroscopy with primary-beam spots of less than 100 nm and beam currents of the order of 1 nA.

Gravitational wave searches using the DSN (Deep Space Network)

NASA Technical Reports Server (NTRS)

Nelson, S. J.; Armstrong, J. W.

1988-01-01

The Deep Space Network Doppler spacecraft link is currently the only method available for broadband gravitational wave searches in the 0.01 to 0.001 Hz frequency range. The DSN's role in the worldwide search for gravitational waves is described by first summarizing from the literature current theoretical estimates of gravitational wave strengths and time scales from various astrophysical sources. Current and future detection schemes for ground based and space based detectors are then discussed. Past, present, and future planned or proposed gravitational wave experiments using DSN Doppler tracking are described. Lastly, some major technical challenges to improve gravitational wave sensitivities using the DSN are discussed.

Progress Toward Accurate Measurements of Power Consumptions of DBD Plasma Actuators

NASA Technical Reports Server (NTRS)

Ashpis, David E.; Laun, Matthew C.; Griebeler, Elmer L.

2012-01-01

The accurate measurement of power consumption by Dielectric Barrier Discharge (DBD) plasma actuators is a challenge due to the characteristics of the actuator current signal. Micro-discharges generate high-amplitude, high-frequency current spike transients superimposed on a low-amplitude, low-frequency current. We have used a high-speed digital oscilloscope to measure the actuator power consumption using the Shunt Resistor method and the Monitor Capacitor method. The measurements were performed simultaneously and compared to each other in a time-accurate manner. It was found that low signal-to-noise ratios of the oscilloscopes used, in combination with the high dynamic range of the current spikes, make the Shunt Resistor method inaccurate. An innovative, nonlinear signal compression circuit was applied to the actuator current signal and yielded excellent agreement between the two methods. The paper describes the issues and challenges associated with performing accurate power measurements. It provides insights into the two methods including new insight into the Lissajous curve of the Monitor Capacitor method. Extension to a broad range of parameters and further development of the compression hardware will be performed in future work.

A New Approach to Special Education Finance: The Resource Cost Model.

ERIC Educational Resources Information Center

Geske, Terry G.; Johnston, Mary Jo

1985-01-01

Describes current practices in Illinois where a personnel reimbursement formula is used to finance special education. Summarizes the basic components of the Resource Cost Model (RCM), a complex school finance formula, and compares and contrasts RCM with Illinois' current method of financing special education. (MLF)

Merging of Research and Teaching in Developmental Biology: Adaptation of Current Scientific Research Papers for Use in Undergraduate Laboratory Exercises

ERIC Educational Resources Information Center

Lee, H. H.; and others

1970-01-01

Describes two laboratory exercises adopted from current research papers for use in an undergraduate developmental biology course. Gives methods, summary of student results, and student comments. Lists lecture topics, text and reprint assignments, and laboratory exercises for course. (EB)

Nested PCR and RFLP analysis based on the 16S rRNA gene

USDA-ARS?s Scientific Manuscript database

Current phytoplasma detection and identification method is primarily based on nested PCR followed by restriction fragment length polymorphism analysis and gel electrophoresis. This method can potentially detect and differentiate all phytoplasmas including those previously not described. The present ...

Teaching Research Methods in Communication Disorders: "A Problem-Based Learning Approach"

ERIC Educational Resources Information Center

Greenwald, Margaret L.

2006-01-01

A critical professional issue in speech-language pathology and audiology is the current shortage of researchers. In this context, the most effective methods for training graduate students in research must be identified and implemented. This article describes a problem-based approach to teaching research methods. In this approach, the instructor…

School Foodservice Personnel's Struggle with Using Labels to Identify Whole-Grain Foods

ERIC Educational Resources Information Center

Chu, Yen Li; Orsted, Mary; Marquart, Len; Reicks, Marla

2012-01-01

Objective: To describe how school foodservice personnel use current labeling methods to identify whole-grain products and the influence on purchasing for school meals. Methods: Focus groups explored labeling methods to identify whole-grain products and barriers to incorporating whole-grain foods in school meals. Qualitative analysis procedures and…

Rationale and Use of Content-Relevant Achievement Tests for the Evaluation of Instructional Programs.

ERIC Educational Resources Information Center

Patalino, Marianne

Problems in current course evaluation methods are discussed and an alternative method is described for the construction, analysis, and interpretation of a test to evaluate instructional programs. The method presented represents a different approach to the traditional overreliance on standardized achievement tests and the total scores they provide.…

DC-Compensated Current Transformer †

PubMed Central

Ripka, Pavel; Draxler, Karel; Styblíková, Renata

2016-01-01

Instrument current transformers (CTs) measure AC currents. The DC component in the measured current can saturate the transformer and cause gross error. We use fluxgate detection and digital feedback compensation of the DC flux to suppress the overall error to 0.15%. This concept can be used not only for high-end CTs with a nanocrystalline core, but it also works for low-cost CTs with FeSi cores. The method described here allows simultaneous measurements of the DC current component. PMID:26805830

Catalysts and methods for converting carbonaceous materials to fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hensley, Jesse; Ruddy, Daniel A.; Schaidle, Joshua A.

Catalysts and processes designed to convert DME and/or methanol and hydrogen (H.sub.2) to desirable liquid fuels are described. These catalysts produce the fuels efficiently and with a high selectivity and yield, and reduce the formation of aromatic hydrocarbons by incorporating H.sub.2 into the products. Also described are process methods to further upgrade these fuels to higher molecular weight liquid fuel mixtures, which have physical properties comparable with current commercially used liquid fuels.

Method and apparatus for generating motor current spectra to enhance motor system fault detection

DOEpatents

Linehan, Daniel J.; Bunch, Stanley L.; Lyster, Carl T.

1995-01-01

A method and circuitry for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed.

Associations of Trying to Lose Weight, Weight Control Behaviors, and Current Cigarette Use among US High School Students

ERIC Educational Resources Information Center

Johnson, Jonetta L.; Eaton, Danice K.; Pederson, Linda L.; Lowry, Richard

2009-01-01

Background: Approximately one-quarter of high school students currently use cigarettes. Previous research has suggested some youth use smoking as a method for losing weight. The purpose of this study was to describe the association of current cigarette use with specific healthy and unhealthy weight control practices among 9th-12th grade students…

A 1 MA, variable risetime pulse generator for high energy density plasma research

NASA Astrophysics Data System (ADS)

Greenly, J. B.; Douglas, J. D.; Hammer, D. A.; Kusse, B. R.; Glidden, S. C.; Sanders, H. D.

2008-07-01

COBRA is a 0.5Ω pulse generator driving loads of order 10nH inductance to >1MA current. The design is based on independently timed, laser-triggered switching of four water pulse-forming lines whose outputs are added in parallel to drive the load current pulse. The detailed design and operation of the switching to give a wide variety of current pulse shapes and rise times from 95to230ns is described. The design and operation of a simple inductive load voltage monitor are described which allows good accounting of load impedance and energy dissipation. A method of eliminating gas bubbles on the underside of nearly horizontal insulator surfaces in water was required for reliable operation of COBRA; a novel and effective solution to this problem is described.

Method of minimizing the effects of parasitic currents

DOEpatents

Chi, Michael C.; Carr, Peter

1983-02-01

A method of minimizing the effect of parasitic currents in secondary batteries having a plurality of cells connected electrically in series and a common electrolyte in communication with the cells is described. Specifically, the parasitic currents flowing through the battery cause a cell imbalance over the charge/discharge cycle. This cell imbalance is minimized by first separating the cells of the battery into two equal groups. Then the battery is charged with the two groups of cells connected electrically in series, and subsequently discharged with the two groups of cells reconnected electrically in series in an inverted sequence.

The SEM description of interaction of a transient electromagnetic wave with an object

NASA Technical Reports Server (NTRS)

Pearson, L. W.; Wilton, D. R.

1980-01-01

The singularity expansion method (SEM), proposed as a means for determining and representing the transient surface current density induced on a scatterer by a transient electromagnetic wave is described. The resulting mathematical description of the transient surface current on the object is discussed. The data required to represent the electromagnetic scattering properties of a given object are examined. Experimental methods which were developed for the determination of the SEM description are discussed. The feasibility of characterizing the surface current induced on aircraft flying in proximity to a lightning stroke by way of SEM is examined.

Increasing accuracy in the assessment of motion sickness: A construct methodology

NASA Technical Reports Server (NTRS)

Stout, Cynthia S.; Cowings, Patricia S.

1993-01-01

The purpose is to introduce a new methodology that should improve the accuracy of the assessment of motion sickness. This construct methodology utilizes both subjective reports of motion sickness and objective measures of physiological correlates to assess motion sickness. Current techniques and methods used in the framework of a construct methodology are inadequate. Current assessment techniques for diagnosing motion sickness and space motion sickness are reviewed, and attention is called to the problems with the current methods. Further, principles of psychophysiology that when applied will probably resolve some of these problems are described in detail.

Developing a Self-Report-Based Sequential Analysis Method for Educational Technology Systems: A Process-Based Usability Evaluation

ERIC Educational Resources Information Center

Lin, Yi-Chun; Hsieh, Ya-Hui; Hou, Huei-Tse

2015-01-01

The development of a usability evaluation method for educational systems or applications, called the self-report-based sequential analysis, is described herein. The method aims to extend the current practice by proposing self-report-based sequential analysis as a new usability method, which integrates the advantages of self-report in survey…

Direct mapping of local redox current density on a monolith electrode by laser scanning.

PubMed

Lee, Seung-Woo; Lopez, Jeffrey; Saraf, Ravi F

2013-09-15

An optical method of mapping local redox reaction over a monolith electrode using simple laser scanning is described. As the optical signal is linearly proportional to the maximum redox current that is measured concomitantly by voltammetry, the optical signal quantitatively maps the local redox current density distribution. The method is demonstrated on two types of reactions: (1) a reversible reaction where the redox moieties are ionic, and (2) an irreversible reaction on two different types of enzymes immobilized on the electrode where the reaction moieties are nonionic. To demonstrate the scanning capability, the local redox behavior on a "V-shaped" electrode is studied where the local length scale and, hence, the local current density, is nonuniform. The ability to measure the current density distribution by this method will pave the way for multianalyte analysis on a monolith electrode using a standard three-electrode configuration. The method is called Scanning Electrometer for Electrical Double-layer (SEED). Copyright © 2013 Elsevier B.V. All rights reserved.

Resilience Metrics for the Electric Power System: A Performance-Based Approach.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vugrin, Eric D.; Castillo, Andrea R; Silva-Monroy, Cesar Augusto

Grid resilience is a concept related to a power system's ability to continue operating and delivering power even in the event that low probability, high-consequence disruptions such as hurricanes, earthquakes, and cyber-attacks occur. Grid resilience objectives focus on managing and, ideally, minimizing potential consequences that occur as a result of these disruptions. Currently, no formal grid resilience definitions, metrics, or analysis methods have been universally accepted. This document describes an effort to develop and describe grid resilience metrics and analysis methods. The metrics and methods described herein extend upon the Resilience Analysis Process (RAP) developed by Watson et al. formore » the 2015 Quadrennial Energy Review. The extension allows for both outputs from system models and for historical data to serve as the basis for creating grid resilience metrics and informing grid resilience planning and response decision-making. This document describes the grid resilience metrics and analysis methods. Demonstration of the metrics and methods is shown through a set of illustrative use cases.« less

A Primer on Wastewater Treatment, July 1976 Edition.

ERIC Educational Resources Information Center

Environmental Protection Agency, Washington, DC. Office of Public Affairs.

This general information pamphlet is concerned with the types of wastewater treatment systems, the need for further treatment, and advanced methods of treating waste. Current methods are described, illustrated and evaluated. Pollution problems from oxygen-demanding wastes, disease-causing agents, plant nutrients, synthetic chemicals, inorganic…

Physical Activity and Healthy Eating in the After-School Environment

ERIC Educational Resources Information Center

Coleman, Karen J.; Geller, Karly S.; Rosenkranz, Richard R.; Dzewaltowski, David A.

2008-01-01

Background: No research to date has extensively described moderate and vigorous physical activity (MVPA) and healthful eating (HE) opportunities in the after-school environment. The current study described the quality of the after-school environment for its impact on children's MVPA and HE. Methods: An alliance of 7 elementary schools and Boys and…

Fluctuating volume-current formulation of electromagnetic fluctuations in inhomogeneous media: Incandescence and luminescence in arbitrary geometries

NASA Astrophysics Data System (ADS)

Polimeridis, Athanasios G.; Reid, M. T. H.; Jin, Weiliang; Johnson, Steven G.; White, Jacob K.; Rodriguez, Alejandro W.

2015-10-01

We describe a fluctuating volume-current formulation of electromagnetic fluctuations that extends our recent work on heat exchange and Casimir interactions between arbitrarily shaped homogeneous bodies [A. W. Rodriguez, M. T. H. Reid, and S. G. Johnson, Phys. Rev. B 88, 054305 (2013), 10.1103/PhysRevB.88.054305] to situations involving incandescence and luminescence problems, including thermal radiation, heat transfer, Casimir forces, spontaneous emission, fluorescence, and Raman scattering, in inhomogeneous media. Unlike previous scattering formulations based on field and/or surface unknowns, our work exploits powerful techniques from the volume-integral equation (VIE) method, in which electromagnetic scattering is described in terms of volumetric, current unknowns throughout the bodies. The resulting trace formulas (boxed equations) involve products of well-studied VIE matrices and describe power and momentum transfer between objects with spatially varying material properties and fluctuation characteristics. We demonstrate that thanks to the low-rank properties of the associated matrices, these formulas are susceptible to fast-trace computations based on iterative methods, making practical calculations tractable. We apply our techniques to study thermal radiation, heat transfer, and fluorescence in complicated geometries, checking our method against established techniques best suited for homogeneous bodies as well as applying it to obtain predictions of radiation from complex bodies with spatially varying permittivities and/or temperature profiles.

A versatile zero ripple topology

NASA Astrophysics Data System (ADS)

Capel, A.; Spruyt, H.; Weinberg, A.; O'Sullivan, D.; Crausaz, A.

A lightweight and efficient converter topology is described that presents zero ripple current on both input and output terminals simultaneously. The static and dynamic analyses are performed by using state representation with the current-injected method. A hardware application suitable for a Space Station battery conditioner is presented as a validation of the theoretical model.

The pediatric intensive care unit business model.

PubMed

Schleien, Charles L

2013-06-01

All pediatric intensivists need a primer on ICU finance. The author describes potential alternate revenue sources for the division. Differentiating units by size or academic affiliation, the author describes drivers of expense. Strategies to manage the bottom line including negotiations for hospital services are covered. Some of the current trends in physician productivity and its described metrics, with particular focus on clinical FTE management is detailed. Methods of using this data to enhance revenue are discussed. Some of the other current trends in the ICU business related to changes at the federal and state level as well as in the insurance sector, moving away from fee-for-service are covered. Copyright © 2013 Elsevier Inc. All rights reserved.

Hidden symmetries in Sasaki-Einstein geometries

NASA Astrophysics Data System (ADS)

Slesar, V.; Visinescu, M.; Vîlcu, G. E.

2017-07-01

We describe a method for constructing Killing-Yano tensors on Sasaki spaces using their geometrical properties, without the need of solving intricate generalized Killing equations. We obtain the Killing-Yano tensors on toric Sasaki-Einstein spaces using the fact that the metric cones of these spaces are Calabi-Yau manifolds which in turn are described in terms of toric data. We extend the search of Killing-Yano tensors on mixed 3-Sasakian manifolds. We illustrate the method by explicit construction of Killing forms on some spaces of current interest.

Determination of plasma density from data on the ion current to cylindrical and planar probes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voloshin, D. G., E-mail: dvoloshin@mics.msu.su; Vasil’eva, A. N.; Kovalev, A. S.

2016-12-15

To improve probe methods of plasma diagnostics, special probe measurements were performed and numerical models describing ion transport to a probe with allowance for collisions were developed. The current–voltage characteristics of cylindrical and planar probes were measured in an RF capacitive discharge in argon at a frequency of 81 MHz and plasma densities of 10{sup 10}–10{sup 11} cm{sup –3}, typical of modern RF reactors. 1D and 2D numerical models based on the particle-in-cell method with Monte Carlo collisions for simulating ion motion and the Boltzmann equilibrium for electrons are developed to describe current collection by a probe. The models weremore » used to find the plasma density from the ion part of the current–voltage characteristic, study the effect of ion collisions, and verify simplified approaches to determining the plasma density. A 1D hydrodynamic model of the ion current to a cylindrical probe with allowance for ion collisions is proposed. For a planar probe, a method to determine the plasma density from the averaged numerical results is developed. A comparative analysis of different approaches to calculating the plasma density from the ion current to a probe is performed.« less

26 CFR 1.901-2A - Dual capacity taxpayers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... or M in country X is not permitted to recover, currently or in the future, expenditures it incurs in... that is a tax only by the facts and circumstances method or the safe harbor method described in... be treated as an amount of tax. Any amount that, either by reason of application of the methods of...

REGIONAL VULNERABILITY ASSESSMENT OF THE MID-ATLANTIC REGION: EVALUATION OF INTEGRATION METHODS AND ASSESSMENTS RESULTS

EPA Science Inventory

This report describes methods for quantitative regional assessment developed by the Regional Vulnerability Assessment (ReVA) program. The goal of ReVA is to develop regional-scale assessments of the magnitude, extent, distribution, and uncertainty of current and anticipated envir...

IMMUNOASSAY METHOD FOR THE DETERMINATION OF PENTACHLOROPHENOL IN SOIL AND SEDIMENT

EPA Science Inventory

The journal article describes the use of a prototype immunoassay method for the determination of pentacholorphenol (PCP) in soil and sediment. PCP was used as a pesticide and wood preservative and is not currently available to the general public. The paper stresses the importan...

A Simple Two Aircraft Conflict Resolution Algorithm

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.

1999-01-01

Conflict detection and resolution methods are crucial for distributed air-ground traffic management in which the crew in the cockpit, dispatchers in operation control centers and air traffic controllers in the ground-based air traffic management facilities share information and participate in the traffic flow and traffic control imctions.This paper describes a conflict detection and a conflict resolution method. The conflict detection method predicts the minimum separation and the time-to-go to the closest point of approach by assuming that both the aircraft will continue to fly at their current speeds along their current headings. The conflict resolution method described here is motivated by the proportional navigation algorithm. It generates speed and heading commands to rotate the line-of-sight either clockwise or counter-clockwise for conflict resolution. Once the aircraft achieve a positive range-rate and no further conflict is predicted, the algorithm generates heading commands to turn back the aircraft to their nominal trajectories. The speed commands are set to the optimal pre-resolution speeds. Six numerical examples are presented to demonstrate the conflict detection and resolution method.

Method development and qualification of capillary zone electrophoresis for investigation of therapeutic monoclonal antibody quality.

PubMed

Suba, Dávid; Urbányi, Zoltán; Salgó, András

2016-10-01

Capillary electrophoresis techniques are widely used in the analytical biotechnology. Different electrophoretic techniques are very adequate tools to monitor size-and charge heterogenities of protein drugs. Method descriptions and development studies of capillary zone electrophoresis (CZE) have been described in literature. Most of them are performed based on the classical one-factor-at-time (OFAT) approach. In this study a very simple method development approach is described for capillary zone electrophoresis: a "two-phase-four-step" approach is introduced which allows a rapid, iterative method development process and can be a good platform for CZE method. In every step the current analytical target profile and an appropriate control strategy were established to monitor the current stage of development. A very good platform was established to investigate intact and digested protein samples. Commercially available monoclonal antibody was chosen as model protein for the method development study. The CZE method was qualificated after the development process and the results were presented. The analytical system stability was represented by the calculated RSD% value of area percentage and migration time of the selected peaks (<0.8% and <5%) during the intermediate precision investigation. Copyright © 2016 Elsevier B.V. All rights reserved.

Survey of NASA V and V Processes/Methods

NASA Technical Reports Server (NTRS)

Pecheur, Charles; Nelson, Stacy

2002-01-01

The purpose of this report is to describe current NASA Verification and Validation (V&V) techniques and to explain how these techniques are applicable to 2nd Generation RLV Integrated Vehicle Health Management (IVHM) software. It also contains recommendations for special V&V requirements for IVHM. This report is divided into the following three sections: 1) Survey - Current NASA V&V Processes/Methods; 2) Applicability of NASA V&V to 2nd Generation RLV IVHM; and 3) Special 2nd Generation RLV IVHM V&V Requirements.

Methods for protecting subsea pipelines and installations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rochelle, W.R.; Simpson, D.M.

1981-01-01

The hazards for subsea pipelines and installations are described. Methods currently being used to protect subsea pipelines and installations are discussed with the emphasis on various trenching methods and equipment. Technical data on progress rates for trenching and feasible depths of trench are given. Possible methods for protection against icebergs are discussed. A case for more comprehensive data on icebergs is presented. Should a pipeline become damaged, repair methods are noted.

Method of Calculating the Correction Factors for Cable Dimensioning in Smart Grids

NASA Astrophysics Data System (ADS)

Simutkin, M.; Tuzikova, V.; Tlusty, J.; Tulsky, V.; Muller, Z.

2017-04-01

One of the main causes of overloading electrical equipment by currents of higher harmonics is the great increasing of a number of non-linear electricity power consumers. Non-sinusoidal voltages and currents affect the operation of electrical equipment, reducing its lifetime, increases the voltage and power losses in the network, reducing its capacity. There are standards that respects emissions amount of higher harmonics current that cannot provide interference limit for a safe level in power grid. The article presents a method for determining a correction factor to the long-term allowable current of the cable, which allows for this influence. Using mathematical models in the software Elcut, it was described thermal processes in the cable in case the flow of non-sinusoidal current. Developed in the article theoretical principles, methods, mathematical models allow us to calculate the correction factor to account for the effect of higher harmonics in the current spectrum for network equipment in any type of non-linear load.

Thin wire pointing method

NASA Technical Reports Server (NTRS)

Green, G.; Mattauch, R. J. (Inventor)

1983-01-01

A method is described for forming sharp tips on thin wires, in particular phosphor bronze wires of diameters such as one-thousandth inch used to contact micron size Schottky barrier diodes, which enables close control of tip shape and which avoids the use of highly toxic solutions. The method includes dipping an end of a phosphor bronze wire into a dilute solution of sulfamic acid and applying a current through the wire to electrochemically etch it. The humidity in the room is controlled to a level of less than 50%, and the voltage applied between the wire and another electrode in the solutions is a half wave rectified voltage. The current through the wire is monitored, and the process is stopped when the current falls to a predetermined low level.

Detecting electroporation by assessing the time constants in the exponential response of human skin to voltage controlled impulse electrical stimulation.

PubMed

Bîrlea, Sinziana I; Corley, Gavin J; Bîrlea, Nicolae M; Breen, Paul P; Quondamatteo, Fabio; OLaighin, Gearóid

2009-01-01

We propose a new method for extracting the electrical properties of human skin based on the time constant analysis of its exponential response to impulse stimulation. As a result of this analysis an adjacent finding has arisen. We have found that stratum corneum electroporation can be detected using this analysis method. We have observed that a one time-constant model is appropriate for describing the electrical properties of human skin at low amplitude applied voltages (<30V), and a two time-constant model best describes skin electrical properties at higher amplitude applied voltages (>30V). Higher voltage amplitudes (>30V) have been proven to create pores in the skin's stratum corneum which offer a new, lower resistance, pathway for the passage of current through the skin. Our data shows that when pores are formed in the stratum corneum they can be detected, in-vivo, due to the fact that a second time constant describes current flow through them.

Minimum Description Length Block Finder, a Method to Identify Haplotype Blocks and to Compare the Strength of Block Boundaries

PubMed Central

Mannila, H.; Koivisto, M.; Perola, M.; Varilo, T.; Hennah, W.; Ekelund, J.; Lukk, M.; Peltonen, L.; Ukkonen, E.

2003-01-01

We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the significance of each block boundary. We have applied the method to the published data of Daly and colleagues. The results expose some problems that exist in the current methods for the evaluation of the significance of predicted block boundaries. Our method, MDL block finder, can be used to compare block borders in different sample sets, and we demonstrate this by applying the MDL-based method to define the block structure in chromosomes from population isolates. PMID:12761696

Minimum description length block finder, a method to identify haplotype blocks and to compare the strength of block boundaries.

PubMed

Mannila, H; Koivisto, M; Perola, M; Varilo, T; Hennah, W; Ekelund, J; Lukk, M; Peltonen, L; Ukkonen, E

2003-07-01

We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the significance of each block boundary. We have applied the method to the published data of Daly and colleagues. The results expose some problems that exist in the current methods for the evaluation of the significance of predicted block boundaries. Our method, MDL block finder, can be used to compare block borders in different sample sets, and we demonstrate this by applying the MDL-based method to define the block structure in chromosomes from population isolates.

Polymer flammability

DOT National Transportation Integrated Search

2005-05-01

This report provides an overview of polymer flammability from a material science perspective and describes currently accepted test methods to quantify burning behavior. Simplifying assumptions about the gas and condensed phase processes of flaming co...

Effect of scrape-off-layer current on reconstructed tokamak equilibrium

DOE PAGES

King, J. R.; Kruger, S. E.; Groebner, R. J.; ...

2017-01-13

Methods are described that extend fields from reconstructed equilibria to include scrape-off-layer current through extrapolated parametrized and experimental fits. The extrapolation includes both the effects of the toroidal-field and pressure gradients which produce scrape-off-layer current after recomputation of the Grad-Shafranov solution. To quantify the degree that inclusion of scrape-off-layer current modifies the equilibrium, the χ-squared goodness-of-fit parameter is calculated for cases with and without scrape-off-layer current. The change in χ-squared is found to be minor when scrape-off-layer current is included however flux surfaces are shifted by up to 3 cm. Here the impact on edge modes of these scrape-off-layer modificationsmore » is also found to be small and the importance of these methods to nonlinear computation is discussed.« less

METHOD OF PEAK CURRENT MEASUREMENT

DOEpatents

Baker, G.E.

1959-01-20

The measurement and recording of peak electrical currents are described, and a method for utilizing the magnetic field of the current to erase a portion of an alternating constant frequency and amplitude signal from a magnetic mediums such as a magnetic tapes is presented. A portion of the flux from the current carrying conductor is concentrated into a magnetic path of defined area on the tape. After the current has been recorded, the tape is played back. The amplitude of the signal from the portion of the tape immediately adjacent the defined flux area and the amplitude of the signal from the portion of the tape within the area are compared with the amplitude of the signal from an unerased portion of the tape to determine the percentage of signal erasure, and thereby obtain the peak value of currents flowing in the conductor.

Field-Induced and Thermal Electron Currents from Earthed Spherical Emitters

NASA Astrophysics Data System (ADS)

Holgate, J. T.; Coppins, M.

2017-04-01

The theories of electron emission from planar surfaces are well understood, but they are not suitable for describing emission from spherical surfaces; their incorrect application to highly curved, nanometer-scale surfaces can overestimate the emitted current by several orders of magnitude. This inaccuracy is of particular concern for describing modern nanoscale electron sources, which continue to be modeled using the planar equations. In this paper, the field-induced and thermal currents are treated in a unified way to produce Fowler-Nordheim-type and Richardson-Schottky-type equations for the emitted current density from earthed nanoscale spherical surfaces. The limits of applicability of these derived expressions are considered along with the energy spectra of the emitted electrons. Within the relevant limits of validity, these equations are shown to reproduce the results of precise numerical calculations of the emitted current densities. The methods used here are adaptable to other one-dimensional emission problems.

The ABPN Maintenance of Certification Program for Psychiatrists: Past History, Current Status, and Future Directions

ERIC Educational Resources Information Center

Faulkner, Larry R.; Tivnan, Patricia W.; Winstead, Daniel K.; Reus, Victor I.; Andrade, Naleen N.; Brooks, Beth Ann; Colenda, Christopher C.; Mrazek, David A.; Reifler, Burton V.; Schneidman, Barbara

2008-01-01

Objective: To describe the American Board of Psychiatry and Neurology (ABPN) Maintenance of Certification Program, its underlying rationale, how it will be implemented now, and what it might look like in the future. Methods: The authors describe the philosophical foundation, specific components, and the implementation timeline of the ABPN…

On-line tool breakage monitoring of vibration tapping using spindle motor current

NASA Astrophysics Data System (ADS)

Li, Guangjun; Lu, Huimin; Liu, Gang

2008-10-01

Input current of driving motor has been employed successfully as monitoring the cutting state in manufacturing processes for more than a decade. In vibration tapping, however, the method of on-line monitoring motor electric current has not been reported. In this paper, a tap failure prediction method is proposed to monitor the vibration tapping process using the electrical current signal of the spindle motor. The process of vibration tapping is firstly described. Then the relationship between the torque of vibration tapping and the electric current of motor is investigated by theoretic deducing and experimental measurement. According to those results, a monitoring method of tool's breakage is proposed through monitoring the ratio of the current amplitudes during adjacent vibration tapping periods. Finally, a low frequency vibration tapping system with motor current monitoring is built up using a servo motor B-106B and its driver CR06. The proposed method has been demonstrated with experiment data of vibration tapping in titanic alloys. The result of experiments shows that the method, which can avoid the tool breakage and giving a few error alarms when the threshold of amplitude ratio is 1.2 and there is at least 2 times overrun among 50 adjacent periods, is feasible for tool breakage monitoring in the process of vibration tapping small thread holes.

Sodium influxes in internally perfused squid giant axon during voltage clamp.

PubMed

Atwater, I; Bezanilla, F; Rojas, E

1969-05-01

1. An experimental method for measuring ionic influxes during voltage clamp in the giant axon of Dosidicus is described; the technique combines intracellular perfusion with a method for controlling membrane potential.2. Sodium influx determinations were carried out while applying rectangular pulses of membrane depolarization. The ratio ;measured sodium influx/computed ionic flux during the early current' is 0.92 +/- 0.12.3. Plots of measured sodium influx and computed ionic flux during the early current against membrane potential are very similar. There was evidence that the membrane potential at which the sodium influx vanishes is the potential at which the early current reverses.

Graphical Methods: A Review of Current Methods and Computer Hardware and Software. Technical Report No. 27.

ERIC Educational Resources Information Center

Bessey, Barbara L.; And Others

Graphical methods for displaying data, as well as available computer software and hardware, are reviewed. The authors have emphasized the types of graphs which are most relevant to the needs of the National Center for Education Statistics (NCES) and its readers. The following types of graphs are described: tabulations, stem-and-leaf displays,…

Method and apparatus for controlling LCL converters using asymmetric voltage cancellation techniques

DOEpatents

Wu, Hunter; Sealy, Kylee Devro; Sharp, Bryan Thomas; Gilchrist, Aaron

2016-01-26

A method and apparatus for LCL resonant converter control utilizing Asymmetric Voltage Cancellation is described. The methods to determine the optimal trajectory of the control variables are discussed. Practical implementations of sensing load parameters are included. Simple PI, PID and fuzzy logic controllers are included with AVC for achieving good transient response characteristics with output current regulation.

Experimental setup for the measurement of induction motor cage currents

NASA Astrophysics Data System (ADS)

Bottauscio, Oriano; Chiampi, Mario; Donadio, Lorenzo; Zucca, Mauro

2005-04-01

An experimental setup for measurement of the currents flowing in the rotor bars of induction motors during synchronous no-load tests is described in the paper. The experimental verification of the high-frequency phenomena in the rotor cage is fundamental for a deep insight of the additional loss estimation by numerical methods. The attention is mainly focused on the analysis and design of the transducers developed for the cage current measurement.

Particle tracing modeling of ion fluxes at geosynchronous orbit during substorms

NASA Astrophysics Data System (ADS)

Brito, T. V.; Jordanova, V.; Woodroffe, J. R.; Henderson, M. G.; Morley, S.; Birn, J.

2016-12-01

The SHIELDS project aims to couple a host of different models for different regions of the magnetosphere using different numerical methods such as MHD, PIC and particle tracing, with the ultimate goal of having a more realistic model of the whole magnetospheric environment capturing, as much as possible, the different physics of the various plasma populations. In that context, we present a modeling framework that can be coupled with a global MHD model to calculate particle fluxes in the inner magnetosphere, which can in turn be used to constantly update the input for a ring current model. In that regard, one advantage of that approach over using spacecraft data is that it produces a much better spatial and temporal coverage of the nightside geosynchronous region and thus a possibly more complete input for the ring current model, which will likely produce more accurate global results for the ring current population. In this presentation, we will describe the particle tracing method in more detail, describe the method used to couple it to the BATS-R-US 3D global MHD code, and the method used to update the flux results to the RAM-SCB ring current model. We will also present the simulation results for the July 18, 2013 period, which showed significant substorm activity. We will compare simulated ion fluxes on the nightside magnetosphere with spacecraft observations to gauge how well our simulations are capturing substorm dynamics.

Some Comments on Topological Approaches to the π-Electron Currents in Conjugated Systems.

PubMed

Dickens, Timothy K; Gomes, José A N F; Mallion, Roger B

2011-11-08

Within the past two years, three sets of independent authors (Mandado, Ciesielski et al., and Randić) have proposed methods in which π-electron currents in conjugated systems are estimated by invoking the concept of circuits of conjugation. These methods are here compared with ostensibly similar approaches published more than 30 years ago by two of the present authors (Gomes and Mallion) and (likewise independently) by Gayoso. Patterns of bond currents and ring currents computed by these methods for the nonalternant isomer of coronene that was studied by Randić are also systematically compared with those calculated by the Hückel-London-Pople-McWeeny (HLPM) "topological" approach and with the ab initio, "ipso-centric" current-density maps of Balaban et al. These all agree that a substantial diamagnetic π-electron current flows around the periphery of the selected structure (which could be thought of as a "perturbed" [18]-annulene), and consideration is given to the differing trends predicted by these several methods for the π-electron currents around its central six-membered ring and in its internal bonds. It is observed that, for any method in which calculated π-electron currents respect Kirchhoff's Laws of current conservation at a junction, consideration of bond currents-as an alternative to the more-traditional ring currents-can give a different insight into the magnetic properties of conjugated systems. However, provided that charge/current conservation is guaranteed-or Kirchhoff's First Law holds for bond currents instead of the more-general current-densities-then ring currents represent a more efficient way of describing the molecular reaction to the external magnetic field: ring currents are independent quantities, while bond currents are not.

Aquarium Culture of Freshwater Invertebrates.

ERIC Educational Resources Information Center

Wood, Timothy S.

1996-01-01

Describes two methods for rearing small aquatic invertebrates using submerged surfaces in an unfiltered current of water where fish are present. Presents suggestions on how to use the invertebrate communities in the classroom. (JRH)

[Molecular typing methods for Pasteurella multocida-A review].

PubMed

Peng, Zhong; Liang, Wan; Wu, Bin

2016-10-04

Pasteurella multocida is an important gram-negative pathogenic bacterium that could infect wide ranges of animals. Humans could also be infected by P. multocida via animal bite or scratching. Current typing methods for P. multocida include serological typing methods and molecular typing methods. Of them, serological typing methods are based on immunological assays, which are too complicated for clinical bacteriological studies. However, the molecular methods including multiple PCRs and multilocus sequence typing (MLST) methods are more suitable for bacteriological studies of P. multocida in clinic, with their simple operation, high efficiency and accurate detection compared to the traditional serological typing methods, they are therefore widely used. In the current review, we briefly describe the molecular typing methods for P. multocida. Our aim is to provide a knowledge-foundation for clinical bacteriological investigation especially the molecular investigation for P. multocida.

Introducing the Medical Ethics Bowl.

PubMed

Merrick, Allison; Green, Rochelle; Cunningham, Thomas V; Eisenberg, Leah R; Hester, D Micah

2016-01-01

Although ethics is an essential component of undergraduate medical education, research suggests that current medical ethics curricula face considerable challenges in improving students' ethical reasoning. This article discusses these challenges and introduces a promising new mode of graduate and professional ethics instruction for overcoming them. We begin by describing common ethics curricula, focusing in particular on established problems with current approaches. Next, we describe a novel method of ethics education and assessment for medical students that we have devised: the Medical Ethics Bowl (MEB). Finally, we suggest the pedagogical advantages of the MEB when compared to other ethics curricula.

Personalized medicine in psychiatry.

PubMed

Wium-Andersen, Ida Kim; Vinberg, Maj; Kessing, Lars Vedel; McIntyre, Roger S

2017-01-01

Personalized medicine is a model in which a patient's unique clinical, genetic, and environmental characteristics are the basis for treatment and prevention. Aim, method, and results: This review aims to describe the current tools, phenomenological features, clinical risk factors, and biomarkers used to provide personalized medicine. Furthermore, this study describes the target areas in which they can be applied including diagnostics, treatment selection and response, assessment of risk of side-effects, and prevention. Personalized medicine in psychiatry is challenged by the current taxonomy, where the diagnostic categories are broad and great biological heterogeneity exists within each category. There is, thus, a gap between the current advanced research prospects and clinical practice, and the current taxonomy is, thus, a poor basis for biological research. The discussion proposes possible solutions to narrow this gap and to move psychiatric research forward towards personalized medicine.

Method and apparatus for generating motor current spectra to enhance motor system fault detection

DOEpatents

Linehan, D.J.; Bunch, S.L.; Lyster, C.T.

1995-10-24

A method and circuitry are disclosed for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed. 29 figs.

A Holarctic Biogeographical Analysis of the Collembola (Arthropoda, Hexapoda) Unravels Recent Post-Glacial Colonization Patterns

PubMed Central

Ávila-Jiménez, María Luisa; Coulson, Stephen James

2011-01-01

We aimed to describe the main Arctic biogeographical patterns of the Collembola, and analyze historical factors and current climatic regimes determining Arctic collembolan species distribution. Furthermore, we aimed to identify possible dispersal routes, colonization sources and glacial refugia for Arctic collembola. We implemented a Gaussian Mixture Clustering method on species distribution ranges and applied a distance- based parametric bootstrap test on presence-absence collembolan species distribution data. Additionally, multivariate analysis was performed considering species distributions, biodiversity, cluster distribution and environmental factors (temperature and precipitation). No clear relation was found between current climatic regimes and species distribution in the Arctic. Gaussian Mixture Clustering found common elements within Siberian areas, Atlantic areas, the Canadian Arctic, a mid-Siberian cluster and specific Beringian elements, following the same pattern previously described, using a variety of molecular methods, for Arctic plants. Species distribution hence indicate the influence of recent glacial history, as LGM glacial refugia (mid-Siberia, and Beringia) and major dispersal routes to high Arctic island groups can be identified. Endemic species are found in the high Arctic, but no specific biogeographical pattern can be clearly identified as a sign of high Arctic glacial refugia. Ocean currents patterns are suggested as being an important factor shaping the distribution of Arctic Collembola, which is consistent with Antarctic studies in collembolan biogeography. The clear relations between cluster distribution and geographical areas considering their recent glacial history, lack of relationship of species distribution with current climatic regimes, and consistency with previously described Arctic patterns in a series of organisms inferred using a variety of methods, suggest that historical phenomena shaping contemporary collembolan distribution can be inferred through biogeographical analysis. PMID:26467728

Safe Passage Data Analysis: Interim Report

DOT National Transportation Integrated Search

1993-04-01

The purpose of this report is to describe quantitatively the costs and benefits of screener : proficiency evaluation and reporting systems (SPEARS) equipment, particularly computer-based : instruction (CBI) systems, compared to current methods of tra...

Electronic field emission models beyond the Fowler-Nordheim one

NASA Astrophysics Data System (ADS)

Lepetit, Bruno

2017-12-01

We propose several quantum mechanical models to describe electronic field emission from first principles. These models allow us to correlate quantitatively the electronic emission current with the electrode surface details at the atomic scale. They all rely on electronic potential energy surfaces obtained from three dimensional density functional theory calculations. They differ by the various quantum mechanical methods (exact or perturbative, time dependent or time independent), which are used to describe tunneling through the electronic potential energy barrier. Comparison of these models between them and with the standard Fowler-Nordheim one in the context of one dimensional tunneling allows us to assess the impact on the accuracy of the computed current of the approximations made in each model. Among these methods, the time dependent perturbative one provides a well-balanced trade-off between accuracy and computational cost.

A Safer and Convenient Synthesis of Sulfathiazole for Undergraduate Organic and Medicinal Chemistry Classes

ERIC Educational Resources Information Center

Boyle, Jeff; Otty, Sandra; Sarojini, Vijayalekshmi

2012-01-01

A safer method for the synthesis of the sulfonamide drug sulfathiazole, for undergraduate classes, is described. This method improves upon procedures currently followed in several undergraduate teaching laboratories for the synthesis of sulfathiazole. Key features of this procedure include the total exclusion of pyridine, which has potential…

Teaching the Scientific Method Using Current News Articles

ERIC Educational Resources Information Center

Palmer, Laura K.; Mahan, Carolyn G.

2013-01-01

We describe a short (less than 50 minutes) activity using news articles from sources such as "Science Daily" to teach students the steps of the scientific method and the difference between primary and secondary literature sources. The flexibility in choosing news articles to examine allowed us to tailor the activity to the specific interests of…

Adapting Individual Psychotherapy for Adults with Intellectual Disabilities: A Comparative Review of the Cognitive-Behavioural and Psychodynamic Literature

ERIC Educational Resources Information Center

Whitehouse, Richard M.; Tudway, Jeremy A.; Look, Roger; Kroese, Biza Stenfert

2006-01-01

Background: Historically, adults with intellectual disabilities have had little access to individual psychotherapy. Over the last 20 years an increasing body of literature has described psychotherapy with this client group and reported methods for adapting traditional psychotherapeutic techniques. Method: The current review identified the…

Physiological Markers of Anxiety Are Increased in Children of Abused Mothers

ERIC Educational Resources Information Center

Jovanovic, Tanja; Smith, Ami; Kamkwalala, Asante; Poole, James; Samples, Tara; Norrholm, Seth D.; Ressler, Kerry J.; Bradley, Bekh

2011-01-01

Background: A growing number of studies indicate that low income, African American men and women living in urban environments are at high risk for trauma exposure, which may have intergenerational effects. The current study employed psychophysiological methods to describe biomarkers of anxiety in children of traumatized mothers. Methods: Study…

Generating Multiple Imputations for Matrix Sampling Data Analyzed with Item Response Models.

ERIC Educational Resources Information Center

Thomas, Neal; Gan, Nianci

1997-01-01

Describes and assesses missing data methods currently used to analyze data from matrix sampling designs implemented by the National Assessment of Educational Progress. Several improved methods are developed, and these models are evaluated using an EM algorithm to obtain maximum likelihood estimates followed by multiple imputation of complete data…

Modeling Adaptive Educational Methods with IMS Learning Design

ERIC Educational Resources Information Center

Specht, Marcus; Burgos, Daniel

2007-01-01

The paper describes a classification system for adaptive methods developed in the area of adaptive educational hypermedia based on four dimensions: What components of the educational system are adapted? To what features of the user and the current context does the system adapt? Why does the system adapt? How does the system get the necessary…

Detection of Test Collusion via Kullback-Leibler Divergence

ERIC Educational Resources Information Center

Belov, Dmitry I.

2013-01-01

The development of statistical methods for detecting test collusion is a new research direction in the area of test security. Test collusion may be described as large-scale sharing of test materials, including answers to test items. Current methods of detecting test collusion are based on statistics also used in answer-copying detection.…

Teaching About Women in Hispanic Literature: Current Methods and Materials.

ERIC Educational Resources Information Center

Maier, Carol

Awareness of a new and altered method of teaching literature, similar to that described by Adrienne Rich, grew from the experience of teaching a small introductory course in twentieth century Hispanic women writers to students with diverse language, cultural, and economic backgrounds. Although about half the students were native Spanish speakers,…

Multiscale Reactive Molecular Dynamics

DTIC Science & Technology

2012-08-15

biology cannot be described without considering electronic and nuclear-level dynamics and their coupling to slower, cooperative motions of the system ...coupling to slower, cooperative motions of the system . These inherently multiscale problems require computationally efficient and accurate methods to...condensed phase systems with computational efficiency orders of magnitudes greater than currently possible with ab initio simulation methods, thus

Water-waves on linear shear currents. A comparison of experimental and numerical results.

NASA Astrophysics Data System (ADS)

Simon, Bruno; Seez, William; Touboul, Julien; Rey, Vincent; Abid, Malek; Kharif, Christian

2016-04-01

Propagation of water waves can be described for uniformly sheared current conditions. Indeed, some mathematical simplifications remain applicable in the study of waves whether there is no current or a linearly sheared current. However, the widespread use of mathematical wave theories including shear has rarely been backed by experimental studies of such flows. New experimental and numerical methods were both recently developed to study wave current interactions for constant vorticity. On one hand, the numerical code can simulate, in two dimensions, arbitrary non-linear waves. On the other hand, the experimental methods can be used to generate waves with various shear conditions. Taking advantage of the simplicity of the experimental protocol and versatility of the numerical code, comparisons between experimental and numerical data are discussed and compared with linear theory for validation of the methods. ACKNOWLEDGEMENTS The DGA (Direction Générale de l'Armement, France) is acknowledged for its financial support through the ANR grant N° ANR-13-ASTR-0007.

Environmental management practices and engineering science: a review and typology for future research.

PubMed

Evangelinos, Konstantinos I; Allan, Stuart; Jones, Keith; Nikolaou, Ioannis E

2014-04-01

Current literature describes a number of environmental management practices and cleaner production methods that facilitate different industrial sectors to address their various environmental impacts. The high number of present practices makes their use especially difficult and complicated. This paper aims to shed light on this field by providing a typology of those environmental management practices (such as environmental management systems, environmental indicators assessment methodologies, and cleaner productions methods) and their limitations. It also describes the strengths and weaknesses of using such tools and thoughts for future research. © 2013 SETAC.

Use and misuse of pharmacoeconomic terms: a definitions primer.

PubMed

Sanchez, L A; Lee, J

1994-01-01

Given the current cost-conscious health care environment, pharmacists must now be able to assess the effects of an agent from safety, efficacy, and value considerations. This article describes the various methodologies that may be used in performing pharmacoeconomic analyses and highlights the use and misuse of pharmacoeconomic terminology. Case studies relating the use of these methods to the pharmacy practice setting are presented. The technical nuances of the various methods are explained to promote a better understanding of the appropriate use of these techniques and the terminology used to describe them.

Study on Insulation Diagnosis of Power Lines in Apartment Houses

NASA Astrophysics Data System (ADS)

Okamoto, Tatsuki; Taki, Shoji; Fukui, Toshiaki; Soga, Akiya; Ezure, Shoichiro; Asano, Jun-Ichi; Uto, Yukio

Insulation diagnosis is vital issue for safety of urban lives despite of the difficulty of power interruption even for the diagnosis. Recently, live-line insulation diagnosis becomes more important and realistic to maintain good insulation conditions of power lines in apartment houses in wide range of residential sizes. This paper describes new trend of insulation diagnosis of power lines of apartment houses based on clip-on current measurement method with a lot of live-line measurement data and also describes the applicability of new live-line insulation diagnostic method.

Reactivity of lignin and lignans: Correlation with molecular orbital calculations

Treesearch

Thomas Elder

2010-01-01

To date, and as can be seen from the other chapters of this text, the structure and chemistry of lignin have been described in terms of results from a wide range of chemical or spectroscopic methods to construct a mosaic picture of the polymer. The current chapter continues this process by describing past, present and potential applications of electronic structure...

US strategy for forest management adaptation to climate change: building a framework for decision making

Treesearch

V. Alaric Sample; Jessica E. Halofsky; David L. Peterson

2014-01-01

This paper describes methods developed to (1) assess current risks, vulnerabilities, and gaps in knowledge; (2) engage internal agency resources and external partners in the development of options and solutions; and (3) manage forest resources for resilience, not just in terms of natural ecosystems but in affected human communities as well. We describe an approach...

Quantification of Microbial Phenotypes

PubMed Central

Martínez, Verónica S.; Krömer, Jens O.

2016-01-01

Metabolite profiling technologies have improved to generate close to quantitative metabolomics data, which can be employed to quantitatively describe the metabolic phenotype of an organism. Here, we review the current technologies available for quantitative metabolomics, present their advantages and drawbacks, and the current challenges to generate fully quantitative metabolomics data. Metabolomics data can be integrated into metabolic networks using thermodynamic principles to constrain the directionality of reactions. Here we explain how to estimate Gibbs energy under physiological conditions, including examples of the estimations, and the different methods for thermodynamics-based network analysis. The fundamentals of the methods and how to perform the analyses are described. Finally, an example applying quantitative metabolomics to a yeast model by 13C fluxomics and thermodynamics-based network analysis is presented. The example shows that (1) these two methods are complementary to each other; and (2) there is a need to take into account Gibbs energy errors. Better estimations of metabolic phenotypes will be obtained when further constraints are included in the analysis. PMID:27941694

Rotor Position Sensorless Control and Its Parameter Sensitivity of Permanent Magnet Motor Based on Model Reference Adaptive System

NASA Astrophysics Data System (ADS)

Ohara, Masaki; Noguchi, Toshihiko

This paper describes a new method for a rotor position sensorless control of a surface permanent magnet synchronous motor based on a model reference adaptive system (MRAS). This method features the MRAS in a current control loop to estimate a rotor speed and position by using only current sensors. This method as well as almost all the conventional methods incorporates a mathematical model of the motor, which consists of parameters such as winding resistances, inductances, and an induced voltage constant. Hence, the important thing is to investigate how the deviation of these parameters affects the estimated rotor position. First, this paper proposes a structure of the sensorless control applied in the current control loop. Next, it proves the stability of the proposed method when motor parameters deviate from the nominal values, and derives the relationship between the estimated position and the deviation of the parameters in a steady state. Finally, some experimental results are presented to show performance and effectiveness of the proposed method.

Power control apparatus and methods for electric vehicles

DOEpatents

Gadh, Rajit; Chung, Ching-Yen; Chu, Chi-Cheng; Qiu, Li

2016-03-22

Electric vehicle (EV) charging apparatus and methods are described which allow the sharing of charge current between multiple vehicles connected to a single source of charging energy. In addition, this charge sharing can be performed in a grid-friendly manner by lowering current supplied to EVs when necessary in order to satisfy the needs of the grid, or building operator. The apparatus and methods can be integrated into charging stations or can be implemented with a middle-man approach in which a multiple EV charging box, which includes an EV emulator and multiple pilot signal generation circuits, is coupled to a single EV charge station.

Determination of diffusion coefficients in polypyrrole thin films using a current pulse relaxation method

NASA Technical Reports Server (NTRS)

Penner, Reginald M.; Vandyke, Leon S.; Martin, Charles R.

1987-01-01

The current pulse E sub oc relaxation method and its application to the determination of diffusion coefficients in electrochemically synthesized polypyrrole thin films is described. Diffusion coefficients for such films in Et4NBF4 and MeCN are determined for a series of submicron film thicknesses. Measurement of the double-layer capacitance, C sub dl, and the resistance, R sub u, of polypyrrole thin films as a function of potential obtained with the galvanostatic pulse method is reported. Measurements of the electrolyte concentration in reduced polypyrrole films are also presented to aid in the interpretation of the data.

Defining Support Requirements During Conceptual Design of Reusable Launch Vehicles

NASA Technical Reports Server (NTRS)

Morris, W. D.; White, N. H.; Davis, W. T.; Ebeling, C. E.

1995-01-01

Current methods for defining the operational support requirements of new systems are data intensive and require significant design information. Methods are being developed to aid in the analysis process of defining support requirements for new launch vehicles during their conceptual design phase that work with the level of information available during this phase. These methods will provide support assessments based on the vehicle design and the operating scenarios. The results can be used both to define expected support requirements for new launch vehicle designs and to help evaluate the benefits of using new technologies. This paper describes the models, their current status, and provides examples of their use.

Permanent Income and the Black-White Test Score Gap. NBER Working Paper No. 17610

ERIC Educational Resources Information Center

Rothstein, Jesse; Wozny, Nathan

2011-01-01

Analysts often examine the black-white test score gap conditional on family income. Typically only a current income measure is available. We argue that the gap conditional on permanent income is of greater interest, and we describe a method for identifying this gap using an auxiliary data set to estimate the relationship between current and…

A Disposable Microfluidic Device with a Screen Printed Electrode for Mimicking Phase II Metabolism

PubMed Central

Vasiliadou, Rafaela; Nasr Esfahani, Mohammad Mehdi; Brown, Nathan J.; Welham, Kevin J.

2016-01-01

Human metabolism is investigated using several in vitro methods. However, the current methodologies are often expensive, tedious and complicated. Over the last decade, the combination of electrochemistry (EC) with mass spectrometry (MS) has a simpler and a cheaper alternative to mimic the human metabolism. This paper describes the development of a disposable microfluidic device with a screen-printed electrode (SPE) for monitoring phase II GSH reactions. The proposed chip has the potential to be used as a primary screening tool, thus complementing the current in vitro methods. PMID:27598162

Restoration of the Donor Face After Facial Allotransplantation

PubMed Central

Grant, Gerald T.; Liacouras, Peter; Santiago, Gabriel F.; Garcia, Juan R.; Al Rakan, Mohammed; Murphy, Ryan; Armand, Mehran; Gordon, Chad R.

2014-01-01

Introduction Current protocols for facial transplantation include the mandatory fabrication of an alloplastic “mask” to restore the congruency of the donor site in the setting of “open casket” burial. However, there is currently a paucity of literature describing the current state-of-the-art and available options. Methods During this study, we identified that most of donor masks are fabricated using conventional methods of impression, molds, silicone, and/or acrylic application by an experienced anaplastologist or maxillofacial prosthetics technician. However, with the recent introduction of several enhanced computer-assisted technologies, our facial transplant team hypothesized that there were areas for improvement with respect to cost and preparation time. Results The use of digital imaging for virtual surgical manipulation, computer-assisted planning, and prefabricated surgical cutting guides—in the setting of facial transplantation—provided us a novel opportunity for digital design and fabrication of a donor mask. The results shown here demonstrate an acceptable appearance for “open-casket” burial while maintaining donor identity after facial organ recovery. Conclusions Several newer techniques for fabrication of facial transplant donor masks exist currently and are described within the article. These encompass digital impression, digital design, and additive manufacturing technology. PMID:24835867

Methods for examining data quality in healthcare integrated data repositories.

PubMed

Huser, Vojtech; Kahn, Michael G; Brown, Jeffrey S; Gouripeddi, Ramkiran

2018-01-01

This paper summarizes content of the workshop focused on data quality. The first speaker (VH) described data quality infrastructure and data quality evaluation methods currently in place within the Observational Data Science and Informatics (OHDSI) consortium. The speaker described in detail a data quality tool called Achilles Heel and latest development for extending this tool. Interim results of an ongoing Data Quality study within the OHDSI consortium were also presented. The second speaker (MK) described lessons learned and new data quality checks developed by the PEDsNet pediatric research network. The last two speakers (JB, RG) described tools developed by the Sentinel Initiative and University of Utah's service oriented framework. The workshop discussed at the end and throughout how data quality assessment can be advanced by combining best features of each network.

Eddy Current System for Material Inspection and Flaw Visualization

NASA Technical Reports Server (NTRS)

Bachnak, R.; King, S.; Maeger, W.; Nguyen, T.

2007-01-01

Eddy current methods have been successfully used in a variety of non-destructive evaluation applications including detection of cracks, measurements of material thickness, determining metal thinning due to corrosion, measurements of coating thickness, determining electrical conductivity, identification of materials, and detection of corrosion in heat exchanger tubes. This paper describes the development of an eddy current prototype that combines positional and eddy-current data to produce a C-scan of tested material. The preliminary system consists of an eddy current probe, a position tracking mechanism, and basic data visualization capability. Initial test results of the prototype are presented in this paper.

A Simple Two Aircraft Conflict Resolution Algorithm

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.

2006-01-01

Conflict detection and resolution methods are crucial for distributed air-ground traffic management in which the crew in, the cockpit, dispatchers in operation control centers sad and traffic controllers in the ground-based air traffic management facilities share information and participate in the traffic flow and traffic control functions. This paper describes a conflict detection, and a conflict resolution method. The conflict detection method predicts the minimum separation and the time-to-go to the closest point of approach by assuming that both the aircraft will continue to fly at their current speeds along their current headings. The conflict resolution method described here is motivated by the proportional navigation algorithm, which is often used for missile guidance during the terminal phase. It generates speed and heading commands to rotate the line-of-sight either clockwise or counter-clockwise for conflict resolution. Once the aircraft achieve a positive range-rate and no further conflict is predicted, the algorithm generates heading commands to turn back the aircraft to their nominal trajectories. The speed commands are set to the optimal pre-resolution speeds. Six numerical examples are presented to demonstrate the conflict detection, and the conflict resolution methods.

Notes on Current Planning for Higher Education in the Federal Republic of Germany.

ERIC Educational Resources Information Center

Heister, Matthias M.

1985-01-01

Objectives, methods, and problems of higher education planning agencies are described, and the work of the Bund-Lander-Kommission fur Bildungsplanung und Forschungsforderung is given particular emphasis. (Author/RM)

Quantifying disbond area

NASA Astrophysics Data System (ADS)

Lowden, D. W.

1992-10-01

Disbonds simulated in a composite helicopter rotor blade were profiled using eddy currents. The method is inherently accurate and reproducible. An algorithm is described for calculating disbond margin. Disbond area is estimated assuming in-service disbondments exhibit circular geometry.

Science and Pseudoscience: A Course for the Citizen of the Twenty-First Century.

ERIC Educational Resources Information Center

Howes, Ruth; Watson, James, Jr.

1981-01-01

Describes a course for general education students focusing on current topics in science, titled pseudoscience. Includes the course's goals, objectives, problems, instructional methods, and results of student performance. (DS)

Multiple Comparisons of Observation Means--Are the Means Significantly Different?

ERIC Educational Resources Information Center

Fahidy, T. Z.

2009-01-01

Several currently popular methods of ascertaining which treatment (population) means are different, via random samples obtained under each treatment, are briefly described and illustrated by evaluating catalyst performance in a chemical reactor.

Bridging Native American Culture and Chemistry: Gas Chromatography Experiments That Examine Native Foods.

ERIC Educational Resources Information Center

Sykes, Andrew G.; Caple, Gerald

1999-01-01

Describes three chemistry experiments that link common foodstuffs traditionally and currently harvested by Native Americans in different parts of North America to modern chemical instrumentation and discovery methods. (CCM)

Compilation of field methods used in geochemical prospecting by the U.S. Geological Survey

USGS Publications Warehouse

Lakin, Hubert William; Ward, Frederick Norville; Almond, Hy

1952-01-01

The field methods described in this report are those currently used in geochemical prospecting by the U. S. Geological Survey. Some have been published, others are being processed for publication, while others are still being investigated. The purpose in compiling these methods is to make them readily available in convenient form. The methods have not been thoroughly tested and none is wholly satisfactory. Research is being continued.

Estimation of hyper-parameters for a hierarchical model of combined cortical and extra-brain current sources in the MEG inverse problem.

PubMed

Morishige, Ken-ichi; Yoshioka, Taku; Kawawaki, Dai; Hiroe, Nobuo; Sato, Masa-aki; Kawato, Mitsuo

2014-11-01

One of the major obstacles in estimating cortical currents from MEG signals is the disturbance caused by magnetic artifacts derived from extra-cortical current sources such as heartbeats and eye movements. To remove the effect of such extra-brain sources, we improved the hybrid hierarchical variational Bayesian method (hyVBED) proposed by Fujiwara et al. (NeuroImage, 2009). hyVBED simultaneously estimates cortical and extra-brain source currents by placing dipoles on cortical surfaces as well as extra-brain sources. This method requires EOG data for an EOG forward model that describes the relationship between eye dipoles and electric potentials. In contrast, our improved approach requires no EOG and less a priori knowledge about the current variance of extra-brain sources. We propose a new method, "extra-dipole," that optimally selects hyper-parameter values regarding current variances of the cortical surface and extra-brain source dipoles. With the selected parameter values, the cortical and extra-brain dipole currents were accurately estimated from the simulated MEG data. The performance of this method was demonstrated to be better than conventional approaches, such as principal component analysis and independent component analysis, which use only statistical properties of MEG signals. Furthermore, we applied our proposed method to measured MEG data during covert pursuit of a smoothly moving target and confirmed its effectiveness. Copyright © 2014 Elsevier Inc. All rights reserved.

Mathematical methods for protein science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hart, W.; Istrail, S.; Atkins, J.

1997-12-31

Understanding the structure and function of proteins is a fundamental endeavor in molecular biology. Currently, over 100,000 protein sequences have been determined by experimental methods. The three dimensional structure of the protein determines its function, but there are currently less than 4,000 structures known to atomic resolution. Accordingly, techniques to predict protein structure from sequence have an important role in aiding the understanding of the Genome and the effects of mutations in genetic disease. The authors describe current efforts at Sandia to better understand the structure of proteins through rigorous mathematical analyses of simple lattice models. The efforts have focusedmore » on two aspects of protein science: mathematical structure prediction, and inverse protein folding.« less

Sodium influxes in internally perfused squid giant axon during voltage clamp

PubMed Central

Atwater, I.; Bezanilla, F.; Rojas, E.

1969-01-01

1. An experimental method for measuring ionic influxes during voltage clamp in the giant axon of Dosidicus is described; the technique combines intracellular perfusion with a method for controlling membrane potential. 2. Sodium influx determinations were carried out while applying rectangular pulses of membrane depolarization. The ratio `measured sodium influx/computed ionic flux during the early current' is 0·92 ± 0·12. 3. Plots of measured sodium influx and computed ionic flux during the early current against membrane potential are very similar. There was evidence that the membrane potential at which the sodium influx vanishes is the potential at which the early current reverses. PMID:5767887

Adaptive methods for nonlinear structural dynamics and crashworthiness analysis

NASA Technical Reports Server (NTRS)

Belytschko, Ted

1993-01-01

The objective is to describe three research thrusts in crashworthiness analysis: adaptivity; mixed time integration, or subcycling, in which different timesteps are used for different parts of the mesh in explicit methods; and methods for contact-impact which are highly vectorizable. The techniques are being developed to improve the accuracy of calculations, ease-of-use of crashworthiness programs, and the speed of calculations. The latter is still of importance because crashworthiness calculations are often made with models of 20,000 to 50,000 elements using explicit time integration and require on the order of 20 to 100 hours on current supercomputers. The methodologies are briefly reviewed and then some example calculations employing these methods are described. The methods are also of value to other nonlinear transient computations.

Quantifying selection and diversity in viruses by entropy methods, with application to the haemagglutinin of H3N2 influenza

PubMed Central

Pan, Keyao; Deem, Michael W.

2011-01-01

Many viruses evolve rapidly. For example, haemagglutinin (HA) of the H3N2 influenza A virus evolves to escape antibody binding. This evolution of the H3N2 virus means that people who have previously been exposed to an influenza strain may be infected by a newly emerged virus. In this paper, we use Shannon entropy and relative entropy to measure the diversity and selection pressure by an antibody in each amino acid site of H3 HA between the 1992–1993 season and the 2009–2010 season. Shannon entropy and relative entropy are two independent state variables that we use to characterize H3N2 evolution. The entropy method estimates future H3N2 evolution and migration using currently available H3 HA sequences. First, we show that the rate of evolution increases with the virus diversity in the current season. The Shannon entropy of the sequence in the current season predicts relative entropy between sequences in the current season and those in the next season. Second, a global migration pattern of H3N2 is assembled by comparing the relative entropy flows of sequences sampled in China, Japan, the USA and Europe. We verify this entropy method by describing two aspects of historical H3N2 evolution. First, we identify 54 amino acid sites in HA that have evolved in the past to evade the immune system. Second, the entropy method shows that epitopes A and B on the top of HA evolve most vigorously to escape antibody binding. Our work provides a novel entropy-based method to predict and quantify future H3N2 evolution and to describe the evolutionary history of H3N2. PMID:21543352

A method for the retrieval of atomic oxygen density and temperature profiles from ground-based measurements of the O(+)(2D-2P) 7320 A twilight airglow

NASA Technical Reports Server (NTRS)

Fennelly, J. A.; Torr, D. G.; Richards, P. G.; Torr, M. R.; Sharp, W. E.

1991-01-01

This paper describes a technique for extracting thermospheric profiles of the atomic-oxygen density and temperature, using ground-based measurements of the O(+)(2D-2P) doublet at 7320 and 7330 A in the twilight airglow. In this method, a local photochemical model is used to calculate the 7320-A intensity; the method also utilizes an iterative inversion procedure based on the Levenberg-Marquardt method described by Press et al. (1986). The results demonstrate that, if the measurements are only limited by errors due to Poisson noise, the altitude profiles of neutral temperature and atomic oxygen concentration can be determined accurately using currently available spectrometers.

A reasoned overview on Boussinesq-type models: the interplay between physics, mathematics and numerics.

PubMed

Brocchini, Maurizio

2013-12-08

This paper, which is largely the fruit of an invited talk on the topic at the latest International Conference on Coastal Engineering, describes the state of the art of modelling by means of Boussinesq-type models (BTMs). Motivations for using BTMs as well as their fundamentals are illustrated, with special attention to the interplay between the physics to be described, the chosen model equations and the numerics in use. The perspective of the analysis is that of a physicist/engineer rather than of an applied mathematician. The chronological progress of the currently available BTMs from the pioneering models of the late 1960s is given. The main applications of BTMs are illustrated, with reference to specific models and methods. The evolution in time of the numerical methods used to solve BTMs (e.g. finite differences, finite elements, finite volumes) is described, with specific focus on finite volumes. Finally, an overview of the most important BTMs currently available is presented, as well as some indications on improvements required and fields of applications that call for attention.

A reasoned overview on Boussinesq-type models: the interplay between physics, mathematics and numerics

PubMed Central

Brocchini, Maurizio

2013-01-01

This paper, which is largely the fruit of an invited talk on the topic at the latest International Conference on Coastal Engineering, describes the state of the art of modelling by means of Boussinesq-type models (BTMs). Motivations for using BTMs as well as their fundamentals are illustrated, with special attention to the interplay between the physics to be described, the chosen model equations and the numerics in use. The perspective of the analysis is that of a physicist/engineer rather than of an applied mathematician. The chronological progress of the currently available BTMs from the pioneering models of the late 1960s is given. The main applications of BTMs are illustrated, with reference to specific models and methods. The evolution in time of the numerical methods used to solve BTMs (e.g. finite differences, finite elements, finite volumes) is described, with specific focus on finite volumes. Finally, an overview of the most important BTMs currently available is presented, as well as some indications on improvements required and fields of applications that call for attention. PMID:24353475

Linen Most Useful: Perspectives on Structure, Chemistry, and Enzymes for Retting Flax

PubMed Central

Akin, Danny E.

2013-01-01

The components of flax (Linum usitatissimum) stems are described and illustrated, with reference to the anatomy and chemical makeup and to applications in processing and products. Bast fiber, which is a major economic product of flax along with linseed and linseed oil, is described with particular reference to its application in textiles, composites, and specialty papers. A short history of retting methods, which is the separation of bast fiber from nonfiber components, is presented with emphasis on water retting, field retting (dew retting), and experimental methods. Past research on enzyme retting, particularly by the use of pectinases as a potential replacement for the current commercial practice of field retting, is reviewed. The importance and mechanism of Ca2+ chelators with pectinases in retting are described. Protocols are provided for retting of both fiber-type and linseed-type flax stems with different types of pectinases. Current and future applications are listed for use of a wide array of enzymes to improve processed fibers and blended yarns. Finally, potential lipid and aromatic coproducts derived from the dust and shive waste streams of fiber processing are indicated. PMID:25969769

Measuring the Earth's Magnetic Field in a Laboratory

ERIC Educational Resources Information Center

Cartacci, A.; Straulino, S.

2008-01-01

Two methods for measuring the Earth's magnetic field are described. In the former, according to Gauss, the Earth's magnetic field is compared with that of a permanent magnet; in the latter, a well-known method, the comparison is made with the magnetic field generated by a current. As all the used instruments are available off the shelf, both…

Evaluating Mediation and Moderation Effects in School Psychology: A Presentation of Methods and Review of Current Practice

ERIC Educational Resources Information Center

Fairchild, Amanda J.; McQuillin, Samuel D.

2010-01-01

Third variable effects elucidate the relation between two other variables, and can describe why they are related or under what conditions they are related. This article demonstrates methods to analyze two third-variable effects: moderation and mediation. The utility of examining moderation and mediation effects in school psychology is described…

Flipping the Graduate Qualitative Research Methods Classroom: Did It Lead to Flipped Learning?

ERIC Educational Resources Information Center

Earley, Mark

2016-01-01

The flipped, or inverted, classroom has gained popularity in a variety of fields and at a variety of educational levels, from K-12 through higher education. This paper describes the author's positive experience flipping a graduate qualitative research methods classroom. After a review of the current literature on flipped classrooms in higher…

Scanning tunneling microscope nanoetching method

DOEpatents

Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

1990-01-01

A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

Future Technology Workshop: A Collaborative Method for the Design of New Learning Technologies and Activities

ERIC Educational Resources Information Center

Vavoula, Giasemi N.; Sharples, Mike

2007-01-01

We describe the future technology workshop (FTW), a method whereby people with everyday knowledge or experience in a specific area of technology use (such as using digital cameras) envision and design the interactions between current and future technology and activity. Through a series of structured workshop sessions, participants collaborate to…

Application of Taylor's series to trajectory propagation

NASA Technical Reports Server (NTRS)

Stanford, R. H.; Berryman, K. W.; Breckheimer, P. J.

1986-01-01

This paper describes the propagation of trajectories by the application of the preprocessor ATOMCC which uses Taylor's series to solve initial value problems in ordinary differential equations. Comparison of the results obtained with those from other methods are presented. The current studies indicate that the ATOMCC preprocessor is an easy, yet fast and accurate method for generating trajectories.

An Assessment of the Department of Education's Approach and Model for Analyzing Lender Profitability.

ERIC Educational Resources Information Center

Jenkins, Sarah; And Others

An assessment was done of the Department of Education's (ED) approach to determining lender profitability for Guaranteed Student Loans. The assessment described the current net present value (NPV) method as well as discussing its strengths and weaknesses. The NPV method has been widely accepted for determining the profitability of different…

Performance of the Proposed New Federal Reference Methods for Measuring Ozone Concentrations in Ambient Air

EPA Science Inventory

The current Federal Reference Method (FRM) for measuring concentrations of ozone in ambient air, described in EPA regulations at 40 CFR Part 50, Appendix D, is based on the dry, gas-phase, chemiluminescence reaction between ethylene (C₂H₄) and any ozone (O

A Model for Engaging Students in a Research Experience Involving Variational Techniques, Mathematica, and Descent Methods.

ERIC Educational Resources Information Center

Mahavier, W. Ted

2002-01-01

Describes a two-semester numerical methods course that serves as a research experience for undergraduate students without requiring external funding or the modification of current curriculum. Uses an engineering problem to introduce students to constrained optimization via a variation of the traditional isoperimetric problem of finding the curve…

Comparative study of methods to measure the density of Cementious powders

PubMed Central

Helsel, Michelle A.; Bentz, Dale

2016-01-01

The accurate measurement of the density of hydraulic cement has an essential role in the determination of concrete mixture proportions. As more supplementary cementitious materials (SCM), such as fly ash, and slag, or cement replacements materials such as limestone and calcium carbonate are used in blended cements, knowledge of the density of each powder or of the blended cement would allow a more accurate calculation of the proportions of a concrete mixture by volume instead of by mass. The current ASTM standard for measuring cement density is the “Test Method for Density of Hydraulic Cements” (ASTM C188-14), which utilizes a liquid displacement method to measure the volume of the cement. This paper will examine advantageous modifications of the current ASTM test, by alcohol substitutions for kerosene. In addition, a gas (helium) pycnometry method is evaluated as a possible alternative to the current standard. The described techniques will be compared to determine the most precise and reproducible method for measuring the density of hydraulic cements and other powders. PMID:27099404

Comparative study of methods to measure the density of Cementious powders.

PubMed

Helsel, Michelle A; Ferraris, Chiara F; Bentz, Dale

2016-11-01

The accurate measurement of the density of hydraulic cement has an essential role in the determination of concrete mixture proportions. As more supplementary cementitious materials (SCM), such as fly ash, and slag, or cement replacements materials such as limestone and calcium carbonate are used in blended cements, knowledge of the density of each powder or of the blended cement would allow a more accurate calculation of the proportions of a concrete mixture by volume instead of by mass. The current ASTM standard for measuring cement density is the "Test Method for Density of Hydraulic Cements" (ASTM C188-14), which utilizes a liquid displacement method to measure the volume of the cement. This paper will examine advantageous modifications of the current ASTM test, by alcohol substitutions for kerosene. In addition, a gas (helium) pycnometry method is evaluated as a possible alternative to the current standard. The described techniques will be compared to determine the most precise and reproducible method for measuring the density of hydraulic cements and other powders.

Unified planar process for fabricating heterojunction bipolar transistors and buried-heterostructure lasers utilizing impurity-induced disordering

NASA Astrophysics Data System (ADS)

Thornton, R. L.; Mosby, W. J.; Chung, H. F.

1988-12-01

We describe results on a novel geometry of heterojunction bipolar transistor that has been realized by impurity-induced disordering. This structure is fabricated by a method that is compatible with techniques for the fabrication of low threshold current buried-heterostructure lasers. We have demonstrated this compatibility by fabricating a hybrid laser/transistor structure that operates as a laser with a threshold current of 6 mA at room temperature, and as a transistor with a current gain of 5.

FGK stars and T Tauri stars: Monograph series on nonthermal phenomena in stellar atmospheres

NASA Technical Reports Server (NTRS)

Cram, Lawrence E. (Editor); Kuhi, Leonard V. (Editor)

1989-01-01

The purpose of this book, FGK Stars and T Tauri Stars, like all other volumes of this series, is to exhibit and describe the best space data and ground based data currently available, and also to describe and critically evaluate the status of current theoretical models and physical mechanisms that have been proposed to interpret these data. The method for obtaining this book was to collect manuscripts from competent volunteer authors, and then to collate and edit these contributions to form a well structured book, which will be distributed to an international community of research astronomers by NASA and by the French CNRS.

A Hybrid Nonlinear Control Scheme for Active Magnetic Bearings

NASA Technical Reports Server (NTRS)

Xia, F.; Albritton, N. G.; Hung, J. Y.; Nelms, R. M.

1996-01-01

A nonlinear control scheme for active magnetic bearings is presented in this work. Magnet winding currents are chosen as control inputs for the electromechanical dynamics, which are linearized using feedback linearization. Then, the desired magnet currents are enforced by sliding mode control design of the electromagnetic dynamics. The overall control scheme is described by a multiple loop block diagram; the approach also falls in the class of nonlinear controls that are collectively known as the 'integrator backstepping' method. Control system hardware and new switching power electronics for implementing the controller are described. Various experiments and simulation results are presented to demonstrate the concepts' potentials.

Eddy current testing for blade edge micro cracks of aircraft engine

NASA Astrophysics Data System (ADS)

Zhang, Wei-min; Xu, Min-dong; Gao, Xuan-yi; Jin, Xin; Qin, Feng

2017-10-01

Based on the problems of low detection efficiency in the micro cracks detection of aircraft engine blades, a differential excitation eddy current testing system was designed and developed. The function and the working principle of the system were described, the problems which contained the manufacture method of simulated cracks, signal generating, signal processing and the signal display method were described. The detection test was carried out by taking a certain model aircraft engine blade with simulated cracks as a tested specimen. The test data was processed by digital low-pass filter in the computer and the crack signals of time domain display and Lissajous figure display were acquired. By comparing the test results, it is verified that Lissajous figure display shows better performance compared to time domain display when the crack angle is small. The test results show that the eddy current testing system designed in this paper is feasible to detect the micro cracks on the aeroengine blade and can effectively improve the detection efficiency of micro cracks in the practical detection work.

From comparative effectiveness research to patient-centered outcomes research: integrating emergency care goals, methods, and priorities.

PubMed

Meisel, Zachary F; Carr, Brendan G; Conway, Patrick H

2012-09-01

Federal legislation placed comparative effectiveness research and patient-centered outcomes research at the center of current and future national investments in health care research. The role of this research in emergency care has not been well described. This article proposes an agenda for researchers and health care providers to consider comparative effectiveness research and patient-centered outcomes research methods and results to improve the care for patients who seek, use, and require emergency care. This objective will be accomplished by (1) exploring the definitions, frameworks, and nomenclature for comparative effectiveness research and patient-centered outcomes research; (2) describing a conceptual model for comparative effectiveness research in emergency care; (3) identifying specific opportunities and examples of emergency care-related comparative effectiveness research; and (4) categorizing current and planned funding for comparative effectiveness research and patient-centered outcomes research that can include emergency care delivery. Copyright © 2012. Published by Mosby, Inc.

High voltage MOSFET devices and methods of making the devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Sujit; Matocha, Kevin; Chatty, Kiran

A SiC MOSFET device having low specific on resistance is described. The device has N+, P-well and JFET regions extended in one direction (Y-direction) and P+ and source contacts extended in an orthogonal direction (X-direction). The polysilicon gate of the device covers the JFET region and is terminated over the P-well region to minimize electric field at the polysilicon gate edge. In use, current flows vertically from the drain contact at the bottom of the structure into the JFET region and then laterally in the X direction through the accumulation region and through the MOSFET channels into the adjacent N+more » region. The current flowing out of the channel then flows along the N+ region in the Y-direction and is collected by the source contacts and the final metal. Methods of making the device are also described.« less

Current contraceptive status among women aged 15-44: United States, 2011-2013.

PubMed

Daniels, Kimberly; Daugherty, Jill; Jones, Jo

2014-12-01

Nearly all women use contraception at some point in their lifetimes, although at any given time they may not be using contraception for reasons such as seeking pregnancy, being pregnant, or not being sexually active. Using data from the 2011-2013 National Survey of Family Growth (NSFG) on contraceptive use in the month of the interview, this report provides a snapshot of current contraceptive status among women aged 15-44 in the United States. In addition to describing use of any method by age, Hispanic origin and race, and educational attainment, patterns of use are described for the four most commonly used contraceptive methods: the oral contraceptive pill, female sterilization, the male condom, and long-acting reversible contraceptives, which include contraceptive implants and intrauterine devices. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

Optimized distortion correction technique for echo planar imaging.

PubMed

Chen , N K; Wyrwicz, A M

2001-03-01

A new phase-shifted EPI pulse sequence is described that encodes EPI phase errors due to all off-resonance factors, including B(o) field inhomogeneity, eddy current effects, and gradient waveform imperfections. Combined with the previously proposed multichannel modulation postprocessing algorithm (Chen and Wyrwicz, MRM 1999;41:1206-1213), the encoded phase error information can be used to effectively remove geometric distortions in subsequent EPI scans. The proposed EPI distortion correction technique has been shown to be effective in removing distortions due to gradient waveform imperfections and phase gradient-induced eddy current effects. In addition, this new method retains advantages of the earlier method, such as simultaneous correction of different off-resonance factors without use of a complicated phase unwrapping procedure. The effectiveness of this technique is illustrated with EPI studies on phantoms and animal subjects. Implementation to different versions of EPI sequences is also described. Magn Reson Med 45:525-528, 2001. Copyright 2001 Wiley-Liss, Inc.

High voltage MOSFET devices and methods of making the devices

DOEpatents

Banerjee, Sujit; Matocha, Kevin; Chatty, Kiran

2015-12-15

A SiC MOSFET device having low specific on resistance is described. The device has N+, P-well and JFET regions extended in one direction (Y-direction) and P+ and source contacts extended in an orthogonal direction (X-direction). The polysilicon gate of the device covers the JFET region and is terminated over the P-well region to minimize electric field at the polysilicon gate edge. In use, current flows vertically from the drain contact at the bottom of the structure into the JFET region and then laterally in the X direction through the accumulation region and through the MOSFET channels into the adjacent N+ region. The current flowing out of the channel then flows along the N+ region in the Y-direction and is collected by the source contacts and the final metal. Methods of making the device are also described.

Thrust Control Loop Design for Electric-Powered UAV

NASA Astrophysics Data System (ADS)

Byun, Heejae; Park, Sanghyuk

2018-04-01

This paper describes a process of designing a thrust control loop for an electric-powered fixed-wing unmanned aerial vehicle equipped with a propeller and a motor. In particular, the modeling method of the thrust system for thrust control is described in detail and the propeller thrust and torque force are modeled using blade element theory. A relation between current and torque of the motor is obtained using an experimental setup. Another relation between current, voltage and angular velocity is also obtained. The electric motor and the propeller dynamics are combined to model the thrust dynamics. The associated trim and linearization equations are derived. Then, the thrust dynamics are coupled with the flight dynamics to allow a proper design for the thrust loop in the flight control. The proposed method is validated by an application to a testbed UAV through simulations and flight test.

Development and Testing of a Coupled Ocean-atmosphere Mesoscale Ensemble Prediction System

DTIC Science & Technology

2011-06-28

wind, temperature, and moisture variables, while the oceanographic ET is derived from ocean current, temperature, and salinity variables. Estimates of...wind, temperature, and moisture variables while the oceanographic ET is derived from ocean current temperature, and salinity variables. Estimates of...uncertainty in the model. Rigorously accurate ensemble methods for describing the distribution of future states given past information include particle

Unsteady transonic flows - Introduction, current trends, applications

NASA Technical Reports Server (NTRS)

Yates, E. C., Jr.

1985-01-01

The computational treatment of unsteady transonic flows is discussed, reviewing the historical development and current techniques. The fundamental physical principles are outlined; the governing equations are introduced; three-dimensional linearized and two-dimensional linear-perturbation theories in frequency domain are described in detail; and consideration is given to frequency-domain FEMs and time-domain finite-difference and integral-equation methods. Extensive graphs and diagrams are included.

The induced electric field due to a current transient

NASA Astrophysics Data System (ADS)

Beck, Y.; Braunstein, A.; Frankental, S.

2007-05-01

Calculations and measurements of the electric fields, induced by a lightning strike, are important for understanding the phenomenon and developing effective protection systems. In this paper, a novel approach to the calculation of the electric fields due to lightning strikes, using a relativistic approach, is presented. This approach is based on a known current wave-pair model, representing the lightning current wave. The model presented is one that describes the lightning current wave, either at the first stage of the descending charge wave from the cloud or at the later stage of the return stroke. The electric fields computed are cylindrically symmetric. A simplified method for the calculation of the electric field is achieved by using special relativity theory and relativistic considerations. The proposed approach, described in this paper, is based on simple expressions (by applying Coulomb's law) compared with much more complicated partial differential equations based on Maxwell's equations. A straight forward method of calculating the electric field due to a lightning strike, modelled as a negative-positive (NP) wave-pair, is determined by using the special relativity theory in order to calculate the 'velocity field' and relativistic concepts for calculating the 'acceleration field'. These fields are the basic elements required for calculating the total field resulting from the current wave-pair model. Moreover, a modified simpler method using sub models is represented. The sub-models are filaments of either static charges or charges at constant velocity only. Combining these simple sub-models yields the total wave-pair model. The results fully agree with that obtained by solving Maxwell's equations for the discussed problem.

NERC Policy 10: Measurement of two generation and load balancing IOS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spicer, P.J.; Galow, G.G.

1999-11-01

Policy 10 will describe specific standards and metrics for most of the reliability functions described in the Interconnected Operations Services Working Group (IOS WG) report. The purpose of this paper is to discuss, in detail, the proposed metrics for two generation and load balancing IOSs: Regulation; Load Following. For purposes of this paper, metrics include both measurement and performance evaluation. The measurement methods discussed are included in the current draft of the proposed Policy 10. The performance evaluation method discussed is offered by the authors for consideration by the IOS ITF (Implementation Task Force) for inclusion into Policy 10.

Dual-Energy CT: New Horizon in Medical Imaging

PubMed Central

Goo, Jin Mo

2017-01-01

Dual-energy CT has remained underutilized over the past decade probably due to a cumbersome workflow issue and current technical limitations. Clinical radiologists should be made aware of the potential clinical benefits of dual-energy CT over single-energy CT. To accomplish this aim, the basic principle, current acquisition methods with advantages and disadvantages, and various material-specific imaging methods as clinical applications of dual-energy CT should be addressed in detail. Current dual-energy CT acquisition methods include dual tubes with or without beam filtration, rapid voltage switching, dual-layer detector, split filter technique, and sequential scanning. Dual-energy material-specific imaging methods include virtual monoenergetic or monochromatic imaging, effective atomic number map, virtual non-contrast or unenhanced imaging, virtual non-calcium imaging, iodine map, inhaled xenon map, uric acid imaging, automatic bone removal, and lung vessels analysis. In this review, we focus on dual-energy CT imaging including related issues of radiation exposure to patients, scanning and post-processing options, and potential clinical benefits mainly to improve the understanding of clinical radiologists and thus, expand the clinical use of dual-energy CT; in addition, we briefly describe the current technical limitations of dual-energy CT and the current developments of photon-counting detector. PMID:28670151

Focused intracochlear electric stimulation with phased array channels.

PubMed

van den Honert, Chris; Kelsall, David C

2007-06-01

A method is described for producing focused intracochlear electric stimulation using an array of N electrodes. For each electrode site, N weights are computed that define the ratios of positive and negative electrode currents required to produce cancellation of the voltage within scala tympani at all of the N-1 other sites. Multiple sites can be stimulated simultaneously by superposition of their respective current vectors. The method allows N independent stimulus waveforms to be delivered to each of the N electrode sites without spatial overlap. Channel interaction from current spread associated with monopolar stimulation is substantially eliminated. The method operates by inverting the spread functions of individual monopoles as measured with the other electrodes. The method was implemented and validated with data from three human subjects implanted with 22-electrode perimodiolar arrays. Results indicate that (1) focusing is realizable with realistic precision; (2) focusing comes at the cost of increased total stimulation current; (3) uncanceled voltages that arise beyond the ends of the array are weak except when stimulating the two end channels; and (4) close perimodiolar positioning of the electrodes may be important for minimizing stimulation current and sensitivity to measurement errors.

Method for evaluating human exposure to 60 HZ electric fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deno, D.W.; Silva, M.

1984-07-01

This paper describes a method that has been successfully used to evaluate human exposure to 60 Hz electric fields. An exposure measuring system that uses an electric field sensor vest and data collection instrumentation is presented. Exposure concepts and activity factors are discussed and experimental data collected with the exposure system are provided. This method can be used to measure exposure to a wide range of electric field with intensities from less than 1 V/m to more than 10 kV/m. Results may be translated to characterize various exposure criteria (time histogram of unperturbed field, surface fields, internal current density, totalmore » body current, etc).« less

Electrical resistance tomography using steel cased boreholes as electrodes

DOEpatents

Daily, W.D.; Ramirez, A.L.

1999-06-22

An electrical resistance tomography method is described which uses steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constrain the models. 2 figs.

Bivariate quadratic method in quantifying the differential capacitance and energy capacity of supercapacitors under high current operation

NASA Astrophysics Data System (ADS)

Goh, Chin-Teng; Cruden, Andrew

2014-11-01

Capacitance and resistance are the fundamental electrical parameters used to evaluate the electrical characteristics of a supercapacitor, namely the dynamic voltage response, energy capacity, state of charge and health condition. In the British Standards EN62391 and EN62576, the constant capacitance method can be further improved with a differential capacitance that more accurately describes the dynamic voltage response of supercapacitors. This paper presents a novel bivariate quadratic based method to model the dynamic voltage response of supercapacitors under high current charge-discharge cycling, and to enable the derivation of the differential capacitance and energy capacity directly from terminal measurements, i.e. voltage and current, rather than from multiple pulsed-current or excitation signal tests across different bias levels. The estimation results the author achieves are in close agreement with experimental measurements, within a relative error of 0.2%, at various high current levels (25-200 A), more accurate than the constant capacitance method (4-7%). The archival value of this paper is the introduction of an improved quantification method for the electrical characteristics of supercapacitors, and the disclosure of the distinct properties of supercapacitors: the nonlinear capacitance-voltage characteristic, capacitance variation between charging and discharging, and distribution of energy capacity across the operating voltage window.

Books and Periodicals.

ERIC Educational Resources Information Center

Lonardo, Michael; And Others

1994-01-01

Special section includes two articles on academic library collection management: "Current Awareness: Acquisitions to Endusers" (Michael Lonardo and Dianne Taylor-Harding) describes methods for announcing recent library acquisitions to faculty; and "Book Acquisitions: A Purchasing System" (Ting Zheng and Joyce Huang) explains a…

THEORETICAL METHODS FOR COMPUTING ELECTRICAL CONDITIONS IN WIRE-PLATE ELECTROSTATIC PRECIPITATORS

EPA Science Inventory

The paper describes a new semi-empirical, approximate theory for predicting electrical conditions. In the approximate theory, analytical expressions are derived for calculating voltage-current characteristics and electric potential, electric field, and space charge density distri...

Development and current applications of assisted fertilization.

PubMed

Palermo, Gianpiero D; Neri, Queenie V; Monahan, Devin; Kocent, Justin; Rosenwaks, Zev

2012-02-01

Since the very early establishment of in vitro insemination, it became clear that one of the limiting steps is the achievement of fertilization. Among the different assisted fertilization methods, intracytoplasmic sperm injection emerged as the ultimate technique to allow fertilization with ejaculated, epididymal, and testicular spermatozoa. This work describes the early steps that brought forth the development of intracytoplasmic sperm injection and its role in assisted reproductive techniques. The current methods to select the preferential male gamete will be elucidated and the concerns related to the offspring of severe male factor couples will be discussed. Copyright © 2012. Published by Elsevier Inc.

Challenges in Building Disease-Based National Health Accounts

PubMed Central

Rosen, Allison B.; Cutler, David M.

2012-01-01

Background Measuring spending on diseases is critical to assessing the value of medical care. Objective To review the current state of cost of illness (COI) estimation methods, identifying their strengths, limitations and uses. We briefly describe the current National Health Expenditure Accounts (NHEA), and then go on to discuss the addition of COI estimation to the NHEA. Conclusion Recommendations are made for future research aimed at identifying the best methods for developing and using disease-based national health accounts to optimize the information available to policymakers as they struggle with difficult resource allocation decisions. PMID:19536017

Intravenous Solutions for Exploration Missions

NASA Technical Reports Server (NTRS)

Miller, Fletcher J.; Niederhaus, Charles; Barlow, Karen; Griffin, DeVon

2007-01-01

This paper describes the intravenous (IV) fluids requirements being developed for medical care during NASA s future exploration class missions. Previous research on IV solution generation and mixing in space is summarized. The current exploration baseline mission profiles are introduced, potential medical conditions described and evaluated for fluidic needs, and operational issues assessed. We briefly introduce potential methods for generating IV fluids in microgravity. Conclusions on the recommended fluid volume requirements are presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hensley, Jesse; Ruddy, Daniel A.; Schaidle, Joshua A.

Catalysts and processes designed to convert DME and/or methanol and hydrogen (H.sub.2) to desirable liquid fuels are described. These catalysts produce the fuels efficiently and with a high selectivity and yield, and reduce the formation of aromatic hydrocarbons by incorporating H.sub.2 into the products. Also described are process methods to further upgrade these fuels to higher molecular weight liquid fuel mixtures, which have physical properties comparable with current commercially used liquid fuels.

Electrical energy consumption control apparatuses and electrical energy consumption control methods

DOEpatents

Hammerstrom, Donald J.

2012-09-04

Electrical energy consumption control apparatuses and electrical energy consumption control methods are described. According to one aspect, an electrical energy consumption control apparatus includes processing circuitry configured to receive a signal which is indicative of current of electrical energy which is consumed by a plurality of loads at a site, to compare the signal which is indicative of current of electrical energy which is consumed by the plurality of loads at the site with a desired substantially sinusoidal waveform of current of electrical energy which is received at the site from an electrical power system, and to use the comparison to control an amount of the electrical energy which is consumed by at least one of the loads of the site.

A real-time PCR diagnostic method for detection of Naegleria fowleri.

PubMed

Madarová, Lucia; Trnková, Katarína; Feiková, Sona; Klement, Cyril; Obernauerová, Margita

2010-09-01

Naegleria fowleri is a free-living amoeba that can cause primary amoebic meningoencephalitis (PAM). While, traditional methods for diagnosing PAM still rely on culture, more current laboratory diagnoses exist based on conventional PCR methods; however, only a few real-time PCR processes have been described as yet. Here, we describe a real-time PCR-based diagnostic method using hybridization fluorescent labelled probes, with a LightCycler instrument and accompanying software (Roche), targeting the Naegleria fowleriMp2Cl5 gene sequence. Using this method, no cross reactivity with other tested epidemiologically relevant prokaryotic and eukaryotic organisms was found. The reaction detection limit was 1 copy of the Mp2Cl5 DNA sequence. This assay could become useful in the rapid laboratory diagnostic assessment of the presence or absence of Naegleria fowleri. Copyright 2009 Elsevier Inc. All rights reserved.

The cleaning of ward floors and the bacteriological study of floor-cleaning machines

PubMed Central

Bate, J. G.

1961-01-01

Current trends in ward flooring materials and cleaning methods are considered from the point of view of the hospital bacteriologist. Methods employed in an investigation into the bacteriological safety of a number of floor-cleaning machines are described, and some considerations governing the choice of vacuum cleaners for ward use are discussed. Images PMID:13687726

Report to the Congress on alternative methods for the Strategic Petroleum Reserve

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-02-01

The purpose of this study is to fulfill the requirements of Public Law No. 101-46, approved June 30, 1989. The study describes and evaluates alternative methods for financing the future expansion of the Strategic petroleum Reserve (SPR), both to the current target level of 750 million barrels and to potential future levels of up to one billion barrels.

Coupling the biophysical and social dimensions of wildfire risk to improve wildfire mitigation planning

Treesearch

Alan A. Ager; Jeffrey D. Kline; A. Paige Fisher

2015-01-01

We describe recent advances in biophysical and social aspects of risk and their potential combined contribution to improve mitigation planning on fire-prone landscapes. The methods and tools provide an improved method for defining the spatial extent of wildfire risk to communities compared to current planning processes. They also propose an expanded role for social...

Estimating Logistics Support of Reusable Launch Vehicles During Conceptual Design

NASA Technical Reports Server (NTRS)

Morris, W. D.; White, N. H.; Davies, W. T.; Ebeling, C. E.

1997-01-01

Methods exist to define the logistics support requirements for new aircraft concepts but are not directly applicable to new launch vehicle concepts. In order to define the support requirements and to discriminate among new technologies and processing choices for these systems, NASA Langley Research Center (LaRC) is developing new analysis methods. This paper describes several methods under development, gives their current status, and discusses the benefits and limitations associated with their use.

The fact of ignorance: revisiting the Socratic method as a tool for teaching critical thinking.

PubMed

Oyler, Douglas R; Romanelli, Frank

2014-09-15

Critical thinking, while highly valued as an ability of health care providers, remains a skill that many educators find difficult to teach. This review provides an analysis examining why current methods of teaching critical thinking to health care students (primarily medical and pharmacy students) often fail and describes a premise and potential utility of the Socratic method as a tool to teach critical thinking in health care education.

A Drive Method for Small Inductance PM Motor Under No-Load Condition

NASA Astrophysics Data System (ADS)

Tanaka, Daisuke; Ohishi, Kiyoshi

The harmonic wave of the exciting current of the motor is generated by the pulsewidth modulated voltage of the inverter. The motors that have low inpedance genetate more harmonics and make larger iron loss. This paper describes an implementation of drive control for a small inductance permanent-magnet motor drive. A comparative experiment has been carried out with conventional methods and the utility of the proposed method has been verified.

Recent Work in Hybrid Radiation Transport Methods with Applications to Commercial Nuclear Power

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulesza, Joel A.

This talk will begin with an overview of hybrid radiation transport methods followed by a discussion of the author’s work to advance current capabilities. The talk will then describe applications for these methods in commercial nuclear power reactor analyses and techniques for experimental validation. When discussing these analytical and experimental activities, the importance of technical standards such as those created and maintained by ASTM International will be demonstrated.

Nondestructive method for detecting defects in photodetector and solar cell devices

DOEpatents

Not Available

The invention described herein is a method for locating semiconductor device defects and for measuring the internal resistance of such devices by making use of the intrinsic distributed resistance nature of the devices. The method provides for forward-biasing a solar cell or other device while it is scanning with an optical spot. The forward-biasing is achieved with either an illuminator light source or an external current source.

Nondestructive method for detecting defects in photodetector and solar cell devices

DOEpatents

Sawyer, David E.

1981-01-01

The invention described herein is a method for locating semiconductor device defects and for measuring the internal resistance of such devices by making use of the intrinsic distributed resistance nature of the devices. The method provides for forward-biasing a solar cell or other device while it is scanning with an optical spot. The forward-biasing is achieved with either an illuminator light source or an external current source.

[Physiotherapeutic care marketing research: current state-of-the art].

PubMed

Babaskin, D V

2011-01-01

Successful introduction of modern technologies into the national health care systems strongly depends on the current pharmaceutical market situation. The present article is focused on the peculiarities of marketing research with special reference to physiotherapeutic services and commodities. Analysis of the structure and sequence of marketing research processes is described along with the methods applied for the purpose including their support by the use of Internet resources and technologies.

Field emission electron source

DOEpatents

Zettl, Alexander Karlwalter; Cohen, Marvin Lou

2000-01-01

A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

Is There a Consensus on Consensus Methodology? Descriptions and Recommendations for Future Consensus Research.

PubMed

Waggoner, Jane; Carline, Jan D; Durning, Steven J

2016-05-01

The authors of this article reviewed the methodology of three common consensus methods: nominal group process, consensus development panels, and the Delphi technique. The authors set out to determine how a majority of researchers are conducting these studies, how they are analyzing results, and subsequently the manner in which they are reporting their findings. The authors conclude with a set of guidelines and suggestions designed to aid researchers who choose to use the consensus methodology in their work.Overall, researchers need to describe their inclusion criteria. In addition to this, on the basis of the current literature the authors found that a panel size of 5 to 11 members was most beneficial across all consensus methods described. Lastly, the authors agreed that the statistical analyses done in consensus method studies should be as rigorous as possible and that the predetermined definition of consensus must be included in the ultimate manuscript. More specific recommendations are given for each of the three consensus methods described in the article.

Modeling of the coupled magnetospheric and neutral wind dynamos

NASA Technical Reports Server (NTRS)

Thayer, Jeffrey P.

1994-01-01

This report summarizes the progress made in the first year of NASA Grant No. NAGW-3508 entitled 'Modeling of the Coupled Magnetospheric and Neutral Wind Dynamos.' The approach taken has been to impose magnetospheric boundary conditions with either pure voltage or current characteristics and solve the neutral wind dynamo equation under these conditions. The imposed boundary conditions determine whether the neutral wind dynamo will contribute to the high-latitude current system or the electric potential. The semi-annual technical report, dated December 15, 1993, provides further detail describing the scientific and numerical approach of the project. The numerical development has progressed and the dynamo solution for the case when the magnetosphere acts as a voltage source has been evaluated completely using spectral techniques. The simulation provides the field-aligned current distribution at high latitudes due to the neutral wind dynamo. A number of geophysical conditions can be simulated to evaluate the importance of the neutral wind dynamo contribution to the field-aligned current system. On average, field-aligned currents generated by the neutral wind dynamo contributed as much as 30 percent to the large-scale field-aligned current system driven by the magnetosphere. A term analysis of the high-latitude neutral wind dynamo equation describing the field aligned current distribution has also been developed to illustrate the important contributing factors involved in the process. The case describing the neutral dynamo response for a magnetosphere acting as a pure current generator requires the existing spectral code to be extended to a pseudo-spectral method and is currently under development.

A method for data base management and analysis for wind tunnel data

NASA Technical Reports Server (NTRS)

Biser, Aileen O.

1987-01-01

To respond to the need for improved data base management and analysis capabilities for wind-tunnel data at the Langley 16-Foot Transonic Tunnel, research was conducted into current methods of managing wind-tunnel data and a method was developed as a solution to this need. This paper describes the development of the data base management and analysis method for wind-tunnel data. The design and implementation of the software system are discussed and examples of its use are shown.

A neurite quality index and machine vision software for improved quantification of neurodegeneration.

PubMed

Romero, Peggy; Miller, Ted; Garakani, Arman

2009-12-01

Current methods to assess neurodegradation in dorsal root ganglion cultures as a model for neurodegenerative diseases are imprecise and time-consuming. Here we describe two new methods to quantify neuroprotection in these cultures. The neurite quality index (NQI) builds upon earlier manual methods, incorporating additional morphological events to increase detection sensitivity for the detection of early degeneration events. Neurosight is a machine vision-based method that recapitulates many of the strengths of NQI while enabling high-throughput screening applications with decreased costs.

Large Aircraft Robotic Paint Stripping (LARPS) system and the high pressure water process

NASA Astrophysics Data System (ADS)

See, David W.; Hofacker, Scott A.; Stone, M. Anthony; Harbaugh, Darcy

1993-03-01

The aircraft maintenance industry is beset by new Environmental Protection Agency (EPA) guidelines on air emissions, Occupational Safety and Health Administration (OSHA) standards, dwindling labor markets, Federal Aviation Administration (FAA) safety guidelines, and increased operating costs. In light of these factors, the USAF's Wright Laboratory Manufacturing Technology Directorate and the Aircraft Division of the Oklahoma City Air Logistics Center initiated a MANTECH/REPTECH effort to automate an alternate paint removal method and eliminate the current manual methylene chloride chemical stripping methods. This paper presents some of the background and history of the LARPS program, describes the LARPS system, documents the projected operational flow, quantifies some of the projected system benefits and describes the High Pressure Water Stripping Process. Certification of an alternative paint removal method to replace the current chemical process is being performed in two phases: Process Optimization and Process Validation. This paper also presents the results of the Process Optimization for metal substrates. Data on the coating removal rate, residual stresses, surface roughness, preliminary process envelopes, and technical plans for process Validation Testing will be discussed.

Evaluation of capillary zone electrophoresis for the determination of protein composition in therapeutic immunoglobulins and human albumins.

PubMed

Christians, Stefan; van Treel, Nadine Denise; Bieniara, Gabriele; Eulig-Wien, Annika; Hanschmann, Kay-Martin; Giess, Siegfried

2016-07-01

Capillary zone electrophoresis (CZE) provides an alternative means of separating native proteins on the basis of their inherent electrophoretic mobilities. The major advantage of CZE is the quantification by UV detection, circumventing the drawbacks of staining and densitometry in the case of gel electrophoresis methods. The data of this validation study showed that CZE is a reliable assay for the determination of protein composition in therapeutic preparations of human albumin and human polyclonal immunoglobulins. Data obtained by CZE are in line with "historical" data obtained by the compendial method, provided that peak integration is performed without time correction. The focus here was to establish a rapid and reliable test to substitute the current gel based zone electrophoresis techniques for the control of protein composition of human immunoglobulins or albumins in the European Pharmacopoeia. We believe that the more advanced and modern CZE method described here is a very good alternative to the procedures currently described in the relevant monographs. Copyright © 2016 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Seasonal and nonseasonal variability of satellite-derived surface pigment concentration in the California Current

NASA Technical Reports Server (NTRS)

Strub, P. Ted; James, Corinne; Thomas, Andrew C.; Abbott, Mark R.

1990-01-01

The large-scale patterns of satellite-derived surface pigment concentration off the west coast of North America are presented and are averaged into monthly mean surface wind fields over the California Current system (CCS) for the July 1979 to June 1986 period. The patterns are discussed in terms of both seasonal and nonseasonal variability for the indicated time period. The large-scale seasonal characteristics of the California Current are summarized. The data and methods used are described, and the problems known to affect the satellite-derived pigment concentrations and the wind data used in the study are discussed. The statistical analysis results are then presented and discussed in light of past observations and theory. Details of the CZCS data processing are described, and details of the principal estimator pattern methodology used here are given.

The SIETTE Automatic Assessment Environment

ERIC Educational Resources Information Center

Conejo, Ricardo; Guzmán, Eduardo; Trella, Monica

2016-01-01

This article describes the evolution and current state of the domain-independent Siette assessment environment. Siette supports different assessment methods--including classical test theory, item response theory, and computer adaptive testing--and integrates them with multidimensional student models used by intelligent educational systems.…

Atrophic Rhinitis of Swine

USDA-ARS?s Scientific Manuscript database

This book chapter for the 8th edition of the OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals describes the current state of knowledge regarding progressive atrophic rhinitis of swine. Topics covered include clinical signs and lesions, characteristics and methods of detection for...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kathawa, J.; Fry, C.; Thoennessen, M., E-mail: thoennessen@nscl.msu.edu

Currently, thirty-eight palladium, thirty-eight antimony, thirty-nine tellurium, thirty-eight iodine, and forty xenon isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

Real-time fault diagnosis for propulsion systems

NASA Technical Reports Server (NTRS)

Merrill, Walter C.; Guo, Ten-Huei; Delaat, John C.; Duyar, Ahmet

1991-01-01

Current research toward real time fault diagnosis for propulsion systems at NASA-Lewis is described. The research is being applied to both air breathing and rocket propulsion systems. Topics include fault detection methods including neural networks, system modeling, and real time implementations.

Method of Conjugate Radii for Solving Linear and Nonlinear Systems

NASA Technical Reports Server (NTRS)

Nachtsheim, Philip R.

1999-01-01

This paper describes a method to solve a system of N linear equations in N steps. A quadratic form is developed involving the sum of the squares of the residuals of the equations. Equating the quadratic form to a constant yields a surface which is an ellipsoid. For different constants, a family of similar ellipsoids can be generated. Starting at an arbitrary point an orthogonal basis is constructed and the center of the family of similar ellipsoids is found in this basis by a sequence of projections. The coordinates of the center in this basis are the solution of linear system of equations. A quadratic form in N variables requires N projections. That is, the current method is an exact method. It is shown that the sequence of projections is equivalent to a special case of the Gram-Schmidt orthogonalization process. The current method enjoys an advantage not shared by the classic Method of Conjugate Gradients. The current method can be extended to nonlinear systems without modification. For nonlinear equations the Method of Conjugate Gradients has to be augmented with a line-search procedure. Results for linear and nonlinear problems are presented.

Counting glomeruli and podocytes: rationale and methodologies

PubMed Central

Puelles, Victor G.; Bertram, John F.

2015-01-01

Purpose of review There is currently much interest in the numbers of both glomeruli and podocytes. This interest stems from greater understanding of the effects of suboptimal fetal events on nephron endowment, the associations between low nephron number and chronic cardiovascular and kidney disease in adults, and the emergence of the podocyte depletion hypothesis. Recent findings Obtaining accurate and precise estimates of glomerular and podocyte number has proven surprisingly difficult. When whole kidneys or large tissue samples are available, design-based stereological methods are considered gold-standard because they are based on principles that negate systematic bias. However, these methods are often tedious and time-consuming, and oftentimes inapplicable when dealing with small samples such as biopsies. Therefore, novel methods suitable for small tissue samples, and innovative approaches to facilitate high through put measurements, such as magnetic resonance imaging (MRI) to estimate glomerular number and flow cytometry to estimate podocyte number, have recently been described. Summary This review describes current gold-standard methods for estimating glomerular and podocyte number, as well as methods developed in the past 3 years. We are now better placed than ever before to accurately and precisely estimate glomerular and podocyte number, and to examine relationships between these measurements and kidney health and disease. PMID:25887899

A Limited In-Flight Evaluation of the Constant Current Loop Strain Measurement Method

NASA Technical Reports Server (NTRS)

Olney, Candida D.; Collura, Joseph V.

1997-01-01

For many years, the Wheatstone bridge has been used successfully to measure electrical resistance and changes in that resistance. However, the inherent problem of varying lead wire resistance can cause errors when the Wheatstone bridge is used to measure strain in a flight environment. The constant current loop signal-conditioning card was developed to overcome that difficulty. This paper describes a limited evaluation of the constant current loop strain measurement method as used in the F-16XL ship 2 Supersonic Laminar Flow Control flight project. Several identical strain gages were installed in close proximity on a shock fence which was mounted under the left wing of the F- 1 6XL ship 2. Two strain gage bridges were configured using the constant current loop, and two were configured using the Wheatstone bridge circuitry. Flight data comparing the output from the constant current loop configured gages to that of the Wheatstone bridges with respect to signal output, error, and noise are given. Results indicate that the constant current loop strain measurement method enables an increased output, unaffected by lead wire resistance variations, to be obtained from strain gages.

A Formal Approach to Requirements-Based Programming

NASA Technical Reports Server (NTRS)

Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

2005-01-01

No significant general-purpose method is currently available to mechanically transform system requirements into a provably equivalent model. The widespread use of such a method represents a necessary step toward high-dependability system engineering for numerous application domains. Current tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The "gap" unfilled by such tools and methods is that the formal models cannot be proven to be equivalent to the requirements. We offer a method for mechanically transforming requirements into a provably equivalent formal model that can be used as the basis for code generation and other transformations. This method is unique in offering full mathematical tractability while using notations and techniques that are well known and well trusted. Finally, we describe further application areas we are investigating for use of the approach.

Equivalence testing using existing reference data: An example with genetically modified and conventional crops in animal feeding studies.

PubMed

van der Voet, Hilko; Goedhart, Paul W; Schmidt, Kerstin

2017-11-01

An equivalence testing method is described to assess the safety of regulated products using relevant data obtained in historical studies with assumedly safe reference products. The method is illustrated using data from a series of animal feeding studies with genetically modified and reference maize varieties. Several criteria for quantifying equivalence are discussed, and study-corrected distribution-wise equivalence is selected as being appropriate for the example case study. An equivalence test is proposed based on a high probability of declaring equivalence in a simplified situation, where there is no between-group variation, where the historical and current studies have the same residual variance, and where the current study is assumed to have a sample size as set by a regulator. The method makes use of generalized fiducial inference methods to integrate uncertainties from both the historical and the current data. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

A Method of Separation Assurance for Instrument Flight Procedures at Non-Radar Airports

NASA Technical Reports Server (NTRS)

Conway, Sheila R.; Consiglio, Maria

2002-01-01

A method to provide automated air traffic separation assurance services during approach to or departure from a non-radar, non-towered airport environment is described. The method is constrained by provision of these services without radical changes or ambitious investments in current ground-based technologies. The proposed procedures are designed to grant access to a large number of airfields that currently have no or very limited access under Instrument Flight Rules (IFR), thus increasing mobility with minimal infrastructure investment. This paper primarily addresses a low-cost option for airport and instrument approach infrastructure, but is designed to be an architecture from which a more efficient, albeit more complex, system may be developed. A functional description of the capabilities in the current NAS infrastructure is provided. Automated terminal operations and procedures are introduced. Rules of engagement and the operations are defined. Results of preliminary simulation testing are presented. Finally, application of the method to more terminal-like operations, and major research areas, including necessary piloted studies, are discussed.

Clinical perspective of cell-free DNA testing for fetal aneuploidies.

PubMed

Gratacós, Eduard; Nicolaides, Kypros

2014-01-01

Cell-free DNA testing in maternal blood provides the most effective method of screening for trisomy 21, with a reported detection rate of 99% and a false positive rate of less than 0.1%. After many years of research, this method is now commercially available and is carried out in an increasing number of patients, and there is an expanding number of conditions that can be screened for. However, the application of these methods in clinical practice requires a careful analysis. Current first-trimester screening strategies are based on a complex combination of tests, aiming at detecting fetal defects and predicting the risk of main pregnancy complications. It is therefore necessary to define the optimal way of combining cell-free DNA testing with current first-trimester screening methods. In this concise review we describe the basis of cell-free DNA testing and discuss the potential approaches for its implementation in combination with current tests in the first trimester. © 2014 S. Karger AG, Basel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ulmer, W

Purpose: During the past decade the quantization of coupled/forced electromagnetic circuits with or without Ohm’s resistance has gained the subject of some fundamental studies, since even problems of quantum electrodynamics can be solved in an elegant manner, e.g. the creation of quantized electromagnetic fields. In this communication, we shall use these principles to describe optimization procedures in the design of klystrons, synchrotron irradiation and high energy bremsstrahlung. Methods: The base is the Hamiltonian of an electromagnetic circuit and the extension to coupled circuits, which allow the study of symmetries and perturbed symmetries in a very apparent way (SU2, SU3, SU4).more » The introduction resistance and forced oscillators for the emission and absorption in such coupled systems provides characteristic resonance conditions, and atomic orbitals can be described by that. The extension to virtual orbitals leads to creation of bremsstrahlung, if the incident electron (velocity v nearly c) is described by a current, which is associated with its inductivitance and the virtual orbital to the charge distribution (capacitance). Coupled systems with forced oscillators can be used to amplify drastically the resonance frequencies to describe klystrons and synchrotron radiation. Results: The cross-section formula for bremsstrahlung given by the propagator method of Feynman can readily be derived. The design of klystrons and synchrotrons inclusive the radiation outcome can be described and optimized by the determination of the mutual magnetic couplings between the oscillators induced by the currents. Conclusions: The presented methods of quantization of circuits inclusive resistance provide rather a straightforward way to understand complex technical processes such as creation of bremsstrahlung or creation of radiation by klystrons and synchrotrons. They can either be used for optimization procedures and, last but not least, for pedagogical purposes with regard to a qualified understanding of radiation physics for students.« less

A technique for setting analytical thresholds in massively parallel sequencing-based forensic DNA analysis

PubMed Central

2017-01-01

Amplicon (targeted) sequencing by massively parallel sequencing (PCR-MPS) is a potential method for use in forensic DNA analyses. In this application, PCR-MPS may supplement or replace other instrumental analysis methods such as capillary electrophoresis and Sanger sequencing for STR and mitochondrial DNA typing, respectively. PCR-MPS also may enable the expansion of forensic DNA analysis methods to include new marker systems such as single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) that currently are assayable using various instrumental analysis methods including microarray and quantitative PCR. Acceptance of PCR-MPS as a forensic method will depend in part upon developing protocols and criteria that define the limitations of a method, including a defensible analytical threshold or method detection limit. This paper describes an approach to establish objective analytical thresholds suitable for multiplexed PCR-MPS methods. A definition is proposed for PCR-MPS method background noise, and an analytical threshold based on background noise is described. PMID:28542338

A technique for setting analytical thresholds in massively parallel sequencing-based forensic DNA analysis.

PubMed

Young, Brian; King, Jonathan L; Budowle, Bruce; Armogida, Luigi

2017-01-01

Amplicon (targeted) sequencing by massively parallel sequencing (PCR-MPS) is a potential method for use in forensic DNA analyses. In this application, PCR-MPS may supplement or replace other instrumental analysis methods such as capillary electrophoresis and Sanger sequencing for STR and mitochondrial DNA typing, respectively. PCR-MPS also may enable the expansion of forensic DNA analysis methods to include new marker systems such as single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) that currently are assayable using various instrumental analysis methods including microarray and quantitative PCR. Acceptance of PCR-MPS as a forensic method will depend in part upon developing protocols and criteria that define the limitations of a method, including a defensible analytical threshold or method detection limit. This paper describes an approach to establish objective analytical thresholds suitable for multiplexed PCR-MPS methods. A definition is proposed for PCR-MPS method background noise, and an analytical threshold based on background noise is described.

FY17 Status Report on the Initial EPP Finite Element Analysis of Grade 91 Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Messner, M. C.; Sham, T. -L.

This report describes a modification to the elastic-perfectly plastic (EPP) strain limits design method to account for cyclic softening in Gr. 91 steel. The report demonstrates that the unmodified EPP strain limits method described in current ASME code case is not conservative for materials with substantial cyclic softening behavior like Gr. 91 steel. However, the EPP strain limits method can be modified to be conservative for softening materials by using softened isochronous stress-strain curves in place of the standard curves developed from unsoftened creep experiments. The report provides softened curves derived from inelastic material simulations and factors describing the transformationmore » of unsoftened curves to a softened state. Furthermore, the report outlines a method for deriving these factors directly from creep/fatigue tests. If the material softening saturates the proposed EPP strain limits method can be further simplified, providing a methodology based on temperature-dependent softening factors that could be implemented in an ASME code case allowing the use of the EPP strain limits method with Gr. 91. Finally, the report demonstrates the conservatism of the modified method when applied to inelastic simulation results and two bar experiments.« less

A Study of the Implementation of Current Cost Accounting in the Republic of Korea Army Procurement Systems.

DTIC Science & Technology

1986-06-01

financial reporting in Republic of Korea Army (ROKA) procurement. A discussion of the nature of the ROKA procurement system and two alternatives to historical cost financial statements are presented. The concepts, methods and procedures of the historical cost/constant dollars financial statements are described. The proposal for current cost/constant dollars financial statements is presented and emphasis is given to the description of four problems in existing ROKA procurement due to using inadequate accounting information. Keywords: Cost accounting, Procurement, Current

Development of Modeling and Simulation for Magnetic Particle Inspection Using Finite Elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jun-Youl

2003-01-01

Magnetic particle inspection (MPI) is a widely used nondestructive inspection method for aerospace applications essentially limited to experiment-based approaches. The analysis of MPI characteristics that affect sensitivity and reliability contributes not only reductions in inspection design cost and time but also improvement of analysis of experimental data. Magnetic particles are easily attracted toward a high magnetic field gradient. Selection of a magnetic field source, which produces a magnetic field gradient large enough to detect a defect in a test sample or component, is an important factor in magnetic particle inspection. In this work a finite element method (FEM) has beenmore » employed for numerical calculation of the MPI simulation technique. The FEM method is known to be suitable for complicated geometries such as defects in samples. This thesis describes the research that is aimed at providing a quantitative scientific basis for magnetic particle inspection. A new FEM solver for MPI simulation has been developed in this research for not only nonlinear reversible permeability materials but also irreversible hysteresis materials that are described by the Jiles-Atherton model. The material is assumed to have isotropic ferromagnetic properties in this research (i.e., the magnetic properties of the material are identical in all directions in a single crystal). In the research, with a direct current field mode, an MPI situation has been simulated to measure the estimated volume of magnetic particles around defect sites before and after removing any external current fields. Currently, this new MPI simulation package is limited to solving problems with the single current source from either a solenoid or an axial directional current rod.« less

Adjusting alloy compositions for selected properties in temperature limited heaters

DOEpatents

Brady; Michael Patrick , Horton, Jr.; Joseph Arno , Vitek; John Michael

2010-03-23

Heaters for treating a subsurface formation are described herein. Such heaters can be obtained by using the systems and methods described herein. The heater includes a heater section including iron, cobalt, and carbon. The heater section has a Curie temperature less than a phase transformation temperature. The Curie temperature is at least 740.degree. C. The heater section provides, when time varying current is applied to the heater section, an electrical resistance.

The current status of the MASHA setup

NASA Astrophysics Data System (ADS)

Vedeneev, V. Yu.; Rodin, A. M.; Krupa, L.; Belozerov, A. V.; Chernysheva, E. V.; Dmitriev, S. N.; Gulyaev, A. V.; Gulyaeva, A. V.; Kamas, D.; Kliman, J.; Komarov, A. B.; Motycak, S.; Novoselov, A. S.; Salamatin, V. S.; Stepantsov, S. V.; Podshibyakin, A. V.; Yukhimchuk, S. A.; Granja, C.; Pospisil, S.

2017-11-01

The MASHA setup designed as the mass-separator with the resolving power of about 1700, which allows mass identification of superheavy nuclides is described. The setup uses solid ISOL (Isotope Separation On-Line) method. In the present article the upgrade of some parts of MASHA are described: target box (rotating target + hot catcher), ion source based on electron cyclotron resonance, data acquisition, beam diagnostics and control systems. The upgrade is undertaken in order to increase the total separation efficiency, reduce the separation time, of the installation and working stability and make possible continuous measurements at high beam currents. Ion source efficiency was measured in autonomous regime with using calibrated gas leaks of Kr and Xe injected directly to ion source. Some results of the first experiments for production of radon isotopes using the multi-nucleon transfer reaction 48Ca+242Pu are described in the present article. The using of TIMEPIX detector with MASHA setup for neutron-rich Rn isotopes identification is also described.

Electromotive force analysis of current transformer during lightning surge inflow using Fourier series expansion

NASA Astrophysics Data System (ADS)

Kim, Youngsun

2017-05-01

The most common structure used for current transformers (CTs) consists of secondary windings around a ferromagnetic core past the primary current being measured. A CT used as a surge protection device (SPD) may experience large inrushes of current, like surges. However, when a large current flows into the primary winding, measuring the magnitude of the current is difficult because the ferromagnetic core becomes magnetically saturated. Several approaches to reduce the saturation effect are described in the literature. A Rogowski coil is representative of several devices that measure large currents. It is an electrical device that measures alternating current (AC) or high-frequency current. However, such devices are very expensive in application. In addition, the volume of a CT must be increased to measure sufficiently large currents, but for installation spaces that are too small, other methods must be used. To solve this problem, it is necessary to analyze the magnetic field and electromotive force (EMF) characteristics when designing a CT. Thus, we proposed an analysis method for the CT under an inrush current using the time-domain finite element method (TDFEM). The input source current of a surge waveform is expanded by a Fourier series to obtain an instantaneous value. An FEM model of the device is derived in a two-dimensional system and coupled with EMF circuits. The time-derivative term in the differential equation is solved in each time step by the finite difference method. It is concluded that the proposed algorithm is useful for analyzing CT characteristics, including the field distribution. Consequently, the proposed algorithm yields a reference for obtaining the effects of design parameters and magnetic materials for special shapes and sizes before the CT is designed and manufactured.

An Overview of the Analysis of Trace Organics in Water.

ERIC Educational Resources Information Center

Trussell, Albert R.; Umphres, Mark D.

1978-01-01

Summarized are current analytical techniques used to classify, isolate, resolve, identify, and quantify organic compounds present in drinking water. A variety of methods are described, then drawbacks and advantages are listed, and research needs and future trends are noted. (CS)

Annual Review of Sociology. Volume 9, 1983.

ERIC Educational Resources Information Center

Turner, Ralph H., Ed.; Short, James F., Jr., Ed.

Twenty-six essays describing current research in sociology are included in this publication. The essays fall into 10 categories: differentiation and stratification; political sociology; social processes; institutions; individual and society; formal organizations; urban sociology; theory and methods; sociology of world regions; and historical…

Evaluation Methods Sourcebook.

ERIC Educational Resources Information Center

Love, Arnold J., Ed.

The chapters commissioned for this book describe key aspects of evaluation methodology as they are practiced in a Canadian context, providing representative illustrations of recent developments in evaluation methodology as it is currently applied. The following chapters are included: (1) "Program Evaluation with Limited Fiscal and Human…

Training for Trade: A Partnership Strategy.

ERIC Educational Resources Information Center

Wismer, Jack N.

1994-01-01

Discusses the role of community colleges in providing international trade education and training, highlighting the importance of building partnerships. Describes methods for building partnerships, eight current community college training-for-trade (TFT) programs, and training services and resources. Suggests that TFT programs must become a…

Method and apparatus for resonant frequency waveform modulation

DOEpatents

Taubman, Matthew S [Richland, WA

2011-06-07

A resonant modulator device and process are described that provide enhanced resonant frequency waveforms to electrical devices including, e.g., laser devices. Faster, larger, and more complex modulation waveforms are obtained than can be obtained by use of conventional current controllers alone.

Life Among the Stars

ERIC Educational Resources Information Center

MOSAIC, 1977

1977-01-01

Explores possibility of extra-terrestrial life, reviewing current hypotheses regarding where in space life would most likely occur. Discusses astrometry and spectroscopy as methods for determining stellar motions. Describes United States and Soviet projects for receiving stellar communications. Relates origin of life on earth to observed high…

Apparatus and Methods for Mitigating Electromagnetic Emissions

NASA Technical Reports Server (NTRS)

Geng, Steven M. (Inventor); Niedra, Janis M. (Inventor)

2013-01-01

Apparatus, methods, and other embodiments associated with mitigation of magnetic fields are described herein. In an embodiment, a method for mitigating an electromagnetic field includes positioning a mitigating coil around a linear alternator of linear motor so that the mitigating coil is coaxially located with an alternator coil; arranging the mitigating coil to generate a field to mitigate an electromagnetic field generated by the alternator coil; and passing an induced current from the alternator coil through the mitigating coil.

Apparatus and Methods for Mitigating Electromagnetic Emissions

NASA Technical Reports Server (NTRS)

Geng, Steven M. (Inventor); Niedra, Janis M. (Inventor)

2016-01-01

Apparatus, methods, and other embodiments associated with mitigation of magnetic fields are described herein. In an embodiment, a method for mitigating an electromagnetic field includes positioning a mitigating coil around a linear alternator of linear motor so that the mitigating coil is coaxially located with an alternator coil; arranging the mitigating coil to generate a field to mitigate an electromagnetic field generated by the alternator coil; and passing an induced current from the alternator coil through the mitigating coil.

The Fact of IgnoranceRevisiting the Socratic Method as a Tool for Teaching Critical Thinking

PubMed Central

Romanelli, Frank

2014-01-01

Critical thinking, while highly valued as an ability of health care providers, remains a skill that many educators find difficult to teach. This review provides an analysis examining why current methods of teaching critical thinking to health care students (primarily medical and pharmacy students) often fail and describes a premise and potential utility of the Socratic method as a tool to teach critical thinking in health care education. PMID:25258449

Exploring Teachers' Technological Pedagogical Content Knowledge (TPACK) in an Online Course: A Mixed Methods Study

ERIC Educational Resources Information Center

Varguez, Ricardo

2012-01-01

The constant expansion of Web 2.0 applications available on the World Wide Web and expansion of technology resources has prompted the need to better prepare current and future educators to make more effective use of such resources in their classrooms. The purpose of this embedded mixed methods case study was to describe the experiences and changes…

A phenomenological study of assessment methods in the inquiry-based science classroom: How do educators decide?

NASA Astrophysics Data System (ADS)

Tash, Gina G.

The purpose of this phenomenological study was to describe the experiences of science educators as they select and develop assessment methods for inquiry learning. Balancing preparations for standardized tests and authentic inquiry assessment experiences can be challenging for science educators. The review of literature revealed that current research focused on instructional methods and assessment, students' assessment experiences, and teachers' instructional methods experiences. There remains a gap in current literature regarding the experiences of science educators as they select and develop assessment methods for inquiry learning. This study filled the gap by providing a description of the experiences of science educators as they select and develop assessments for inquiry learning. The participants in this study were 16 fifth through eighth grade science teachers who participate in the Alabama Math, Science, and Technology Initiative (AMSTI) in northwest Alabama. A phenomenological research method was chosen in order to describe the experiences of AMSTI science teachers as they select and develop assessments for inquiry learning. Data were collected through interviews and focus group discussions. The data analysis used a modified Stevick-Colaizzi-Keen framework. The results showed AMSTI science teachers use a variety of assessment resources and methods, feel pressures to meet Adequate Yearly Progress (AYP), and implement varying degrees of change in their assessment process due to No Child Left Behind (NCLB). Contributing a positive social change, this study's findings supplied science teachers with descriptions of successful inquiry classrooms and creative assessments that correspond to inquiry-based learning methods.

Methamphetamine Vaccines: Improvement through Hapten Design.

PubMed

Collins, Karen C; Schlosburg, Joel E; Bremer, Paul T; Janda, Kim D

2016-04-28

Methamphetamine (MA) addiction is a serious public health problem, and current methods to abate addiction and relapse are currently ineffective for mitigating this growing global epidemic. Development of a vaccine targeting MA would provide a complementary strategy to existing behavioral therapies, but this has proven challenging. Herein, we describe optimization of both hapten design and formulation, identifying a vaccine that elicited a robust anti-MA immune response in mice, decreasing methamphetamine-induced locomotor activity.

A review of the integrate-and-fire neuron model: II. Inhomogeneous synaptic input and network properties.

PubMed

Burkitt, A N

2006-08-01

The integrate-and-fire neuron model describes the state of a neuron in terms of its membrane potential, which is determined by the synaptic inputs and the injected current that the neuron receives. When the membrane potential reaches a threshold, an action potential (spike) is generated. This review considers the model in which the synaptic input varies periodically and is described by an inhomogeneous Poisson process, with both current and conductance synapses. The focus is on the mathematical methods that allow the output spike distribution to be analyzed, including first passage time methods and the Fokker-Planck equation. Recent interest in the response of neurons to periodic input has in part arisen from the study of stochastic resonance, which is the noise-induced enhancement of the signal-to-noise ratio. Networks of integrate-and-fire neurons behave in a wide variety of ways and have been used to model a variety of neural, physiological, and psychological phenomena. The properties of the integrate-and-fire neuron model with synaptic input described as a temporally homogeneous Poisson process are reviewed in an accompanying paper (Burkitt in Biol Cybern, 2006).

Understanding Prolonged Cessation From Heroin Use: Findings From a Community-Based Sample

PubMed Central

Weiss, Linda; Gass, Jonathon; Egan, James E.; Ompad, Danielle C.; Trezza, Claudia; Vlahov, David

2014-01-01

Background There is abundant literature describing heroin initiation, co-morbidities, and treatment. Few studies focus on cessation, examining the factors that motivate and facilitate it. Methods The CHANGE study utilized mixed methods to investigate heroin cessation among low-income New York City participants. This paper describes findings from qualitative interviews with 20 former and 11 current heroin users. Interviews focused on background and current activities, supports, drug history, cessation attempts, and motivators and facilitators to cessation. Results Participants found motivation for cessation in improved quality of life; combination of treatment, strategic avoidance of triggers, and engagement in alternative activities, including support groups, exercise, and faith-based practice. Several reported that progress toward goals served as motivators that increased confidence and facilitated cessation. Ultimatums were key motivators for some participants. Beyond that, they could not articulate factors that distinguished successful from unsuccessful cessation attempts, although data suggest that those who were successful could describe more individualized and concrete—rather than general—motivators and strategies. Conclusions Our findings indicate that cessation may be facilitated by multifaceted and individualized strategies, suggesting a need for personal and comprehensive approaches to treatment. PMID:25052788

Esthetic and functional reconstruction after parotidectomy in pediatric patients - A case series.

PubMed

Bryant, Lucas M; Cognetti, David; Baker, Adam; Roy, Sudeep; Johnston, Douglas R; Curry, Joseph; Krein, Howard

2015-12-01

Parotidectomy is a mainstay of treatment for benign and malignant parotid lesions in children and adults. Depending on surgical methods used and tumor size, parotidectomy may result in significant facial disfigurement as well as functional challenges. We describe a series of four pediatric patients, ages 13-16 who presented to our clinic with a parotid mass. All patients underwent parotidectomy with immediate reconstruction by local tissue rearrangement or free fat graft. Esthetic and functional reconstruction after parotidectomy is not well described in pediatric otolaryngology literature. A review of current literature and description of reconstructive methods is included. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Malaria Molecular Epidemiology: Lessons from the International Centers of Excellence for Malaria Research Network

PubMed Central

Escalante, Ananias A.; Ferreira, Marcelo U.; Vinetz, Joseph M.; Volkman, Sarah K.; Cui, Liwang; Gamboa, Dionicia; Krogstad, Donald J.; Barry, Alyssa E.; Carlton, Jane M.; van Eijk, Anna Maria; Pradhan, Khageswar; Mueller, Ivo; Greenhouse, Bryan; Andreina Pacheco, M.; Vallejo, Andres F.; Herrera, Socrates; Felger, Ingrid

2015-01-01

Molecular epidemiology leverages genetic information to study the risk factors that affect the frequency and distribution of malaria cases. This article describes molecular epidemiologic investigations currently being carried out by the International Centers of Excellence for Malaria Research (ICEMR) network in a variety of malaria-endemic settings. First, we discuss various novel approaches to understand malaria incidence and gametocytemia, focusing on Plasmodium falciparum and Plasmodium vivax. Second, we describe and compare different parasite genotyping methods commonly used in malaria epidemiology and population genetics. Finally, we discuss potential applications of molecular epidemiological tools and methods toward malaria control and elimination efforts. PMID:26259945

Regression analysis of informative current status data with the additive hazards model.

PubMed

Zhao, Shishun; Hu, Tao; Ma, Ling; Wang, Peijie; Sun, Jianguo

2015-04-01

This paper discusses regression analysis of current status failure time data arising from the additive hazards model in the presence of informative censoring. Many methods have been developed for regression analysis of current status data under various regression models if the censoring is noninformative, and also there exists a large literature on parametric analysis of informative current status data in the context of tumorgenicity experiments. In this paper, a semiparametric maximum likelihood estimation procedure is presented and in the method, the copula model is employed to describe the relationship between the failure time of interest and the censoring time. Furthermore, I-splines are used to approximate the nonparametric functions involved and the asymptotic consistency and normality of the proposed estimators are established. A simulation study is conducted and indicates that the proposed approach works well for practical situations. An illustrative example is also provided.

Characterization of YBa2Cu3O7, including critical current density Jc, by trapped magnetic field

NASA Technical Reports Server (NTRS)

Chen, In-Gann; Liu, Jianxiong; Weinstein, Roy; Lau, Kwong

1992-01-01

Spatial distributions of persistent magnetic field trapped by sintered and melt-textured ceramic-type high-temperature superconductor (HTS) samples have been studied. The trapped field can be reproduced by a model of the current consisting of two components: (1) a surface current Js and (2) a uniform volume current Jv. This Js + Jv model gives a satisfactory account of the spatial distribution of the magnetic field trapped by different types of HTS samples. The magnetic moment can be calculated, based on the Js + Jv model, and the result agrees well with that measured by standard vibrating sample magnetometer (VSM). As a consequence, Jc predicted by VSM methods agrees with Jc predicted from the Js + Jv model. The field mapping method described is also useful to reveal the granular structure of large HTS samples and regions of weak links.

Physics and instrumentation for imaging in-vivo drug distribution.

PubMed

Singh, M; Waluch, V

2000-03-15

Several imaging methods are currently available to measure drugs noninvasively. Of these, two techniques are today central to such measurements: nuclear imaging and magnetic resonance imaging/spectroscopy (MRI and MRS). While other methods, such as optical techniques, are rapidly gaining in interest, they have not yet attained the degree of development that makes them effective in measuring drugs in living systems, except in a small number of examples. The following introduction provides some basic elements of the potential and the limitations of both nuclear imaging and MRI/MRS techniques, methods that will be used in the studies described in the articles in this issue. However, and for those desiring to gain a better understanding of both methods, the reader is advised to consult much more extensive reviews and books describing such methods. A suggested list of books and articles on Nuclear Imaging and MRI/MRS is given.

Design and modeling of a planar probe for power measurements in a capacitive plasma sheath

NASA Astrophysics Data System (ADS)

Gahan, D.; Hopkins, M. B.; Ellingboe, A. R.

2004-09-01

The design and modeling of a planar probe for power measurement in a capacitive RF sheath is described. The probe is to be biased negatively, using a DC power supply, while simultaneously being driven with an RF voltage. A simple model has been developed which describes the voltage, current and impedance from the generator to the probe surface incorporating the transmission line. A conventional method to determine the power through such a probe would be to measure the voltage, current and their phase relationship very close to the probe surface. This can be very difficult to do with much accuracy since the load is almost purely reactive. An alternative method is discussed. The model shows that for certain lengths of transmission line there exists a point on that transmission line where the imaginary impedance goes to zero. If the power is measured at this point where the current and voltage are almost in phase the result should be more accurate. A brief description of the model is given along with some results for its validation. The operation of the power sensor used is also explained.

Planar MEMS bio-chip for recording ion-channel currents in biological cells

NASA Astrophysics Data System (ADS)

Pandey, Santosh; Ferdous, Zannatul; White, Marvin H.

2003-10-01

We describe a planar MEMS silicon structure to record ion-channel currents in biological cells. The conventional method of performing an electrophysiological experiment, 'patch-clamping,' employs a glass micropipette. Despite careful treatments of the micropipette tip, such as fire polishing and surface coating, the latter is a source of thermal noise because of its inherent, tapered, conical structure, which gives rise to a large pipette resistance. This pipette resistance, when coupled with the self-capacitance of the biological cell, limits the available bandwidth and processing of fast transient, ion channel current pulses. In this work, we reduce considerably the pipette resistance with a planar micropipette on a silicon chip to permit the resolution of sub-millisecond, ion-channel pulses. We discuss the design topology of the device, describe the fabrication sequence, and highlight important critical issues. The design of an integrated on-chip CMOS instrumentation amplifier is described, which has a low-noise front-end, input-offset cancellation, correlated double sampling (CDS), and an ultra-high gain in the order of 1012V/A.

Analysis of off-axis solenoid fields using the magnetic scalar potential: An application to a Zeeman-slower for cold atoms

NASA Astrophysics Data System (ADS)

Muniz, Sérgio R.; Bagnato, Vanderlei S.; Bhattacharya, M.

2015-06-01

In a region free of currents, magnetostatics can be described by the Laplace equation of a scalar magnetic potential, and one can apply the same methods commonly used in electrostatics. Here, we show how to calculate the general vector field inside a real (finite) solenoid, using only the magnitude of the field along the symmetry axis. Our method does not require integration or knowledge of the current distribution and is presented through practical examples, including a nonuniform finite solenoid used to produce cold atomic beams via laser cooling. These examples allow educators to discuss the nontrivial calculation of fields off-axis using concepts familiar to most students, while offering the opportunity to introduce themes of current modern research.

Spectromicroscopy and coherent diffraction imaging: focus on energy materials applications.

PubMed

Hitchcock, Adam P; Toney, Michael F

2014-09-01

Current and future capabilities of X-ray spectromicroscopy are discussed based on coherence-limited imaging methods which will benefit from the dramatic increase in brightness expected from a diffraction-limited storage ring (DLSR). The methods discussed include advanced coherent diffraction techniques and nanoprobe-based real-space imaging using Fresnel zone plates or other diffractive optics whose performance is affected by the degree of coherence. The capabilities of current systems, improvements which can be expected, and some of the important scientific themes which will be impacted are described, with focus on energy materials applications. Potential performance improvements of these techniques based on anticipated DLSR performance are estimated. Several examples of energy sciences research problems which are out of reach of current instrumentation, but which might be solved with the enhanced DLSR performance, are discussed.

Enhancing Neurosurgical Education in Low- and Middle-income Countries: Current Methods and New Advances

PubMed Central

LIANG, Kevin E; BERNSTEIN, Ilia; KATO, Yoko; KAWASE, Takeshi; HODAIE, Mojgan

2016-01-01

Low- and middle-income countries (LMICs) face a critical shortage of basic surgical services. Adequate neurosurgical services can have a far-reaching positive impact on society’s health care and, consequently, the economic development in LMICs. Yet surgery, and specifically neurosurgery has been a long neglected sector of global health. This article reviews the current efforts to enhance neurosurgery education in LMICs and outlines ongoing approaches for improvement. In addition, we introduce the concept of a sustainable and cost-effective model to enhance neurosurgical resources in LMICs and describe the process and methods of online curriculum development. PMID:27616319

Beliefs about the role of parenting in feeding and childhood obesity among mothers of lower socioeconomic status.

PubMed

Kalinowski, Alison; Krause, Kylene; Berdejo, Carla; Harrell, Kristina; Rosenblum, Katherine; Lumeng, Julie C

2012-01-01

To examine beliefs about the role of parenting in feeding and childhood obesity among mothers of lower socioeconomic status. Individual semistructured, audiotaped interview with 91 mothers of preschool-aged children (49% of mothers obese, 21% of children obese) in the midwestern United States. Participant comments were transcribed and common themes were identified using the constant comparative method and NVivo software. Mothers often described their parents' feeding style as authoritarian or neglectful, and their own current style as comparatively indulgent and better. Mothers described parents of overweight children as inept or neglectful, but they never described their own parenting as such. Encouraging mothers to reflect on how they were fed as children, how it may influence their current parenting, and how the relationship between mothering and child obesity is complex are important nutrition education opportunities. Copyright © 2012 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

NASA Technical Reports Server (NTRS)

Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

2004-01-01

A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including sensor networks and autonomous systems. Currently available tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The gap that current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the classes of systems whose behavior can be described as a finite (but significant) set of scenarios, we offer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

General field and office procedures for indirect discharge measurements

USGS Publications Warehouse

Benson, M.A.; Dalrymple, Tate

2001-04-01

The discharge of streams is usually measured by the current-meter method. During flood periods, however, it is frequently impossible or impractical to measure the discharges by this method when they occur. Consequently, many peak discharges must be determined after the passage of the flood by indirect methods, such as slope-area, contracted-opening, flow-over-dam, and flow-through-culvert, rather than by direct current-meter measurement. Indirect methods of determining peak discharge are based on hydraulic equations which relate the discharge to the water-surface profile and the geometry of the channel. A field survey is made after the flood to determine the location and elevation of high-water marks and the characteristics of the channel. Detailed descriptions of the general procedures used in collecting the field data and in computing the discharge are given in this report. Each of the methods requires special procedures described in subsequent chapters.

Using multi-scale entropy and principal component analysis to monitor gears degradation via the motor current signature analysis

NASA Astrophysics Data System (ADS)

Aouabdi, Salim; Taibi, Mahmoud; Bouras, Slimane; Boutasseta, Nadir

2017-06-01

This paper describes an approach for identifying localized gear tooth defects, such as pitting, using phase currents measured from an induction machine driving the gearbox. A new tool of anomaly detection based on multi-scale entropy (MSE) algorithm SampEn which allows correlations in signals to be identified over multiple time scales. The motor current signature analysis (MCSA) in conjunction with principal component analysis (PCA) and the comparison of observed values with those predicted from a model built using nominally healthy data. The Simulation results show that the proposed method is able to detect gear tooth pitting in current signals.

Reconstruction of the action potential of ventricular myocardial fibres

PubMed Central

Beeler, G. W.; Reuter, H.

1977-01-01

1. A mathematical model of membrane action potentials of mammalian ventricular myocardial fibres is described. The reconstruction model is based as closely as possible on ionic currents which have been measured by the voltage-clamp method. 2. Four individual components of ionic current were formulated mathematically in terms of Hodgkin—Huxley type equations. The model incorporates two voltage- and time-dependent inward currents, the excitatory inward sodium current, iNa, and a secondary or slow inward current, is, primarily carried by calcium ions. A time-independent outward potassium current, iK1, exhibiting inward-going rectification, and a voltage- and time-dependent outward current, ix1, primarily carried by potassium ions, are further elements of the model. 3. The iNa is primarily responsible for the rapid upstroke of the action potential, while the other current components determine the configuration of the plateau of the action potential and the re-polarization phase. The relative importance of inactivation of is and of activation of ix1 for termination of the plateau is evaluated by the model. 4. Experimental phenomena like slow recovery of the sodium system from inactivation, frequency dependence of the action potential duration, all-or-nothing re-polarization, membrane oscillations are adequately described by the model. 5. Possible inadequacies and shortcomings of the model are discussed. PMID:874889

Addiction Competencies in the 2009 CACREP Clinical Mental Health Counseling Program Standards

ERIC Educational Resources Information Center

Lee, Tiffany K.; Craig, Stephen E.; Fetherson, Bianca T. L.; Simpson, C. Dennis

2013-01-01

The Council for Accreditation of Counseling and Related Educational Programs developed addiction competencies for clinical mental health counseling students. This article highlights these competencies, provides an overview of current addiction training, and describes methods to integrate addiction education into curricula.

Learning/cost-improvement curves

NASA Technical Reports Server (NTRS)

Delionback, L. M.

1976-01-01

Review guide is an aid to manager or engineer who must determine production costs for components, systems, or services. Methods are described by which manufacturers may use historical data, task characteristics, and current cost data to estimate unit prices as function of number of units to be produced.

Focusing on Student Academic Outcomes. A Working Paper.

ERIC Educational Resources Information Center

Alexander, Joanne M.; Stark, Joan S.

Current methods and instruments for assessing college student academic outcomes are identified and described, and possible outcome measures of NCRIPTAL's (National Center for Research to Improve Postsecondary Teaching and Learning) are suggested. Section I defines college outcomes from several perspectives, including pressures for outcome…

Milieu Therapy with the Adolescent Sociopath.

ERIC Educational Resources Information Center

Walker, Betty A.

1978-01-01

This paper defines sociopathy and presents current findings on its causes and treatment. A milieu therapy program is described, including the preventive and active treatment methods used to keep the adolescent sociopath fully occupied in constructive activities and "sponsor" relationships to overcome antisocial behavior patterns. (Author/SJL)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This manual of the Chemical Hazard Response Information System (CHRIS) has been developed to present current information and assist on-scene coordinators (OSC) on techniques, equipment, and systems that are available to combat and minimize the damage that can be expected when a hazardous chemical is discharged into navigable waters. The handbook describes the content and use of CHRIS and discusses the causes of accidental discharges of hazardous chemicals. It provides a quick reference guide to the selection of response methods and describes these methods in detail. The handbook is also complemented by an appendix containing a review of the state-of-the-artmore » response equipment and systems and a comprehensive catalogue of response equipment. In this handbook response methods are divided into two categories: cautionary and corrective. Cautionary responses, which should be promptly applied to preserve human and animal life, include restricting entry into the area affected by the discharge and use of the water polluted by the discharge, as well as evacuation of threatened areas. Corrective responses include methods of stopping or reducing a further discharge of the chemical, containment procedures, and methods of collection, recovery, and treatment. Methods of cleaning an affected shoreline and treatment of an exposed waterfront are also described.« less

Studies of Low Luminosity Active Galactic Nuclei with Monte Carlo and Magnetohydrodynamic Simulations

NASA Astrophysics Data System (ADS)

Hilburn, Guy Louis

Results from several studies are presented which detail explorations of the physical and spectral properties of low luminosity active galactic nuclei. An initial Sagittarius A* general relativistic magnetohydrodynamic simulation and Monte Carlo radiation transport model suggests accretion rate changes as the dominant flaring method. A similar study on M87 introduces new methods to the Monte Carlo model for increased consistency in highly energetic sources. Again, accretion rate variation seems most appropriate to explain spectral transients. To more closely resolve the methods of particle energization in active galactic nuclei accretion disks, a series of localized shearing box simulations explores the effect of numerical resolution on the development of current sheets. A particular focus on numerically describing converged current sheet formation will provide new methods for consideration of turbulence in accretion disks.

Spectral methods in edge-diffraction theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arnold, J.M.

Spectral methods for the construction of uniform asymptotic representations of the field diffracted by an aperture in a plane screen are reviewed. These are separated into contrasting approaches, roughly described as physical and geometrical. It is concluded that the geometrical methods provide a direct route to the construction of uniform representations that are formally identical to the equivalent-edge-current concept. Some interpretive and analytical difficulties that complicate the physical methods of obtaining uniform representations are analyzed. Spectral synthesis proceeds directly from the ray geometry and diffraction coefficients, without any intervening current representation, and the representation is uniform at shadow boundaries andmore » caustics of the diffracted field. The physical theory of diffraction postulates currents on the diffracting screen that give rise to the diffracted field. The difficulties encountered in evaluating the current integrals are throughly examined, and it is concluded that the additional data provided by the physical theory of diffraction (diffraction coefficients off the Keller diffraction cone) are not actually required for obtaining uniform asymptotics at the leading order. A new diffraction representation that generalizes to arbitrary plane-convex apertures a formula given by Knott and Senior [Proc. IEEE 62, 1468 (1974)] for circular apertures is deduced. 34 refs., 1 fig.« less

Detection methods and performance criteria for genetically modified organisms.

PubMed

Bertheau, Yves; Diolez, Annick; Kobilinsky, André; Magin, Kimberly

2002-01-01

Detection methods for genetically modified organisms (GMOs) are necessary for many applications, from seed purity assessment to compliance of food labeling in several countries. Numerous analytical methods are currently used or under development to support these needs. The currently used methods are bioassays and protein- and DNA-based detection protocols. To avoid discrepancy of results between such largely different methods and, for instance, the potential resulting legal actions, compatibility of the methods is urgently needed. Performance criteria of methods allow evaluation against a common standard. The more-common performance criteria for detection methods are precision, accuracy, sensitivity, and specificity, which together specifically address other terms used to describe the performance of a method, such as applicability, selectivity, calibration, trueness, precision, recovery, operating range, limit of quantitation, limit of detection, and ruggedness. Performance criteria should provide objective tools to accept or reject specific methods, to validate them, to ensure compatibility between validated methods, and be used on a routine basis to reject data outside an acceptable range of variability. When selecting a method of detection, it is also important to consider its applicability, its field of applications, and its limitations, by including factors such as its ability to detect the target analyte in a given matrix, the duration of the analyses, its cost effectiveness, and the necessary sample sizes for testing. Thus, the current GMO detection methods should be evaluated against a common set of performance criteria.

A practical method to rapidly dissolve metallic stents.

PubMed

Bradshaw, Scott H; Kennedy, Lloyd; Dexter, David F; Veinot, John P

2009-01-01

Metallic stents are commonly used in many clinical applications including peripheral vascular disease intervention, biliary obstruction, endovascular repair of aneurysms, and percutaneous coronary interventions. In the examination of vascular stent placement, it is important to determine if the stent is open or has become obstructed. This is increasingly important in the era of drug-eluting stent usage in coronary arteries. We describe a practical, rapid and cost-effective method to dissolve most metallic stents leaving the vascular and luminal tissues intact. This practical method may replace the laborious and expensive plastic embedding methods currently utilized.

Novel Method To Differentiate Human Embryonic Stem Cells Into Dopaminergic Nerve Cells | NCI Technology Transfer Center | TTC

Cancer.gov

The National Institute on Drug Abuse's Development and Plasticity Section is seeking statements of capability or interest from parties interested in licensing opportunities to further develop, evaluate, or commercialize novel methods to differentiate human embryonic stem cells into dopaminergic nerve cells. The invention described here is a novel method of differentiating human embryonic stem cells (hESCs) into dopaminergic nerve cells, which is preferable to the currently available dopaminergic differentiation techniques.

Evidence-Based Indicators of Neuropsychological Change in the Individual Patient: Relevant Concepts and Methods

PubMed Central

Duff, Kevin

2012-01-01

Repeated assessments are a relatively common occurrence in clinical neuropsychology. The current paper will review some of the relevant concepts (e.g., reliability, practice effects, alternate forms) and methods (e.g., reliable change index, standardized based regression) that are used in repeated neuropsychological evaluations. The focus will be on the understanding and application of these concepts and methods in the evaluation of the individual patient through examples. Finally, some future directions for assessing change will be described. PMID:22382384

NUEN-618 Class Project: Actually Implicit Monte Carlo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vega, R. M.; Brunner, T. A.

2017-12-14

This research describes a new method for the solution of the thermal radiative transfer (TRT) equations that is implicit in time which will be called Actually Implicit Monte Carlo (AIMC). This section aims to introduce the TRT equations, as well as the current workhorse method which is known as Implicit Monte Carlo (IMC). As the name of the method proposed here indicates, IMC is a misnomer in that it is only semi-implicit, which will be shown in this section as well.

Quantitative Determination of Caffeine in Beverages Using a Combined SPME-GC/MS Method

NASA Astrophysics Data System (ADS)

Pawliszyn, Janusz; Yang, Min J.; Orton, Maureen L.

1997-09-01

Solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS) has been applied to the analysis of various caffeinated beverages. Unlike the current methods, this technique is solvent free and requires no pH adjustments. The simplicity of the SPME-GC/MS method lends itself to a good undergraduate laboratory practice. This publication describes the analytical conditions and presents the data for determination of caffeine in coffee, tea, and coke. Quantitation by isotopic dilution is also illustrated.

Refinements to the Graves and Pitarka (2010) Broadband Ground-Motion Simulation Method

DOE PAGES

Graves, Robert; Pitarka, Arben

2014-12-17

This brief article describes refinements to the Graves and Pitarka (2010) broadband ground-motion simulation methodology (GP2010 hereafter) that have been implemented in version 14.3 of the Southern California Earthquake Center (SCEC) Broadband Platform (BBP). The updated version of our method on the current SCEC BBP is referred to as GP14.3. Here, our simulation technique is a hybrid approach that combines low- and high-frequency motions computed with different methods into a single broadband response.

Methods and apparatus for measurement of the resistivity of geological formations from within cased wells in presence of acoustic and magnetic energy sources

DOEpatents

Vail, W.B. III.

1991-08-27

Methods and apparatus are provided for measuring the acoustically modulated electronic properties of geological formations and cement layers adjacent to cased boreholes. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. Voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the leakage current conducted into formation in the vicinity of those electrodes. Simultaneously subjecting the casing and formation to an acoustic source acoustically modulates the leakage current measured thereby providing a measure of the acoustically modulated electronic properties of the adjacent formation. Similarly, methods and apparatus are also described which measure the leakage current into formation while simultaneously subjecting the casing to an applied magnetic field which therefore allows measurement of the magnetically modulated electronic properties of the casing and the adjacent formation. 9 figures.

Methods and apparatus for measurement of the resistivity of geological formations from within cased wells in presence of acoustic and magnetic energy sources

DOEpatents

Vail, III, William B.

1991-01-01

Methods and apparatus are provided for measuring the acoustically modulated electronic properties of geological formations and cement layers adjacent to cased boreholes. Current is passed from an electrode in electrical contact with the interior of the borehole casing to an electrode on the surface of the earth. Voltage measuring electrodes in electrical contact with the interior of the casing measure the voltage at various points thereon. The voltage differences between discrete pairs of the voltage measuring electrodes provide a measurement of the leakage current conducted into formation in the vicinity of those electrodes. Simultaneously subjecting the casing and formation to an acoustic source acoustically modulates the leakage current measured thereby providing a measure of the acoustically modulated electronic properties of the adjacent formation. Similarly, methods and apparatus are also described which measure the leakage current into formation while simultaneously subjecting the casing to an applied magnetic field which therefore allows measurement of the magnetically modulated electronic properties of the casing and the adjacent formation.

Nuclear electromagnetic charge and current operators in Chiral EFT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Girlanda, Luca; Marcucci, Laura Elisa; Pastore, Saori

2013-08-01

We describe our method for deriving the nuclear electromagnetic charge and current operators in chiral perturbation theory, based on time-ordered perturbation theory. We then discuss possible strategies for fixing the relevant low-energy constants, from the magnetic moments of the deuteron and of the trinucleons, and from the radiative np capture cross sections, and identify a scheme which, partly relying on {Delta} resonance saturation, leads to a reasonable pattern of convergence of the chiral expansion.

Interaction between polymer constituents and the structure of biopolymers

NASA Technical Reports Server (NTRS)

Rein, R.

1974-01-01

The paper reviews the current status of methods for calculating intermolecular interactions between biopolymer units. The nature of forces contributing to the various domains of intermolecular separations is investigated, and various approximations applicable in the respective regions are examined. The predictive value of current theory is tested by establishing a connection with macroscopic properties and comparing the theoretical predicted values with those derived from experimental data. This has led to the introduction of a statistical model describing DNA.

[INHALED ANTIBIOTICS IN TREATMENT OF NOSOCOMIAL PNEUMONIA].

PubMed

Kuzovlev, A N; Moroz, V V; Golubev, A M

2015-01-01

Nosocomial pneumonia is the most common infection in intensive care units. Currently the problem of resistance of noso-comial pathogens to miost of antibiotics is crucial. Using of inhaled antibiotics in combination with intravenous drugs is eff ective and safe method for treatment of nosocomial pneumonia. The literature review describes current opportunities of ihhaled antibiotic therapy of nosocomial pneumonia, descriptions of drugs, the advantages and disadvantages of this treatment. Special attention is paid for using inhaled aminoglycosides for nosocomial pneumonia.

Design and analysis of an automatic method of measuring silicon-controlled-rectifier holding current

NASA Technical Reports Server (NTRS)

Maslowski, E. A.

1971-01-01

The design of an automated SCR holding-current measurement system is described. The circuits used in the measurement system were designed to meet the major requirements of automatic data acquisition, reliability, and repeatability. Performance data are presented and compared with calibration data. The data verified the accuracy of the measurement system. Data taken over a 48-hr period showed that the measurement system operated satisfactorily and met all the design requirements.

Recent advances in plasma devices based on plasma lens configuration for manipulating high-current heavy ion beams.

PubMed

Dobrovolskiy, A; Dunets, S; Evsyukov, A; Goncharov, A; Gushenets, V; Litovko, I; Oks, E

2010-02-01

We describe new results of development of novel generation cylindrical plasma devices based on the electrostatic plasma lens configuration and concept of electrons magnetic insulation. The crossed electric and magnetic fields plasma lens configuration provides us with the attractive and suitable method for establishing a stable plasma discharge at low pressure. Using plasma lens configuration in this way some cost-effective plasma devices were developed for ion treatment and deposition of exotic coatings and the effective lens was first proposed for manipulating high-current beams of negatively charged particles. Here we describe operation and features of these plasma devices, and results of theoretical consideration of mechanisms determining their optimal operation conditions.

How to detect carbapenemase producers? A literature review of phenotypic and molecular methods.

PubMed

Hammoudi, D; Moubareck, C Ayoub; Sarkis, D Karam

2014-12-01

This review describes the current state-of-art of carbapenemase detection methods. Identification of carbapenemases is first based on conventional phenotypic tests including antimicrobial susceptibility testing, modified-Hodge test and carbapenemase-inhibitor culture tests. Second, molecular characterization of carbapenemase genes by PCR sequencing is essential. Third, innovative biochemical and spectrometric detection may be applied. Copyright © 2014 Elsevier B.V. All rights reserved.

Instruments for the nondestructive testing of materials and products: Handbook. Volumes 1 & 2 (2nd revised and enlarged edition)

NASA Astrophysics Data System (ADS)

Kliuev, V. V.

Data on the general design and principles of operation of various instruments and systems for the nondestructive testing of materials and products of various kinds are presented, and test procedures are described. Methods discussed include optical, thermal, capillary, RF, and X-ray testing techniques. The discussion also covers magnetic, electromagnetic, eddy-current, acoustic, and combined nondestructive testing methods.

Annual Review of Sociology. Volume 7, 1981.

ERIC Educational Resources Information Center

Turner, Ralph H., Ed.; Short, James F., Jr., Ed.

Fifteen essays describing current research in sociology are included in this publication. Almost all the authors are with departments of sociology in U.S. colleges and universities. The essays fall into ten broad categories: theory and method, social processes, institutions, formal organizations, political and economic sociology, differentiation…

Group Treatment in Acquired Brain Injury Rehabilitation

ERIC Educational Resources Information Center

Bertisch, Hilary; Rath, Joseph F.; Langenbahn, Donna M.; Sherr, Rose Lynn; Diller, Leonard

2011-01-01

The current article describes critical issues in adapting traditional group-treatment methods for working with individuals with reduced cognitive capacity secondary to acquired brain injury. Using the classification system based on functional ability developed at the NYU Rusk Institute of Rehabilitation Medicine (RIRM), we delineate the cognitive…

Reduced-molecular-weight derivatives of frost grape polysaccharide

USDA-ARS?s Scientific Manuscript database

A new Type II arabinogalactan was recently described as an abundant gum exudate from stems of wildfrost grape (Vitus riparia Michx.). The purpose of the current study is to more thoroughly characterize the physical properties of this frost grape polysaccharide (FGP), and develop methods to modify th...

Double layer field shaping systems for toroidal plasmas

DOEpatents

Ohyabu, Nobuyoshi

1982-01-01

Methods and apparatus for plasma generation, confinement and control such as Tokamak plasma systems are described having a two layer field shaping coil system comprising an inner coil layer close to the plasma and an outer coil layer to minimize the current in the inner coil layer.

The Cries for Excellence: Echoes from the Past.

ERIC Educational Resources Information Center

Podeschi, Ronald; Hackbarth, David

1986-01-01

The current reform movement in American education is viewed in comparison to the mood of educators during the Sputnik period in the 1950s. One method of comparison described is a literature review of popular magazines published during the period October 1957 through October 1958. (CT)

Synthesizing Evidence: Synthesis Methods for Evidence Clearinghouses

ERIC Educational Resources Information Center

Valentine, Jeff; Lau, Timothy

2015-01-01

Following the theme of the first two presentations, this presentation will focus on the choices available for research synthesis when summarizing research evidence. The presenters will describe the current research synthesis practice of the What Works Clearinghouse (WWC) as well as several alternative models, including inverse-variance weighted…

Moodog: Tracking Student Activity in Online Course Management Systems

ERIC Educational Resources Information Center

Zhang, Hangjin; Almeroth, Kevin

2010-01-01

Many universities are currently using Course Management Systems (CMSes) to conduct online learning, for example, by distributing course materials or submitting homework assignments. However, most CMSes do not include comprehensive activity tracking and analysis capabilities. This paper describes a method to track students' online learning…

Strength Training. Rationale for Current Guidelines for Adult Fitness Programs.

ERIC Educational Resources Information Center

Feigenbaum, Matthew S.; Pollock, Michael L.

1997-01-01

Strength training is an effective method of developing musculoskeletal strength and is often prescribed for fitness, health, and for prevention and rehabilitation of orthopedic injuries. This paper describes and presents a rationale for the population-specific strength training guidelines established by major health organizations. (SM)

Quantification and Compensation of Eddy-Current-Induced Magnetic Field Gradients

PubMed Central

Spees, William M.; Buhl, Niels; Sun, Peng; Ackerman, Joseph J.H.; Neil, Jeffrey J.; Garbow, Joel R.

2011-01-01

Two robust techniques for quantification and compensation of eddy-current-induced magnetic-field gradients and static magnetic-field shifts (ΔB0) in MRI systems are described. Purpose-built 1-D or 6-point phantoms are employed. Both procedures involve measuring the effects of a prior magnetic-field-gradient test pulse on the phantom’s free induction decay (FID). Phantom-specific analysis of the resulting FID data produces estimates of the time-dependent, eddy-current-induced magnetic field gradient(s) and ΔB0 shift. Using Bayesian methods, the time dependencies of the eddy-current-induced decays are modeled as sums of exponentially decaying components, each defined by an amplitude and time constant. These amplitudes and time constants are employed to adjust the scanner’s gradient pre-emphasis unit and eliminate undesirable eddy-current effects. Measurement with the six-point sample phantom allows for simultaneous, direct estimation of both on-axis and cross-term eddy-current-induced gradients. The two methods are demonstrated and validated on several MRI systems with actively-shielded gradient coil sets. PMID:21764614

Quantification and compensation of eddy-current-induced magnetic-field gradients.

PubMed

Spees, William M; Buhl, Niels; Sun, Peng; Ackerman, Joseph J H; Neil, Jeffrey J; Garbow, Joel R

2011-09-01

Two robust techniques for quantification and compensation of eddy-current-induced magnetic-field gradients and static magnetic-field shifts (ΔB0) in MRI systems are described. Purpose-built 1-D or six-point phantoms are employed. Both procedures involve measuring the effects of a prior magnetic-field-gradient test pulse on the phantom's free induction decay (FID). Phantom-specific analysis of the resulting FID data produces estimates of the time-dependent, eddy-current-induced magnetic field gradient(s) and ΔB0 shift. Using Bayesian methods, the time dependencies of the eddy-current-induced decays are modeled as sums of exponentially decaying components, each defined by an amplitude and time constant. These amplitudes and time constants are employed to adjust the scanner's gradient pre-emphasis unit and eliminate undesirable eddy-current effects. Measurement with the six-point sample phantom allows for simultaneous, direct estimation of both on-axis and cross-term eddy-current-induced gradients. The two methods are demonstrated and validated on several MRI systems with actively-shielded gradient coil sets. Copyright © 2011 Elsevier Inc. All rights reserved.

Head-mounted eye tracking: a new method to describe infant looking.

PubMed

Franchak, John M; Kretch, Kari S; Soska, Kasey C; Adolph, Karen E

2011-01-01

Despite hundreds of studies describing infants' visual exploration of experimental stimuli, researchers know little about where infants look during everyday interactions. The current study describes the first method for studying visual behavior during natural interactions in mobile infants. Six 14-month-old infants wore a head-mounted eye-tracker that recorded gaze during free play with mothers. Results revealed that infants' visual exploration is opportunistic and depends on the availability of information and the constraints of infants' own bodies. Looks to mothers' faces were rare following infant-directed utterances but more likely if mothers were sitting at infants' eye level. Gaze toward the destination of infants' hand movements was common during manual actions and crawling, but looks toward obstacles during leg movements were less frequent. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

Logit-normal mixed model for Indian monsoon precipitation

NASA Astrophysics Data System (ADS)

Dietz, L. R.; Chatterjee, S.

2014-09-01

Describing the nature and variability of Indian monsoon precipitation is a topic of much debate in the current literature. We suggest the use of a generalized linear mixed model (GLMM), specifically, the logit-normal mixed model, to describe the underlying structure of this complex climatic event. Four GLMM algorithms are described and simulations are performed to vet these algorithms before applying them to the Indian precipitation data. The logit-normal model was applied to light, moderate, and extreme rainfall. Findings indicated that physical constructs were preserved by the models, and random effects were significant in many cases. We also found GLMM estimation methods were sensitive to tuning parameters and assumptions and therefore, recommend use of multiple methods in applications. This work provides a novel use of GLMM and promotes its addition to the gamut of tools for analysis in studying climate phenomena.

Theory and computation of optimal low- and medium-thrust transfers

NASA Technical Reports Server (NTRS)

Chuang, C.-H.

1994-01-01

This report describes the current state of development of methods for calculating optimal orbital transfers with large numbers of burns. Reported on first is the homotopy-motivated and so-called direction correction method. So far this method has been partially tested with one solver; the final step has yet to be implemented. Second is the patched transfer method. This method is rooted in some simplifying approximations made on the original optimal control problem. The transfer is broken up into single-burn segments, each single-burn solved as a predictor step and the whole problem then solved with a corrector step.

Methods of high current magnetic field generator for transcranial magnetic stimulation application

NASA Astrophysics Data System (ADS)

Bouda, N. R.; Pritchard, J.; Weber, R. J.; Mina, M.

2015-05-01

This paper describes the design procedures and underlying concepts of a novel High Current Magnetic Field Generator (HCMFG) with adjustable pulse width for transcranial magnetic stimulation applications. This is achieved by utilizing two different switching devices, the MOSFET and insulated gate bipolar transistor (IGBT). Results indicate that currents as high as ±1200 A can be generated with inputs of +/-20 V. Special attention to tradeoffs between field generators utilizing IGBT circuits (HCMFG1) and MOSFET circuits (HCMFG2) was considered. The theory of operation, design, experimental results, and electronic setup are presented and analyzed.

Bird flight and airplane flight. [instruments to measure air currents and flight characteristics

NASA Technical Reports Server (NTRS)

Magnan, A.

1980-01-01

Research was based on a series of mechanical, electrical, and cinematographic instruments developed to measure various features of air current behavior as well as bird and airplane flight. Investigation of rising obstruction and thermal currents led to a theory of bird flight, especially of the gliding and soaring types. It was shown how a knowledge of bird flight can be applied to glider and ultimately motorized aircraft construction. The instruments and methods used in studying stress in airplanes and in comparing the lift to drag ratios of airplanes and birds are described.

Methods of high current magnetic field generator for transcranial magnetic stimulation application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bouda, N. R., E-mail: nybouda@iastate.edu; Pritchard, J.; Weber, R. J.

This paper describes the design procedures and underlying concepts of a novel High Current Magnetic Field Generator (HCMFG) with adjustable pulse width for transcranial magnetic stimulation applications. This is achieved by utilizing two different switching devices, the MOSFET and insulated gate bipolar transistor (IGBT). Results indicate that currents as high as ±1200 A can be generated with inputs of +/−20 V. Special attention to tradeoffs between field generators utilizing IGBT circuits (HCMFG{sub 1}) and MOSFET circuits (HCMFG{sub 2}) was considered. The theory of operation, design, experimental results, and electronic setup are presented and analyzed.

Multigrid techniques for unstructured meshes

NASA Technical Reports Server (NTRS)

Mavriplis, D. J.

1995-01-01

An overview of current multigrid techniques for unstructured meshes is given. The basic principles of the multigrid approach are first outlined. Application of these principles to unstructured mesh problems is then described, illustrating various different approaches, and giving examples of practical applications. Advanced multigrid topics, such as the use of algebraic multigrid methods, and the combination of multigrid techniques with adaptive meshing strategies are dealt with in subsequent sections. These represent current areas of research, and the unresolved issues are discussed. The presentation is organized in an educational manner, for readers familiar with computational fluid dynamics, wishing to learn more about current unstructured mesh techniques.

Current state and future perspectives of loop-mediated isothermal amplification (LAMP)-based diagnosis of filamentous fungi and yeasts.

PubMed

Niessen, Ludwig

2015-01-01

Loop-mediated isothermal amplification is a rather novel method of enzymatic deoxyribonucleic acid amplification which can be applied for the diagnosis of viruses, bacteria, and fungi. Although firmly established in viral and bacterial diagnosis, the technology has only recently been applied to a noteworthy number of species in the filamentous fungi and yeasts. The current review gives an overview of the literature so far published on the topic by discussing the different groups of fungal organisms to which the method has been applied. Moreover, the method is described in detail as well as the different possibilities available for signal detection and quantification and sample preparation. Future perspective of loop-mediated isothermal amplification-based assays is discussed in the light of applicability for fungal diagnostics.

Single reaction, real time RT-PCR detection of all known avian and human metapneumoviruses.

PubMed

Lemaitre, E; Allée, C; Vabret, A; Eterradossi, N; Brown, P A

2018-01-01

Current molecular methods for the detection of avian and human metapneumovirus (AMPV, HMPV) are specifically targeted towards each virus species or individual subgroups of these. Here a broad range SYBR Green I real time RT-PCR was developed which amplified a highly conserved fragment of sequence in the N open reading frame. This method was sufficiently efficient and specific in detecting all MPVs. Its validation according to the NF U47-600 norm for the four AMPV subgroups estimated low limits of detection between 1000 and 10copies/μL, similar with detection levels described previously for real time RT-PCRs targeting specific subgroups. RNA viruses present a challenge for the design of durable molecular diagnostic test due to the rate of change in their genome sequences which can vary substantially in different areas and over time. The fact that the regions of sequence for primer hybridization in the described method have remained sufficiently conserved since the AMPV and HMPV diverged, should give the best chance of continued detection of current subgroups and of potential unknown or future emerging MPV strains. Copyright © 2017 Elsevier B.V. All rights reserved.

Novel hermetic packaging methods for MOEMS

NASA Astrophysics Data System (ADS)

Stark, David

2003-01-01

Hermetic packaging of micro-optoelectromechanical systems (MOEMS) is an immature technology, lacking industry-consensus methods and standards. Off-the-shelf, catalog window assemblies are not yet available. Window assemblies are in general custom designed and manufactured for each new product, resulting in longer than acceptable cycle times, high procurement costs and questionable reliability. There are currently two dominant window-manufacturing methods wherein a metal frame is attached to glass, as well as a third, less-used method. The first method creates a glass-to-metal seal by heating the glass above its Tg to fuse it to the frame. The second method involves first metallizing the glass where it is to be attached to the frame, and then soldering the glass to the frame. The third method employs solder-glass to bond the glass to the frame. A novel alternative with superior features compared to the three previously described window-manufacturing methods is proposed. The new approach lends itself to a plurality of glass-to-metal attachment techniques. Benefits include lower temperature processing than two of the current methods and potentially more cost-effective manufacturing than all three of today"s attachment methods.

Single Transducer Ultrasonic Imaging Method that Eliminates the Effect of Plate Thickness Variation in the Image

NASA Technical Reports Server (NTRS)

Roth, Don J.

1996-01-01

This article describes a single transducer ultrasonic imaging method that eliminates the effect of plate thickness variation in the image. The method thus isolates ultrasonic variations due to material microstructure. The use of this method can result in significant cost savings because the ultrasonic image can be interpreted correctly without the need for machining to achieve precise thickness uniformity during nondestructive evaluations of material development. The method is based on measurement of ultrasonic velocity. Images obtained using the thickness-independent methodology are compared with conventional velocity and c-scan echo peak amplitude images for monolithic ceramic (silicon nitride), metal matrix composite and polymer matrix composite materials. It was found that the thickness-independent ultrasonic images reveal and quantify correctly areas of global microstructural (pore and fiber volume fraction) variation due to the elimination of thickness effects. The thickness-independent ultrasonic imaging method described in this article is currently being commercialized under a cooperative agreement between NASA Lewis Research Center and Sonix, Inc.

Experience report: Using formal methods for requirements analysis of critical spacecraft software

NASA Technical Reports Server (NTRS)

Lutz, Robyn R.; Ampo, Yoko

1994-01-01

Formal specification and analysis of requirements continues to gain support as a method for producing more reliable software. However, the introduction of formal methods to a large software project is difficult, due in part to the unfamiliarity of the specification languages and the lack of graphics. This paper reports results of an investigation into the effectiveness of formal methods as an aid to the requirements analysis of critical, system-level fault-protection software on a spacecraft currently under development. Our experience indicates that formal specification and analysis can enhance the accuracy of the requirements and add assurance prior to design development in this domain. The work described here is part of a larger, NASA-funded research project whose purpose is to use formal-methods techniques to improve the quality of software in space applications. The demonstration project described here is part of the effort to evaluate experimentally the effectiveness of supplementing traditional engineering approaches to requirements specification with the more rigorous specification and analysis available with formal methods.

Gaseous Sulfate Solubility in Glass: Experimental Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bliss, Mary

2013-11-30

Sulfate solubility in glass is a key parameter in many commercial glasses and nuclear waste glasses. This report summarizes key publications specific to sulfate solubility experimental methods and the underlying physical chemistry calculations. The published methods and experimental data are used to verify the calculations in this report and are expanded to a range of current technical interest. The calculations and experimental methods described in this report will guide several experiments on sulfate solubility and saturation for the Hanford Waste Treatment Plant Enhanced Waste Glass Models effort. There are several tables of sulfate gas equilibrium values at high temperature tomore » guide experimental gas mixing and to achieve desired SO3 levels. This report also describes the necessary equipment and best practices to perform sulfate saturation experiments for molten glasses. Results and findings will be published when experimental work is finished and this report is validated from the data obtained.« less

Trends in Mediation Analysis in Nursing Research: Improving Current Practice.

PubMed

Hertzog, Melody

2018-06-01

The purpose of this study was to describe common approaches used by nursing researchers to test mediation models and evaluate them within the context of current methodological advances. MEDLINE was used to locate studies testing a mediation model and published from 2004 to 2015 in nursing journals. Design (experimental/correlation, cross-sectional/longitudinal, model complexity) and analysis (method, inclusion of test of mediated effect, violations/discussion of assumptions, sample size/power) characteristics were coded for 456 studies. General trends were identified using descriptive statistics. Consistent with findings of reviews in other disciplines, evidence was found that nursing researchers may not be aware of the strong assumptions and serious limitations of their analyses. Suggestions for strengthening the rigor of such studies and an overview of current methods for testing more complex models, including longitudinal mediation processes, are presented.

Characterization of DUT impedance in immunity test setups

NASA Astrophysics Data System (ADS)

Hassanpour Razavi, Seyyed Ali; Frei, Stephan

2016-09-01

Several immunity test procedures for narrowband radiated electromagnetic energy are available for automotive components. The ISO 11452 series describes the most commonly used test methods. The absorber line shielded enclosure (ALSE) is often considered as the most reliable method. However, testing with the bulk current injection (BCI) can be done with less efforts and is often preferred. As the test setup in both procedures is quite similar, there were several trials for finding appropriate modifications to the BCI in order to increase the matching to the ALSE. However, the lack of knowledge regarding the impedance of the tested component, makes it impossible to find the equivalent current to be injected by the BCI and a good match cannot be achieved. In this paper, three approaches are proposed to estimate the termination impedance indirectly by using different current probes.

Microplasma fabrication: from semiconductor technology for 2D-chips and microfluidic channels to rapid prototyping and 3D-printing of microplasma devices

NASA Astrophysics Data System (ADS)

Shatford, R.; Karanassios, Vassili

2014-05-01

Microplasmas are receiving attention in recent conferences and current scientific literature. In our laboratory, microplasmas-on-chips proved to be particularly attractive. The 2D- and 3D-chips we developed became hybrid because they were fitted with a quartz plate (quartz was used due to its transparency to UV). Fabrication of 2D- and 3D-chips for microplasma research is described. The fabrication methods described ranged from semiconductor fabrication technology, to Computer Numerical Control (CNC) machining, to 3D-printing. These methods may prove to be useful for those contemplating in entering microplasma research but have no access to expensive semiconductor fabrication equipment.

Gearing

NASA Technical Reports Server (NTRS)

Coy, J. J.; Townsend, D. P.; Zaretsky, E. V.

1985-01-01

Gearing technology in its modern form has a history of only 100 years. However, the earliest form of gearing can probably be traced back to fourth century B.C. Greece. Current gear practice and recent advances in the technology are drawn together. The history of gearing is reviewed briefly in the Introduction. Subsequent sections describe types of gearing and their geometry, processing, and manufacture. Both conventional and more recent methods of determining gear stress and deflections are considered. The subjects of life prediction and lubrication are additions to the literature. New and more complete methods of power loss predictions as well as an optimum design of spur gear meshes are described. Conventional and new types of power transmission systems are presented.

Self-assembly concepts in the formation of nanostructured particles using a liquid-phase synthesis method

NASA Astrophysics Data System (ADS)

Nandiyanto, Asep Bayu Dani

2016-02-01

When synthesizing particles using a liquid-phase synthesis method, reactant components show interaction with the reaction system itself. However, current reports described successful synthesis of material with only partial information on the component-component interaction and possible self-assembly mechanism occurring during the material synthesis process. Here, self-assembly concepts in the formation of nanostructured particles are presented. Influences of self-assembly parameters (i.e., surface charge, size, and concentration of components involving the reaction) on self-organized material fabrication are described. Because understanding the interaction of the component provides significant information in regard to practical uses, this report can be relevant to further material development and fabrication.

Malaria Molecular Epidemiology: Lessons from the International Centers of Excellence for Malaria Research Network.

PubMed

Escalante, Ananias A; Ferreira, Marcelo U; Vinetz, Joseph M; Volkman, Sarah K; Cui, Liwang; Gamboa, Dionicia; Krogstad, Donald J; Barry, Alyssa E; Carlton, Jane M; van Eijk, Anna Maria; Pradhan, Khageswar; Mueller, Ivo; Greenhouse, Bryan; Pacheco, M Andreina; Vallejo, Andres F; Herrera, Socrates; Felger, Ingrid

2015-09-01

Molecular epidemiology leverages genetic information to study the risk factors that affect the frequency and distribution of malaria cases. This article describes molecular epidemiologic investigations currently being carried out by the International Centers of Excellence for Malaria Research (ICEMR) network in a variety of malaria-endemic settings. First, we discuss various novel approaches to understand malaria incidence and gametocytemia, focusing on Plasmodium falciparum and Plasmodium vivax. Second, we describe and compare different parasite genotyping methods commonly used in malaria epidemiology and population genetics. Finally, we discuss potential applications of molecular epidemiological tools and methods toward malaria control and elimination efforts. © The American Society of Tropical Medicine and Hygiene.

Quantum Monte Carlo methods for nuclear physics

DOE PAGES

Carlson, J.; Gandolfi, S.; Pederiva, F.; ...

2015-09-09

Quantum Monte Carlo methods have proved valuable to study the structure and reactions of light nuclei and nucleonic matter starting from realistic nuclear interactions and currents. These ab-initio calculations reproduce many low-lying states, moments, and transitions in light nuclei, and simultaneously predict many properties of light nuclei and neutron matter over a rather wide range of energy and momenta. The nuclear interactions and currents are reviewed along with a description of the continuum quantum Monte Carlo methods used in nuclear physics. These methods are similar to those used in condensed matter and electronic structure but naturally include spin-isospin, tensor, spin-orbit,more » and three-body interactions. A variety of results are presented, including the low-lying spectra of light nuclei, nuclear form factors, and transition matrix elements. Low-energy scattering techniques, studies of the electroweak response of nuclei relevant in electron and neutrino scattering, and the properties of dense nucleonic matter as found in neutron stars are also described. Furthermore, a coherent picture of nuclear structure and dynamics emerges based upon rather simple but realistic interactions and currents.« less

Developing and Validating Personas in e-Commerce: A Heuristic Approach

NASA Astrophysics Data System (ADS)

Thoma, Volker; Williams, Bryn

A multi-method persona development process in a large e-commerce business is described. Personas are fictional representations of customers that describe typical user attributes to facilitate a user-centered approach in interaction design. In the current project persona attributes were derived from various data sources, such as stakeholder interviews, user tests and interviews, data mining, customer surveys, and ethnographic (direct observation, diary studies) research. The heuristic approach of using these data sources conjointly allowed for an early validation of relevant persona dimensions.

Reconstruction of multiple cracks from experimental electrostatic boundary measurements

NASA Technical Reports Server (NTRS)

Bryan, Kurt; Liepa, Valdis; Vogelius, Michael

1993-01-01

An algorithm for recovering a collection of linear cracks in a homogeneous electrical conductor from boundary measurements of voltages induced by specified current fluxes is described. The technique is a variation of Newton's method and is based on taking weighted averages of the boundary data. An apparatus that was constructed specifically for generating laboratory data on which to test the algorithm is also described. The algorithm is applied to a number of different test cases and the results are discussed.

Silicon carbide sewing thread

NASA Technical Reports Server (NTRS)

Sawko, Paul M. (Inventor)

1995-01-01

Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems provide lightweight thermal insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

Measuring Feedforward Inhibition and Its Impact on Local Circuit Function.

PubMed

Hull, Court

2017-05-01

This protocol describes a series of approaches to measure feedforward inhibition in acute brain slices from the cerebellar cortex. Using whole-cell voltage and current clamp recordings from Purkinje cells in conjunction with electrical stimulation of the parallel fibers, these methods demonstrate how to measure the relationship between excitation and inhibition in a feedforward circuit. This protocol also describes how to measure the impact of feedforward inhibition on Purkinje cell excitability, with an emphasis on spike timing. © 2017 Cold Spring Harbor Laboratory Press.

An interactive wire-wrap board layout program

NASA Technical Reports Server (NTRS)

Schlutsmeyer, A.

1987-01-01

An interactive computer-graphics-based tool for specifying the placement of electronic parts on a wire-wrap circuit board is presented. Input is a data file (currently produced by a commercial logic design system) which describes the parts used and their interconnections. Output includes printed reports describing the parts and wire paths, parts counts, placement lists, board drawing, and a tape to send to the wire-wrap vendor. The program should reduce the engineer's layout time by a factor of 3 to 5 as compared to manual methods.

Laboratory Experiment on Electrokinetic Remediation of Soil

ERIC Educational Resources Information Center

Elsayed-Ali, Alya H.; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E.

2011-01-01

Electrokinetic remediation is a method of decontaminating soil containing heavy metals and polar organic contaminants by passing a direct current through the soil. An undergraduate chemistry laboratory is described to demonstrate electrokinetic remediation of soil contaminated with copper. A 30 cm electrokinetic cell with an applied voltage of 30…

Paediatric Palliative Care and Intellectual Disability--A Unique Context

ERIC Educational Resources Information Center

Duc, Jacqueline K.; Herbert, Anthony Robert; Heussler, Helen S.

2017-01-01

Background: Paediatric palliative care is a nuanced area of practice with additional complexities in the context of intellectual disability. There is currently minimal research to guide clinicians working in this challenging area of care. Method: This study describes the complex care of children with life-limiting conditions and intellectual…

Using Key Performance Indicators to Drive Strategic Decision Making.

ERIC Educational Resources Information Center

Dolence, Michael G.; Norris, Donald M.

1994-01-01

A nine-step method for defining and pursuing key performance indicators (KPIs), derived from a strategic planning process, is outlined, and its applications at the University of Northern Colorado and Illinois Benedictine College are described and tabulated. A chart summarizes current and projected KPIs for Illinois Benedictine College for each…

Understanding Information about Mortality among People with Intellectual and Developmental Disabilities in Canada

ERIC Educational Resources Information Center

Ouellette-Kuntz, Hélène; Shooshtari, Shahin; Balogh, Robert; Martens, Patricia

2015-01-01

Background: This paper reviews what is currently known about mortality among Canadians with intellectual and developmental disabilities and describes opportunities for ongoing monitoring. Methods: In-hospital mortality among adults with intellectual and developmental disabilities in Ontario was examined using hospital data. Mortality was compared…

Family Therapy Training in Child and Adolescent Psychiatry Fellowship Programs

ERIC Educational Resources Information Center

Rait, Douglas Samuel

2012-01-01

Objective: This study describes the current state of family therapy training in a sample of child and adolescent psychiatry fellowship programs. Method: Child and adolescent psychiatry fellows (N = 66) from seven training programs completed a questionnaire assessing demographics, family therapy training experiences, common models of treatment and…

Employees on the Move!

ERIC Educational Resources Information Center

Levin, Sarah

This paper describes a method for designing, implementing, and evaluating a work-site physical activity campaign aimed at employees who are currently sedentary in their leisure time. Inactivity is a major but modifiable risk factor for coronary heart disease. Increasing the activity levels of underactive adults would have a positive impact on…

Exemplary Science: Best Practices in Professional Development

ERIC Educational Resources Information Center

Yager, Robert E.

2005-01-01

This collection of 16 essays is ideal for staff development providers (university faculty, district supervisors, lead teachers, and principals) as well as preservice science methods instructors. Each essay describes a specific program designed to train current or future teachers to carry out the constructivist, inquiry-based approach of the…

Course Syllabus: Science, Technology and Society.

ERIC Educational Resources Information Center

Garner, Douglas

1985-01-01

Describes the aims, methods, project, and topics of a course designed so that students may explore the impact of science and technology on society. Units include: technology (pro and con); nuclear deterrence; politics and technical decisions; and computers. Includes a list of audiovisual resources (with title, source, and current cost). (DH)

An Investigation of the Aerodynamics and Cooling of a Horizontally-Opposed Engine Installation

NASA Technical Reports Server (NTRS)

Miley, S. J.

1977-01-01

A research program to investigate the aerodynamics of reciprocating aircraft engine cooling installations is discussed. Current results from a flight test program are presented concerning installation flow measurement methods. The influence of different inlet designs on installation cooling effectiveness and efficiency are described.

Mobile Phone Mood Charting for Adolescents

ERIC Educational Resources Information Center

Matthews, Mark; Doherty, Gavin; Sharry, John; Fitzpatrick, Carol

2008-01-01

Mobile phones may provide a useful and engaging platform for supporting therapeutic services working with adolescents. This paper examines the potential benefits of the mobile phone for self-charting moods in comparison to existing methods in current practice. The paper describes a mobile phone application designed by the authors which allows…

Perspectives on Treatment for Communication Deficits Associated with Right Hemisphere Brain Damage

ERIC Educational Resources Information Center

Blake, Margaret Lehman

2007-01-01

Purpose: To describe the current treatment research for communication (prosodic, discourse, and pragmatic) deficits associated with right hemisphere brain damage and to provide suggestions for treatment selection given the paucity of evidence specifically for this population. Method: The discussion covers (a) clinical decision processes and…

Modeling Noisy Data with Differential Equations Using Observed and Expected Matrices

ERIC Educational Resources Information Center

Deboeck, Pascal R.; Boker, Steven M.

2010-01-01

Complex intraindividual variability observed in psychology may be well described using differential equations. It is difficult, however, to apply differential equation models in psychological contexts, as time series are frequently short, poorly sampled, and have large proportions of measurement and dynamic error. Furthermore, current methods for…

A Method to Analyze How Various Parts of Clouds Influence Each Other's Brightness

NASA Technical Reports Server (NTRS)

Varnai, Tamas; Marshak, Alexander; Lau, William (Technical Monitor)

2001-01-01

This paper proposes a method for obtaining new information on 3D radiative effects that arise from horizontal radiative interactions in heterogeneous clouds. Unlike current radiative transfer models, it can not only calculate how 3D effects change radiative quantities at any given point, but can also determine which areas contribute to these 3D effects, to what degree, and through what mechanisms. After describing the proposed method, the paper illustrates its new capabilities both for detailed case studies and for the statistical processing of large datasets. Because the proposed method makes it possible, for the first time, to link a particular change in cloud properties to the resulting 3D effect, in future studies it can be used to develop new radiative transfer parameterizations that would consider 3D effects in practical applications currently limited to 1D theory-such as remote sensing of cloud properties and dynamical cloud modeling.

Qualitative Methods in Patient-Centered Outcomes Research.

PubMed

Vandermause, Roxanne; Barg, Frances K; Esmail, Laura; Edmundson, Lauren; Girard, Samantha; Perfetti, A Ross

2017-02-01

The Patient-Centered Outcomes Research Institute (PCORI), created to fund research guided by patients, caregivers, and the broader health care community, offers a new research venue. Many (41 of 50) first funded projects involved qualitative research methods. This study was completed to examine the current state of the science of qualitative methodologies used in PCORI-funded research. Principal investigators participated in phenomenological interviews to learn (a) how do researchers using qualitative methods experience seeking funding for, implementing and disseminating their work; and (b) how may qualitative methods advance the quality and relevance of evidence for patients? Results showed the experience of doing qualitative research in the current research climate as "Being a bona fide qualitative researcher: Staying true to research aims while negotiating challenges," with overlapping patterns: (a) researching the elemental, (b) expecting surprise, and (c) pushing boundaries. The nature of qualitative work today was explicitly described and is rendered in this article.

Sonochemical approaches to enhanced oil recovery.

PubMed

Abramov, Vladimir O; Abramova, Anna V; Bayazitov, Vadim M; Altunina, Lyubov K; Gerasin, Artyom S; Pashin, Dmitriy M; Mason, Timothy J

2015-07-01

Oil production from wells reduces with time and the well becomes uneconomic unless enhanced oil recovery (EOR) methods are applied. There are a number of methods currently available and each has specific advantages and disadvantages depending on conditions. Currently there is a big demand for new or improved technologies in this field, the hope is that these might also be applicable to wells which have already been the subject of EOR. The sonochemical method of EOR is one of the most promising methods and is important in that it can also be applied for the treatment of horizontal wells. The present article reports the theoretical background of the developed sonochemical technology for EOR in horizontal wells; describes the requirements to the equipment needed to embody the technology. The results of the first field tests of the technology are reported. Copyright © 2014 Elsevier B.V. All rights reserved.

A review of the quantum current standard

NASA Astrophysics Data System (ADS)

Kaneko, Nobu-Hisa; Nakamura, Shuji; Okazaki, Yuma

2016-03-01

The electric current, voltage, and resistance standards are the most important standards related to electricity and magnetism. Of these three standards, only the ampere, which is the unit of electric current, is an International System of Units (SI) base unit. However, even with modern technology, relatively large uncertainty exists regarding the generation and measurement of current. As a result of various innovative techniques based on nanotechnology and novel materials, new types of junctions for quantum current generation and single-electron current sources have recently been proposed. These newly developed methods are also being used to investigate the consistency of the three quantum electrical effects, i.e. the Josephson, quantum Hall, and single-electron tunneling effects, which are also known as ‘the quantum metrology triangle’. This article describes recent research and related developments regarding current standards and quantum-metrology-triangle experiments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, Jih-Sheng

This paper introduces control system design based softwares, SIMNON and MATLAB/SIMULINK, for power electronics system simulation. A complete power electronics system typically consists of a rectifier bridge along with its smoothing capacitor, an inverter, and a motor. The system components, featuring discrete or continuous, linear or nonlinear, are modeled in mathematical equations. Inverter control methods,such as pulse-width-modulation and hysteresis current control, are expressed in either computer algorithms or digital circuits. After describing component models and control methods, computer programs are then developed for complete systems simulation. Simulation results are mainly used for studying system performances, such as input and outputmore » current harmonics, torque ripples, and speed responses. Key computer programs and simulation results are demonstrated for educational purposes.« less

ICASE/LaRC Workshop on Adaptive Grid Methods

NASA Technical Reports Server (NTRS)

South, Jerry C., Jr. (Editor); Thomas, James L. (Editor); Vanrosendale, John (Editor)

1995-01-01

Solution-adaptive grid techniques are essential to the attainment of practical, user friendly, computational fluid dynamics (CFD) applications. In this three-day workshop, experts gathered together to describe state-of-the-art methods in solution-adaptive grid refinement, analysis, and implementation; to assess the current practice; and to discuss future needs and directions for research. This was accomplished through a series of invited and contributed papers. The workshop focused on a set of two-dimensional test cases designed by the organizers to aid in assessing the current state of development of adaptive grid technology. In addition, a panel of experts from universities, industry, and government research laboratories discussed their views of needs and future directions in this field.

Library & Information Services: an Astronomer's Wishlist

NASA Astrophysics Data System (ADS)

Andernach, Heinz

I review some of the past and current methods for retrieval of literature and other published information, excluding commercial services. Much of this is a personal view and based on experience made at various institutions, some of them neither with an adequately complete astronomy library, nor with a professional astronomy librarian. Rather than describing current retrieval methods, a few of their weaknesses are identified which merit future improval. Despite the availability of powerful electronic tools, we need to improve efforts in safeguarding published numerical and textual information in a format readily usable by astronomers. Comments are made on a user-friendly arrangement of a library, and on useful tasks for librarians with available time.

A Combined EOF/Variational Approach for Mapping Radar-Derived Sea Surface Currents

DTIC Science & Technology

2011-01-01

Section 4 describes the results of experiments with the real observations off the Opal Coast of the Eastern English Channel. It is shown that the...To assess the method’s performance, we conducted twin-data experiments with simulated HFR data (Section 3) and real observations off the Opal Coast...the Opal coast of the Pas de Calais in northern France. 4.1. The data In May-June 2003. two HF radars were deployed to monitor surface currents

Silicon nanoparticles: applications in cell biology and medicine

PubMed Central

O’Farrell, Norah; Houlton, Andrew; Horrocks, Benjamin R

2006-01-01

In this review, we describe the synthesis, physical properties, surface functionalization, and biological applications of silicon nanoparticles (also known as quantum dots). We compare them against current technologies, such as fluorescent organic dyes and heavy metal chalcogenide-based quantum dots. In particular, we examine the many different methods that can be used to both create and modify these nanoparticles and the advantages they may have over current technologies that have stimulated research into designing silicon nanoparticles for in vitro and in vivo applications. PMID:17722279

Electrical and Biological Effects of Transmission Lines: A Review.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jack M.

1989-06-01

This review describes the electrical properties of a-c and d-c transmission lines and the resulting effects on plants, animals, and people. Methods used by BPA to mitigate undesirable effects are also discussed. Although much of the information in this review pertains to high-voltage transmission lines, information on distribution lines and electrical appliances is included. The electrical properties discussed are electric and magnetic fields and corona: first for alternating-current (a-c) lines, then for direct current (d-c).

AZTEC: A parallel iterative package for the solving linear systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hutchinson, S.A.; Shadid, J.N.; Tuminaro, R.S.

1996-12-31

We describe a parallel linear system package, AZTEC. The package incorporates a number of parallel iterative methods (e.g. GMRES, biCGSTAB, CGS, TFQMR) and preconditioners (e.g. Jacobi, Gauss-Seidel, polynomial, domain decomposition with LU or ILU within subdomains). Additionally, AZTEC allows for the reuse of previous preconditioning factorizations within Newton schemes for nonlinear methods. Currently, a number of different users are using this package to solve a variety of PDE applications.

Facilities and Methods Used in Full-scale Airplane Crash-fire Investigation

NASA Technical Reports Server (NTRS)

Black, Dugald O.

1952-01-01

The facilities and the techniques employed in the conduct of full scale airplane crash-fire studies currently being conducted at the NACA Lewis laboratory are discussed herein. This investigation is part of a comprehensive study of the airplane crash-fire problem. The crash configuration chosen, the general physical layout of the crash site, the test methods, the instrumentation, the data-recording systems, and the post-crash examination procedure are described

EBIC Characterization and Hydrogen Passivation in Silicon Sheet

NASA Technical Reports Server (NTRS)

Hanoka, J. I.

1985-01-01

As a general qualitative tool, the electron beam induced current (EBIC) method can be very useful in imaging recombination in silicon sheet used for solar cells. Work using EBIC on EFG silicon ribbon is described. In particular, some efforts at making the technique more quantitative and hence more useful, some limitations of the method, and finally specific application to hydrogen passivation is treated. Some brief remarks are made regarding the technique itself.

The use of photogrammetric and stereophotogrammetric methods in aerodynamic experiments

NASA Astrophysics Data System (ADS)

Shmyreva, V. N.; Iakovlev, V. A.

The possibilities afforded by photogrammetry and stereophotogrammetry in current aerodynamic experiments, methods of image recording, and observation data processing are briefly reviewed. Some specific experiments illustrating the application of stereophotogrammetry are described. The applications discussed include the monitoring of model position in wind tunnels, determination of model deformations and displacements, determination of the deformations of real structural elements in static strength tests, and solution of a variety of problems in hydrodynamics.

Personality psychology: lexical approaches, assessment methods, and trait concepts reveal only half of the story--why it is time for a paradigm shift.

PubMed

Uher, Jana

2013-03-01

This article develops a comprehensive philosophy-of-science for personality psychology that goes far beyond the scope of the lexical approaches, assessment methods, and trait concepts that currently prevail. One of the field's most important guiding scientific assumptions, the lexical hypothesis, is analysed from meta-theoretical viewpoints to reveal that it explicitly describes two sets of phenomena that must be clearly differentiated: 1) lexical repertoires and the representations that they encode and 2) the kinds of phenomena that are represented. Thus far, personality psychologists largely explored only the former, but have seriously neglected studying the latter. Meta-theoretical analyses of these different kinds of phenomena and their distinct natures, commonalities, differences, and interrelations reveal that personality psychology's focus on lexical approaches, assessment methods, and trait concepts entails a) erroneous meta-theoretical assumptions about what the phenomena being studied actually are, and thus how they can be analysed and interpreted, b) that contemporary personality psychology is largely based on everyday psychological knowledge, and c) a fundamental circularity in the scientific explanations used in trait psychology. These findings seriously challenge the widespread assumptions about the causal and universal status of the phenomena described by prominent personality models. The current state of knowledge about the lexical hypothesis is reviewed, and implications for personality psychology are discussed. Ten desiderata for future research are outlined to overcome the current paradigmatic fixations that are substantially hampering intellectual innovation and progress in the field.

Finite-element 3D simulation tools for high-current relativistic electron beams

NASA Astrophysics Data System (ADS)

Humphries, Stanley; Ekdahl, Carl

2002-08-01

The DARHT second-axis injector is a challenge for computer simulations. Electrons are subject to strong beam-generated forces. The fields are fully three-dimensional and accurate calculations at surfaces are critical. We describe methods applied in OmniTrak, a 3D finite-element code suite that can address DARHT and the full range of charged-particle devices. The system handles mesh generation, electrostatics, magnetostatics and self-consistent particle orbits. The MetaMesh program generates meshes of conformal hexahedrons to fit any user geometry. The code has the unique ability to create structured conformal meshes with cubic logic. Organized meshes offer advantages in speed and memory utilization in the orbit and field solutions. OmniTrak is a versatile charged-particle code that handles 3D electric and magnetic field solutions on independent meshes. The program can update both 3D field solutions from the calculated beam space-charge and current-density. We shall describe numerical methods for orbit tracking on a hexahedron mesh. Topics include: 1) identification of elements along the particle trajectory, 2) fast searches and adaptive field calculations, 3) interpolation methods to terminate orbits on material surfaces, 4) automatic particle generation on multiple emission surfaces to model space-charge-limited emission and field emission, 5) flexible Child law algorithms, 6) implementation of the dual potential model for 3D magnetostatics, and 7) assignment of charge and current from model particle orbits for self-consistent fields.

Eigenanalysis and Graph Theory Combined to Determine the Seasonal and Solar-Cycle Variations of Polar Magnetic Fields

NASA Astrophysics Data System (ADS)

Shore, R. M.; Freeman, M. P.; Gjerloev, J. W.

2017-12-01

We apply the meteorological analysis method of Empirical Orthogonal Functions (EOF) to ground magnetometer measurements, and subsequently use graph theory to classify the results. The EOF method is used to characterise and separate contributions to the variability of the Earth's external magnetic field (EMF) in the northern polar region. EOFs decompose the noisy EMF data into a small number of independent spatio-temporal basis functions, which collectively describe the majority of the magnetic field variance. We use these basis functions (computed monthly) to infill where data are missing, providing a self-consistent description of the EMF at 5-minute resolution spanning 1997-2009 (solar cycle 23). The EOF basis functions are calculated independently for each of the 144 months (i.e. 1997-2009) analysed. Since (by definition) the basis vectors are ranked by their contribution to the total variance, their rank will change from month to month. We use graph theory to find clusters of quantifiably-similar spatial basis functions, and thereby track similar patterns throughout the span of 144 months. We find that the discovered clusters can be associated with well-known individual Disturbance Polar (DP)-type equivalent current systems (e.g. DP2, DP1, DPY, NBZ), or with the motion of these systems. Via this method, we thus describe the varying behaviour of these current systems over solar cycle 23. We present their seasonal and solar cycle variations and examine the response of each current system to solar wind driving.

African american mothers' self-described discipline strategies with young children.

PubMed

Lecuyer, Elizabeth A; Christensen, Julie J; Kearney, Margaret H; Kitzman, Harriet J

2011-01-01

African American families have been described as using higher levels of non-abusive physical discipline with their children than European American families. Few if any studies have documented AA families' use of disciplinary strategies in their own words, however, or their reasons for their use. In this qualitative study, 51 African American mothers from a 1992 Memphis sample described their disciplinary strategies with their 12 to 19 month old children. Seventy-seven percent of mothers described using verbal teaching along with non-abusive physical discipline, such as tapping their children's hands. Mothers also expressed concern about being too strict, described awareness of their children's developmental limits, and used non-physical disciplinary methods, consistent with positive accepting parent-child relationships. These findings are important because the low-income girls who experienced such parenting in the 1990s are now young mothers themselves. Current practice guidelines encourage new mothers to think about how they themselves were parented; the knowledge from this study may assist practitioners to engage present-day African American mothers in supportive discussions about physical and non-physical discipline methods with young children.

Analysis of current distribution in a large superconductor

NASA Astrophysics Data System (ADS)

Hamajima, Takataro; Alamgir, A. K. M.; Harada, Naoyuki; Tsuda, Makoto; Ono, Michitaka; Takano, Hirohisa

An imbalanced current distribution which is often observed in cable-in-conduit (CIC) superconductors composed of multistaged, triplet type sub-cables, can deteriorate the performance of the coils. It is, hence very important to analyze the current distribution in a superconductor and find out methods to realize a homogeneous current distribution in the conductor. We apply magnetic flux conservation in a loop contoured by electric center lines of filaments in two arbitrary strands located on adjacent layers in a coaxial multilayer superconductor, and thereby analyze the current distribution in the conductor. A generalized formula governing the current distribution can be described as explicit functions of the superconductor construction parameters, such as twist pitch, twist direction and radius of individual layer. We numerically analyze a homogeneous current distribution as a function of the twist pitches of layers, using the fundamental formula. Moreover, it is demonstrated that we can control current distribution in the coaxial superconductor.

A proof of principle spheromak experiment: The next step on a recently opened path to economical fusion power

NASA Astrophysics Data System (ADS)

Jarboe, Thomas; Marklin, George; Nelson, Brian; Sutherland, Derek; HIT Team Team

2013-10-01

A proof of principle experiment to study closed-flux energy confinement of a spheromak sustained by imposed dynamo current drive is described. A two-fluid validated NIMROD code has simulated closed-flux sustainment on a stable spheromak using imposed dynamo current drive (IDCD), demonstrating that dynamo current drive is compatible with closed flux. (submitted for publication and see adjacent poster.(spsap)) HIT-SI, a = 0.25 m, has achieved 90 kA of toroidal current, current gains of nearly 4, and operation from 5.5 kHz to 68 kHz, demonstrating the robustness of the method.(spsap) Finally, a reactor design study using fusion technology developed for ITER and modern nuclear technology shows a design that is economically superior to coal.(spsap) The spheromak reactor and development path are about a factor of 10 less expensive than that of the tokamak/stellarator. These exciting results justify a proof of principle (PoP) confinement experiment of a spheromak sustained by IDCD. Such an experiment (R = 1.5 m, a = 1 m, Itor = 3 . 2 MA, n = 4e19/m3, T = 3 keV) is described in detail.

A method to select human-system interfaces for nuclear power plants

DOE PAGES

Hugo, Jacques Victor; Gertman, David Ira

2015-10-19

The new generation of nuclear power plants (NPPs) will likely make use of state-of-the-art technologies in many areas of the plant. The analysis, design, and selection of advanced human–system interfaces (HSIs) constitute an important part of power plant engineering. Designers need to consider the new capabilities afforded by these technologies in the context of current regulations and new operational concepts, which is why they need a more rigorous method by which to plan the introduction of advanced HSIs in NPP work areas. Much of current human factors research stops at the user interface and fails to provide a definitive processmore » for integration of end user devices with instrumentation and control (I&C) and operational concepts. The current lack of a clear definition of HSI technology, including the process for integration, makes characterization and implementation of new and advanced HSIs difficult. This paper describes how new design concepts in the nuclear industry can be analyzed and how HSI technologies associated with new industrial processes might be considered. Furthermore, it also describes a basis for an understanding of human as well as technology characteristics that could be incorporated into a prioritization scheme for technology selection and deployment plans.« less

Generic dynamical phase transition in one-dimensional bulk-driven lattice gases with exclusion

NASA Astrophysics Data System (ADS)

Lazarescu, Alexandre

2017-06-01

Dynamical phase transitions are crucial features of the fluctuations of statistical systems, corresponding to boundaries between qualitatively different mechanisms of maintaining unlikely values of dynamical observables over long periods of time. They manifest themselves in the form of non-analyticities in the large deviation function of those observables. In this paper, we look at bulk-driven exclusion processes with open boundaries. It is known that the standard asymmetric simple exclusion process exhibits a dynamical phase transition in the large deviations of the current of particles flowing through it. That phase transition has been described thanks to specific calculation methods relying on the model being exactly solvable, but more general methods have also been used to describe the extreme large deviations of that current, far from the phase transition. We extend those methods to a large class of models based on the ASEP, where we add arbitrary spatial inhomogeneities in the rates and short-range potentials between the particles. We show that, as for the regular ASEP, the large deviation function of the current scales differently with the size of the system if one considers very high or very low currents, pointing to the existence of a dynamical phase transition between those two regimes: high current large deviations are extensive in the system size, and the typical states associated to them are Coulomb gases, which are highly correlated; low current large deviations do not depend on the system size, and the typical states associated to them are anti-shocks, consistently with a hydrodynamic behaviour. Finally, we illustrate our results numerically on a simple example, and we interpret the transition in terms of the current pushing beyond its maximal hydrodynamic value, as well as relate it to the appearance of Tracy-Widom distributions in the relaxation statistics of such models. , which features invited work from the best early-career researchers working within the scope of J. Phys. A. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Alexandre Lazarescu was selected by the Editorial Board of J. Phys. A as an Emerging Talent.

Correction of eddy current distortions in high angular resolution diffusion imaging.

PubMed

Zhuang, Jiancheng; Lu, Zhong-Lin; Vidal, Christine Bouteiller; Damasio, Hanna

2013-06-01

To correct distortions caused by eddy currents induced by large diffusion gradients during high angular resolution diffusion imaging without any auxiliary reference scans. Image distortion parameters were obtained by image coregistration, performed only between diffusion-weighted images with close diffusion gradient orientations. A linear model that describes distortion parameters (translation, scale, and shear) as a function of diffusion gradient directions was numerically computed to allow individualized distortion correction for every diffusion-weighted image. The assumptions of the algorithm were successfully verified in a series of experiments on phantom and human scans. Application of the proposed algorithm in high angular resolution diffusion images markedly reduced eddy current distortions when compared to results obtained with previously published methods. The method can correct eddy current artifacts in the high angular resolution diffusion images, and it avoids the problematic procedure of cross-correlating images with significantly different contrasts resulting from very different gradient orientations or strengths. Copyright © 2012 Wiley Periodicals, Inc.

Towards the development of universal, fast and highly accurate docking/scoring methods: a long way to go

PubMed Central

Moitessier, N; Englebienne, P; Lee, D; Lawandi, J; Corbeil, C R

2008-01-01

Accelerating the drug discovery process requires predictive computational protocols capable of reducing or simplifying the synthetic and/or combinatorial challenge. Docking-based virtual screening methods have been developed and successfully applied to a number of pharmaceutical targets. In this review, we first present the current status of docking and scoring methods, with exhaustive lists of these. We next discuss reported comparative studies, outlining criteria for their interpretation. In the final section, we describe some of the remaining developments that would potentially lead to a universally applicable docking/scoring method. PMID:18037925

Imaging indicator for ESD safety testing.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whinnery, LeRoy L.,; Nissen, April; Keifer, Patrick N.

2013-05-01

This report describes the development of a new detection method for electrostatic discharge (ESD) testing of explosives, using a single-lens reflex (SLR) digital camera and a 200-mm macro lens. This method has demonstrated several distinct advantages to other current ESD detection methods, including the creation of a permanent record, an enlarged image for real-time viewing as well as extended periods of review, and ability to combine with most other Go/No-Go sensors. This report includes details of the method, including camera settings and position, and results with wellcharacterized explosives PETN and RDX, and two ESD-sensitive aluminum powders.

Applications of fuzzy ranking methods to risk-management decisions

NASA Astrophysics Data System (ADS)

Mitchell, Harold A.; Carter, James C., III

1993-12-01

The Department of Energy is making significant improvements to its nuclear facilities as a result of more stringent regulation, internal audits, and recommendations from external review groups. A large backlog of upgrades has resulted. Currently, a prioritization method is being utilized which relies on a matrix of potential consequence and probability of occurrence. The attributes of the potential consequences considered include likelihood, exposure, public health and safety, environmental impact, site personnel safety, public relations, legal liability, and business loss. This paper describes an improved method which utilizes fuzzy multiple attribute decision methods to rank proposed improvement projects.

Research accomplished at the Knowledge Based Systems Lab: IDEF3, version 1.0

NASA Technical Reports Server (NTRS)

Mayer, Richard J.; Menzel, Christopher P.; Mayer, Paula S. D.

1991-01-01

An overview is presented of the foundations and content of the evolving IDEF3 process flow and object state description capture method. This method is currently in beta test. Ongoing efforts in the formulation of formal semantics models for descriptions captured in the outlined form and in the actual application of this method can be expected to cause an evolution in the method language. A language is described for the representation of process and object state centered system description. IDEF3 is a scenario driven process flow modeling methodology created specifically for these types of descriptive activities.

‘Someday it will be the norm’: physician perspectives on the utility of genome sequencing for patient care in the MedSeq Project

PubMed Central

Vassy, Jason L; Christensen, Kurt D; Slashinski, Melody J; Lautenbach, Denise M; Raghavan, Sridharan; Robinson, Jill Oliver; Blumenthal-Barby, Jennifer; Feuerman, Lindsay Zausmer; Lehmann, Lisa Soleymani; Murray, Michael F; Green, Robert C; McGuire, Amy L

2015-01-01

Aim To describe practicing physicians’ perceived clinical utility of genome sequencing. Materials & methods We conducted a mixed-methods analysis of data from 18 primary care physicians and cardiologists in a study of the clinical integration of whole-genome sequencing. Physicians underwent brief genomics continuing medical education before completing surveys and semi-structured interviews. Results Physicians described sequencing as currently lacking clinical utility because of its uncertain interpretation and limited impact on clinical decision-making, but they expressed the idea that its clinical integration was inevitable. Potential clinical uses for sequencing included complementing other clinical information, risk stratification, motivating patient behavior change and pharmacogenetics. Conclusion Physicians given genomics continuing medical education use the language of both evidence-based and personalized medicine in describing the utility of genome-wide testing in patient care. PMID:25642274

Validation of holistic nursing competencies: role-delineation study, 2012.

PubMed

Erickson, Helen Lorraine; Erickson, Margaret Elizabeth; Campbell, Joan A; Brekke, Mary E; Sandor, M Kay

2013-12-01

The American Holistic Nurses Credentialing Corporation (AHNCC), certifying body for nurses practicing within the precepts of holistic nursing, uses a systematic process to guide program development. A previous publication described their early work that distinguished basic and advanced holistic nursing and development of related examinations. A more recent publication described the work of AHNCC from 2004 to 2012, including a role-delineation study (RDS) that was undertaken to identify and validate competencies currently used by holistic nurses. A final report describes the RDS design, methods, and raw data information. This article discusses AHNCC's goals for undertaking the 2012 Holistic Nursing RDS and the implications for the certification programs.

Implementation of a Goal-Based Systems Engineering Process Using the Systems Modeling Language (SysML)

NASA Technical Reports Server (NTRS)

Patterson, Jonathan D.; Breckenridge, Jonathan T.; Johnson, Stephen B.

2013-01-01

Building upon the purpose, theoretical approach, and use of a Goal-Function Tree (GFT) being presented by Dr. Stephen B. Johnson, described in a related Infotech 2013 ISHM abstract titled "Goal-Function Tree Modeling for Systems Engineering and Fault Management", this paper will describe the core framework used to implement the GFTbased systems engineering process using the Systems Modeling Language (SysML). These two papers are ideally accepted and presented together in the same Infotech session. Statement of problem: SysML, as a tool, is currently not capable of implementing the theoretical approach described within the "Goal-Function Tree Modeling for Systems Engineering and Fault Management" paper cited above. More generally, SysML's current capabilities to model functional decompositions in the rigorous manner required in the GFT approach are limited. The GFT is a new Model-Based Systems Engineering (MBSE) approach to the development of goals and requirements, functions, and its linkage to design. As a growing standard for systems engineering, it is important to develop methods to implement GFT in SysML. Proposed Method of Solution: Many of the central concepts of the SysML language are needed to implement a GFT for large complex systems. In the implementation of those central concepts, the following will be described in detail: changes to the nominal SysML process, model view definitions and examples, diagram definitions and examples, and detailed SysML construct and stereotype definitions.

Methods and compositions for protection of cells and tissues from computed tomography radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grdina, David J.

Described are methods for preventing or inhibiting genomic instability and in cells affected by diagnostic radiology procedures employing ionizing radiation. Embodiments include methods of preventing or inhibiting genomic instability and in cells affected by computed tomography (CT) radiation. Subjects receiving ionizing radiation may be those persons suspected of having cancer, or cancer patients having received or currently receiving cancer therapy, and or those patients having received previous ionizing radiation, including those who are approaching or have exceeded the recommended total radiation dose for a person.

Space infrared telescope pointing control system. Automated star pattern recognition

NASA Technical Reports Server (NTRS)

Powell, J. D.; Vanbezooijen, R. W. H.

1985-01-01

The Space Infrared Telescope Facility (SIRTF) is a free flying spacecraft carrying a 1 meter class cryogenically cooled infrared telescope nearly three oders of magnitude most sensitive than the current generation of infrared telescopes. Three automatic target acquisition methods will be presented that are based on the use of an imaging star tracker. The methods are distinguished by the number of guidestars that are required per target, the amount of computational capability necessary, and the time required for the complete acquisition process. Each method is described in detail.

Inductive High Power Transfer Technologies for Electric Vehicles

NASA Astrophysics Data System (ADS)

Madzharov, Nikolay D.; Tonchev, Anton T.

2014-03-01

Problems associated with "how to charge the battery pack of the electric vehicle" become more important every passing day. Most logical solution currently is the non-contact method of charge, possessing a number of advantages over standard contact methods for charging. This article focuses on methods for Inductive high power contact-less transfer of energy at relatively small distances, their advantages and disadvantages. Described is a developed Inductive Power Transfer (IPT) system for fast charging of electric vehicles with nominal power of 30 kW over 7 to 9 cm air gap.

Radiobacteriolysis: a New Technique Using Chromium-51 for Assaying Anti- Vibrio cholerae Antibodies

PubMed Central

Blachman, Uzy; Clark, W. R.; Pickett, M. J.

1973-01-01

A new method for detecting and quantitating antibodies against Vibrio cholerae is described. The reaction involves the release of radiochromium from prelabeled vibrios in the presence of specific antibody and complement. The entire assay can be completed within 5 hr. The method is highly reproducible, immunologically specific, temperature- and complement-dependent, and significantly more sensitive than other methods currently used for titration of anti-Vibrio cholerae antibodies. The technique is also potentially applicable to titration of antibodies against other gram-negative bacteria. PMID:4570279

Absolute calorimetric calibration of low energy brachytherapy sources

NASA Astrophysics Data System (ADS)

Stump, Kurt E.

In the past decade there has been a dramatic increase in the use of permanent radioactive source implants in the treatment of prostate cancer. A small radioactive source encapsulated in a titanium shell is used in this type of treatment. The radioisotopes used are generally 125I or 103Pd. Both of these isotopes have relatively short half-lives, 59.4 days and 16.99 days, respectively, and have low-energy emissions and a low dose rate. These factors make these sources well suited for this application, but the calibration of these sources poses significant metrological challenges. The current standard calibration technique involves the measurement of ionization in air to determine the source air-kerma strength. While this has proved to be an improvement over previous techniques, the method has been shown to be metrologically impure and may not be the ideal means of calbrating these sources. Calorimetric methods have long been viewed to be the most fundamental means of determining source strength for a radiation source. This is because calorimetry provides a direct measurement of source energy. However, due to the low energy and low power of the sources described above, current calorimetric methods are inadequate. This thesis presents work oriented toward developing novel methods to provide direct and absolute measurements of source power for low-energy low dose rate brachytherapy sources. The method is the first use of an actively temperature-controlled radiation absorber using the electrical substitution method to determine total contained source power of these sources. The instrument described operates at cryogenic temperatures. The method employed provides a direct measurement of source power. The work presented here is focused upon building a metrological foundation upon which to establish power-based calibrations of clinical-strength sources. To that end instrument performance has been assessed for these source strengths. The intent is to establish the limits of the current instrument to direct further work in this field. It has been found that for sources with powers above approximately 2 muW the instrument is able to determine the source power in agreement to within less than 7% of what is expected based upon the current source strength standard. For lower power sources, the agreement is still within the uncertainty of the power measurement, but the calorimeter noise dominates. Thus, to provide absolute calibration of lower power sources additional measures must be taken. The conclusion of this thesis describes these measures and how they will improve the factors that limit the current instrument. The results of the work presented in this thesis establish the methodology of active radiometric calorimetey for the absolute calibration of radioactive sources. The method is an improvement over previous techniques in that there is no reliance upon the thermal properties of the materials used or the heat flow pathways on the source measurements. The initial work presented here will help to shape future refinements of this technique to allow lower power sources to be calibrated with high precision and high accuracy.

A circumcision method in an old surgical textbook (Cerrahiyyetul Haniyye): reminding of a forgotten procedure.

PubMed

Senayli, Atilla; Aksu, Murat; Atalar, Munir

2014-07-08

Circumcision is one of the historical surgical procedures. Some sources throughout the history contain various definitions about different circumcision methods. we described the details of the method, and aimed to remind the possibility of contemporary usage. We compared circumcision chapters of Sabuncuoglu and Zahrawi to explain the historical origin of Sabuncuoglu's favorite circumcision method. We found a method which might be summarized as "knotting with rope technique" in one of historical textbooks named as Cerrahiyyetul Haniyye (Imperial Surgery) written by Serefeddin Sabuncuoglu (1385-1468?) in 1465. This circumcision method is not used currently. In addition this method has not been defined in the history of medical literature yet.

Special Test Methods for Batteries

NASA Technical Reports Server (NTRS)

Gross, S.

1984-01-01

Various methods are described for measuring heat generation in primary and secondary batteries as well as the specific heat of batteries and cell thermal conductance. Problems associated with determining heat generation in large batteries are examined. Special attention is given to monitoring temperature gradients in nickel cadmium cells, the use of auxiliary electrodes for conducting tests on battery charge control, evaluating the linear sweep of current from charge to discharge, and determining zero current voltage. The fast transient behavior of batteries in the microsecond range, and the electrical conductance of nickel sinters in the thickness direction are also considered. Mechanical problems experienced in the vibration of Ni-Cd batteries and tests to simulate cyclic fatigue of the steel table connecting the plates to the comb are considered. Methods of defining the distribution of forces when cells are compressed during battery packaging are also explored.

Special test methods for batteries

NASA Astrophysics Data System (ADS)

Gross, S.

1984-09-01

Various methods are described for measuring heat generation in primary and secondary batteries as well as the specific heat of batteries and cell thermal conductance. Problems associated with determining heat generation in large batteries are examined. Special attention is given to monitoring temperature gradients in nickel cadmium cells, the use of auxiliary electrodes for conducting tests on battery charge control, evaluating the linear sweep of current from charge to discharge, and determining zero current voltage. The fast transient behavior of batteries in the microsecond range, and the electrical conductance of nickel sinters in the thickness direction are also considered. Mechanical problems experienced in the vibration of Ni-Cd batteries and tests to simulate cyclic fatigue of the steel table connecting the plates to the comb are considered. Methods of defining the distribution of forces when cells are compressed during battery packaging are also explored.

Unity PF current-source rectifier based on dynamic trilogic PWM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiao Wang; Boon-Teck Ooi

1993-07-01

One remaining step in perfecting the stand-along, unity power factor, regulated current-source PWM rectifier is to reduce cost, by bringing the 12-valve converter (consisting of three single-phase full bridges that operate with two-level or bilogic PWM) to the six-valve bridge. However, the six-valve topology requires a three-level or trilogic PWM strategy that can handle feedback signals. This feature was not available until now. The paper describes a general method of translating three-phase bilogic PWM signals to three-phase trilogic PWM signals. The method of translation retains the characteristics of the bilogic PWM, including the frequency bandwidth. Experiments show that the trilogicmore » PWM signals produced by the method can not only handle stabilizing feedback signals but also signals for active filtering.« less

Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

NASA Technical Reports Server (NTRS)

Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

2005-01-01

A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including distributed software systems, sensor networks, robot operation, complex scripts for spacecraft integration and testing, and autonomous systems. Currently available tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The gap that current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the classes of systems whose behavior can be described as a finite (but significant) set of scenarios, we offer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

NASA Technical Reports Server (NTRS)

Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

2005-01-01

A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including distributed software systems, sensor networks, robot operation, complex scripts for spacecraft integration and testing, and autonomous systems. Currently available tools and methods that start with a formal model of a: system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The "gap" that current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the ciasses of systems whose behavior can be described as a finite (but significant) set of scenarios, we offer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

Statistical methods for nuclear material management

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen W.M.; Bennett, C.A.

1988-12-01

This book is intended as a reference manual of statistical methodology for nuclear material management practitioners. It describes statistical methods currently or potentially important in nuclear material management, explains the choice of methods for specific applications, and provides examples of practical applications to nuclear material management problems. Together with the accompanying training manual, which contains fully worked out problems keyed to each chapter, this book can also be used as a textbook for courses in statistical methods for nuclear material management. It should provide increased understanding and guidance to help improve the application of statistical methods to nuclear material managementmore » problems.« less

Phase change materials handbook

NASA Technical Reports Server (NTRS)

Hale, D. V.; Hoover, M. J.; Oneill, M. J.

1971-01-01

This handbook is intended to provide theory and data needed by the thermal design engineer to bridge the gap between research achievements and actual flight systems, within the limits of the current state of the art of phase change materials (PCM) technology. The relationship between PCM and more conventional thermal control techniques is described and numerous space and terrestrial applications of PCM are discussed. Material properties of the most promising PCMs are provided; the purposes and use of metallic filler materials in PCM composites are presented; and material compatibility considerations relevant to PCM design are included. The engineering considerations of PCM design are described, especially those pertaining to the thermodynamic and heat transfer phenomena peculiar to PCM design. Methods of obtaining data not currently available are presented. The special problems encountered in the space environment are described. Computational tools useful to the designer are discussed. In summary, each aspect of the PCM problem important to the design engineer is covered to the extent allowed by the scope of this effort and the state of the art.

Modeling of shock wave propagation in large amplitude ultrasound.

PubMed

Pinton, Gianmarco F; Trahey, Gregg E

2008-01-01

The Rankine-Hugoniot relation for shock wave propagation describes the shock speed of a nonlinear wave. This paper investigates time-domain numerical methods that solve the nonlinear parabolic wave equation, or the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, and the conditions they require to satisfy the Rankine-Hugoniot relation. Two numerical methods commonly used in hyperbolic conservation laws are adapted to solve the KZK equation: Godunov's method and the monotonic upwind scheme for conservation laws (MUSCL). It is shown that they satisfy the Rankine-Hugoniot relation regardless of attenuation. These two methods are compared with the current implicit solution based method. When the attenuation is small, such as in water, the current method requires a degree of grid refinement that is computationally impractical. All three numerical methods are compared in simulations for lithotripters and high intensity focused ultrasound (HIFU) where the attenuation is small compared to the nonlinearity because much of the propagation occurs in water. The simulations are performed on grid sizes that are consistent with present-day computational resources but are not sufficiently refined for the current method to satisfy the Rankine-Hugoniot condition. It is shown that satisfying the Rankine-Hugoniot conditions has a significant impact on metrics relevant to lithotripsy (such as peak pressures) and HIFU (intensity). Because the Godunov and MUSCL schemes satisfy the Rankine-Hugoniot conditions on coarse grids, they are particularly advantageous for three-dimensional simulations.

Sonoelastography in the musculoskeletal system: Current role and future directions.

PubMed

Winn, Naomi; Lalam, Radhesh; Cassar-Pullicino, Victor

2016-11-28

Ultrasound is an essential modality within musculoskeletal imaging, with the recent addition of elastography. The elastic properties of tissues are different from the acoustic impedance used to create B mode imaging and the flow properties used within Doppler imaging, hence elastography provides a different form of tissue assessment. The current role of ultrasound elastography in the musculoskeletal system will be reviewed, in particular with reference to muscles, tendons, ligaments, joints and soft tissue tumours. The different ultrasound elastography methods currently available will be described, in particular strain elastography and shear wave elastography. Future directions of ultrasound elastography in the musculoskeletal system will also be discussed.

Ultra-fast low concentration detection of Candida pathogens utilizing high resolution micropore chips.

PubMed

Mulero, Rafael; Lee, Dong Heun; Kutzler, Michele A; Jacobson, Jeffrey M; Kim, Min Jun

2009-01-01

Although Candida species are the fourth most common cause of nosocomial blood stream infections in the United States, early diagnostic tools for invasive candidemia are lacking. Due to an increasing rate of candidemia, a new screening system is needed to detect the Candida species in a timely manner. Here we describe a novel method of detection using a solid-state micro-scale pore similar to the operational principles of a Coulter counter. With a steady electrolyte current flowing through the pore, measurements are taken of changes in the current corresponding to the shape of individual yeasts as they translocate or travel through the pore. The direct ultra-fast low concentration electrical addressing of C. albicans has established criteria for distinguishing individual yeast based on their structural properties, which may reduce the currently used methods' complexity for both identification and quantification capabilities in mixed blood samples.

A Bookmarking Service for Organizing and Sharing URLs

NASA Technical Reports Server (NTRS)

Keller, Richard M.; Wolfe, Shawn R.; Chen, James R.; Mathe, Nathalie; Rabinowitz, Joshua L.

1997-01-01

Web browser bookmarking facilities predominate as the method of choice for managing URLs. In this paper, we describe some deficiencies of current bookmarking schemes, and examine an alternative to current approaches. We present WebTagger(TM), an implemented prototype of a personal bookmarking service that provides both individuals and groups with a customizable means of organizing and accessing Web-based information resources. In addition, the service enables users to supply feedback on the utility of these resources relative to their information needs, and provides dynamically-updated ranking of resources based on incremental user feedback. Individuals may access the service from anywhere on the Internet, and require no special software. This service greatly simplifies the process of sharing URLs within groups, in comparison with manual methods involving email. The underlying bookmark organization scheme is more natural and flexible than current hierarchical schemes supported by the major Web browsers, and enables rapid access to stored bookmarks.

When Less Is More in Cognitive Diagnosis: A Rapid Online Method for Diagnosing Learner Task-Specific Expertise

ERIC Educational Resources Information Center

Kalyuga, Slava

2008-01-01

Rapid cognitive diagnosis allows measuring current levels of learner domain-specific knowledge in online learning environments. Such measures are required for individualizing instructional support in real time, as students progress through a learning session. This article describes 2 experiments designed to validate a rapid online diagnostic…

Evaluating Reactions and Transfer of Skills from Blackboard Training

ERIC Educational Resources Information Center

Martin, Florence; Brooks, Robin Freeman; Gayford, Matthew C.; Hall, Herman A., IV; Whitfield, Kimberly Y.

2011-01-01

This article describes the methods that were used to evaluate the "Blackboard Basics" and "Teaching in Blackboard" courses that are currently being offered by the Office of e-Learning at a southeastern university in the United States. This report includes a description of the background of this course, the purpose of the…

A Tool for Estimating Variability in Wood Preservative Treatment Retention

Treesearch

Patricia K. Lebow; Adam M. Taylor; Timothy M. Young

2015-01-01

Composite sampling is standard practice for evaluation of preservative retention levels in preservative-treated wood. Current protocols provide an average retention value but no estimate of uncertainty. Here we describe a statistical method for calculating uncertainty estimates using the standard sampling regime with minimal additional chemical analysis. This tool can...

76 FR 9544 - Antidumping Methodologies in Proceedings Involving Non-Market Economies: Valuing the Factor of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

... parties to comment on these methodological issues described above. Request for Comment on Interim Industry... comments. \\15\\ Indicator: GNI per capita, Atlas Method (current US$) is obtained from http://data.worldbank... methodology, the Department has encountered a number of methodological and practical challenges that must be...

The National Assessment Approach to Objectives and Exercise Development.

ERIC Educational Resources Information Center

Ward, Barbara

The National Assessment of Educational Progress (NAEP) item development procedures, possible improvements or alternatives to these procedures, and methods used to control potential sources of errors of interpretation are described. Current procedures call for the assessment of 9-, 13- and 17-year-olds in subject areas typically taught in schools.…

Description and Recognition of the Concept of Social Capital in Higher Education System

ERIC Educational Resources Information Center

Tonkaboni, Forouzan; Yousefy, Alireza; Keshtiaray, Narges

2013-01-01

The current research is intended to describe and recognize the concept of social capital in higher education based on theoretical method in a descriptive-analytical approach. Description and Recognition of the data, gathered from theoretical and experimental studies, indicated that social capital is one of the most important indices for…

A Resource Center for the Stimulation of Post Secondary Education Innovation via Computer Network.

ERIC Educational Resources Information Center

Savin, William

The goal of the project described here was to improve the quality of postsecondary education by offering institutions of higher learning information on currently funded educational projects through an interactive database, the Educational Resources Directory (ERD), which contains information on new methods, curricula, and educational technology.…

Information Metering: Paving the Way for Pay-per-View Information.

ERIC Educational Resources Information Center

Hawkins, Donald T.

1996-01-01

Describes information metering technology as a method that information providers use to provide information collections to users in encrypted form and charge them only for the parts actually used. Discusses how two current information metering systems (Wave Systems Corporation and CD-MAX) operate, the institutions using their systems, and the…

University Student Perceptions about the Motives for and Consequences of Nonmedical Use of Prescription Drugs (NMUPD)

ERIC Educational Resources Information Center

Parks, Kathleen A.; Levonyan-Radloff, Kristine; Przybyla, Sarahmona M.; Darrow, Sherri; Muraven, Mark; Hequembourg, Amy

2017-01-01

Objective: The purpose of the current study was to increase qualitative understanding of student motives for and consequences associated with nonmedical use of prescription drugs. Participants: Sixty-one students participated in eight focus groups between April and November 2013. Methods: Students described prescription drugs commonly used for…

What Can Jesus Teach Us about Student Engagement?

ERIC Educational Resources Information Center

James, Glenn; Martinez, Elda; Herbers, Sherry

2015-01-01

This article examines Jesus's teaching methods as described in the four Gospels, highlighting the ways in which He led listeners to participate actively in their learning. We identify similarities between many of Jesus's techniques and current practices in the field of student engagement, with a focus on applications for instructors in higher…

Neurology Didactic Curricula for Psychiatry Residents: A Review of the Literature and a Survey of Program Directors

ERIC Educational Resources Information Center

Reardon, Claudia L.; Walaszek, Art

2012-01-01

Objective: Minimal literature exists on neurology didactic instruction offered to psychiatry residents, and there is no model neurology didactic curriculum offered for psychiatry residency programs. The authors sought to describe the current state of neurology didactic training in psychiatry residencies. Methods: The authors electronically…

The Role of International Medical Graduate Psychiatrists in the United States Healthcare System

ERIC Educational Resources Information Center

Boulet, John Robin; Cassimatis, Emmanuel G.; Opalek, Amy

2012-01-01

Objective: International medical graduates (IMGs) make up a substantial proportion of the United States physician workforce, including psychiatrists in practice. The purpose of this study was to describe, based on current data, the characteristics and qualities of IMG psychiatrists who provide patient care in the US. Method: Physician data from…

Education and Training in Psychiatry in the U.K.

ERIC Educational Resources Information Center

Carney, Stuart; Bhugra, Dinesh K.

2013-01-01

Background/Objective: Recent training and education changes have raised important issues in delivery of psychiatric education at all levels. In this article, the authors describe the current status of mental health education in the training of all doctors and postgraduate training and education in psychiatry in the U.K. Method: The authors explore…

RLMS Micro-File: Current State of Catalog Card Reproduction. Supplement 1.

ERIC Educational Resources Information Center

Nitecki, Joseph Z., Comp.

Nine papers on various aspects and methods of catalog card reproduction are included in this supplement. Many reports include cost analyses and comparisons. A lengthy paper describes the history and the present use of technology of the Library of Congress card production operations. Other reports cover offset press and computer output microfilm…

Learning through a Foreign Language: Models, Methods and Outcomes.

ERIC Educational Resources Information Center

Masih, John, Ed.

This book presents European perspectives on the means of structuring curricula that integrate content and language teaching, drawing on the experience of practitioners at a range of levels. It also provides details of the outcomes of such programs and describes the current and future challenges for wider scale adoption of content and language…

A Systematic Review of Research on the Flipped Learning Method in Engineering Education

ERIC Educational Resources Information Center

Karabulut-Ilgu, Aliye; Jaramillo Cherrez, Nadia; Jahren, Charles T.

2018-01-01

The purpose of this article is to describe the current state of knowledge and practice in the flipped learning approach in engineering education and to provide guidance for practitioners by critically appraising and summarizing existing research. This article is a qualitative synthesis of quantitative and qualitative research investigating the…

Characterizing and Predicting Outcomes of Communication Delays in Infants and Toddlers: Implications for Clinical Practice

ERIC Educational Resources Information Center

Paul, Rhea; Roth, Froma P.

2011-01-01

Purpose: This article focuses on using currently available data to assist speech-language pathologists (SLPs) in making decisions regarding a child's eligibility and considerations for recommended "dosage" of early intervention (EI) services. Method: Literature describing the characteristics of infants and toddlers who are likely recipients of EI…

A climate-change scenario for the Columbia River Basin.

Treesearch

Sue A. Ferguson

1997-01-01

This work describes the method used to generate a climate-change scenario for the Columbia River basin. The scenario considers climate patterns that may change if the atmospheric concentration of carbon dioxide (C02), or its greenhouse gas equivalent, were to double over pre-Industrial Revolution values. Given the current rate of increase in...

Techniques employed by the NASA White Sands Test Facility to ensure oxygen system component safety

NASA Technical Reports Server (NTRS)

Stradling, J. S.; Pippen, D. L.; Frye, G. W.

1983-01-01

Methods of ascertaining the safety and suitability of a variety of oxygen system components are discussed. Additionally, qualification and batch control requirements for soft goods in oxygen systems are presented. Current oxygen system component qualification test activities in progress at White Sands Test Facility are described.

Index-in-retrospect and breeding objectives characterizing genetic improvement programs for South African Nguni cattle

USDA-ARS?s Scientific Manuscript database

The objective of the current study was to describe the historical selection applied to Nguni cattle in South Africa. Index-in-retrospect methods were applied to data originating from the National Beef Cattle Improvement Scheme. Data used were estimated breeding values (EBV) for animals born during t...

Resident-Directed Long-Term Care: Staff Provision of Choice during Morning Care

ERIC Educational Resources Information Center

Simmons, Sandra F.; Rahman, Annie; Beuscher, Linda; Jani, Victoria; Durkin, Daniel W.; Schnelle, John F.

2011-01-01

Purpose: To develop an observational protocol to assess the quality of staff-resident communication relevant to choice and describe staff-resident interactions as preliminary evidence of the usefulness of the tool to assess current nursing home practices related to offering choice during morning care provision. Design and Methods: This study…

Patterns of Physical Activity Outside of School Time among Japanese Junior High School Students

ERIC Educational Resources Information Center

He, Li; Ishii, Kaori; Shibata, Ai; Adachi, Minoru; Nonoue, Keiko; Oka, Koichiro

2013-01-01

Background: Physical activity is beneficial for adolescent health. The physical activity patterns of Japanese adolescents are relatively unknown. Therefore, this study aimed to describe the current patterns of physical activity and to identify sex and grade differences among them. Methods: The participants comprised 714 Japanese adolescents aged…

The Utility of Implicit Learning in the Teaching of Rules

ERIC Educational Resources Information Center

Saetrevik, Bjorn; Reber, Rolf; Sannum, Petter

2006-01-01

The potential impact of implicit learning on education has been repeatedly stressed, though little research has examined this connection directly. The current paper describes two experiments that, inspired by artificial grammar learning experiments, examine the utility of implicit learning as a method for teaching atomic bonding rules to 11-12…

Acquisition of Scientific Literature in Developing Countries. 5: Arab Gulf Countries.

ERIC Educational Resources Information Center

Ali, S. Nazim

1989-01-01

Summarizes the development of science and technology in the Arab Gulf States and discusses the collection building of the libraries in the region, focusing on problems of censorship and finance. Current purchasing methods are described, and the need for automation in acquisitions work and for centralized and cooperative purchasing is discussed.…

A New Nonparametric Levene Test for Equal Variances

ERIC Educational Resources Information Center

Nordstokke, David W.; Zumbo, Bruno D.

2010-01-01

Tests of the equality of variances are sometimes used on their own to compare variability across groups of experimental or non-experimental conditions but they are most often used alongside other methods to support assumptions made about variances. A new nonparametric test of equality of variances is described and compared to current "gold…

Commonsense System Pricing; Or, How Much Will that $1,200 Computer Really Cost?

ERIC Educational Resources Information Center

Crawford, Walt

1984-01-01

Three methods employed to price and sell computer equipment are discussed: computer pricing, hardware pricing, system pricing (system includes complete computer and support hardware system and relatively complete software package). Advantages of system pricing are detailed, the author's system is described, and 10 systems currently available are…

Potential Applications and Impact of Microelectronic and Telecommunication Technology in Health Care Delivery. Final Report.

ERIC Educational Resources Information Center

Mandex, Inc., Vienna, VA.

This compendium of current and recent innovative methods of health care delivery focuses on telemedicine, and educational and energy management and control applications. Each application is doumented in a project abstract describing the system and the technology employed, and citing relevant information sources and a personal or organizational…

Development of a Comprehensive Heart Disease Knowledge Questionnaire

ERIC Educational Resources Information Center

Bergman, Hannah E.; Reeve, Bryce B.; Moser, Richard P.; Scholl, Sarah; Klein, William M. P.

2011-01-01

Background: Heart disease is the number one killer of both men and women in the United States, yet a comprehensive and evidence-based heart disease knowledge assessment is currently not available. Purpose: This paper describes the two-phase development of a novel heart disease knowledge questionnaire. Methods: After review and critique of the…

Proteomics in the Classroom: An Investigative Study of Proteins in Microorganisms

ERIC Educational Resources Information Center

Benskin, Jon; Chen, Sixue

2012-01-01

As advances in biotechnology and molecular biology rapidly expand in research settings, it is vital that we continue to prepare high school students to enter and thrive in those modern laboratories. This multistep, inquiry-based lab describes highly adaptable methods to teach students not only current molecular techniques and technologies, but…

Twenty-First Century Literacy: A Matter of Scale from Micro to Mega

ERIC Educational Resources Information Center

Brown, Abbie; Slagter van Tryon, Patricia J.

2010-01-01

Twenty-first century technologies require educators to look for new ways to teach literacy skills. Current communication methods are combinations of traditional and newer, network-driven forms. This article describes the changes twenty-first century technologies cause in the perception of time, size, distance, audience, and available data, and…

SHARP: A multi-mission artificial intelligence system for spacecraft telemetry monitoring and diagnosis

NASA Technical Reports Server (NTRS)

Lawson, Denise L.; James, Mark L.

1989-01-01

The Spacecraft Health Automated Reasoning Prototype (SHARP) is a system designed to demonstrate automated health and status analysis for multi-mission spacecraft and ground data systems operations. Telecommunications link analysis of the Voyager 2 spacecraft is the initial focus for the SHARP system demonstration which will occur during Voyager's encounter with the planet Neptune in August, 1989, in parallel with real time Voyager operations. The SHARP system combines conventional computer science methodologies with artificial intelligence techniques to produce an effective method for detecting and analyzing potential spacecraft and ground systems problems. The system performs real time analysis of spacecraft and other related telemetry, and is also capable of examining data in historical context. A brief introduction is given to the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory. The current method of operation for monitoring the Voyager Telecommunications subsystem is described, and the difficulties associated with the existing technology are highlighted. The approach taken in the SHARP system to overcome the current limitations is also described, as well as both the conventional and artificial intelligence solutions developed in SHARP.

Summary of Work for Joint Research Interchanges with DARWIN Integrated Product Team 1998

NASA Technical Reports Server (NTRS)

Hesselink, Lambertus

1999-01-01

The intent of Stanford University's SciVis group is to develop technologies that enabled comparative analysis and visualization techniques for simulated and experimental flow fields. These techniques would then be made available under the Joint Research Interchange for potential injection into the DARWIN Workspace Environment (DWE). In the past, we have focused on techniques that exploited feature based comparisons such as shock and vortex extractions. Our current research effort focuses on finding a quantitative comparison of general vector fields based on topological features. Since the method relies on topological information, grid matching and vector alignment is not needed in the comparison. This is often a problem with many data comparison techniques. In addition, since only topology based information is stored and compared for each field, there is a significant compression of information that enables large databases to be quickly searched. This report will briefly (1) describe current technologies in the area of comparison techniques, (2) will describe the theory of our new method and finally (3) summarize a few of the results.

Summary of Work for Joint Research Interchanges with DARWIN Integrated Product Team

NASA Technical Reports Server (NTRS)

Hesselink, Lambertus

1999-01-01

The intent of Stanford University's SciVis group is to develop technologies that enabled comparative analysis and visualization techniques for simulated and experimental flow fields. These techniques would then be made available un- der the Joint Research Interchange for potential injection into the DARWIN Workspace Environment (DWE). In the past, we have focused on techniques that exploited feature based comparisons such as shock and vortex extractions. Our current research effort focuses on finding a quantitative comparison of general vector fields based on topological features. Since the method relies on topological information, grid matching an@ vector alignment is not needed in the comparison. This is often a problem with many data comparison techniques. In addition, since only topology based information is stored and compared for each field, there is a significant compression of information that enables large databases to be quickly searched. This report will briefly (1) describe current technologies in the area of comparison techniques, (2) will describe the theory of our new method and finally (3) summarize a few of the results.

Making Full Use of the Longitudinal Design of the Current Population Survey: Methods for Linking Records Across 16 Months *

PubMed Central

Drew, Julia A. Rivera; Flood, Sarah; Warren, John Robert

2015-01-01

Data from the Current Population Survey (CPS) are rarely analyzed in a way that takes advantage of the CPS’s longitudinal design. This is mainly because of the technical difficulties associated with linking CPS files across months. In this paper, we describe the method we are using to create unique identifiers for all CPS person and household records from 1989 onward. These identifiers—available along with CPS basic and supplemental data as part of the on-line Integrated Public Use Microdata Series (IPUMS)—make it dramatically easier to use CPS data for longitudinal research across any number of substantive domains. To facilitate the use of these new longitudinal IPUMS-CPS data, we also outline seven different ways that researchers may choose to link CPS person records across months, and we describe the sample sizes and sample retention rates associated with these seven designs. Finally, we discuss a number of unique methodological challenges that researchers will confront when analyzing data from linked CPS files. PMID:26113770

SHARP: A multi-mission AI system for spacecraft telemetry monitoring and diagnosis

NASA Technical Reports Server (NTRS)

Lawson, Denise L.; James, Mark L.

1989-01-01

The Spacecraft Health Automated Reasoning Prototype (SHARP) is a system designed to demonstrate automated health and status analysis for multi-mission spacecraft and ground data systems operations. Telecommunications link analysis of the Voyager II spacecraft is the initial focus for the SHARP system demonstration which will occur during Voyager's encounter with the planet Neptune in August, 1989, in parallel with real-time Voyager operations. The SHARP system combines conventional computer science methodologies with artificial intelligence techniques to produce an effective method for detecting and analyzing potential spacecraft and ground systems problems. The system performs real-time analysis of spacecraft and other related telemetry, and is also capable of examining data in historical context. A brief introduction is given to the spacecraft and ground systems monitoring process at the Jet Propulsion Laboratory. The current method of operation for monitoring the Voyager Telecommunications subsystem is described, and the difficulties associated with the existing technology are highlighted. The approach taken in the SHARP system to overcome the current limitations is also described, as well as both the conventional and artificial intelligence solutions developed in SHARP.

[A NEW APPROACH FOR FOOD PREFERENCE TESTING IN ANIMAL EXPERIMENTATION].

PubMed

Albertin, S V

2015-10-01

An article describes the original method allowing to study a mechanism of food preference related to the sensory properties of foods in animals. The method gives a good possibility to select the role of visual and orosensory signaling in food preference as well as to model the processes of physiological and pathological food and drug dependence in animal experiments. The role of discrete food presentation in the formation of the current motivations and food preferences was discussed.

Evolution of monitoring for Giardia and Cryptosporidium in water.

PubMed

Efstratiou, Artemis; Ongerth, Jerry; Karanis, Panagiotis

2017-10-15

This review describes the evolution of monitoring methodology for Cryptosporidium and Giardia in water since the 1970's. Methods in current use for Giardia and Cryptosporidium in water are highlighted, though attention is given to all available published methods by country and continent. The review is intended to stimulate research leading to future improvements and further developments in monitoring methodology for Giardia, Cryptosporidium and other waterborne protozoan parasites in water. Copyright © 2017. Published by Elsevier Ltd.

ELECTROSTATIC ACCELERATORS (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerbier, R.

1962-04-01

The various methods presently in use for producing the continuous high voltage necessary for the operation of electrostatic accelerators are reviewed. The methods considered are voltage multiplier units (Greinacher and Morganstern types) and electrostatic instruments (Van de Graaff and Trump machines and Felici rotnting cylinder instruments). The electrostatic accelerators used at Grenoble which give currents of several milliamperes at voltages up to 1.2 Mv are described. In this energy region electron accelerators and neutron generators offer very interesting possibilities. (auth)

Protein arginine methylation: Cellular functions and methods of analysis.

PubMed

Pahlich, Steffen; Zakaryan, Rouzanna P; Gehring, Heinz

2006-12-01

During the last few years, new members of the growing family of protein arginine methyltransferases (PRMTs) have been identified and the role of arginine methylation in manifold cellular processes like signaling, RNA processing, transcription, and subcellular transport has been extensively investigated. In this review, we describe recent methods and findings that have yielded new insights into the cellular functions of arginine-methylated proteins, and we evaluate the currently used procedures for the detection and analysis of arginine methylation.

Application of plausible reasoning to AI-based control systems

NASA Technical Reports Server (NTRS)

Berenji, Hamid; Lum, Henry, Jr.

1987-01-01

Some current approaches to plausible reasoning in artificial intelligence are reviewed and discussed. Some of the most significant recent advances in plausible and approximate reasoning are examined. A synergism among the techniques of uncertainty management is advocated, and brief discussions on the certainty factor approach, probabilistic approach, Dempster-Shafer theory of evidence, possibility theory, linguistic variables, and fuzzy control are presented. Some extensions to these methods are described, and the applications of the methods are considered.

Endemic pemphigus foliaceus over a century: Part I

PubMed Central

Abréu-Vélez, Ana María; Reason, Iara J. de Messias; Howard, Michael S.; Roselino, Ana Maria

2010-01-01

Background: Endemic pemphigus foliaceus (EPF) is the only known autoimmune disease presenting in circumscribed geographic areas. Aim: We aim to provide information concerning the natural course of EPF, including systemic compromise in the presteroid era, which has been largely unavailable in the current medical literature. Material & Methods: By a retrospective review of the literature we aim to compile and compare the focus of EPF and the current knowledge about them. The main aim of this review is to summarize our current knowledge of EPF, including data described almost one century ago; and, to include several unindexed reports, which may have not been available to many current scientists and health care personnel. Results: Foci of EPF have been described in several Central American and South American countries, affecting predominately young people and Amerindians, with an additional female predilection. Although most cases have occurred in Brazil, some cases have been reported in Peru, Paraguay, El Salvador, and Venezuela. Another variant of EPF has been described in El Bagre, Colombia, affecting older men and a few post-menopausal females. Finally, another type of EPF was described in nomadic tribes affecting females of child bearing age in Tunisia, Africa. Conclusion: Our understanding of EPF has been hampered by a lack of government attention to these diseases, especially in some South and Central American countries. Other factors that have made past studies of EPF difficult include 1) that the disease foci are often located in rural areas bordering the rain forest of underdeveloped countries; and 2) military conflicts in some of these areas. PMID:22624115

Circulating Tumor Cells: A Review of Non-EpCAM-Based Approaches for Cell Enrichment and Isolation.

PubMed

Gabriel, Marta Tellez; Calleja, Lidia Rodriguez; Chalopin, Antoine; Ory, Benjamin; Heymann, Dominique

2016-04-01

Circulating tumor cells (CTCs) are biomarkers for noninvasively measuring the evolution of tumor genotypes during treatment and disease progression. Recent technical progress has made it possible to detect and characterize CTCs at the single-cell level in blood. Most current methods are based on epithelial cell adhesion molecule (EpCAM) detection, but numerous studies have demonstrated that EpCAM is not a universal marker for CTC detection because it fails to detect both carcinoma cells that undergo epithelial-mesenchymal transition (EMT) and CTCs of mesenchymal origin. Moreover, EpCAM expression has been found in patients with benign diseases. A large proportion of the current studies and reviews about CTCs describe EpCAM-based methods, but there is evidence that not all tumor cells can be detected using this marker. Here we describe the most recent EpCAM-independent methods for enriching, isolating, and characterizing CTCs on the basis of physical and biological characteristics and point out the main advantages and disadvantages of these methods. CTCs offer an opportunity to obtain key biological information required for the development of personalized medicine. However, there is no universal marker of these cells. To strengthen the clinical utility of CTCs, it is important to improve existing technologies and develop new, non-EpCAM-based systems to enrich and isolate CTCs. © 2016 American Association for Clinical Chemistry.

A combination of HPLC and automated data analysis for monitoring the efficiency of high-pressure homogenization.

PubMed

Eggenreich, Britta; Rajamanickam, Vignesh; Wurm, David Johannes; Fricke, Jens; Herwig, Christoph; Spadiut, Oliver

2017-08-01

Cell disruption is a key unit operation to make valuable, intracellular target products accessible for further downstream unit operations. Independent of the applied cell disruption method, each cell disruption process must be evaluated with respect to disruption efficiency and potential product loss. Current state-of-the-art methods, like measuring the total amount of released protein and plating-out assays, are usually time-delayed and involve manual intervention making them error-prone. An automated method to monitor cell disruption efficiency at-line is not available to date. In the current study we implemented a methodology, which we had originally developed to monitor E. coli cell integrity during bioreactor cultivations, to automatically monitor and evaluate cell disruption of a recombinant E. coli strain by high-pressure homogenization. We compared our tool with a library of state-of-the-art methods, analyzed the effect of freezing the biomass before high-pressure homogenization and finally investigated this unit operation in more detail by a multivariate approach. A combination of HPLC and automated data analysis describes a valuable, novel tool to monitor and evaluate cell disruption processes. Our methodology, which can be used both in upstream (USP) and downstream processing (DSP), describes a valuable tool to evaluate cell disruption processes as it can be implemented at-line, gives results within minutes after sampling and does not need manual intervention.

An Effective and Reproducible Model of Ventricular Fibrillation in Crossbred Yorkshire Swine (Sus scrofa) for Use in Physiologic Research.

PubMed

Burgert, James M; Johnson, Arthur D; Garcia-Blanco, Jose C; Craig, W John; O'Sullivan, Joseph C

2015-10-01

Transcutaneous electrical induction (TCEI) has been used to induce ventricular fibrillation (VF) in laboratory swine for physiologic and resuscitation research. Many studies do not describe the method of TCEI in detail, thus making replication by future investigators difficult. Here we describe a detailed method of electrically inducing VF that was used successfully in a prospective, experimental resuscitation study. Specifically, an electrical current was passed through the heart to induce VF in crossbred Yorkshire swine (n = 30); the current was generated by using two 22-gauge spinal needles, with one placed above and one below the heart, and three 9V batteries connected in series. VF developed in 28 of the 30 pigs (93%) within 10 s of beginning the procedure. In the remaining 2 swine, VF was induced successfully after medial redirection of the superior parasternal needle. The TCEI method is simple, reproducible, and cost-effective. TCEI may be especially valuable to researchers with limited access to funding, sophisticated equipment, or colleagues experienced in interventional cardiology techniques. The TCEI method might be most appropriate for pharmacologic studies requiring VF, VF resulting from the R-on-T phenomenon (as in prolonged QT syndrome), and VF arising from other ectopic or reentrant causes. However, the TCEI method does not accurately model the most common cause of VF, acute coronary occlusive disease. Researchers must consider the limitations of TCEI that may affect internal and external validity of collected data, when designing experiments using this model of VF.

Acquisition, representation and rule generation for procedural knowledge

NASA Technical Reports Server (NTRS)

Ortiz, Chris; Saito, Tim; Mithal, Sachin; Loftin, R. Bowen

1991-01-01

Current research into the design and continuing development of a system for the acquisition of procedural knowledge, its representation in useful forms, and proposed methods for automated C Language Integrated Production System (CLIPS) rule generation is discussed. The Task Analysis and Rule Generation Tool (TARGET) is intended to permit experts, individually or collectively, to visually describe and refine procedural tasks. The system is designed to represent the acquired knowledge in the form of graphical objects with the capacity for generating production rules in CLIPS. The generated rules can then be integrated into applications such as NASA's Intelligent Computer Aided Training (ICAT) architecture. Also described are proposed methods for use in translating the graphical and intermediate knowledge representations into CLIPS rules.

Fast Bound Methods for Large Scale Simulation with Application for Engineering Optimization

NASA Technical Reports Server (NTRS)

Patera, Anthony T.; Peraire, Jaime; Zang, Thomas A. (Technical Monitor)

2002-01-01

In this work, we have focused on fast bound methods for large scale simulation with application for engineering optimization. The emphasis is on the development of techniques that provide both very fast turnaround and a certificate of Fidelity; these attributes ensure that the results are indeed relevant to - and trustworthy within - the engineering context. The bound methodology which underlies this work has many different instantiations: finite element approximation; iterative solution techniques; and reduced-basis (parameter) approximation. In this grant we have, in fact, treated all three, but most of our effort has been concentrated on the first and third. We describe these below briefly - but with a pointer to an Appendix which describes, in some detail, the current "state of the art."

Correlative light and electron microscopic detection of GFP-labeled proteins using modular APEX.

PubMed

Ariotti, Nicholas; Hall, Thomas E; Parton, Robert G

2017-01-01

The use of green fluorescent protein (GFP) and related proteins has revolutionized light microscopy. Here we describe a rapid and simple method to localize GFP-tagged proteins in cells and in tissues by electron microscopy (EM) using a modular approach involving a small GFP-binding peptide (GBP) fused to the ascorbate peroxidase-derived APEX2 tag. We provide a method for visualizing GFP-tagged proteins by light and EM in cultured cells and in the zebrafish using modular APEX-GBP. Furthermore, we describe in detail the benefits of this technique over many of the currently available correlative light and electron microscopy approaches and demonstrate APEX-GBP is readily applicable to modern three-dimensional techniques. Copyright © 2017 Elsevier Inc. All rights reserved.

Debridement and wound bed preparation.

PubMed

Falabella, Anna F

2006-01-01

Debridement can play a vital role in wound bed preparation and the removal of barriers that impair wound healing. In accordance with the TIME principles, debridement can help remove nonviable tissue, control inflammation or infection, decrease excess moisture, and stimulate a nonadvancing wound edge. There are many types of debridement, each with a set of advantages and disadvantages that must be clearly understood by the healthcare team. Failure to use the correct debridement method for a given type of wound may lead to further delays in healing, increase patient suffering, and unnecessarily increase the cost of care. This review article discusses the various methods of debridement, describes currently available debriding agents, evaluates the clinical data regarding their efficacy and safety, and describes strategies for the management of problematic nonhealing wounds.

Simulations of inorganic-bioorganic interfaces to discover new materials: insights, comparisons to experiment, challenges, and opportunities.

PubMed

Heinz, Hendrik; Ramezani-Dakhel, Hadi

2016-01-21

Natural and man-made materials often rely on functional interfaces between inorganic and organic compounds. Examples include skeletal tissues and biominerals, drug delivery systems, catalysts, sensors, separation media, energy conversion devices, and polymer nanocomposites. Current laboratory techniques are limited to monitor and manipulate assembly on the 1 to 100 nm scale, time-consuming, and costly. Computational methods have become increasingly reliable to understand materials assembly and performance. This review explores the merit of simulations in comparison to experiment at the 1 to 100 nm scale, including connections to smaller length scales of quantum mechanics and larger length scales of coarse-grain models. First, current simulation methods, advances in the understanding of chemical bonding, in the development of force fields, and in the development of chemically realistic models are described. Then, the recognition mechanisms of biomolecules on nanostructured metals, semimetals, oxides, phosphates, carbonates, sulfides, and other inorganic materials are explained, including extensive comparisons between modeling and laboratory measurements. Depending on the substrate, the role of soft epitaxial binding mechanisms, ion pairing, hydrogen bonds, hydrophobic interactions, and conformation effects is described. Applications of the knowledge from simulation to predict binding of ligands and drug molecules to the inorganic surfaces, crystal growth and shape development, catalyst performance, as well as electrical properties at interfaces are examined. The quality of estimates from molecular dynamics and Monte Carlo simulations is validated in comparison to measurements and design rules described where available. The review further describes applications of simulation methods to polymer composite materials, surface modification of nanofillers, and interfacial interactions in building materials. The complexity of functional multiphase materials creates opportunities to further develop accurate force fields, including reactive force fields, and chemically realistic surface models, to enable materials discovery at a million times lower computational cost compared to quantum mechanical methods. The impact of modeling and simulation could further be increased by the advancement of a uniform simulation platform for organic and inorganic compounds across the periodic table and new simulation methods to evaluate system performance in silico.

Greater Role of Geostrophic Currents on Ekman Dynamics in the Western Arctic Ocean as a Mechanism for Beaufort Gyre Stabilization

NASA Astrophysics Data System (ADS)

Steele, M.; Zhong, W.; Zhang, J.; Zhao, J.

2017-12-01

Seven different methods, with and without including geostrophic currents, were used to explore Ekman dynamics in the western Arctic Ocean for the period 1992-2014. Results show that surface geostrophic currents have been increasing and are much stronger than Ekman layer velocities in recent years (2003-2014) when the oceanic Beaufort Gyre (BG) is spinning up in the region. The new methods that include geostrophic currents result in more realistic Ekman pumping velocities than a previous iterative method that does not consider geostrophic currents and therefore overestimates Ekman pumping velocities by up to 52% in the central area of the BG over the period 2003-2014. When the BG is spinning up as seen in recent years, geostrophic currents become stronger, which tend to modify the ice-ocean stress and to cause an Ekman divergence that counteracts wind-driven Ekman convergence in the Canada Basin. This is a mechanism we have identified to play an important and growing role in stabilizing the Ekman convergence and therefore the BG in recent years. This mechanism may be used to explain three scenarios that describe the interplay of changes in wind forcing, sea ice motion, and geostrophic currents that control the variability of the Ekman dynamics in the central BG during 1992-2014. Results also reveal several upwelling regions in the southern and northern Canada Basin and the Chukchi Abyssal Plain which may plays a significant role in biological processes in these regions.

Greater Role of Geostrophic Currents in Ekman Dynamics in the Western Arctic Ocean as a Mechanism for Beaufort Gyre Stabilization

NASA Astrophysics Data System (ADS)

Zhong, Wenli; Steele, Michael; Zhang, Jinlun; Zhao, Jinping

2018-01-01

Seven different methods, with and without including geostrophic currents, were used to explore Ekman dynamics in the western Arctic Ocean for the period 1992-2014. Results show that surface geostrophic currents have been increasing and are much stronger than Ekman layer velocities in recent years (2003-2014) when the oceanic Beaufort Gyre (BG) is spinning up in the region. The new methods that include geostrophic currents result in more realistic Ekman pumping velocities than a previous iterative method that does not consider geostrophic currents and therefore overestimates Ekman pumping velocities by up to 52% in the central area of the BG over the period 2003-2014. When the BG is spinning up as seen in recent years, geostrophic currents become stronger, which tend to modify the ice-ocean stress and moderate the wind-driven Ekman convergence in the Canada Basin. This is a mechanism we have identified to play an important and growing role in stabilizing the Ekman convergence and therefore the BG in recent years. This mechanism may be used to explain three scenarios that describe the interplay of changes in wind forcing, sea ice motion, and geostrophic currents that control the variability of the Ekman dynamics in the central BG during 1992-2014. Results also reveal several upwelling regions in the southern and northern Canada Basin and the Chukchi Abyssal Plain which may play a significant role in physical and biological processes in these regions.

Measurement of ROS homeostasis in isolated mitochondria.

PubMed

Tretter, L; Ambrus, A

2014-01-01

In this chapter, we describe the currently most advanced methods applied for the quantitative assessment of ROS homeostasis inside the mitochondrion. These techniques are of particular interest in the field of oxidative stress. After discussing the importance of quantifying mitochondrial ROS homeostasis, three major aspects of this phenomenon and the pertinent methodologies for detection are delineated in detail. First the most important methods, based on fluorimetric or spectrophotometric approaches, for the detection of mitochondrial ROS are described. Elimination of ROS generated inside the mitochondrion is another crucial mechanism that also needs to be quantified accurately to estimate the antioxidant capacity of mitochondria under specific conditions. Since ROS generation and elimination manifest in concert, there needs to exist independent methods for the estimation of the net effect. Such a sensitive biochemical marker in the mitochondrion is aconitase, a citric acid cycle enzyme which is greatly sensitive to ROS. We describe two procedures for the precise determination of aconitase activity. A few auxiliary techniques and good practices having relevance in the successful accomplishment of the more delicate approaches are also mentioned. All other relevant technical considerations including advantages/disadvantages of the various methods and the most common artifacts are also discussed.

Magnetic isolation of Plasmodium falciparum schizonts iRBCs to generate a high parasitaemia and synchronized in vitro culture.

PubMed

Mata-Cantero, Lydia; Lafuente, Maria J; Sanz, Laura; Rodriguez, Manuel S

2014-03-21

The establishment of methods for an in vitro continuous culture of Plasmodium falciparum is essential for gaining knowledge into its biology and for the development of new treatments. Previously, several techniques have been used to synchronize, enrich and concentrate P. falciparum, although obtaining cultures with high parasitaemia continues being a challenging process. Current methods produce high parasitaemia levels of synchronized P. falciparum cultures by frequent changes of culture medium or reducing the haematocrit. However, these methods are time consuming and sometimes lead to the loss of synchrony. A procedure that combines Percoll and sorbitol treatments, the use of magnetic columns, and the optimization of the in vitro culture conditions to reach high parasitaemia levels for synchronized Plasmodium falciparum cultures is described. A new procedure has been established using P. falciparum 3D7, combining previous reported methodologies to achieve in vitro parasite cultures that reach parasitaemia up to 40% at any intra-erythrocytic stage. High parasitaemia levels are obtained only one day after magnetic column purification without compromising the parasite viability and synchrony. The described procedure allows obtaining a large scale synchronized parasite culture at a high parasitaemia with less manipulations than other methods previously described.

Deep Aquifer Remediation Tools (DARTs): A new technology for ground-water remediation

USGS Publications Warehouse

Naftz, David L.; Davis, James A.

1999-01-01

Potable ground-water supplies throughout the world are contaminated or threatened by advancing plumes containing radionuclides, metals, and organic compounds. Currently (1999), the most widely used method of ground-water remediation is a combination of extraction, ex-situ treatment, and discharge of the treated water, commonly known as pump and treat. Pump-and-treat methods are costly and often ineffective in meeting long-term protection standards (Travis and Doty, 1990; Gillham and Burris, 1992; National Research Council, 1994). This fact sheet describes a new and potentially cost-effective technology for removal of organic and inorganic contaminants from ground water. The U.S. Geological Survey (USGS) is currently exploring the possibilities of obtaining a U.S. Patent for this technology.

Polymeric Packaging for Fully Implantable Wireless Neural Microsensors

PubMed Central

Aceros, Juan; Yin, Ming; Borton, David A.; Patterson, William R.; Bull, Christopher; Nurmikko, Arto V.

2014-01-01

We present polymeric packaging methods used for subcutaneous, fully implantable, broadband, and wireless neurosensors. A new tool for accelerated testing and characterization of biocompatible polymeric packaging materials and processes is described along with specialized test units to simulate our fully implantable neurosensor components, materials and fabrication processes. A brief description of the implantable systems is presented along with their current encapsulation methods based on polydimethylsiloxane (PDMS). Results from in-vivo testing of multiple implanted neurosensors in swine and non-human primates are presented. Finally, a novel augmenting polymer thin film material to complement the currently employed PDMS is introduced. This thin layer coating material is based on the Plasma Enhanced Chemical Vapor Deposition (PECVD) process of Hexamethyldisiloxane (HMDSO) and Oxygen (O2). PMID:23365999

Which design for which question? An exploration toward a translation table for comparative effectiveness research.

PubMed

Montori, Victor M; Kim, Simon P; Guyatt, Gordon H; Shah, Nilay D

2012-05-01

In this paper, we explore the relative value that different methods offer in answering some stereotypical comparative effectiveness research questions with the goal of informing development of a 'translation table'--a selection tool for choosing appropriate methods for specific comparative effectiveness research questions. This paper was written as a parallel effort to Greenfield and Kaplan (also in this volume) to support the endeavor described in the manuscript by Tunis et al. (also in this volume). Originally based on four cases, the current article has been shortened to two cases for the current discussion. These cases represent research priorities proposed to orient the work of the Patient-Centered Outcomes Research Institute, comparative clinical effectiveness and comparative health services.

Magnetotomography—a new method for analysing fuel cell performance and quality

NASA Astrophysics Data System (ADS)

Hauer, Karl-Heinz; Potthast, Roland; Wüster, Thorsten; Stolten, Detlef

Magnetotomography is a new method for the measurement and analysis of the current density distribution of fuel cells. The method is based on the measurement of the magnetic flux surrounding the fuel cell stack caused by the current inside the stack. As it is non-invasive, magnetotomography overcomes the shortcomings of traditional methods for the determination of current density in fuel cells [J. Stumper, S.A. Campell, D.P. Wilkinson, M.C. Johnson, M. Davis, In situ methods for the determination of current distributions in PEM fuel cells, Electrochem. Acta 43 (1998) 3773; S.J.C. Cleghorn, C.R. Derouin, M.S. Wilson, S. Gottesfeld, A printed circuit board approach to measuring current distribution in a fuel cell, J. Appl. Electrochem. 28 (1998) 663; Ch. Wieser, A. Helmbold, E. Gülzow, A new technique for two-dimensional current distribution measurements in electro-chemical cells, J. Appl. Electrochem. 30 (2000) 803; Grinzinger, Methoden zur Ortsaufgelösten Strommessung in Polymer Elektrolyt Brennstoffzellen, Diploma thesis, TU-München, 2003; Y.-G. Yoon, W.-Y. Lee, T.-H. Yang, G.-G. Park, C.-S. Kim, Current distribution in a single cell of PEMFC, J. Power Sources 118 (2003) 193-199; M.M. Mench, C.Y. Wang, An in situ method for determination of current distribution in PEM fuel cells applied to a direct methanol fuel cell, J. Electrochem. Soc. 150 (2003) A79-A85; S. Schönbauer, T. Kaz, H. Sander, E. Gülzow, Segmented bipolar plate for the determination of current distribution in polymer electrolyte fuel cells, in: Proceedings of the Second European PEMFC Forum, vol. 1, Lucerne/Switzerland, 2003, pp. 231-237; G. Bender, S.W. Mahlon, T.A. Zawodzinski, Further refinements in the segmented cell approach to diagnosing performance in polymer electrolyte fuel cells, J. Power Sources 123 (2003) 163-171]. After several years of research a complete prototype system is now available for research on single cells and stacks. This paper describes the basic system (fundamentals, hardware and software) as well as the state of development until December 2003. Initial findings on a full-size single cell will be presented together with an outlook on the planned next steps.

Metal- and additive-free photoinduced borylation of haloarenes.

PubMed

Mfuh, Adelphe M; Schneider, Brett D; Cruces, Westley; Larionov, Oleg V

2017-03-01

Boronic acids and esters have critical roles in the areas of synthetic organic chemistry, molecular sensors, materials science, drug discovery, and catalysis. Many of the current applications of boronic acids and esters require materials with very low levels of transition metal contamination. Most of the current methods for the synthesis of boronic acids, however, require transition metal catalysts and ligands that must be removed via additional purification procedures. This protocol describes a simple, metal- and additive-free method of conversion of haloarenes directly to boronic acids and esters. This photoinduced borylation protocol does not require expensive and toxic metal catalysts or ligands, and it produces innocuous and easy-to-remove by-products. Furthermore, the reaction can be carried out on multigram scales in common-grade solvents without the need for reaction mixtures to be deoxygenated. The setup and purification steps are typically accomplished within 1-3 h. The reactions can be run overnight, and the protocol can be completed within 13-16 h. Two representative procedures that are described in this protocol provide details for preparation of a boronic acid (3-cyanopheylboronic acid) and a boronic ester (1,4-benzenediboronic acid bis(pinacol)ester). We also discuss additional details of the method that will be helpful in the application of the protocol to other haloarene substrates.

New method to monitor RF safety in MRI-guided interventions based on RF induced image artefacts.

PubMed

van den Bosch, Michiel R; Moerland, Marinus A; Lagendijk, Jan J W; Bartels, Lambertus W; van den Berg, Cornelis A T

2010-02-01

Serious tissue heating may occur at the tips of elongated metallic structures used in MRI-guided interventions, such as vascular guidewires, catheters, biopsy needles, and brachytherapy needles. This heating is due to resonating electromagnetic radiofrequency (RF) waves along the structure. Since it is hard to predict the exact length at which resonance occurs under in vivo conditions, there is a need for methods to monitor this resonance behavior. In this study, the authors propose a method based on the RF induced image artefacts and demonstrate its applicability in two phantom experiments. The authors developed an analytical model that describes the RF induced image artefacts as a function of the induced current in an elongated metallic structure placed parallel to the static magnetic field. It describes the total RF field as a sum of the RF fields produced by the transmit coil of the MR scanner and by the elongated metallic structure. Several spoiled gradient echo images with different nominal flip angle settings were acquired to map the B1+ field, which is a quantitative measure for the RF distortion around the structure. From this map, the current was extracted by fitting the analytical model. To investigate the sensitivity of our method we performed two phantom experiments with different setup parameters: One that mimics a brachytherapy needle insertion and one that resembles a guidewire intervention. In the first experiment, a short needle was placed centrally in the MR bore to ensure that the induced currents would be small. In the second experiment, a longer wire was placed in an off-center position to mimic a worst case scenario for the patient. In both experiments, a Luxtron (Santa Clara, CA) fiberoptic temperature sensor was positioned at the structure tip to record the temperature. In the first experiment, no significant temperature increases were measured, while the RF image artefacts and the induced currents in the needle increased with the applied insertion depth. The maximum induced current in the needle was 44 mA. Furthermore, a standing wave pattern became clearly visible for larger insertion depths. In the second experiment, significant temperature increases up to 2.4 degrees C in 1 min were recorded during the image acquisitions. The maximum current value was 1.4 A. In both experiments, a proper estimation of the current in the metallic structure could be made using our analytical model. The authors have developed a method to quantitatively determine the induced current in an elongated metallic structure from its RF distortion. This creates a powerful and sensitive method to investigate the resonant behavior of RF waves along elongated metallic structures used for MRI-guided interventions, for example, to monitor the RF safety or to inspect the influence of coating on the resonance length. Principally, it can be applied under in vivo conditions and for noncylindrical metallic structures such as hip implants by taking their geometry into account.

Composite Flexible Blanket Insulation

NASA Technical Reports Server (NTRS)

Kourtides, Demetrius A. (Inventor); Pitts, William C. (Inventor); Goldstein, Howard E. (Inventor); Sawko, Paul M. (Inventor)

1991-01-01

Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with the currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems are useful in providing lightweight insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

Magnetic resonance-guided prostate interventions.

PubMed

Haker, Steven J; Mulkern, Robert V; Roebuck, Joseph R; Barnes, Agnieska Szot; Dimaio, Simon; Hata, Nobuhiko; Tempany, Clare M C

2005-10-01

We review our experience using an open 0.5-T magnetic resonance (MR) interventional unit to guide procedures in the prostate. This system allows access to the patient and real-time MR imaging simultaneously and has made it possible to perform prostate biopsy and brachytherapy under MR guidance. We review MR imaging of the prostate and its use in targeted therapy, and describe our use of image processing methods such as image registration to further facilitate precise targeting. We describe current developments with a robot assist system being developed to aid radioactive seed placement.

ELECTROMAGNETIC STIRRING IN ZONE REFINING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braun, I.; Frank, F.C.; Marshall, S.

1958-02-01

The efficiency of the zone refining process can obviously be increased by stirring the molten zone to disperse the impurity-rich layer at the solid- liquid surface. Induction heating is sometimes preferred to radiant heat because it produces more convection, but no marked improvement has been reported. Pfann and Dorsi(1967) have described a method of stirring the melt by passing an electric current through the ingot and compressing a magnetic field across the molten zone. Preliminary results obtained by using a rotating magnetic field us the stirring agent during the purification of aluminum are described. (A.C.)

A novel technique for fetal heart rate estimation from Doppler ultrasound signal

PubMed Central

2011-01-01

Background The currently used fetal monitoring instrumentation that is based on Doppler ultrasound technique provides the fetal heart rate (FHR) signal with limited accuracy. It is particularly noticeable as significant decrease of clinically important feature - the variability of FHR signal. The aim of our work was to develop a novel efficient technique for processing of the ultrasound signal, which could estimate the cardiac cycle duration with accuracy comparable to a direct electrocardiography. Methods We have proposed a new technique which provides the true beat-to-beat values of the FHR signal through multiple measurement of a given cardiac cycle in the ultrasound signal. The method consists in three steps: the dynamic adjustment of autocorrelation window, the adaptive autocorrelation peak detection and determination of beat-to-beat intervals. The estimated fetal heart rate values and calculated indices describing variability of FHR, were compared to the reference data obtained from the direct fetal electrocardiogram, as well as to another method for FHR estimation. Results The results revealed that our method increases the accuracy in comparison to currently used fetal monitoring instrumentation, and thus enables to calculate reliable parameters describing the variability of FHR. Relating these results to the other method for FHR estimation we showed that in our approach a much lower number of measured cardiac cycles was rejected as being invalid. Conclusions The proposed method for fetal heart rate determination on a beat-to-beat basis offers a high accuracy of the heart interval measurement enabling reliable quantitative assessment of the FHR variability, at the same time reducing the number of invalid cardiac cycle measurements. PMID:21999764

Comparison of traditional nondestructive analysis of RERTR fuel plates with digital radiographic techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidsmeier, T.; Koehl, R.; Lanham, R.

2008-07-15

The current design and fabrication process for RERTR fuel plates utilizes film radiography during the nondestructive testing and characterization. Digital radiographic methods offer a potential increases in efficiency and accuracy. The traditional and digital radiographic methods are described and demonstrated on a fuel plate constructed with and average of 51% by volume fuel using the dispersion method. Fuel loading data from each method is analyzed and compared to a third baseline method to assess accuracy. The new digital method is shown to be more accurate, save hours of work, and provide additional information not easily available in the traditional method.more » Additional possible improvements suggested by the new digital method are also raised. (author)« less

Current and future molecular diagnostics for ocular infectious diseases.

PubMed

Doan, Thuy; Pinsky, Benjamin A

2016-11-01

Confirmation of ocular infections can pose great challenges to the clinician. A fundamental limitation is the small amounts of specimen that can be obtained from the eye. Molecular diagnostics can circumvent this limitation and have been shown to be more sensitive than conventional culture. The purpose of this review is to describe new molecular methods and to discuss the applications of next-generation sequencing-based approaches in the diagnosis of ocular infections. Efforts have focused on improving the sensitivity of pathogen detection using molecular methods. This review describes a new molecular target for Toxoplasma gondii-directed polymerase chain reaction assays. Molecular diagnostics for Chlamydia trachomatis and Acanthamoeba species are also discussed. Finally, we describe a hypothesis-free approach, metagenomic deep sequencing, which can detect DNA and RNA pathogens from a single specimen in one test. In some cases, this method can provide the geographic location and timing of the infection. Pathogen-directed PCRs have been powerful tools in the diagnosis of ocular infections for over 20 years. The use of next-generation sequencing-based approaches, when available, will further improve sensitivity of detection with the potential to improve patient care.

Fractal propagation method enables realistic optical microscopy simulations in biological tissues

PubMed Central

Glaser, Adam K.; Chen, Ye; Liu, Jonathan T.C.

2017-01-01

Current simulation methods for light transport in biological media have limited efficiency and realism when applied to three-dimensional microscopic light transport in biological tissues with refractive heterogeneities. We describe here a technique which combines a beam propagation method valid for modeling light transport in media with weak variations in refractive index, with a fractal model of refractive index turbulence. In contrast to standard simulation methods, this fractal propagation method (FPM) is able to accurately and efficiently simulate the diffraction effects of focused beams, as well as the microscopic heterogeneities present in tissue that result in scattering, refractive beam steering, and the aberration of beam foci. We validate the technique and the relationship between the FPM model parameters and conventional optical parameters used to describe tissues, and also demonstrate the method’s flexibility and robustness by examining the steering and distortion of Gaussian and Bessel beams in tissue with comparison to experimental data. We show that the FPM has utility for the accurate investigation and optimization of optical microscopy methods such as light-sheet, confocal, and nonlinear microscopy. PMID:28983499

Silicon solar cell process development, fabrication and analysis

NASA Technical Reports Server (NTRS)

Minahan, J. A.

1981-01-01

The fabrication of solar cells from several unconventional silicon materials is described, and cell performance measured and analyzed. Unconventional materials evaluated are edge defined film fed grown (EFG), heat exchanger method (HEM), dendritic web grown, and continuous CZ silicons. Resistivity, current voltage, and spectral sensitivity of the cells were measured. Current voltage was measured under AM0 and AM1 conditions. Maximum conversion efficiencies of cells fabricated from these and other unconventional silicons were compared and test results analyzed. The HEM and continuous CZ silicon were found to be superior to silicon materials considered previously.

The applications of nanotechnology in food industry.

PubMed

Rashidi, Ladan; Khosravi-Darani, Kianoush

2011-09-01

Nanotechnology has the potential of application in the food industry and processing as new tools for pathogen detection, disease treatment delivery systems, food packaging, and delivery of bioactive compounds to target sites. The application of nanotechnology in food systems will provide new methods to improve safety and the nutritional value of food products. This article will review the current advances of applications of nanotechnology in food science and technology. Also, it describes new current food laws for nanofood and novel articles in the field of risk assessment of using nanotechnology in the food industry.

Circular current loops, magnetic dipoles and spherical harmonic analysis.

USGS Publications Warehouse

Alldredge, L.R.

1980-01-01

Spherical harmonic analysis (SHA) is the most used method of describing the Earth's magnetic field, even though spherical harmonic coefficients (SHC) almost completely defy interpretation in terms of real sources. Some moderately successful efforts have been made to represent the field in terms of dipoles placed in the core in an effort to have the model come closer to representing real sources. Dipole sources are only a first approximation to the real sources which are thought to be a very complicated network of electrical currents in the core of the Earth. -Author

A Gas-Kinetic Scheme for Reactive Flows

NASA Technical Reports Server (NTRS)

Lian,Youg-Sheng; Xu, Kun

1998-01-01

In this paper, the gas-kinetic BGK scheme for the compressible flow equations is extended to chemical reactive flow. The mass fraction of the unburnt gas is implemented into the gas kinetic equation by assigning a new internal degree of freedom to the particle distribution function. The new variable can be also used to describe fluid trajectory for the nonreactive flows. Due to the gas-kinetic BGK model, the current scheme basically solves the Navier-Stokes chemical reactive flow equations. Numerical tests validate the accuracy and robustness of the current kinetic method.

Noninvasive techniques for probing neurocircuitry and treating illness: vagus nerve stimulation (VNS), transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS)

PubMed Central

George, Mark S; Aston-Jones, Gary

2010-01-01

Although the preceding chapters discuss much of the new knowledge of neurocircuitry of neuropsychiatric diseases, and an invasive approach to treatment, this chapter describes and reviews the noninvasive methods of testing circuit-based theories and treating neuropsychiatric diseases that do not involve implanting electrodes into the brain or on its surface. These techniques are transcranial magnetic stimulation, vagus nerve stimulation, and transcranial direct current stimulation. Two of these approaches have FDA approval as therapies. PMID:19693003

Optimization of multifocal transcranial current stimulation for weighted cortical pattern targeting from realistic modeling of electric fields

PubMed Central

Ruffini, Giulio; Fox, Michael D.; Ripolles, Oscar; Miranda, Pedro Cavaleiro; Pascual-Leone, Alvaro

2014-01-01

Recently, multifocal transcranial current stimulation (tCS) devices using several relatively small electrodes have been used to achieve more focal stimulation of specific cortical targets. However, it is becoming increasingly recognized that many behavioral manifestations of neurological and psychiatric disease are not solely the result of abnormality in one isolated brain region but represent alterations in brain networks. In this paper we describe a method for optimizing the configuration of multifocal tCS for stimulation of brain networks, represented by spatially extended cortical targets. We show how, based on fMRI, PET, EEG or other data specifying a target map on the cortical surface for excitatory, inhibitory or neutral stimulation and a constraint of the maximal number of electrodes, a solution can be produced with the optimal currents and locations of the electrodes. The method described here relies on a fast calculation of multifocal tCS electric fields (including components normal and tangential to the cortical boundaries) using a five layer finite element model of a realistic head. Based on the hypothesis that the effects of current stimulation are to first order due to the interaction of electric fields with populations of elongated cortical neurons, it is argued that the optimization problem for tCS stimulation can be defined in terms of the component of the electric field normal to the cortical surface. Solutions are found using constrained least squares to optimize current intensities, while electrode number and their locations are selected using a genetic algorithm. For direct current tCS (tDCS) applications, we provide some examples of this technique using an available tCS system providing 8 small Ag/AgCl stimulation electrodes. We demonstrate the approach both for localized and spatially extended targets defined using rs-fcMRI and PET data, with clinical applications in stroke and depression. Finally, we extend these ideas to more general stimulation protocols, such as alternating current tCS (tACS). PMID:24345389

How [NOT] to Measure a Solar Cell to Get the Highest Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Emery, Keith

The multibillion-dollar photovoltaic (PV) industry sells products by the watt; the calibration labs measure this parameter at the cell and module level with the lowest possible uncertainty of 1-2 percent. The methods and procedures to achieve a measured 50 percent efficiency on a thin-film solar cell are discussed. This talk will describe methods that ignore procedures that increase the uncertainty. Your questions will be answered concerning 'Everything you Always Wanted to Know about Efficiency Enhancements But Were Afraid to Ask.' The talk will cover a step-by-step procedure using examples found in literature or encountered in customer samples by the Nationalmore » Renewable Energy Laboratory's (NREL's) PV Performance Characterization Group on how to artificially enhance the efficiency. The procedures will describe methods that have been used to enhance the current voltage and fill factor.« less

Update on hypertrophic scar treatment

PubMed Central

Rabello, Felipe Bettini; Souza, Cleyton Dias; Júnior, Jayme Adriano Farina

2014-01-01

Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin. PMID:25141117

A General Architecture for Intelligent Tutoring of Diagnostic Classification Problem Solving

PubMed Central

Crowley, Rebecca S.; Medvedeva, Olga

2003-01-01

We report on a general architecture for creating knowledge-based medical training systems to teach diagnostic classification problem solving. The approach is informed by our previous work describing the development of expertise in classification problem solving in Pathology. The architecture envelops the traditional Intelligent Tutoring System design within the Unified Problem-solving Method description Language (UPML) architecture, supporting component modularity and reuse. Based on the domain ontology, domain task ontology and case data, the abstract problem-solving methods of the expert model create a dynamic solution graph. Student interaction with the solution graph is filtered through an instructional layer, which is created by a second set of abstract problem-solving methods and pedagogic ontologies, in response to the current state of the student model. We outline the advantages and limitations of this general approach, and describe it’s implementation in SlideTutor–a developing Intelligent Tutoring System in Dermatopathology. PMID:14728159

An Exact Formula for Calculating Inverse Radial Lens Distortions

PubMed Central

Drap, Pierre; Lefèvre, Julien

2016-01-01

This article presents a new approach to calculating the inverse of radial distortions. The method presented here provides a model of reverse radial distortion, currently modeled by a polynomial expression, that proposes another polynomial expression where the new coefficients are a function of the original ones. After describing the state of the art, the proposed method is developed. It is based on a formal calculus involving a power series used to deduce a recursive formula for the new coefficients. We present several implementations of this method and describe the experiments conducted to assess the validity of the new approach. Such an approach, non-iterative, using another polynomial expression, able to be deduced from the first one, can actually be interesting in terms of performance, reuse of existing software, or bridging between different existing software tools that do not consider distortion from the same point of view. PMID:27258288

Rapid polymerase chain reaction diagnosis of white-nose syndrome in bats

USGS Publications Warehouse

Lorch, J.M.; Gargas, A.; Meteyer, C.U.; Berlowski-Zier, B. M.; Green, D.E.; Shearn-Bochsler, V.; Thomas, N.J.; Blehert, D.S.

2010-01-01

A newly developed polymerase chain reaction (PCR)-based method to rapidly and specifically detect Geomyces destructans on the wings of infected bats from small quantities (1-2 mg) of tissue is described in the current study (methods for culturing and isolating G. destructans from bat skin are also described). The lower limits of detection for PCR were 5 fg of purified fungal DNA or 100 conidia per 2 mg of wing tissue. By using histology as the standard, the PCR had a diagnostic specificity of 100% and a diagnostic sensitivity of 96%, whereas the diagnostic sensitivity of culture techniques was only 54%. The accuracy and fast turnaround time of PCR provides field biologists with valuable information on infection status more rapidly than traditional methods, and the small amount of tissue required for the test would allow diagnosis of white-nose syndrome in live animals.

Eddy current compensation for delta relaxation enhanced MR by dynamic reference phase modulation.

PubMed

Hoelscher, Uvo Christoph; Jakob, Peter M

2013-04-01

Eddy current compensation by dynamic reference phase modulation (eDREAM) is a compensation method for eddy current fields induced by B 0 field-cycling which occur in delta relaxation enhanced MR (dreMR) imaging. The presented method is based on a dynamic frequency adjustment and prevents eddy current related artifacts. It is easy to implement and can be completely realized in software for any imaging sequence. In this paper, the theory of eDREAM is derived and two applications are demonstrated. The theory describes how to model the behavior of the eddy currents and how to implement the compensation. Phantom and in vivo measurements are carried out and demonstrate the benefits of eDREAM. A comparison of images acquired with and without eDREAM shows a significant improvement in dreMR image quality. Images without eDREAM suffer from severe artifacts and do not allow proper interpretation while images with eDREAM are artifact free. In vivo experiments demonstrate that dreMR imaging without eDREAM is not feasible as artifacts completely change the image contrast. eDREAM is a flexible eddy current compensation for dreMR. It is capable of completely removing the influence of eddy currents such that the dreMR images do not suffer from artifacts.

Forecasting of the electrical actuators condition using stator’s current signals

NASA Astrophysics Data System (ADS)

Kruglova, T. N.; Yaroshenko, I. V.; Rabotalov, N. N.; Melnikov, M. A.

2017-02-01

This article describes a forecasting method for electrical actuators realized through the combination of Fourier transformation and neural network techniques. The method allows finding the value of diagnostic functions in the iterating operating cycle and the number of operational cycles in time before the BLDC actuator fails. For forecasting of the condition of the actuator, we propose a hierarchical structure of the neural network aiming to reduce the training time of the neural network and improve estimation accuracy.

Catalysts and methods for converting carbonaceous materials to fuels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hensley, Jesse; Ruddy, Daniel A.; Schaidle, Joshua A.

This disclosure relates to catalysts and processes designed to convert DME and/or methanol and hydrogen (H.sub.2) to desirable liquid fuels. These catalysts produce the fuels efficiently and with a high selectivity and yield, and reduce the formation of aromatic hydrocarbons by incorporating H.sub.2 into the products. This disclosure also describes process methods to further upgrade these fuels to higher molecular weight liquid fuel mixtures, which have physical properties comparable with current commercially used liquid fuels.

MRIVIEW: An interactive computational tool for investigation of brain structure and function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ranken, D.; George, J.

MRIVIEW is a software system which uses image processing and visualization to provide neuroscience researchers with an integrated environment for combining functional and anatomical information. Key features of the software include semi-automated segmentation of volumetric head data and an interactive coordinate reconciliation method which utilizes surface visualization. The current system is a precursor to a computational brain atlas. We describe features this atlas will incorporate, including methods under development for visualizing brain functional data obtained from several different research modalities.

Combined quantum and molecular mechanics (QM/MM).

PubMed

Friesner, Richard A

2004-12-01

We describe the current state of the art of mixed quantum mechanics/molecular mechanics (QM/MM) methodology, with a particular focus on modeling of enzymatic reactions. Over the past decade, the effectiveness of these methods has increased dramatically, based on improved quantum chemical methods, advances in the description of the QM/MM interface, and reductions in the cost/performance of computing hardware. Two examples of pharmaceutically relevant applications, cytochrome P450 and class C β-lactamase, are presented.: © 2004 Elsevier Ltd . All rights reserved.

Instrumentation for measuring lake and reservoir evaporation by the energy-budget and mass-transfer methods

USGS Publications Warehouse

Sturrock, A.M.

1985-01-01

Instrumentation currently used by the U.S. Geological Survey in studies of lake and reservoir evaporation is described in this paper. This instrumentation is used for the measurement of solar and terrestrial energy necessary to apply the mass-transfer or energy budget methods. The energy budget requires a quantative determination of all form of energy entering or leaving the lake as well as determination of the change in storage of energy within the lake. (USGS)

Reef Fish Survey Techniques: Assessing the Potential for Standardizing Methodologies.

PubMed

Caldwell, Zachary R; Zgliczynski, Brian J; Williams, Gareth J; Sandin, Stuart A

2016-01-01

Dramatic changes in populations of fishes living on coral reefs have been documented globally and, in response, the research community has initiated efforts to assess and monitor reef fish assemblages. A variety of visual census techniques are employed, however results are often incomparable due to differential methodological performance. Although comparability of data may promote improved assessment of fish populations, and thus management of often critically important nearshore fisheries, to date no standardized and agreed-upon survey method has emerged. This study describes the use of methods across the research community and identifies potential drivers of method selection. An online survey was distributed to researchers from academic, governmental, and non-governmental organizations internationally. Although many methods were identified, 89% of survey-based projects employed one of three methods-belt transect, stationary point count, and some variation of the timed swim method. The selection of survey method was independent of the research design (i.e., assessment goal) and region of study, but was related to the researcher's home institution. While some researchers expressed willingness to modify their current survey protocols to more standardized protocols (76%), their willingness decreased when methodologies were tied to long-term datasets spanning five or more years. Willingness to modify current methodologies was also less common among academic researchers than resource managers. By understanding both the current application of methods and the reported motivations for method selection, we hope to focus discussions towards increasing the comparability of quantitative reef fish survey data.

Mitigation of stress: new treatment alternatives.

PubMed

Subhani, Ahmad Rauf; Kamel, Nidal; Mohamad Saad, Mohamad Naufal; Nandagopal, Nanda; Kang, Kenneth; Malik, Aamir Saeed

2018-02-01

Complaints of stress are common in modern life. Psychological stress is a major cause of lifestyle-related issues, contributing to poor quality of life. Chronic stress impedes brain function, causing impairment of many executive functions, including working memory, decision making and attentional control. The current study sought to describe newly developed stress mitigation techniques, and their influence on autonomic and endocrine functions. The literature search revealed that the most frequently studied technique for stress mitigation was biofeedback (BFB). However, evidence suggests that neurofeedback (NFB) and noninvasive brain stimulation (NIBS) could potentially provide appropriate approaches. We found that recent studies of BFB methods have typically used measures of heart rate variability, respiration and skin conductance. In contrast, studies of NFB methods have typically utilized neurocomputation techniques employing electroencephalography, functional magnetic resonance imaging and near infrared spectroscopy. NIBS studies have typically utilized transcranial direct current stimulation methods. Mitigation of stress is a challenging but important research target for improving quality of life.

Indirect rotor position sensing in real time for brushless permanent magnet motor drives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ertugrul, N.; Acarnley, P.P.

1998-07-01

This paper describes a modern solution to real-time rotor position estimation of brushless permanent magnet (PM) motor drives. The position estimation scheme, based on flux linkage and line-current estimation, is implemented in real time by using the abc reference frame, and it is tested dynamically. The position estimation model of the test motor, development of hardware, and basic operation of the digital signal processor (DSP) are discussed. The overall position estimation strategy is accomplished with a fast DSP (TMS320C30). The method is a shaft position sensorless method that is applicable to a wide range of excitation types in brushless PMmore » motors without any restriction on the motor model and the current excitation. Both rectangular and sinewave-excited brushless PM motor drives are examined, and the results are given to demonstrate the effectiveness of the method with dynamic loads in closed estimated position loop.« less

Investigation of conductive thermal control coatings by a contactless method in vacuo

NASA Technical Reports Server (NTRS)

Viehmann, W.; Shai, C. M.; Sanford, E. L.

1977-01-01

A technique for determining the conductance per unit area of thermal control coatings for electrostatically clean spacecraft is described. In order to simulate orbital conditions more closely, current-density-voltage (j-V) curves are obtained by a contactless method in which the paint on an aluminum substrate is the anode of a vacuum diode configuration with a tungsten filament cathode. Conductances per unit area which satisfy the International Sun Earth Explorer (ISEE) requirement were observed on black paints containing carbon and in white and green paints filled with zinc oxide which were fired in order to induce defect conductivity. Because of surface effects and the nonhomogeneous nature of paints, large discrepancies were found between measurements with the contactless method and measurements employing metallic contacts, particularly at low current densities. Therefore, measurements with metallic contacts are considered to be of questionable value in deciding the suitability of coatings for electrostatic charge control.

A Structured Peer-Mentoring Method for Physical Activity Behavior Change Among Adolescents.

PubMed

Smith, Laureen H; Petosa, Rick L

2016-10-01

Despite national guidelines for regular physical activity, most adolescents are not physically active. Schools serve an estimated 60 million youth and provide an educational environment to meet the current physical activity guidelines. The obesity epidemic and chronic disease comorbidities associated with physical inactivity are not likely to be reversed without a strong contribution from local schools. This article describes how a structured peer-mentoring method provides a feasible, flexible, and tailored means to meet the current guidelines for best practice in a school setting. Structured peer mentoring using trained high school mentors to support behavior change in younger peers is an innovative method to meeting the School Health Guidelines to Promote Healthy Eating and Physical Activity Through structured peer mentoring, adolescents are provided consistent social support in a caring and personalized manner. This support builds skills and competencies enhancing self-efficacy to sustain a lifetime of physical activity behavior. © The Author(s) 2016.

A Structured Peer-Mentoring Method for Physical Activity Behavior Change Among Adolescents

PubMed Central

Smith, Laureen H.; Petosa, Rick L.

2016-01-01

Despite national guidelines for regular physical activity, most adolescents are not physically active. Schools serve an estimated 60 million youth and provide an educational environment to meet the current physical activity guidelines. The obesity epidemic and chronic disease comorbidities associated with physical inactivity are not likely to be reversed without a strong contribution from local schools. This article describes how a structured peer-mentoring method provides a feasible, flexible, and tailored means to meet the current guidelines for best practice in a school setting. Structured peer mentoring using trained high school mentors to support behavior change in younger peers is an innovative method to meeting the School Health Guidelines to Promote Healthy Eating and Physical Activity. Through structured peer mentoring, adolescents are provided consistent social support in a caring and personalized manner. This support builds skills and competencies enhancing self-efficacy to sustain a lifetime of physical activity behavior. PMID:27257081