Science.gov

Sample records for abstract current methods

  1. Geothermal Energy: Current abstracts

    SciTech Connect

    Ringe, A.C.

    1988-02-01

    This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

  2. Current Abstracts Nuclear Reactors and Technology

    SciTech Connect

    Bales, J.D.; Hicks, S.C.

    1993-01-01

    This publication Nuclear Reactors and Technology (NRT) announces on a monthly basis the current worldwide information available from the open literature on nuclear reactors and technology, including all aspects of power reactors, components and accessories, fuel elements, control systems, and materials. This publication contains the abstracts of DOE reports, journal articles, conference papers, patents, theses, and monographs added to the Energy Science and Technology Database during the past month. Also included are US information obtained through acquisition programs or interagency agreements and international information obtained through acquisition programs or interagency agreements and international information obtained through the International Energy Agency`s Energy Technology Data Exchange or government-to-government agreements. The digests in NRT and other citations to information on nuclear reactors back to 1948 are available for online searching and retrieval on the Energy Science and Technology Database and Nuclear Science Abstracts (NSA) database. Current information, added daily to the Energy Science and Technology Database, is available to DOE and its contractors through the DOE Integrated Technical Information System. Customized profiles can be developed to provide current information to meet each user`s needs.

  3. Eddy-current analysis of isolated permanent-magnet drives using two- and three-dimensional finite-element methods (abstract)

    NASA Astrophysics Data System (ADS)

    Ferreira, C. A.

    1990-05-01

    Present drive systems which rely on mechanical devices for torque transmission have some negative features: the driven component cannot be isolated from the drive motor, rotating seals have inherent leakage and friction problems, and mechanical failures often occur due to torque overloads. Magnetic couplings are especially well suited for use in isolated-drive systems. This is often the case in military and aerospace applications where pumps and compressors are vital parts of the thermal and fuel operating systems. The application of permanent-magnet couplings in isolated drives requires accurate calculation of the eddy-current losses induced on the hermetic vessel. This is because the losses along with the required output torque dictate the size and efficiency of the permanent-magnet coupling. The vessel isolates the drive member from the driven member of the turbocompressor. The paper will show the formulation of the computational method based on the Poynting-vector theorem and the concept of motional electric field intensity. The eddy-current losses are calculated using two- and three-dimensional magnetostatic finite-element (FE) analysis. A comparison of the results obtained by two- and three-dimensional FE analysis is made. The results of the analysis will be compared to test data for verification. The test-facility setup and procedure will also be described. This state-of-the-art technique for computation of eddy-current losses has several advantages over conventional analysis methods: the nonlinearities of the magnetic circuit are taken into account, magnetic field fringing and end-leakage effects are not neglected, and the method does not rely on the use of empirical factors. The significant benefits of this approach are that trial-and-error experimental design approaches are eliminated and test data provide validation of analytical results.

  4. Implementing abstract multigrid or multilevel methods

    NASA Technical Reports Server (NTRS)

    Douglas, Craig C.

    1993-01-01

    Multigrid methods can be formulated as an algorithm for an abstract problem that is independent of the partial differential equation, domain, and discretization method. In such an abstract setting, problems not arising from partial differential equations can be treated. A general theory exists for linear problems. The general theory was motivated by a series of abstract solvers (Madpack). The latest version was motivated by the theory. Madpack now allows for a wide variety of iterative and direct solvers, preconditioners, and interpolation and projection schemes, including user callback ones. It allows for sparse, dense, and stencil matrices. Mildly nonlinear problems can be handled. Also, there is a fast, multigrid Poisson solver (two and three dimensions). The type of solvers and design decisions (including language, data structures, external library support, and callbacks) are discussed. Based on the author's experiences with two versions of Madpack, a better approach is proposed. This is based on a mixed language formulation (C and FORTRAN + preprocessor). Reasons for not using FORTRAN, C, or C++ (individually) are given. Implementing the proposed strategy is not difficult.

  5. [Special methodology, qualitative methods and abstract concepts].

    PubMed

    Delgado, Ana R

    2010-08-01

    Generally speaking, this paper comments on the role of qualitative methods in scientific psychology. To begin with, general and special methodology are defined; then, the main uses of qualitative methods are described and the focus of the paper on the study of meaning and of abstract concepts in the context of embodied cognition is justified. It is emphasized that three uses of qualitative methods converge in the study of embodied cognition: (1) classification, given that it is centered on concepts, (2) discovery, because theories are not yet well articulated and inductive effort is required, and (3) the study of meaning. The final recommendation is to profit from the opportunity of constructing special techniques that the transformation of cognitive psychology is favoring; in this context, varieties of emotion become a privileged object of study.

  6. Current Literature on Venereal Disease, 1972. Number One. Abstracts and Bibliography.

    ERIC Educational Resources Information Center

    Lea, Mildred V., Ed.

    Presented are abstracts of documents and research pertaining to the clinical description, laboratory diagnosis, management, and therapy of syphilis and gonorrhea. Abstracted case studies of other minor venereal and related diseases are also included, as are bibliographies on current research and evaluation, public health methods, and behavioral…

  7. Current Literature on Venereal Disease, 1972. Number Two. Abstracts and Bibliography.

    ERIC Educational Resources Information Center

    Lea, Mildred V., Ed.

    Presented are abstracts of documents and research pertaining to the clinical description, laboratory diagnosis, management, and therapy of syphilis and gonorrhea. Abstracted case studies of other minor venereal and related diseases are also included, as are bibliographies on current research and evaluation, public health methods, and behavioral…

  8. Current Literature on Venereal Disease, 1972. Number Three. Abstracts and Bibliography.

    ERIC Educational Resources Information Center

    Lea, Mildred V., Ed.

    Presented are abstracts of documents and research pertaining to the clinical description, laboratory diagnosis, management, and therapy of syphilis and gonorrhea. Abstracted case studies of other minor venereal and related diseases are also included, as are bibliographies on current research and evaluation, public health methods, and behavioral…

  9. Abstracts

    ERIC Educational Resources Information Center

    American Biology Teacher, 1977

    1977-01-01

    Included are over 50 abstracts of papers being presented at the 1977 National Association of Biology Teachers Convention. Included in each abstract are the title, author, and summary of the paper. Topics include photographic techniques environmental studies, and biological instruction. (MA)

  10. Extended abstract: Partial row projection methods

    SciTech Connect

    Bramley, R.; Lee, Y.

    1996-12-31

    Accelerated row projection (RP) algorithms for solving linear systems Ax = b are a class of iterative methods which in theory converge for any nonsingular matrix. RP methods are by definition ones that require finding the orthogonal projection of vectors onto the null space of block rows of the matrix. The Kaczmarz form, considered here because it has a better spectrum for iterative methods, has an iteration matrix that is the product of such projectors. Because straightforward Kaczmarz method converges slowly for practical problems, typically an outer CG acceleration is applied. Definiteness, symmetry, or localization of the eigenvalues, of the coefficient matrix is not required. In spite of this robustness, work has generally been limited to structured systems such as block tridiagonal matrices because unlike many iterative solvers, RP methods cannot be implemented by simply supplying a matrix-vector multiplication routine. Finding the orthogonal projection of vectors onto the null space of block rows of the matrix in practice requires accessing the actual entries in the matrix. This report introduces a new partial RP algorithm which retains advantages of the RP methods.

  11. A method for automatically abstracting visual documents

    NASA Technical Reports Server (NTRS)

    Rorvig, Mark E.

    1994-01-01

    Visual documents--motion sequences on film, videotape, and digital recording--constitute a major source of information for the Space Agency, as well as all other government and private sector entities. This article describes a method for automatically selecting key frames from visual documents. These frames may in turn be used to represent the total image sequence of visual documents in visual libraries, hypermedia systems, and training algorithm reduces 51 minutes of video sequences to 134 frames; a reduction of information in the range of 700:1.

  12. Development of a Computerized Current Awareness Service Using "Chemical Abstracts" Condensates

    ERIC Educational Resources Information Center

    Roberts, Anita B.; And Others

    1972-01-01

    The experiences in developing current awareness services for selective dissemination of information from Chemical Abstracts'' Condensates data base are described. File standardization, the weighted-term method of searching, and the algorithm used to perform the search on the CDC 6600 computer and a user survey are discussed. (2 references)…

  13. Methods for solving reasoning problems in abstract argumentation - A survey.

    PubMed

    Charwat, Günther; Dvořák, Wolfgang; Gaggl, Sarah A; Wallner, Johannes P; Woltran, Stefan

    2015-03-01

    Within the last decade, abstract argumentation has emerged as a central field in Artificial Intelligence. Besides providing a core formalism for many advanced argumentation systems, abstract argumentation has also served to capture several non-monotonic logics and other AI related principles. Although the idea of abstract argumentation is appealingly simple, several reasoning problems in this formalism exhibit high computational complexity. This calls for advanced techniques when it comes to implementation issues, a challenge which has been recently faced from different angles. In this survey, we give an overview on different methods for solving reasoning problems in abstract argumentation and compare their particular features. Moreover, we highlight available state-of-the-art systems for abstract argumentation, which put these methods to practice.

  14. Sessions with Associated Abstracts by Day: Teaching Materials and Methods.

    ERIC Educational Resources Information Center

    Physiologist, 1984

    1984-01-01

    Presented are abstracts of five papers on teaching materials/methods presented at the 35th annual meeting of the American Physiological Society. Topic areas include expert system used as a teacher/consultant in hemostasis problems, computer assisted testing, and excitation/conduction properties of membranes as illustrated by the compound action…

  15. Numerical methods and measurement systems for nonlinear magnetic circuits (abstract)

    NASA Astrophysics Data System (ADS)

    Heitbrink, Axel; Dieter Storzer, Hans; Beyer, Adalbert

    1994-05-01

    In the past years an increasing interest in calculation methods of circuits containing magnetic nonlinearities could be observed. For this reason a new method was developed which makes it possible to calculate the steady state solution of such circuits by the help of an interactive cad program. The modular concept of the software allows to separate the circuit into nonlinear and linear subnetworks. When regarding nonlinear magnetic elements one can choose between several numerical models for the description of the hysteresis loops or an inbuilt realtime measurement system can be activated to get the dynamic hysteresis loops. The measurement system is also helpful for the parameter extraction for the numerical hysteresis models. A modified harmonic-balance algorithm and a set of iteration schemes is used for solving the network function. The combination of the realtime measurement system and modern numerical methods brings up a productive total concept for the exact calculation of nonlinear magnetic circuits. A special application class will be discussed which is given by earth-leakage circuit breakers. These networks contain a toroidal high permeable NiFe alloy and a relay as nonlinear elements (cells) and some resistors, inductors, and capacitors as linear elements. As input dc signals at the primary winding of the core any curveform must be regarded, especially 135° phasecutted pulses. These signals with extreme higher frequency components make it impossible to use numerical models for the description of the nonlinear behavior of the core and the relays. So for both elements the realtime measurement system must be used during the iteration process. During each iteration step the actual magnetization current is sent to the measurement system, which measures the dynamic hysteresis loop at the probe. These values flow back into the iteration process. A graphic subsystem allows a look at the waveforms of all voltages and current when the iterations take place. One

  16. Non-Traditional Methods of Teaching Abstract Algebra

    ERIC Educational Resources Information Center

    Capaldi, Mindy

    2014-01-01

    This article reports on techniques of teaching abstract algebra which were developed to achieve multiple student objectives: reasoning and communication skills, deep content knowledge, student engagement, independence, and pride. The approach developed included a complementary combination of inquiry-based learning, individual (not group) homework…

  17. 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.

  18. Kernel current source density method.

    PubMed

    Potworowski, Jan; Jakuczun, Wit; Lȩski, Szymon; Wójcik, Daniel

    2012-02-01

    Local field potentials (LFP), the low-frequency part of extracellular electrical recordings, are a measure of the neural activity reflecting dendritic processing of synaptic inputs to neuronal populations. To localize synaptic dynamics, it is convenient, whenever possible, to estimate the density of transmembrane current sources (CSD) generating the LFP. In this work, we propose a new framework, the kernel current source density method (kCSD), for nonparametric estimation of CSD from LFP recorded from arbitrarily distributed electrodes using kernel methods. We test specific implementations of this framework on model data measured with one-, two-, and three-dimensional multielectrode setups. We compare these methods with the traditional approach through numerical approximation of the Laplacian and with the recently developed inverse current source density methods (iCSD). We show that iCSD is a special case of kCSD. The proposed method opens up new experimental possibilities for CSD analysis from existing or new recordings on arbitrarily distributed electrodes (not necessarily on a grid), which can be obtained in extracellular recordings of single unit activity with multiple electrodes.

  19. Methods for solving reasoning problems in abstract argumentation – A survey

    PubMed Central

    Charwat, Günther; Dvořák, Wolfgang; Gaggl, Sarah A.; Wallner, Johannes P.; Woltran, Stefan

    2015-01-01

    Within the last decade, abstract argumentation has emerged as a central field in Artificial Intelligence. Besides providing a core formalism for many advanced argumentation systems, abstract argumentation has also served to capture several non-monotonic logics and other AI related principles. Although the idea of abstract argumentation is appealingly simple, several reasoning problems in this formalism exhibit high computational complexity. This calls for advanced techniques when it comes to implementation issues, a challenge which has been recently faced from different angles. In this survey, we give an overview on different methods for solving reasoning problems in abstract argumentation and compare their particular features. Moreover, we highlight available state-of-the-art systems for abstract argumentation, which put these methods to practice. PMID:25737590

  20. Neural network evaluation of tokamak current profiles for real time control (abstract)

    SciTech Connect

    Wroblewski, D.

    1997-01-01

    Active feedback control of the current profile, requiring real-time determination of the current profile parameters, is envisioned for tokamaks operating in enhanced confinement regimes. The distribution of toroidal current in a tokamak is now routinely evaluated based on external (magnetic probes, flux loops) and internal (motional Stark effect) measurements of the poloidal magnetic field. However, the analysis involves reconstruction of magnetohydrodynamic equilibrium and is too intensive computationally to be performed in real time. In the present study, a neural network is used to provide a mapping from the magnetic measurements (internal and external) to selected parameters of the safety factor profile. The single-pass, feedforward calculation of output of a trained neural network is very fast, making this approach particularly suitable for real-time applications. The network was trained on a large set of simulated equilibrium data for the DIII-D tokamak. The database encompasses a large variety of current profiles including the hollow current profiles important for reversed central shear operation. The parameters of safety factor profile (a quantity related to the current profile through the magnetic field tilt angle) estimated by the neural network include central safety factor, q{sub 0}, minimum value of q, q{sub min}, and the location of q{sub min}. Very good performance of the trained neural network both for simulated test data and for experimental data is demonstrated. {copyright} {ital 1997 American Institute of Physics.}

  1. Neural network evaluation of tokamak current profiles for real time control (abstract)

    NASA Astrophysics Data System (ADS)

    Wróblewski, Dariusz

    1997-01-01

    Active feedback control of the current profile, requiring real-time determination of the current profile parameters, is envisioned for tokamaks operating in enhanced confinement regimes. The distribution of toroidal current in a tokamak is now routinely evaluated based on external (magnetic probes, flux loops) and internal (motional Stark effect) measurements of the poloidal magnetic field. However, the analysis involves reconstruction of magnetohydrodynamic equilibrium and is too intensive computationally to be performed in real time. In the present study, a neural network is used to provide a mapping from the magnetic measurements (internal and external) to selected parameters of the safety factor profile. The single-pass, feedforward calculation of output of a trained neural network is very fast, making this approach particularly suitable for real-time applications. The network was trained on a large set of simulated equilibrium data for the DIII-D tokamak. The database encompasses a large variety of current profiles including the hollow current profiles important for reversed central shear operation. The parameters of safety factor profile (a quantity related to the current profile through the magnetic field tilt angle) estimated by the neural network include central safety factor, q0, minimum value of q, qmin, and the location of qmin. Very good performance of the trained neural network both for simulated test data and for experimental data is demonstrated.

  2. Mechanism of orientation of stimulating currents in magnetic brain stimulation (abstract)

    NASA Astrophysics Data System (ADS)

    Ueno, S.; Matsuda, T.

    1991-04-01

    We made a functional map of the human motor cortex related to the hand and foot areas by stimulating the human brain with a focused magnetic pulse. We observed that each functional area in the cortex has an optimum direction for which stimulating currents can produce neural excitation. The present report focuses on the mechanism which is responsible for producing this anisotropic response to brain stimulation. We first obtained a functional map of the brain related to the left ADM (abductor digiti minimi muscles). When the stimulating currents were aligned in the direction from the left to the right hemisphere, clear EMG (electromyographic) responses were obtained only from the left ADM to magnetic stimulation of both hemisphere. When the stimulating currents were aligned in the direction from the right to the left hemisphere, clear EMG signals were obtained only from the right ADM to magnetic stimulation of both hemisphere. The functional maps of the brain were sensitive to changes in the direction of the stimulating currents. To explain the phenomena obtained in the experiments, we developed a model of neural excitation elicited by magnetic stimulation. When eddy currents which are induced by pulsed magnetic fields flow in the direction from soma to the distal part of neural fiber, depolarized area in the distal part are excited, and the membrane excitation propagates along the nerve fiber. In contrast, when the induced currents flow in the direction from the distal part to soma, hyperpolarized parts block or inhibit neural excitation even if the depolarized parts near the soma can be excited. The model explains our observation that the orientation of the induced current vectors reflect both the functional and anatomical organization of the neural fibers in the brain.

  3. Current Literature on Venereal Disease, 1973. Number One. Abstracts and Bibliography.

    ERIC Educational Resources Information Center

    Center for Disease Control (DHEW/PHS), Atlanta, GA.

    This report presents a survey of recently published literature in the field of venereal disease. The five main topics covered are a) diagnosis and management of syphilis and other treponematoses, b) gonorrhea, c) minor venereal and related diseases, d) public health methods, and e) behavioral studies. The material in each of these sections…

  4. Copper Mountain conference on multigrid methods. Preliminary proceedings -- List of abstracts

    SciTech Connect

    1995-12-31

    This report contains abstracts of the papers presented at the conference. Papers cover multigrid algorithms and applications of multigrid methods. Applications include the following: solution of elliptical problems; electric power grids; fluid mechanics; atmospheric data assimilation; thermocapillary effects on weld pool shape; boundary-value problems; prediction of hurricane tracks; modeling multi-dimensional combustion and detailed chemistry; black-oil reservoir simulation; image processing; and others.

  5. CURRENT METHODS FOR DETECTION OF CRYPTOSPORIDIUM SPECIES

    EPA Science Inventory

    Current methods for detecting protozoa in water produce results that are highly variable. It is difficult to determine if the methods themselves, or the procedures for testing these methods, are the source of the variability. If testing procedures are responsible for high varia...

  6. The Art of Abstracting.

    ERIC Educational Resources Information Center

    Cremmins, Edward T.

    A three-stage analytical reading method for the composition of informative and indicative abstracts by authors and abstractors is presented in this monograph, along with background information on the abstracting process and a discussion of professional considerations in abstracting. An introduction to abstracts and abstracting precedes general…

  7. Current methods for detecting ethylene in plants

    PubMed Central

    Cristescu, Simona M.; Mandon, Julien; Arslanov, Denis; De Pessemier, Jérôme; Hermans, Christian; Harren, Frans J. M.

    2013-01-01

    Background In view of ethylene's critical developmental and physiological roles the gaseous hormone remains an active research topic for plant biologists. Progress has been made to understand the ethylene biosynthesis pathway and the mechanisms of perception and action. Still numerous questions need to be answered and findings to be validated. Monitoring gas production will very often complete the picture of any ethylene research topic. Therefore the search for suitable ethylene measuring methods for various plant samples either in the field, greenhouses, laboratories or storage facilities is strongly motivated. Scope This review presents an update of the current methods for ethylene monitoring in plants. It focuses on the three most-used methods – gas chromatography detection, electrochemical sensing and optical detection – and compares them in terms of sensitivity, selectivity, time response and price. Guidelines are provided for proper selection and application of the described sensor methodologies and some specific applications are illustrated of laser-based detector for monitoring ethylene given off by Arabidopsis thaliana upon various nutritional treatments. Conclusions Each method has its advantages and limitations. The choice for the suitable ethylene sensor needs careful consideration and is driven by the requirements for a specific application. PMID:23243188

  8. Teaching Methods for Science and Technology: Visualized Teaching and Cultivating the Capacity for Scientific Abstraction

    ERIC Educational Resources Information Center

    Chinese Education, 1973

    1973-01-01

    Improvement of the student's ability to analyze and solve problems by effectively relating the use of visual aids to the cultivation of capacity for scientific abstraction is discussed. These basic theory courses are based on the dialectical materialistic theory of knowledge and Mao's instruction on the unity of theory and reality.'' (SM)

  9. Current status of diagnostic methods for henipavirus.

    PubMed

    Tamin, A; Rota, P A

    2013-01-01

    Hendra virus (HeV) and Nipah virus (NiV) are the causative agents of emerging transboundary animal disease in pigs and horses. They also cause fatal disease in humans. NiV has a case fatality rate of 40 - 100%. In the initial NiV outbreak in Malaysia in 1999, about 1.1 million pigs had to be culled. The economic impact was estimated to be approximately US$450 million. Worldwide, HeV has caused more than 60 deaths in horses with 7 human cases and 4 deaths. Since the initial outbreak, HeV spillovers from Pteropus bats to horses and humans continue. This article presents a brief review on the currently available diagnostic methods for henipavirus infections, including advances achieved since the initial outbreak, and a gap analysis of areas needing improvement.

  10. Instrumentation Analysis: An Automated Method for Producing Numeric Abstractions of Heap-Manipulating Programs

    DTIC Science & Technology

    2010-11-29

    Magill et al., 2006, Distefano et al., 2006, Chang et al., 2007, Calcagno et al., 2009, Yang et al., 2008] has firmly established separation logic as...branch x 6= nil⇒ x := x.next; goto L1, x = nil⇒ halt end A shape analysis such as those in [Berdine et al., 2007, Gotsman et al., 2007, Distefano ...abstract interpretation terms, see [ Distefano et al., 2006] and [Berdine et al., 2007]. We begin our discussion by describing the restricted form of

  11. Apparatus and method for critical current measurements

    DOEpatents

    Martin, Joe A.; Dye, Robert C.

    1992-01-01

    An apparatus for the measurement of the critical current of a superconductive sample, e.g., a clad superconductive sample, the apparatus including a conductive coil, a means for maintaining the coil in proximity to a superconductive sample, an electrical connection means for passing a low amplitude alternating current through the coil, a cooling means for maintaining the superconductive sample at a preselected temperature, a means for passing a current through the superconductive sample, and, a means for monitoring reactance of the coil, is disclosed, together with a process of measuring the critical current of a superconductive material, e.g., a clad superconductive material, by placing a superconductive material into the vicinity of the conductive coil of such an apparatus, cooling the superconductive material to a preselected temperature, passing a low amplitude alternating current through the coil, the alternating current capable of generating a magnetic field sufficient to penetrate, e.g., any cladding, and to induce eddy currents in the superconductive material, passing a steadily increasing current through the superconductive material, the current characterized as having a different frequency than the alternating current, and, monitoring the reactance of the coil with a phase sensitive detector as the current passed through the superconductive material is steadily increased whereby critical current of the superconductive material can be observed as the point whereat a component of impedance deviates.

  12. HUMAN FECAL SOURCE IDENTIFICATION: REAL-TIME QUANTITATIVE PCR METHOD STANDARDIZATION - abstract

    EPA Science Inventory

    Method standardization or the formal development of a protocol that establishes uniform performance benchmarks and practices is necessary for widespread adoption of a fecal source identification approach. Standardization of a human-associated fecal identification method has been...

  13. Direct current power delivery system and method

    DOEpatents

    Zhang, Di; Garces, Luis Jose; Dai, Jian; Lai, Rixin

    2016-09-06

    A power transmission system includes a first unit for carrying out the steps of receiving high voltage direct current (HVDC) power from an HVDC power line, generating an alternating current (AC) component indicative of a status of the first unit, and adding the AC component to the HVDC power line. Further, the power transmission system includes a second unit for carrying out the steps of generating a direct current (DC) voltage to transfer the HVDC power on the HVDC power line, wherein the HVDC power line is coupled between the first unit and the second unit, detecting a presence or an absence of the added AC component in the HVDC power line, and determining the status of the first unit based on the added AC component.

  14. EVALUATION OF THE CARBON FOOTPRINT OF AN INNOVATIVE SEWER REHABILITATION METHOD - abstract

    EPA Science Inventory

    A benefit of trenchless methods touted by many practitioners when compared to open cut construction is lower carbon dioxide emissions. In an attempt to verify these claims, tools have been developed that calculate the environmental impact of traditional open cut methods and commo...

  15. Cost-of-illness studies : a review of current methods.

    PubMed

    Akobundu, Ebere; Ju, Jing; Blatt, Lisa; Mullins, C Daniel

    2006-01-01

    The number of cost-of-illness (COI) studies has expanded considerably over time. One outcome of this growth is that the reported COI estimates are inconsistent across studies, thereby raising concerns over the validity of the estimates and methods. Several factors have been identified in the literature as reasons for the observed variation in COI estimates. To date, the variation in the methods used to calculate costs has not been examined in great detail even though the variations in methods are a major driver of variation in COI estimates. The objective of this review was to document the variation in the methodologies employed in COI studies and to highlight the benefits and limitations of these methods. The review of COI studies was implemented following a four-step procedure: (i) a structured literature search of MEDLINE, JSTOR and EconLit; (ii) a review of abstracts using pre-defined inclusion and exclusion criteria; (iii) a full-text review using pre-defined inclusion and exclusion criteria; and (iv) classification of articles according to the methods used to calculate costs. This review identified four COI estimation methods (Sum_All Medical, Sum_Diagnosis Specific, Matched Control and Regression) that were used in categorising articles. Also, six components of direct medical costs and five components of indirect/non-medical costs were identified and used in categorising articles.365 full-length articles were reflected in the current review following the structured literature search. The top five cost components were emergency room/inpatient hospital costs, outpatient physician costs, drug costs, productivity losses and laboratory costs. The dominant method, Sum_Diagnosis Specific, was a total costing approach that restricted the summation of medical expenditures to those related to a diagnosis of the disease of interest. There was considerable variation in the methods used within disease subcategories. In several disease subcategories (e.g. asthma, dementia

  16. Hysteroscopic Sterilization: History and Current Methods

    PubMed Central

    Greenberg, James A

    2008-01-01

    For many practicing obstetrician-gynecologists, tubal ligation was the gold standard by which female sterilization techniques were measured. Yet gynecologic surgeons have simultaneously sought to occlude the fallopian tubes transcervically to avoid discomfort and complications associated with transabdominal approaches. In this review, the history of transcervical sterilization is discussed. Past, current, and upcoming techniques are reviewed. This article focuses on interval sterilization techniques, thus removing post-vaginal and post-cesarean delivery tubal ligations from the discussion. PMID:19015762

  17. An extended abstract: A heuristic repair method for constraint-satisfaction and scheduling problems

    NASA Technical Reports Server (NTRS)

    Minton, Steven; Johnston, Mark D.; Philips, Andrew B.; Laird, Philip

    1992-01-01

    The work described in this paper was inspired by a surprisingly effective neural network developed for scheduling astronomical observations on the Hubble Space Telescope. Our heuristic constraint satisfaction problem (CSP) method was distilled from an analysis of the network. In the process of carrying out the analysis, we discovered that the effectiveness of the network has little to do with its connectionist implementation. Furthermore, the ideas employed in the network can be implemented very efficiently within a symbolic CSP framework. The symbolic implementation is extremely simple. It also has the advantage that several different search strategies can be employed, although we have found that hill-climbing methods are particularly well-suited for the applications that we have investigated. We begin the paper with a brief review of the neural network. Following this, we describe our symbolic method for heuristic repair.

  18. Abstract Applets: A Method for Integrating Numerical Problem Solving into the Undergraduate Physics Curriculum

    SciTech Connect

    Peskin, Michael E

    2003-02-13

    In upper-division undergraduate physics courses, it is desirable to give numerical problem-solving exercises integrated naturally into weekly problem sets. I explain a method for doing this that makes use of the built-in class structure of the Java programming language. I also supply a Java class library that can assist instructors in writing programs of this type.

  19. A novel computational method to simulate non-enzymatic self-replication. [Abstract only

    NASA Technical Reports Server (NTRS)

    Navarro-Gonzalez, Rafael; Reggia, James A.; Wu, Jayoung; Chou, Hui-Hsien

    1994-01-01

    Non-enzymatic, template-directed synthesis of oligonucleotides has been extensively studied in the laboratory as a model to understand the kind of chemical processes that might have contributed to the origin of life on Earth. Several oligonucleotides have been shown to catalyze the synthesis of their complements from activated mononucleotides; however, a restricted number of them have been found to self-replicate. Recently we developed an efficient modified cellular automata method that supports the study of self-replicating oligonucleotides. With this method the oligonucleotide molecules are represented as active cells imbedded in a two-dimensional array of inactive cells symbolizing the environment. Random movements and probability-governed chemical reactions occurring in a cellular space can effectively simulate the experimental behavior observed in self-directed replication of oligonucleotides.

  20. Current methods of radio occultation data inversion

    NASA Technical Reports Server (NTRS)

    Kliore, A. J.

    1972-01-01

    The methods of Abel integral transform and ray-tracing inversion have been applied to data received from radio occultation experiments as a means of obtaining refractive index profiles of the ionospheres and atmospheres of Mars and Venus. In the case of Mars, certain simplifications are introduced by the assumption of small refractive bending in the atmosphere. General inversion methods, independent of the thin atmosphere approximation, have been used to invert the data obtained from the radio occultation of Mariner 5 by Venus; similar methods will be used to analyze data obtained from Jupiter with Pioneers F and G, as well as from the other outer planets in the Outer Planet Grand Tour Missions.

  1. Current Bioengineering Methods for Whole Kidney Regeneration

    PubMed Central

    Yamanaka, Shuichiro; Yokoo, Takashi

    2015-01-01

    Kidney regeneration is likely to provide an inexhaustible source of tissues and organs for immunosuppression-free transplantation. It is currently garnering considerable attention and might replace kidney dialysis as the ultimate therapeutic strategy for renal failure. However, anatomical complications make kidney regeneration difficult. Here, we review recent advances in the field of kidney regeneration, including (i) the directed differentiation of induced pluripotent stem cells/embryonic stem cells into kidney cells; (ii) blastocyst decomplementation; (iii) use of a decellularized cadaveric scaffold; (iv) embryonic organ transplantation; and (v) use of a nephrogenic niche for growing xenoembryos for de novo kidney regeneration from stem cells. All these approaches represent potentially promising therapeutic strategies for the treatment of patients with chronic kidney disease. Although many obstacles to kidney regeneration remain, we hope that innovative strategies and reliable research will ultimately allow the restoration of renal function in patients with end-stage kidney disease. PMID:26089921

  2. Eddy Current Method for Fatigue Testing

    NASA Technical Reports Server (NTRS)

    Simpson, John W. (Inventor); Fulton, James P. (Inventor); Wincheski, Russell A. (Inventor); Todhunter, Ronald G. (Inventor); Namkung, Min (Inventor); Nath, Shridhar C. (Inventor)

    1997-01-01

    Flux-focusing electromagnetic sensor using a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks and material loss in high conductivity material. A ferrous shield isolates a high-turn pick-up coil from an excitation coil. Use of the magnetic shield produces a null voltage output across the receiving coil in presence of an unflawed sample. Redistribution of the current flow in the sample caused by the presence of flaws. eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. Maximum sensor output is obtained when positioned symmetrically above the crack. By obtaining position of maximum sensor output, it is possible to track the fault and locate the area surrounding its tip. Accuracy of tip location is enhanced by two unique features of the sensor; a very high signal-to-noise ratio of the probe's output resulting in an extremely smooth signal peak across the fault, and a rapidly decaying sensor output outside a small area surrounding the crack tip enabling the search region to be clearly defined. Under low frequency operation, material thinning due to corrosion causes incomplete shielding of the pick-up coil. Low frequency output voltage of the probe is therefore a direct indicator of thickness of the test sample. Fatigue testing a conductive material is accomplished by applying load to the material, applying current to the sensor, scanning the material with the sensor, monitoring the sensor output signal, adjusting material load based on the sensor output signal of the sensor, and adjusting position of the sensor based on its output signal.

  3. Core temperature measurement: methods and current insights.

    PubMed

    Moran, Daniel S; Mendal, Liran

    2002-01-01

    Climatic injuries, including hypothermia, hyperthermia and heat stroke, are common in many sports activities. Body core temperature (T(c)) measurement for the sportsperson can influence individual performance and may help to prevent injuries. Monitoring internal body T(c) accurately requires invasive methods of measurement. The mercury thermometer, most commonly used to measure oral temperature (T(oral)), has been almost exclusively the only instrument for measuring T(c) since the 18th century. Rectal (T(re)) and oesophageal temperatures (T(oes)) have been the most preferred measurement sites employed in thermoregulatory investigations. However, these measurement sites (T(re), T(oes), T(oral)), and the methods used to measure T(c) at these sites, are not convenient. T(oral) measurements are not always possible or accurate. T(oes) is undesirable because of the difficulty of inserting the thermistor, irritation to nasal passages and general subject discomfort. T(re) is not suitable under many circumstances as it is labour intensive and has a prolonged response time. However, T(re) remains the most accurately available method for monitoring T(c) in thermal illness that occurs during sports activities. In addition, T(re) and T(oes) require wire connections between the thermistor and the monitoring device. The purpose of this paper is to review the various existing methods of T(c) measurements in order to focus on the breakthrough needed for a simple, noninvasive, universally used device for T(c) measurement which is essential for preventing climatic injuries during sports events.

  4. Current status of fluoride volatility method development

    SciTech Connect

    Uhlir, J.; Marecek, M.; Skarohlid, J.

    2013-07-01

    The Fluoride Volatility Method is based on a separation process, which comes out from the specific property of uranium, neptunium and plutonium to form volatile hexafluorides whereas most of fission products (mainly lanthanides) and higher transplutonium elements (americium, curium) present in irradiated fuel form nonvolatile tri-fluorides. Fluoride Volatility Method itself is based on direct fluorination of the spent fuel, but before the fluorination step, the removal of cladding material and subsequent transformation of the fuel into a powdered form with a suitable grain size have to be done. The fluorination is made with fluorine gas in a flame fluorination reactor, where the volatile fluorides (mostly UF{sub 6}) are separated from the non-volatile ones (trivalent minor actinides and majority of fission products). The subsequent operations necessary for partitioning of volatile fluorides are the condensation and evaporation of volatile fluorides, the thermal decomposition of PuF{sub 6} and the finally distillation and sorption used for the purification of uranium product. The Fluoride Volatility Method is considered to be a promising advanced pyrochemical reprocessing technology, which can mainly be used for the reprocessing of oxide spent fuels coming from future GEN IV fast reactors.

  5. X-ray Ross filter method for impurity transport studies on DIII-D (abstract)

    NASA Astrophysics Data System (ADS)

    Bogatu, I. N.; Kim, J. S.; Egdell, D. H.; Snider, R. T.; Brooks, N. H.; Wade, M. R.; West, W. P.

    2001-01-01

    The injection of Ar into the region of the DIII-D divertor is a promising technique for energy dissipation (through radiation and collisions) and consequently for reduction of the heat load on the plates. An important problem related to this technique, is the inherent poisoning of the core plasma by migrating Ar. The Ar core contamination seems also to improve the thermal transport in an advanced operating mode of the tokamak. It is therefore of great importance to measure the evolution of the impurity concentration profile within the core plasma. This goal could be achieved by using the Ross filter method in conjunction with the existing x-ray diagnostics on DIII-D. A basic Ross filter system consists of two identical detectors placed behind two different x-ray absorbing foils looking at the same plasma volume. The foils are made of different elements or compounds with adjacent or nearly adjacent atomic numbers. Their accurate thickness causes the x-ray transmission curves of the two foils to be effectively identical over the entire energy range except within the narrow region between their absorption edges. Since the transmission characteristics of the foils above and below their absorption edges are the same, any difference in the two detected signals is proportional to the total x-ray power of the emission spectrum between these two edge energies. An x-ray Ross filter with its energy pass band centered on the Ar XVII Kα line at 3.14 keV has been designed. This allows for the discrimination of the Ar Kα line only, regardless of Ar ionization state, against any background radiation with energies outside the energy pass band. The Ross filter was installed in front of two of the fan shaped poloidal x-ray arrays on DIII-D. The first measurements showed very good discrimination against Ne, another injected impurity. Emissivity profile evolution of the Kα lines and Ar enhanced continuum within the energy pass band of the Ross filter can be determined from the x

  6. Does "Social Work Abstracts" Work?

    ERIC Educational Resources Information Center

    Holden, Gary; Barker, Kathleen; Covert-Vail, Lucinda; Rosenberg, Gary; Cohen, Stephanie A.

    2008-01-01

    Objective: The current study seeks to provide estimates of the adequacy of journal coverage in the Social Work Abstracts (SWA) database. Method: A total of 23 journals listed in the Journal Citation Reports social work category during the 1997 to 2005 period were selected for study. Issue-level coverage estimates were obtained for SWA and…

  7. Current methods and advances in bone densitometry

    NASA Technical Reports Server (NTRS)

    Guglielmi, G.; Gluer, C. C.; Majumdar, S.; Blunt, B. A.; Genant, H. K.

    1995-01-01

    Bone mass is the primary, although not the only, determinant of fracture. Over the past few years a number of noninvasive techniques have been developed to more sensitively quantitate bone mass. These include single and dual photon absorptiometry (SPA and DPA), single and dual X-ray absorptiometry (SXA and DXA) and quantitative computed tomography (QCT). While differing in anatomic sites measured and in their estimates of precision, accuracy, and fracture discrimination, all of these methods provide clinically useful measurements of skeletal status. It is the intent of this review to discuss the pros and cons of these techniques and to present the new applications of ultrasound (US) and magnetic resonance (MRI) in the detection and management of osteoporosis.

  8. Carbon footprint: current methods of estimation.

    PubMed

    Pandey, Divya; Agrawal, Madhoolika; Pandey, Jai Shanker

    2011-07-01

    Increasing greenhouse gaseous concentration in the atmosphere is perturbing the environment to cause grievous global warming and associated consequences. Following the rule that only measurable is manageable, mensuration of greenhouse gas intensiveness of different products, bodies, and processes is going on worldwide, expressed as their carbon footprints. The methodologies for carbon footprint calculations are still evolving and it is emerging as an important tool for greenhouse gas management. The concept of carbon footprinting has permeated and is being commercialized in all the areas of life and economy, but there is little coherence in definitions and calculations of carbon footprints among the studies. There are disagreements in the selection of gases, and the order of emissions to be covered in footprint calculations. Standards of greenhouse gas accounting are the common resources used in footprint calculations, although there is no mandatory provision of footprint verification. Carbon footprinting is intended to be a tool to guide the relevant emission cuts and verifications, its standardization at international level are therefore necessary. Present review describes the prevailing carbon footprinting methods and raises the related issues.

  9. Transport critical current of MgB2 wires: pulsed current of varying rate compared to direct current method

    NASA Astrophysics Data System (ADS)

    See, K. W.; Xu, X.; Horvat, J.; Cook, C. D.; Dou, S. X.

    2011-10-01

    The measurement of transport critical current (Ic) for MgB2 wires and tapes has been investigated with two different techniques, the conventional four-probe arrangement with direct current (DC) power source, and a tailored triangle pulse at different rates of current change. The DC method has been widely used and practiced by various groups, but suffers from inevitable heating effects when high currents are used at low magnetic fields. The pulsed current method has no heating effects, but the critical current can depend on the rate of the current change (dI/dt) in the pulse. Our pulsed current measurements with varying dI/dt show that the same values of Ic are obtained as with the DC method, but without the artifacts of heating. Our method is particularly useful at low field regions which are often inaccessible by DC methods. We also performed a finite element method (FEM) analysis to obtain the time dependent heat distribution in MgB2 due to the electric potential produced at the current contacts to the superconducting sample and its gradient around the contacts. This gradient is defined as the current transfer length (CTL) of the samples and leads to Joule heating of the wire near the contacts. The FEM results provide further evidence of the limitation of the DC method in obtaining high transport critical current.

  10. Abstraction in mathematics.

    PubMed Central

    Ferrari, Pier Luigi

    2003-01-01

    Some current interpretations of abstraction in mathematical settings are examined from different perspectives, including history and learning. It is argued that abstraction is a complex concept and that it cannot be reduced to generalization or decontextualization only. In particular, the links between abstraction processes and the emergence of new objects are shown. The role that representations have in abstraction is discussed, taking into account both the historical and the educational perspectives. As languages play a major role in mathematics, some ideas from functional linguistics are applied to explain to what extent mathematical notations are to be considered abstract. Finally, abstraction is examined from the perspective of mathematics education, to show that the teaching ideas resulting from one-dimensional interpretations of abstraction have proved utterly unsuccessful. PMID:12903658

  11. Prediction method abstracts

    SciTech Connect

    1994-12-31

    This conference was held December 4--8, 1994 in Asilomar, California. The purpose of this meeting was to provide a forum for exchange of state-of-the-art information concerning the prediction of protein structure. Attention if focused on the following: comparative modeling; sequence to fold assignment; and ab initio folding.

  12. Research Abstracts.

    ERIC Educational Resources Information Center

    Plotnick, Eric

    2001-01-01

    Presents research abstracts from the ERIC Clearinghouse on Information and Technology. Topics include: classroom communication apprehension and distance education; outcomes of a distance-delivered science course; the NASA/Kennedy Space Center Virtual Science Mentor program; survey of traditional and distance learning higher education members;…

  13. Research Abstracts.

    ERIC Educational Resources Information Center

    Plotnik, Eric

    2001-01-01

    Presents six research abstracts from the ERIC (Educational Resources Information Center) database. Topics include: effectiveness of distance versus traditional on-campus education; improved attribution recall from diversification of environmental context during computer-based instruction; qualitative analysis of situated Web-based learning;…

  14. Abstract Constructions.

    ERIC Educational Resources Information Center

    Pietropola, Anne

    1998-01-01

    Describes a lesson designed to culminate a year of eighth-grade art classes in which students explore elements of design and space by creating 3-D abstract constructions. Outlines the process of using foam board and markers to create various shapes and optical effects. (DSK)

  15. Abstract and keywords.

    PubMed

    Peh, W C G; Ng, K H

    2008-09-01

    The abstract of a scientific paper represents a concise, accurate and factual mini-version of the paper contents. Abstract format may vary according to the individual journal. For original articles, a structured abstract usually consists of the following headings: aims (or objectives), materials and methods, results and conclusion. A few keywords that capture the main topics of the paper help indexing in the medical literature.

  16. Organizational Communication Abstracts--1975.

    ERIC Educational Resources Information Center

    Falcione, Raymond L.; And Others

    This document includes nearly 700 brief abstracts of works published in 1975 that are relevant to the field of organizational communication. The introduction presents a rationale for the project, a review of research methods developed by the authors for the preparation of abstracts, a statement of limitations as to the completeness of the coverage…

  17. Method and apparatus for measuring low currents in capacitance devices

    DOEpatents

    Kopp, M.K.; Manning, F.W.; Guerrant, G.C.

    1986-06-04

    A method and apparatus for measuring subnanoampere currents in capacitance devices is reported. The method is based on a comparison of the voltages developed across the capacitance device with that of a reference capacitor in which the current is adjusted by means of a variable current source to produce a stable voltage difference. The current varying means of the variable current source is calibrated to provide a read out of the measured current. Current gain may be provided by using a reference capacitor which is larger than the device capacitance with a corresponding increase in current supplied through the reference capacitor. The gain is then the ratio of the reference capacitance to the device capacitance. In one illustrated embodiment, the invention makes possible a new type of ionizing radiation dose-rate monitor where dose-rate is measured by discharging a reference capacitor with a variable current source at the same rate that radiation is discharging an ionization chamber. The invention eliminates high-megohm resistors and low current ammeters used in low-current measuring instruments.

  18. Eddy Current System and Method for Crack Detection

    NASA Technical Reports Server (NTRS)

    Wincheski, Russell A. (Inventor); Simpson, John W. (Inventor)

    2012-01-01

    An eddy current system and method enables detection of sub-surface damage in a cylindrical object. The invention incorporates a dual frequency, orthogonally wound eddy current probe mounted on a stepper motor-controlled scanning system. The system is designed to inspect for outer surface damage from the interior of the cylindrical object.

  19. Direct current uninterruptible power supply method and system

    DOEpatents

    Sinha, Gautam

    2003-12-02

    A method and system are described for providing a direct current (DC) uninterruptible power supply with the method including, for example: continuously supplying fuel to a turbine; converting mechanical power from the turbine into alternating current (AC) electrical power; converting the AC electrical power to DC power within a predetermined voltage level range; supplying the DC power to a load; and maintaining a DC load voltage within the predetermined voltage level range by adjusting the amount of fuel supplied to the turbine.

  20. Method and apparatus to trigger superconductors in current limiting devices

    DOEpatents

    Yuan, Xing; Hazelton, Drew Willard; Walker, Michael Stephen

    2004-10-26

    A method and apparatus for magnetically triggering a superconductor in a superconducting fault current limiter to transition from a superconducting state to a resistive state. The triggering is achieved by employing current-carrying trigger coil or foil on either or both the inner diameter and outer diameter of a superconductor. The current-carrying coil or foil generates a magnetic field with sufficient strength and the superconductor is disposed within essentially uniform magnetic field region. For superconductor in a tubular-configured form, an additional magnetic field can be generated by placing current-carrying wire or foil inside the tube and along the center axial line.

  1. Motor monitoring method and apparatus using high frequency current components

    DOEpatents

    Casada, D.A.

    1996-05-21

    A motor current analysis method and apparatus for monitoring electrical-motor-driven devices are disclosed. The method and apparatus utilize high frequency portions of the motor current spectra to evaluate the condition of the electric motor and the device driven by the electric motor. The motor current signal produced as a result of an electric motor is monitored and the low frequency components of the signal are removed by a high-pass filter. The signal is then analyzed to determine the condition of the electrical motor and the driven device. 16 figs.

  2. Motor monitoring method and apparatus using high frequency current components

    DOEpatents

    Casada, Donald A.

    1996-01-01

    A motor current analysis method and apparatus for monitoring electrical-motor-driven devices. The method and apparatus utilize high frequency portions of the motor current spectra to evaluate the condition of the electric motor and the device driven by the electric motor. The motor current signal produced as a result of an electric motor is monitored and the low frequency components of the signal are removed by a high-pass filter. The signal is then analyzed to determine the condition of the electrical motor and the driven device.

  3. Abstracts of SIG Sessions.

    ERIC Educational Resources Information Center

    Proceedings of the ASIS Annual Meeting, 1997

    1997-01-01

    Presents abstracts of SIG Sessions. Highlights include digital collections; information retrieval methods; public interest/fair use; classification and indexing; electronic publication; funding; globalization; information technology projects; interface design; networking in developing countries; metadata; multilingual databases; networked…

  4. Motor current signature analysis method for diagnosing motor operated devices

    DOEpatents

    Haynes, Howard D.; Eissenberg, David M.

    1990-01-01

    A motor current noise signature analysis method and apparatus for remotely monitoring the operating characteristics of an electric motor-operated device such as a motor-operated valve. Frequency domain signal analysis techniques are applied to a conditioned motor current signal to distinctly identify various operating parameters of the motor driven device from the motor current signature. The signature may be recorded and compared with subsequent signatures to detect operating abnormalities and degradation of the device. This diagnostic method does not require special equipment to be installed on the motor-operated device, and the current sensing may be performed at remote control locations, e.g., where the motor-operated devices are used in accessible or hostile environments.

  5. Maps of current density using density-functional methods

    NASA Astrophysics Data System (ADS)

    Soncini, A.; Teale, A. M.; Helgaker, T.; de Proft, F.; Tozer, D. J.

    2008-08-01

    The performance of several density-functional theory (DFT) methods for the calculation of current densities induced by a uniform magnetic field is examined. Calculations are performed using the BLYP and KT3 generalized-gradient approximations, together with the B3LYP hybrid functional. For the latter, both conventional and optimized effective potential (OEP) approaches are used. Results are also determined from coupled-cluster singles-and-doubles (CCSD) electron densities by a DFT constrained search procedure using the approach of Wu and Yang (WY). The current densities are calculated within the CTOCD-DZ2 distributed origin approach. Comparisons are made with results from Hartree-Fock (HF) theory. Several small molecules for which correlation is known to be especially important in the calculation of magnetic response properties are considered-namely, O3, CO, PN, and H2CO. As examples of aromatic and antiaromatic systems, benzene and planarized cyclooctatetraene molecules are considered, with specific attention paid to the ring current phenomenon and its Kohn-Sham orbital origin. Finally, the o-benzyne molecule is considered as a computationally challenging case. The HF and DFT induced current maps show qualitative differences, while among the DFT methods the maps show a similar qualitative structure. To assess quantitative differences in the calculated current densities with different methods, the maximal moduli of the induced current densities are compared and integration of the current densities to yield shielding constants is performed. In general, the maximal modulus is reduced in moving from HF to B3LYP and BLYP, and further reduced in moving to KT3, OEP(B3LYP), and WY(CCSD). The latter three methods offer the most accurate shielding constants in comparison with both experimental and ab initio data and hence the more reliable route to DFT calculation of induced current density in molecules.

  6. Differential Thermostimulated Discharge Current Method for Studying Electrets

    NASA Astrophysics Data System (ADS)

    Mekishev, G. A.; Yovcheva, T. A.; Viraneva, A. P.; Gencheva, E. A.

    2010-01-01

    The thermostimulated discharge current method (TSDC) is widely used for the study of charge storage mechanisms in electrets. A new discharged technique, called differential, which consists in discharging a charged sample through an otherwise identical but uncharged one, has been proposed by J.-P. Reboul and A. Toureille. In the present paper a new version of the differential thermostimulated discharge current method is advanced. In contrast to the differential technique described earlier, the measuring cell allows to realize typical differential technique. In this case the measuring system records the difference of the thermostimulated currents of two samples which have been preliminary charged (or thermally treated) under the same or different conditions. Samples of 0.85 mm thick polymethylmethacrylate are used to demonstrate an operation of the developed differential TSDC method.

  7. Adaptive Current Control Method for Hybrid Active Power Filter

    NASA Astrophysics Data System (ADS)

    Chau, Minh Thuyen

    2016-09-01

    This paper proposes an adaptive current control method for Hybrid Active Power Filter (HAPF). It consists of a fuzzy-neural controller, identification and prediction model and cost function. The fuzzy-neural controller parameters are adjusted according to the cost function minimum criteria. For this reason, the proposed control method has a capability on-line control clings to variation of the load harmonic currents. Compared to the single fuzzy logic control method, the proposed control method shows the advantages of better dynamic response, compensation error in steady-state is smaller, able to online control is better and harmonics cancelling is more effective. Simulation and experimental results have demonstrated the effectiveness of the proposed control method.

  8. Probability of detection models for eddy current NDE methods

    SciTech Connect

    Rajesh, S.N.

    1993-04-30

    The development of probability of detection (POD) models for a variety of nondestructive evaluation (NDE) methods is motivated by a desire to quantify the variability introduced during the process of testing. Sources of variability involved in eddy current methods of NDE include those caused by variations in liftoff, material properties, probe canting angle, scan format, surface roughness and measurement noise. This thesis presents a comprehensive POD model for eddy current NDE. Eddy current methods of nondestructive testing are used widely in industry to inspect a variety of nonferromagnetic and ferromagnetic materials. The development of a comprehensive POD model is therefore of significant importance. The model incorporates several sources of variability characterized by a multivariate Gaussian distribution and employs finite element analysis to predict the signal distribution. The method of mixtures is then used for estimating optimal threshold values. The research demonstrates the use of a finite element model within a probabilistic framework to the spread in the measured signal for eddy current nondestructive methods. Using the signal distributions for various flaw sizes the POD curves for varying defect parameters have been computed. In contrast to experimental POD models, the cost of generating such curves is very low and complex defect shapes can be handled very easily. The results are also operator independent.

  9. Trends in Modern Subject Analysis with Reference to Text Derivative Indexing and Abstracting Methods: The State of the Art.

    ERIC Educational Resources Information Center

    Wright, Kieth C.

    1972-01-01

    This paper briefly reviews the information explosion of the last thirty years and the various attempts made to organize that information in new ways. Section B offers a brief historic review of modern classification and subject heading theory. Section C reviews the literature of automatic indexing, automatic abstracting, and automatic…

  10. Computers in Abstract Algebra

    ERIC Educational Resources Information Center

    Nwabueze, Kenneth K.

    2004-01-01

    The current emphasis on flexible modes of mathematics delivery involving new information and communication technology (ICT) at the university level is perhaps a reaction to the recent change in the objectives of education. Abstract algebra seems to be one area of mathematics virtually crying out for computer instructional support because of the…

  11. Method and apparatus for producing co-current fluid contact

    DOEpatents

    Trutna, W.R.

    1997-12-09

    An improved packing system and method are disclosed wherein a packing section includes a liquid distributor and a separator placed above the distributor so that gas rising through the liquid distributor contacts liquid in the distributor, forming a gas-liquid combination which rises in co-current flow to the separator. Liquid is collected in the separator, from which gas rises. 13 figs.

  12. Method and apparatus for producing co-current fluid contact

    DOEpatents

    Trutna, William R.

    1997-01-01

    An improved packing system and method are disclosed wherein a packing section includes a liquid distributor and a separator placed above the distributor so that gas rising through the liquid distributor contacts liquid in the distributor, forming a gas-liquid combination which rises in co-current flow to the separator. Liquid is collected in the separator, from which gas rises.

  13. Method and apparatus for reducing the harmonic currents in alternating-current distribution networks

    DOEpatents

    Beverly, Leon H.; Hance, Richard D.; Kristalinski, Alexandr L.; Visser, Age T.

    1996-01-01

    An improved apparatus and method reduce the harmonic content of AC line and neutral line currents in polyphase AC source distribution networks. The apparatus and method employ a polyphase Zig-Zag transformer connected between the AC source distribution network and a load. The apparatus and method also employs a mechanism for increasing the source neutral impedance of the AC source distribution network. This mechanism can consist of a choke installed in the neutral line between the AC source and the Zig-Zag transformer.

  14. Method and apparatus for reducing the harmonic currents in alternating-current distribution networks

    DOEpatents

    Beverly, L.H.; Hance, R.D.; Kristalinski, A.L.; Visser, A.T.

    1996-11-19

    An improved apparatus and method reduce the harmonic content of AC line and neutral line currents in polyphase AC source distribution networks. The apparatus and method employ a polyphase Zig-Zag transformer connected between the AC source distribution network and a load. The apparatus and method also employs a mechanism for increasing the source neutral impedance of the AC source distribution network. This mechanism can consist of a choke installed in the neutral line between the AC source and the Zig-Zag transformer. 23 figs.

  15. Automatic Abstraction in Planning

    NASA Technical Reports Server (NTRS)

    Christensen, J.

    1991-01-01

    Traditionally, abstraction in planning has been accomplished by either state abstraction or operator abstraction, neither of which has been fully automatic. We present a new method, predicate relaxation, for automatically performing state abstraction. PABLO, a nonlinear hierarchical planner, implements predicate relaxation. Theoretical, as well as empirical results are presented which demonstrate the potential advantages of using predicate relaxation in planning. We also present a new definition of hierarchical operators that allows us to guarantee a limited form of completeness. This new definition is shown to be, in some ways, more flexible than previous definitions of hierarchical operators. Finally, a Classical Truth Criterion is presented that is proven to be sound and complete for a planning formalism that is general enough to include most classical planning formalisms that are based on the STRIPS assumption.

  16. Literature Abstracts.

    PubMed

    S, P; S, A; H, A; M, J D; S, A; Foods, A; S, A; M, J D; S, A; Pharmaceuticals, B; Foods, A

    1971-05-01

    1. General Principles: 'Application of the Statistical Theory of Rubber Elasticity to the Effect of Heat on Wheat Gluten', by R. Bale and H. G. Muller. 1. General Principles: 'Processing of Non-Newtonian Foods', by S. D. Holdworth (Fruit and Veg. Preserv. Res. Assoc., Chipping Camden, Glos., England), Process Biochem. 4 (10) (October, 1969), 15-21, 33. 1. General Principles: 'A Quick Method of Measuring the Surface Texture of Aggregate', by D. F. Orchid and W. O. Yondell (School of Highway Eng., Univ. of South Wales, Rendwick, N. S. W.), paper presented at the Australian Road Res. Board's 1970 Biennial Conf. 1. General Principles: 'The Deformation and Fracture Behaviour of the Binder in Bituminous Road Surfacing Materials under Traffic Loading', by E. J. Dickinson and H. P. Witt (Australian Road Research Board, 60 Denmark Street, Kew. Vic. 3101, Aust.), paper presented at the Australian Road Research Board, 1970 Biennial Conference. 2. Instrumentation and Methodology: 'Design and Evaluation of a Pressure Attachment for a Rotational Rheometer', by K. R. M. Vora, L. L. Augsburger, and R. F. Shangraw (Dept. of Pharmacy, School of Pharmacy, University of Maryland, Baltimore, Maryland 21201, U. S. A.), J. Pharm. Sci. 59 (1970), 1012-16. 2. Instrumentation and Methodology: 'Materials for Standardizing the FMC Tenderometer', by L. M. Staley (Univ. of British Columbia, Vancouver, B. C., Canada), Can. Inst. Food Technol. J. 3 (1970), 116-117. 2. Instrumentation and Methodology: 'An Electronic Recording Viscometer for Food Products', by P. W. Voisey and J. M. deMan (Eng. Res. Service, Res. Branch, Canada Dept. of Agr., Ottawa and Univ. of Guelph, Guelph, Canada), Can. Inst. Food Technol. J. 3 (1970), 130-135. 2. Instrumentation and Methodology: 'Test Cells for Objective Textural Measurements', by P. W. Voisey (Eng. Res. Service, Res. Branch, Canada Dept. of Agr., Ottawa), Can. Inst. Food Technol. J. 3 (1970), 93-102. 3. Objdve Measurements: 'An Empirical Equation Describing

  17. 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.

  18. Improved method for Faraday current sensor data processing

    NASA Astrophysics Data System (ADS)

    Ferrari, José A.; Perciante, César D.; Lagos, Alejandro; Frins, Erna M.

    2001-11-01

    There are several practical problems that have made difficult the prompt application of Faraday current sensors in industrial environments. Two of them are the multiplicative noise generated by mechanical vibrations and the normalization of the output signal. In this paper we propose a logarithmical processing and a posterior bandpass filtering of the sensor data in order to solve simultaneously both issues. Experimental results demonstrating the viability of the procedure and a comparison with standard processing methods are presented.

  19. Methods for rotational speed reduction for alternating current electric motors

    NASA Astrophysics Data System (ADS)

    Kagan, A. V.; Glukhanich, D. Y.

    2017-02-01

    The analysis of rotational speed reduction methods for alternating current electric motors are given, assigned to low-speed electric drives of various power levels. The integrated classification of electric machines of well-known types is given, the rotational speed reduction method being used as the basis. The main advantages and disadvantages, defining perspectives for the application in various low-speed electric drives, are explained. The approximate bounds of engineering expediency of the applications of the motors are given for obtaining certain assessments in selection of a type of the drive motor.

  20. Delivering Advanced Methods in Mathematical Programming to Students of All Disciplines Using Abstraction, Modularity and Open-Ended Assignments

    ERIC Educational Resources Information Center

    Ezra, Elishai; Nahmias, Yaakov

    2015-01-01

    The advent of integrated multidisciplinary research has given rise to some of the most important breakthroughs of our time, but has also set significant challenges to the current educational paradigm. Current academic education often limits cross-discipline discussion, depends on close-ended problems, and restricts utilization of interdisciplinary…

  1. Generalized Abstract Symbolic Summaries

    NASA Technical Reports Server (NTRS)

    Person, Suzette; Dwyer, Matthew B.

    2009-01-01

    Current techniques for validating and verifying program changes often consider the entire program, even for small changes, leading to enormous V&V costs over a program s lifetime. This is due, in large part, to the use of syntactic program techniques which are necessarily imprecise. Building on recent advances in symbolic execution of heap manipulating programs, in this paper, we develop techniques for performing abstract semantic differencing of program behaviors that offer the potential for improved precision.

  2. 2002 NASPSA Conference Abstracts.

    ERIC Educational Resources Information Center

    Journal of Sport & Exercise Psychology, 2002

    2002-01-01

    Contains abstracts from the 2002 conference of the North American Society for the Psychology of Sport and Physical Activity. The publication is divided into three sections: the preconference workshop, "Effective Teaching Methods in the Classroom;" symposia (motor development, motor learning and control, and sport psychology); and free…

  3. Current microscopic methods for the neural ECM analysis.

    PubMed

    Zeug, Andre; Stawarski, Michal; Bieganska, Katarzyna; Korotchenko, Svetlana; Wlodarczyk, Jakub; Dityatev, Alexander; Ponimaskin, Evgeni

    2014-01-01

    The extracellular matrix (ECM) occupies the space between both neurons and glial cells and thus provides a microenvironment that regulates multiple aspects of neural activities. Because of the vital role of ECM as a natural environment of cells in vivo, there is a growing interest to develop methodology allowing for the detailed structural and functional analyses of ECM. In this chapter, we provide the detailed overview of current microscopic methods used for ECM analysis and also describe general labeling strategies for ECM visualization. Since ECM remodeling involves the proteolytic cleavage of ECM, we will also describe current experimental approaches to image the proteolytic reorganization and/or degradation of ECM. The special focus of this chapter is set to the application of Förster resonance energy transfer-based approaches to monitor intracellular and extracellular matrix functions with high spatiotemporal resolution.

  4. Development of a Mobile Tracer Correlation Method for Assessment of Air Emissions from Landfills and Other Area Sources (Abstract)

    EPA Science Inventory

    Work toward a standardized version of a mobile tracer correlation measurement method is discussed. The method used for assessment of methane emissions from 15 landfills in 56 field deployments from 2009 to 2013. This general area source measurement method uses advances in instrum...

  5. Using abstract language signals power.

    PubMed

    Wakslak, Cheryl J; Smith, Pamela K; Han, Albert

    2014-07-01

    Power can be gained through appearances: People who exhibit behavioral signals of power are often treated in a way that allows them to actually achieve such power (Ridgeway, Berger, & Smith, 1985; Smith & Galinsky, 2010). In the current article, we examine power signals within interpersonal communication, exploring whether use of concrete versus abstract language is seen as a signal of power. Because power activates abstraction (e.g., Smith & Trope, 2006), perceivers may expect higher power individuals to speak more abstractly and therefore will infer that speakers who use more abstract language have a higher degree of power. Across a variety of contexts and conversational subjects in 7 experiments, participants perceived respondents as more powerful when they used more abstract language (vs. more concrete language). Abstract language use appears to affect perceived power because it seems to reflect both a willingness to judge and a general style of abstract thinking.

  6. Investigating physical controls on methane and carbon dioxide fluxes over reservoirs using the eddy covariance method-abstract

    EPA Science Inventory

    Reservoirs are a globally important source of carbon to the atmosphere. Several recent studies have found that both carbon dioxide (CO2) and methane (CH4) emissions from reservoirs are currently being underestimated by up to 50%. This underestimation is due to inadequate characte...

  7. Mechanical Engineering Department technical abstracts

    SciTech Connect

    Denney, R.M.

    1982-07-01

    The Mechanical Engineering Department publishes listings of technical abstracts twice a year to inform readers of the broad range of technical activities in the Department, and to promote an exchange of ideas. Details of the work covered by an abstract may be obtained by contacting the author(s). Overall information about current activities of each of the Department's seven divisions precedes the technical abstracts.

  8. Contained Morcellation: Review of Current Methods and Future Directions

    PubMed Central

    Taylan, Enes; Sahin, Cagdas; Zeybek, Burak; Akdemir, Ali

    2017-01-01

    Power morcellation of surgical specimen during laparoscopic surgery is a practical technology that provides the opportunity to perform several minimally invasive procedures. However, this technology brought forward additional risks and complications associated with dissemination of both benign and malignant tissues inside the abdominal cavity. Based on startling cases, Food and Drug Administration (FDA) announced a discouraging statement on the use of power morcellators that decreased the number of minimally invasive approaches in the following period. As a response to these concerns and negative impacts of the FDA statement, researchers developed several new approaches resulting in contained or in-bag morcellation methods. In this review, we aimed to discuss these current methods and provide an insight for future developments. PMID:28352629

  9. Current methods for estimating the rate of photorespiration in leaves.

    PubMed

    Busch, F A

    2013-07-01

    Photorespiration is a process that competes with photosynthesis, in which Rubisco oxygenates, instead of carboxylates, its substrate ribulose 1,5-bisphosphate. The photorespiratory metabolism associated with the recovery of 3-phosphoglycerate is energetically costly and results in the release of previously fixed CO2. The ability to quantify photorespiration is gaining importance as a tool to help improve plant productivity in order to meet the increasing global food demand. In recent years, substantial progress has been made in the methods used to measure photorespiration. Current techniques are able to measure multiple aspects of photorespiration at different points along the photorespiratory C2 cycle. Six different methods used to estimate photorespiration are reviewed, and their advantages and disadvantages discussed.

  10. Current Human Reliability Analysis Methods Applied to Computerized Procedures

    SciTech Connect

    Ronald L. Boring

    2012-06-01

    Computerized procedures (CPs) are an emerging technology within nuclear power plant control rooms. While CPs have been implemented internationally in advanced control rooms, to date no US nuclear power plant has implemented CPs in its main control room (Fink et al., 2009). Yet, CPs are a reality of new plant builds and are an area of considerable interest to existing plants, which see advantages in terms of enhanced ease of use and easier records management by omitting the need for updating hardcopy procedures. The overall intent of this paper is to provide a characterization of human reliability analysis (HRA) issues for computerized procedures. It is beyond the scope of this document to propose a new HRA approach or to recommend specific methods or refinements to those methods. Rather, this paper serves as a review of current HRA as it may be used for the analysis and review of computerized procedures.

  11. Current HPLC Methods for Assay of Nano Drug Delivery Systems.

    PubMed

    Tekkeli, Serife Evrim Kepekci; Kiziltas, Mustafa Volkan

    2016-12-22

    In nano drug formulations the mechanism of release is a critical process to recognize controlled and targeted drug delivery systems. In order to gain high bioavailability and specificity from the drug to reach its therapeutic goal, the active substance must be loaded into the nanoparticles efficiently. Therefore, the amount in biological fluids or tissues and the remaining amount in nano carriers are very important parameters to understand the potential of the nano drug delivery systems. For this aim, suitable and validated quantitation methods are required to determine released drug concentrations from nano pharmaceutical formulations. HPLC (High Performance Liquid Chromatography) is one of the most common techniques used for determination of released drug content out of nano drug formulations, in different physical conditions, over different periods of time. Since there are many types of HPLC methods depending on detector and column types, it is a challenge for the researchers to choose a suitable method that is simple, fast and validated HPLC techniques for their nano drug delivery systems. This review's goal is to compare HPLC methods that are currently used in different nano drug delivery systems in order to provide detailed and useful information for researchers.

  12. Current and Prospective Methods for Plant Disease Detection

    PubMed Central

    Fang, Yi; Ramasamy, Ramaraja P.

    2015-01-01

    Food losses due to crop infections from pathogens such as bacteria, viruses and fungi are persistent issues in agriculture for centuries across the globe. In order to minimize the disease induced damage in crops during growth, harvest and postharvest processing, as well as to maximize productivity and ensure agricultural sustainability, advanced disease detection and prevention in crops are imperative. This paper reviews the direct and indirect disease identification methods currently used in agriculture. Laboratory-based techniques such as polymerase chain reaction (PCR), immunofluorescence (IF), fluorescence in-situ hybridization (FISH), enzyme-linked immunosorbent assay (ELISA), flow cytometry (FCM) and gas chromatography-mass spectrometry (GC-MS) are some of the direct detection methods. Indirect methods include thermography, fluorescence imaging and hyperspectral techniques. Finally, the review also provides a comprehensive overview of biosensors based on highly selective bio-recognition elements such as enzyme, antibody, DNA/RNA and bacteriophage as a new tool for the early identification of crop diseases. PMID:26287253

  13. Investigation of Current Methods to Identify Helicopter Gear Health

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Lewicki, David G.; Le, Dy D.

    2007-01-01

    This paper provides an overview of current vibration methods used to identify the health of helicopter transmission gears. The gears are critical to the transmission system that provides propulsion, lift and maneuvering of the helicopter. This paper reviews techniques used to process vibration data to calculate conditions indicators (CI s), guidelines used by the government aviation authorities in developing and certifying the Health and Usage Monitoring System (HUMS), condition and health indicators used in commercial HUMS, and different methods used to set thresholds to detect damage. Initial assessment of a method to set thresholds for vibration based condition indicators applied to flight and test rig data by evaluating differences in distributions between comparable transmissions are also discussed. Gear condition indicator FM4 values are compared on an OH58 helicopter during 14 maneuvers and an OH58 transmission test stand during crack propagation tests. Preliminary results show the distributions between healthy helicopter and rig data are comparable and distributions between healthy and damaged gears show significant differences.

  14. Investigation of Current Methods to Identify Helicopter Gear Health

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Lewicki, David G.; Le, Dy D.

    2007-01-01

    This paper provides an overview of current vibration methods used to identify the health of helicopter transmission gears. The gears are critical to the transmission system that provides propulsion, lift and maneuvering of the helicopter. This paper reviews techniques used to process vibration data to calculate conditions indicators (CI's), guidelines used by the government aviation authorities in developing and certifying the Health and Usage Monitoring System (HUMS), condition and health indicators used in commercial HUMS, and different methods used to set thresholds to detect damage. Initial assessment of a method to set thresholds for vibration based condition indicators applied to flight and test rig data by evaluating differences in distributions between comparable transmissions are also discussed. Gear condition indicator FM4 values are compared on an OH58 helicopter during 14 maneuvers and an OH58 transmission test stand during crack propagation tests. Preliminary results show the distributions between healthy helicopter and rig data are comparable and distributions between healthy and damaged gears show significant differences.

  15. A Critical Analysis of SocINDEX and Sociological Abstracts Using an Evaluation Method for the Practicing Bibliographer

    ERIC Educational Resources Information Center

    Mellone, James T.

    2010-01-01

    This study provides a database evaluation method for the practicing bibliographer that is more than a brief review yet less than a controlled experiment. The author establishes evaluation criteria in the context of the bibliographic instruction provided to meet the research requirements of undergraduate sociology majors at Queens College, City…

  16. Critical and supercritical current measurements by a magnetic induction method

    NASA Astrophysics Data System (ADS)

    Harris, E. A.; Bishop, J. E. L.; Havill, R. L.; Ward, P. J.

    1988-10-01

    The temperature dependence of the critical current and current-voltage characteristics at supercritical currents have been measured in the low field limit on toroidal samples of the ceramic high Tc superconductor YBa 2Cu 3O 7- δ by a contactless magnetic induction technique that is sensitive to the transport supercurrent but not to any intragrain current loops. The sample constitutes a tertiary winding on a small ferrite transformer core. The secondary voltage provides a very sensitive indication of when the critical current is exceeded, and when it is integrated it yields the supercritical current-voltage characteristic.

  17. Current Methods of Adipogenic Differentiation of Mesenchymal Stem Cells

    PubMed Central

    Scott, Michelle A.; Nguyen, Virginia T.; Levi, Benjamin

    2011-01-01

    There has been a recent increase in our understanding in the isolation, culture, and differentiation of mesenchymal stem cells (MSCs). Concomitantly, the availability of MSCs has increased, with cells now commercially available, including human MSCs from adipose tissue and bone marrow. Despite an increased understanding of MSC biology and an increase in their availability, standardization of techniques for adipogenic differentiation of MSCs is lacking. The following review will explore the variability in adipogenic differentiation in vitro, specifically in 3T3-L1 and primary MSCs derived from both adipose tissue and bone marrow. A review of alternative methods of adipogenic induction is also presented, including the use of specific peroxisome proliferator-activated receptor-gamma agonists as well as bone morphogenetic proteins. Finally, we define a standard, commonly used adipogenic differentiation medium in the hopes that this will be adopted for the future standardization of laboratory techniques—however, we also highlight the essentially arbitrary nature of this decision. With the current, rapid pace of electronic publications, it becomes imperative for standardization of such basic techniques so that interlaboratory results may be easily compared and interpreted. PMID:21526925

  18. Current methods of adipogenic differentiation of mesenchymal stem cells.

    PubMed

    Scott, Michelle A; Nguyen, Virginia T; Levi, Benjamin; James, Aaron W

    2011-10-01

    There has been a recent increase in our understanding in the isolation, culture, and differentiation of mesenchymal stem cells (MSCs). Concomitantly, the availability of MSCs has increased, with cells now commercially available, including human MSCs from adipose tissue and bone marrow. Despite an increased understanding of MSC biology and an increase in their availability, standardization of techniques for adipogenic differentiation of MSCs is lacking. The following review will explore the variability in adipogenic differentiation in vitro, specifically in 3T3-L1 and primary MSCs derived from both adipose tissue and bone marrow. A review of alternative methods of adipogenic induction is also presented, including the use of specific peroxisome proliferator-activated receptor-gamma agonists as well as bone morphogenetic proteins. Finally, we define a standard, commonly used adipogenic differentiation medium in the hopes that this will be adopted for the future standardization of laboratory techniques--however, we also highlight the essentially arbitrary nature of this decision. With the current, rapid pace of electronic publications, it becomes imperative for standardization of such basic techniques so that interlaboratory results may be easily compared and interpreted.

  19. Current methods of laboratory diagnosis of Chlamydia trachomatis infections.

    PubMed Central

    Black, C M

    1997-01-01

    Infections caused by Chlamydia trachomatis are probably the most common sexually transmitted diseases in the United States. Commonly unrecognized and often inadequately treated, chlamydial infections can ascend the reproductive tract and cause pelvic inflammatory disease, which often results in the devastating consequences of infertility, ectopic pregnancy, or chronic pelvic pain. C. trachomatis infections are also known to increase the risk for human immunodeficiency virus infection. The obligate intracellular life cycle of C. trachomatis has traditionally required laboratory diagnostic tests that are technically demanding, labor-intensive, expensive, and difficult to access. In spite of these historical challenges, however, laboratory diagnosis of C. trachomatis has been a rapidly advancing area in which there is presently a wide array of commercial diagnostic technologies, costs, manufacturers. This review describes and compares the diagnostic methods for C. trachomatis infection that are currently approved for use in the United States, including the newest DNA amplification technologies which are yet to be licensed for commercial use. Issues to consider in selecting a test for purposes of screening versus diagnosis based on prevalence, performance, legal, social, and cost issues are also discussed. PMID:8993862

  20. Apparatuses and method for converting electromagnetic radiation to direct current

    DOEpatents

    Kotter, Dale K; Novack, Steven D

    2014-09-30

    An energy conversion device may include a first antenna and a second antenna configured to generate an AC current responsive to incident radiation, at least one stripline, and a rectifier coupled with the at least one stripline along a length of the at least one stripline. An energy conversion device may also include an array of nanoantennas configured to generate an AC current in response to receiving incident radiation. Each nanoantenna of the array includes a pair of resonant elements, and a shared rectifier operably coupled to the pair of resonant elements, the shared rectifier configured to convert the AC current to a DC current. The energy conversion device may further include a bus structure operably coupled with the array of nanoantennas and configured to receive the DC current from the array of nanoantennas and transmit the DC current away from the array of nanoantennas.

  1. 76 FR 71934 - Tobacco Transition Payment Program; Availability of Current Assessment Methods Determination...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-21

    ... Farm Service Agency Tobacco Transition Payment Program; Availability of Current Assessment Methods... regarding two consolidated determinations with respect to the current methods used to calculate manufacturer... matter, that the continued use of current procedure to calculate manufacturer and importer assessments...

  2. Electrochemical synthesis of nanosized hydroxyapatite by pulsed direct current method

    SciTech Connect

    Nur, Adrian; Rahmawati, Alifah; Ilmi, Noor Izzati; Affandi, Samsudin; Widjaja, Arief

    2014-02-24

    Synthesis of nanosized of hydroxyapatite (HA) by electrochemical pulsed direct current (PDC) method has been studied. The aim of this work is to study the influence of various PDC parameters (pH initial, electrode distance, duty cycle, frequency, and amplitude) on particle surface area of HA powders. The electrochemical synthesis was prepared in solution Ca{sup 2+}/EDTA{sup 4−}/PO{sub 4}{sup 3+} at concentration 0.25/0.25/0.15 M for 24 h. The electrochemical cell was consisted of two carbon rectangular electrodes connected to a function generator to produce PDC. There were two treatments for particles after electrosynthesized, namely without aging and aged for 2 days at 40 °C. For both cases, the particles were filtered and washed by demineralized water to eliminate the impurities and unreacted reactants. Then, the particles were dried at 100 °C for 2 days. The dried particles were characterized by X-ray diffraction, surface area analyzer, scanning electron microscopy (SEM), Fourier transform infrared spectra and thermogravimetric and differential thermal analysis. HA particles can be produced when the initial pH > 6. The aging process has significant effect on the produced HA particles. SEM images of HA particles showed that the powders consisted of agglomerates composed of fine crystallites and have morphology plate-like and sphere. The surface area of HA particles is in the range of 25 – 91 m{sup 2}/g. The largest particle surface area of HA was produced at 4 cm electrode distance, 80% cycle duty, frequency 0.1 Hz, amplitude 9 V and with aging process.

  3. A Novel Method Using Abstract Convex Underestimation in Ab-Initio Protein Structure Prediction for Guiding Search in Conformational Feature Space.

    PubMed

    Hao, Xiao-Hu; Zhang, Gui-Jun; Zhou, Xiao-Gen; Yu, Xu-Feng

    2016-01-01

    To address the searching problem of protein conformational space in ab-initio protein structure prediction, a novel method using abstract convex underestimation (ACUE) based on the framework of evolutionary algorithm was proposed. Computing such conformations, essential to associate structural and functional information with gene sequences, is challenging due to the high-dimensionality and rugged energy surface of the protein conformational space. As a consequence, the dimension of protein conformational space should be reduced to a proper level. In this paper, the high-dimensionality original conformational space was converted into feature space whose dimension is considerably reduced by feature extraction technique. And, the underestimate space could be constructed according to abstract convex theory. Thus, the entropy effect caused by searching in the high-dimensionality conformational space could be avoided through such conversion. The tight lower bound estimate information was obtained to guide the searching direction, and the invalid searching area in which the global optimal solution is not located could be eliminated in advance. Moreover, instead of expensively calculating the energy of conformations in the original conformational space, the estimate value is employed to judge if the conformation is worth exploring to reduce the evaluation time, thereby making computational cost lower and the searching process more efficient. Additionally, fragment assembly and the Monte Carlo method are combined to generate a series of metastable conformations by sampling in the conformational space. The proposed method provides a novel technique to solve the searching problem of protein conformational space. Twenty small-to-medium structurally diverse proteins were tested, and the proposed ACUE method was compared with It Fix, HEA, Rosetta and the developed method LEDE without underestimate information. Test results show that the ACUE method can more rapidly and more

  4. CURRENT METHODS AND RESEARCH STRATEGIES FOR MODELING ATMOSPHERIC MERCURY

    EPA Science Inventory

    The atmospheric pathway of the global mercury cycle is known to be the primary source of mercury contamination to most threatened aquatic ecosystems. Current efforts toward numerical modeling of atmospheric mercury are hindered by an incomplete understanding of emissions, atmosp...

  5. Are all abstracts created equal??

    PubMed

    Weinert, Clarann

    2010-05-01

    The preparation of a strong, convincing abstract is a necessary professional skill and prized art form for nurse scientists and clinical scholars. The power and the role of an abstract are often overlooked. Abstracts are used in a variety of scholarly forums including articles submitted for publication, research proposals, and responses to "calls for abstracts" for presentations at scientific conferences. The purpose of this article is to emphasize the highlights of the "art" rather than the "cookbook" details associated with preparing an abstract. Each of the critical stages of abstract development is explored-planning, drafting, reviewing, peer reviewing, editing, and packaging. Likewise, a few, hopefully helpful, hints on developing the six key elements-background, purpose, sample, methods, results, and implications-of the scientific abstract are given. Polishing, the essential skill of preparing an abstract, takes time and persistence and will pay off in the long run. The well-crafted abstract is an initial step in the process of getting research and scholarly pursuits noticed and accepted.

  6. A comparison of methods currently used in inclusive design.

    PubMed

    Goodman-Deane, Joy; Ward, James; Hosking, Ian; Clarkson, P John

    2014-07-01

    Inclusive design has unique challenges because it aims to improve usability for a wide range of users. This typically includes people with lower levels of ability, as well as mainstream users. This paper examines the effectiveness of two methods that are used in inclusive design: user trials and exclusion calculations (an inclusive design inspection method). A study examined three autoinjectors using both methods (n=30 for the user trials). The usability issues identified by each method are compared and the effectiveness of the methods is discussed. The study found that each method identified different kinds of issues, all of which are important for inclusive design. We therefore conclude that a combination of methods should be used in inclusive design rather than relying on a single method. Recommendations are also given for how the individual methods can be used more effectively in this context.

  7. System and method for generating current by selective electron heating

    DOEpatents

    Fisch, Nathaniel J.; Boozer, Allen H.

    1984-01-01

    A system for the generation of toroidal current in a plasma which is prepared in a toroidal magnetic field. The system utilizes the injection of high-frequency waves into the plasma by means of waveguides. The wave frequency and polarization are chosen such that when the waveguides are tilted in a predetermined fashion, the wave energy is absorbed preferentially by electrons traveling in one toroidal direction. The absorption of energy in this manner produces a toroidal electric current even when the injected waves themselves do not have substantial toroidal momentum. This current can be continuously maintained at modest cost in power and may be used to confine the plasma. The system can operate efficiently on fusion grade tokamak plasmas.

  8. A method for sputtering with low frequency alternating current

    SciTech Connect

    Timberlake, J.R.

    1993-12-31

    Low frequency alternating current sputtering is provided by connecting a low frequency alternating current to a high voltage transformer having outer taps and a center tap for stepping up the voltage of the alternating currentThe center tap of the tmsformer is connected to a vacuum vessel containing argon or helium gas. Target electrodes, in close proximity to each other, and containing material with which the substrates will be coated, are connected to the outer taps of the ftwsformer. With an applied potential, the gas will ionize and sputtering from the target electrodes onto the substrate will then result. The target electrodes can be copper or boron, and the substrate can be stainless steel, aluminum, or titanium. Copper coatings produced are used in place of nickel and/or copper striking.

  9. Method for sputtering with low frequency alternating current

    DOEpatents

    Timberlake, J.R.

    1996-04-30

    Low frequency alternating current sputtering is provided by connecting a low frequency alternating current source to a high voltage transformer having outer taps and a center tap for stepping up the voltage of the alternating current. The center tap of the transformer is connected to a vacuum vessel containing argon or helium gas. Target electrodes, in close proximity to each other, and containing material with which the substrates will be coated, are connected to the outer taps of the transformer. With an applied potential, the gas will ionize and sputtering from the target electrodes onto the substrate will then result. The target electrodes can be copper or boron, and the substrate can be stainless steel, aluminum, or titanium. Copper coatings produced are used in place of nickel and/or copper striking. 6 figs.

  10. Method for sputtering with low frequency alternating current

    DOEpatents

    Timberlake, John R.

    1996-01-01

    Low frequency alternating current sputtering is provided by connecting a low frequency alternating current source to a high voltage transformer having outer taps and a center tap for stepping up the voltage of the alternating current. The center tap of the transformer is connected to a vacuum vessel containing argon or helium gas. Target electrodes, in close proximity to each other, and containing material with which the substrates will be coated, are connected to the outer taps of the transformer. With an applied potential, the gas will ionize and sputtering from the target electrodes onto the substrate will then result. The target electrodes can be copper or boron, and the substrate can be stainless steel, aluminum, or titanium. Copper coatings produced are used in place of nickel and/or copper striking.

  11. A Structured Implicit Abstraction Method to Evaluate whether Content of Counseling before Prostate Cancer Screening is Consistent with Recommendations by Experts

    PubMed Central

    Farrell, Michael H.; Chan, Evelyn C.Y.; Ladouceur, Lynnea K.; Stein, Jeffrey M.

    2009-01-01

    Objective To assess the content of counseling about prostate-specific antigen (PSA) screening. Guidelines recommend informed consent before screening because of concerns about benefits versus risks. As part of the professional practice standard for informed consent, clinicians should include content customarily provided by experts. Methods 40 transcripts of conversations between medicine residents and standardized patients were abstracted using an instrument derived from an expert Delphi panel that ranked 10 “facts that experts believe men ought to know.” Results Transcripts contained definite criteria for an average of 1.7 facts, and either definite or partial criteria for 5.1 facts. Second- and third-year residents presented more facts than interns (p=0.01). The most common facts were “false positive PSA tests can occur” and “use of the PSA test as a screening test is controversial.” There was an r=0.88 correlation between inclusion by residents and the experts’ ranking. Conclusion Counseling varied but most transcripts included some expert-recommended facts. The absence of other facts could be a quality deficit or an effort to prioritize messages and lessen cognitive demands on the patient. Practice implications Clinicians should adapt counseling for each patient, but our abstraction approach may help to assess the quality of informed consent over larger populations. PMID:19837527

  12. Validation of a New Placebo Interferential Current Method: A New Placebo Method of Electrostimulation.

    PubMed

    Mendonça Araújo, Fernanda; Alves Menezes, Mayara; Martins de Araújo, Ariane; Abner Dos Santos Sousa, Thiago; Vasconcelos Lima, Lucas; Ádan Nunes Carvalho, Elyson; Melo DeSantana, Josimari

    2016-04-05

    OBJECTIVE : The present study aimed to investigate if a new placebo device for interferential current (IFC) that delivers current during only the first 40 seconds of stimulation is effective at promoting adequate subject blinding. METHODS : Seventy-five subjects were recruited and enrolled into three groups: active IFC, inactive placebo, and new placebo. Pressure pain threshold (PPT), cutaneous sensory threshold (CST), and pain intensity were measured before and after the intervention. After the final assessment, the subjects and the investigator who applied the current were asked about the type of stimulation administered. RESULTS : None of the placebo forms studied resulted in significant changes to PPT, CST, or pain intensity. The subjects stimulated with active IFC at high intensities (> 17 mA) of stimulation showed higher PPT and CST and lower pain intensity than subjects stimulated at low intensities (p< 0.03). The new placebo method blinded the investigator in 100% of cases of IFC and 60% of subjects stimulated, whereas for inactive placebo, the investigator was blinded at a rate of 0% and 34% of subjects. CONCLUSION : The new method of placebo IFC was effective for blinding of research investigators and most of the active IFC-treated subjects, promoting an appropriate placebo method.

  13. Evaluation of Current Assessment Methods in Engineering Entrepreneurship Education

    ERIC Educational Resources Information Center

    Purzer, Senay; Fila, Nicholas; Nataraja, Kavin

    2016-01-01

    Quality assessment is an essential component of education that allows educators to support student learning and improve educational programs. The purpose of this study is to evaluate the current state of assessment in engineering entrepreneurship education. We identified 52 assessment instruments covered in 29 journal articles and conference…

  14. Current Methods for Evaluation of Physical Security System Effectiveness.

    DTIC Science & Technology

    1981-05-01

    Method (Mission Research Corporation ) FSNM Fixed Site Neutralization Model (Vector Research, Inc., for Sandia Laboratories, Albuquerque) PROSE...METHODS a. Security System Performance Assessment Method (SSPAM) (Mission Research Corporation )--The SSPAM concept is an ambitious attempt to carry...Descriptions; Volume III: SSPAM Results; MRC-R-564, Mission Research Corporation , April 1980 Sanderlin, J.C., and Rathman, C.E., A Concept for

  15. Shunt attachment and method for interfacing current collection systems

    DOEpatents

    Denney, P.E.; Iyer, N.C.; Hannan, W.F. III.

    1992-12-08

    A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature. 6 figs.

  16. Shunt attachment and method for interfacing current collection systems

    DOEpatents

    Denney, Paul E.; Iyer, Natraj C.; Hannan, III, William F.

    1992-01-01

    A composite brush to shunt attachment wherein a volatile component of a composite but mostly metallic brush, used for current collection purposes, does not upon welding or brazing, adversely affect the formation of the interfacial bond with a conductive shunt which carries the current from the zone of the brush. The brush to shunt attachment for a brush material of copper-graphite composite and a shunt of copper, or substituting silver for copper as an alternative, is made through a hot isostatic pressing (HIP). The HIP process includes applying high pressure and temperature simultaneously at the brush to shunt interface, after it has been isolated or canned in a metal casing in which the air adjacent to the interface has been evacuated and the interfacial area has been sealed before the application of pressure and temperature.

  17. Shielding current analysis by current-vector-potential method: Application to HTS film with multiply-connected structure

    NASA Astrophysics Data System (ADS)

    Kamitani, A.; Takayama, T.; Ikuno, S.

    2013-11-01

    The performance of the virtual voltage method is compared with that of the conventional method in which integral forms of Faraday’s law along crack surfaces are treated as natural boundary conditions. As a result, it is found that there is a significant difference between numerical solutions by the two methods. In this sense, not the conventional method but the virtual voltage method should be employed to the shielding current analysis in a high-temperature superconducting film with cracks. By means of the virtual voltage method, the influence of a crack on the inductive method is investigated numerically. The results of computations show that, if the threshold current changes remarkably from its ambient value, a part of a crack is contained in the projection of the field-generating coil onto the film surface. Furthermore, the applicability of the inductive method to the crack detection is investigated numerically.

  18. Animal models of transcranial direct current stimulation: Methods and mechanisms.

    PubMed

    Jackson, Mark P; Rahman, Asif; Lafon, Belen; Kronberg, Gregory; Ling, Doris; Parra, Lucas C; Bikson, Marom

    2016-11-01

    The objective of this review is to summarize the contribution of animal research using direct current stimulation (DCS) to our understanding of the physiological effects of transcranial direct current stimulation (tDCS). We comprehensively address experimental methodology in animal studies, broadly classified as: (1) transcranial stimulation; (2) direct cortical stimulation in vivo and (3) in vitro models. In each case advantages and disadvantages for translational research are discussed including dose translation and the overarching "quasi-uniform" assumption, which underpins translational relevance in all animal models of tDCS. Terminology such as anode, cathode, inward current, outward current, current density, electric field, and uniform are defined. Though we put key animal experiments spanning decades in perspective, our goal is not simply an exhaustive cataloging of relevant animal studies, but rather to put them in context of ongoing efforts to improve tDCS. Cellular targets, including excitatory neuronal somas, dendrites, axons, interneurons, glial cells, and endothelial cells are considered. We emphasize neurons are always depolarized and hyperpolarized such that effects of DCS on neuronal excitability can only be evaluated within subcellular regions of the neuron. Findings from animal studies on the effects of DCS on plasticity (LTP/LTD) and network oscillations are reviewed extensively. Any endogenous phenomena dependent on membrane potential changes are, in theory, susceptible to modulation by DCS. The relevance of morphological changes (galvanotropy) to tDCS is also considered, as we suggest microscopic migration of axon terminals or dendritic spines may be relevant during tDCS. A majority of clinical studies using tDCS employ a simplistic dose strategy where excitability is singularly increased or decreased under the anode and cathode, respectively. We discuss how this strategy, itself based on classic animal studies, cannot account for the

  19. Abstraction and Consolidation

    ERIC Educational Resources Information Center

    Monaghan, John; Ozmantar, Mehmet Fatih

    2004-01-01

    What is involved in consolidating a new mathematical abstraction? This paper examines the work of one student who was working on a task designed to consolidate two recently constructed absolute function abstractions. The study adopts an activity theoretic model of abstraction in context. Selected protocol data are presented. The initial state of…

  20. Abstraction and Consolidation

    ERIC Educational Resources Information Center

    Monaghan, John; Ozmantar, Mehmet Fatih

    2006-01-01

    The framework for this paper is a recently developed theory of abstraction in context. The paper reports on data collected from one student working on tasks concerned with absolute value functions. It examines the relationship between mathematical constructions and abstractions. It argues that an abstraction is a consolidated construction that can…

  1. [Current trends in the development of salmonella detection methods].

    PubMed

    Krüger, G

    1989-11-01

    The cultural methods require 4 to 7 days for presumptive evidence of Salmonella in foodstuffs. Attempts in time shortening have resulted in combination of pre-enrichment or selective enrichment with time saving genetical or immunological tests. Proceedings of enzyme immunoassays for applications in Salmonella screening are important. Involving monoclonal antibodies, fluorescent or chemiluminescent substrates, there are some commercial Salmonella test kits. Especially rapid EIA methods, here advantages and disadvantages are discussed.

  2. Methods of and apparatus for levitating an eddy current probe

    DOEpatents

    Stone, William J.

    1988-05-03

    An eddy current probe is supported against the force of gravity with an air earing while being urged horizontally toward the specimen being examined by a spring and displaced horizontally against the force of the spring pneumatically. The pneumatic displacement is accomplished by flowing air between a plenum chamber fixed with respect to the probe and the surface of the specimen. In this way, the surface of the specimen can be examined without making mechanical contact therewith while precisely controlling the distance at which the probe stands-off from the surface of the specimen.

  3. Stellar Presentations (Abstract)

    NASA Astrophysics Data System (ADS)

    Young, D.

    2015-12-01

    (Abstract only) The AAVSO is in the process of expanding its education, outreach and speakers bureau program. powerpoint presentations prepared for specific target audiences such as AAVSO members, educators, students, the general public, and Science Olympiad teams, coaches, event supervisors, and state directors will be available online for members to use. The presentations range from specific and general content relating to stellar evolution and variable stars to specific activities for a workshop environment. A presentation—even with a general topic—that works for high school students will not work for educators, Science Olympiad teams, or the general public. Each audience is unique and requires a different approach. The current environment necessitates presentations that are captivating for a younger generation that is embedded in a highly visual and sound-bite world of social media, twitter and U-Tube, and mobile devices. For educators, presentations and workshops for themselves and their students must support the Next Generation Science Standards (NGSS), the Common Core Content Standards, and the Science Technology, Engineering and Mathematics (STEM) initiative. Current best practices for developing relevant and engaging powerpoint presentations to deliver information to a variety of targeted audiences will be presented along with several examples.

  4. Current stem cell delivery methods for myocardial repair.

    PubMed

    Sheng, Calvin C; Zhou, Li; Hao, Jijun

    2013-01-01

    Heart failure commonly results from an irreparable damage due to cardiovascular diseases (CVDs), the leading cause of morbidity and mortality in the United States. In recent years, the rapid advancements in stem cell research have garnered much praise for paving the way to novel therapies in reversing myocardial injuries. Cell types currently investigated for cellular delivery include embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and adult stem cell lineages such as skeletal myoblasts, bone-marrow-derived stem cells (BMSCs), mesenchymal stem cells (MSCs), and cardiac stem cells (CSCs). To engraft these cells into patients' damaged myocardium, a variety of approaches (intramyocardial, transendocardial, transcoronary, venous, intravenous, intracoronary artery and retrograde venous administrations and bioengineered tissue transplantation) have been developed and explored. In this paper, we will discuss the pros and cons of these delivery modalities, the current state of their therapeutic potentials, and a multifaceted evaluation of their reported clinical feasibility, safety, and efficacy. While the issues of optimal delivery approach, the best progenitor stem cell type, the most effective dose, and timing of administration remain to be addressed, we are highly optimistic that stem cell therapy will provide a clinically viable option for myocardial regeneration.

  5. Does the Current Minimum Validate (or Invalidate) Cycle Prediction Methods?

    NASA Technical Reports Server (NTRS)

    Hathaway, David H.

    2010-01-01

    This deep, extended solar minimum and the slow start to Cycle 24 strongly suggest that Cycle 24 will be a small cycle. A wide array of solar cycle prediction techniques have been applied to predicting the amplitude of Cycle 24 with widely different results. Current conditions and new observations indicate that some highly regarded techniques now appear to have doubtful utility. Geomagnetic precursors have been reliable in the past and can be tested with 12 cycles of data. Of the three primary geomagnetic precursors only one (the minimum level of geomagnetic activity) suggests a small cycle. The Sun's polar field strength has also been used to successfully predict the last three cycles. The current weak polar fields are indicative of a small cycle. For the first time, dynamo models have been used to predict the size of a solar cycle but with opposite predictions depending on the model and the data assimilation. However, new measurements of the surface meridional flow indicate that the flow was substantially faster on the approach to Cycle 24 minimum than at Cycle 23 minimum. In both dynamo predictions a faster meridional flow should have given a shorter cycle 23 with stronger polar fields. This suggests that these dynamo models are not yet ready for solar cycle prediction.

  6. Abstraction and Problem Reformulation

    NASA Technical Reports Server (NTRS)

    Giunchiglia, Fausto

    1992-01-01

    In work done jointly with Toby Walsh, the author has provided a sound theoretical foundation to the process of reasoning with abstraction (GW90c, GWS9, GW9Ob, GW90a). The notion of abstraction formalized in this work can be informally described as: (property 1), the process of mapping a representation of a problem, called (following historical convention (Sac74)) the 'ground' representation, onto a new representation, called the 'abstract' representation, which, (property 2) helps deal with the problem in the original search space by preserving certain desirable properties and (property 3) is simpler to handle as it is constructed from the ground representation by "throwing away details". One desirable property preserved by an abstraction is provability; often there is a relationship between provability in the ground representation and provability in the abstract representation. Another can be deduction or, possibly inconsistency. By 'throwing away details' we usually mean that the problem is described in a language with a smaller search space (for instance a propositional language or a language without variables) in which formulae of the abstract representation are obtained from the formulae of the ground representation by the use of some terminating rewriting technique. Often we require that the use of abstraction results in more efficient .reasoning. However, it might simply increase the number of facts asserted (eg. by allowing, in practice, the exploration of deeper search spaces or by implementing some form of learning). Among all abstractions, three very important classes have been identified. They relate the set of facts provable in the ground space to those provable in the abstract space. We call: TI abstractions all those abstractions where the abstractions of all the provable facts of the ground space are provable in the abstract space; TD abstractions all those abstractions wllere the 'unabstractions' of all the provable facts of the abstract space are

  7. Protein Microarrays with Novel Microfluidic Methods: Current Advances.

    PubMed

    Dixit, Chandra K; Aguirre, Gerson R

    2014-07-01

    Microfluidic-based micromosaic technology has allowed the pattering of recognition elements in restricted micrometer scale areas with high precision. This controlled patterning enabled the development of highly multiplexed arrays multiple analyte detection. This arraying technology was first introduced in the beginning of 2001 and holds tremendous potential to revolutionize microarray development and analyte detection. Later, several microfluidic methods were developed for microarray application. In this review we discuss these novel methods and approaches which leverage the property of microfluidic technologies to significantly improve various physical aspects of microarray technology, such as enhanced imprinting homogeneity, stability of the immobilized biomolecules, decreasing assay times, and reduction of the costs and of the bulky instrumentation.

  8. Current methodology and methods in psychophysiological studies of creative thinking.

    PubMed

    Bechtereva, N P; Danko, S G; Medvedev, S V

    2007-05-01

    Important points on methodology and detailed description of methods used in polymodal psychophysiological studies of human verbal creative thinking are presented. The psychophysiological studies were conducted with healthy volunteers during implementations of specially developed and adapted psychological tests aimed to bring the subjects into states of verbal creative thinking. Four different task sets ("story composition", "associative chains", "original definitions", "proverb sense flipping") were developed and applied. Positron emission tomography of regional cerebral blood flow (rCBF) and state-related quantitative electroencephalography (power and coherence evaluated) were used. The effectiveness of the methods is illustrated with figures.

  9. [Detection of early forms of keratoconus - current screening methods].

    PubMed

    Goebels, S; Eppig, T; Seitz, B; Langenbucher, A

    2013-10-01

    The detection of early forms of keratoconus is still a challenge for clinicians. Beside clinical examination and diagnosis of keratoconus, a series of examination techniques has been established in clinical routine to assist in the diagnosis of early forms of keratoconus: corneal topography for measuring the geometry of the corneal front surface, tomography for measuring the geometry of structures of the anterior segment of the eye, aberrometers for evaluation of optical aberrations of the entire eye, and a system for investigation of the biomechanical properties of the cornea. These instruments provide software tools which are designed for diagnostic support in keratoconus. In this review article, we provide an overview over the spectrum of measurement systems currently on the market focussing on their performance for detecting (early forms of) keratoconus. In detail, we focus on dedicated keratoconus screening software modules of topography, tomography, aberrometry and biomechanics.

  10. Abstraction and reformulation in artificial intelligence.

    PubMed Central

    Holte, Robert C.; Choueiry, Berthe Y.

    2003-01-01

    This paper contributes in two ways to the aims of this special issue on abstraction. The first is to show that there are compelling reasons motivating the use of abstraction in the purely computational realm of artificial intelligence. The second is to contribute to the overall discussion of the nature of abstraction by providing examples of the abstraction processes currently used in artificial intelligence. Although each type of abstraction is specific to a somewhat narrow context, it is hoped that collectively they illustrate the richness and variety of abstraction in its fullest sense. PMID:12903653

  11. Limitations of the current methods used to compute meteors orbits

    NASA Astrophysics Data System (ADS)

    Egal, A.; Gural, P.; Vaubaillon, J.; Colas, F.; Thuillot, W.

    2015-10-01

    The Cameras for BEtter Resolution NETwork (CABERNET) project aims to provide the most accurate meteoroid orbits achievable working with digital recordings of night sky imagery. The level of performance obtained is governed by the technical attributes of the collection systems and having both accurate and robust data processing. The technical challenges have been met by employing three cameras, each with a field of view of 40°x26° and a spatial (angular) resolution of 0.01°/pixel. The single image snapshots of meteors achieve temporal discrimination along the track through the use of an electronic shutter coupled to the cameras, operating at a sample rate between 100Hz and 200Hz. The numerical processing of meteor trajectories has already been explored by many authors. This included an examination of the intersecting planes method developed by Ceplecha (1987), the least squares method of Borovicka (1990), and the multi-fit parameterization method published by Gural (2012). After a comparison of these three techniques, we chose to implement Gural 's method, employing several non-linear minimization techniques and trying to match the modeling as close as possible to the basic data measured, i.e. the meteor space-time positions in the sequence of images. This approach results in a more precise and reliable way to determine both the meteor trajectory and velocity through the atmosphere.

  12. Endoscopic Evaluation of Adenoids: Reproducibility Analysis of Current Methods

    PubMed Central

    Hermann, Juliana Sato; Sallum, Ana Carolina; Pignatari, Shirley Shizue Nagata

    2013-01-01

    Objectives To investigate intra- and interexaminers' reproducibility of usual adenoid hypertrophy assessment methods, according to nasofiberendoscopic examination. Methods Forty children of both sexes, ages ranging between 4 and 14 years, presenting with nasal obstruction and oral breathing suspected to be caused by adenoid hypertrophy, were enrolled in this study. Patients were evaluated by nasofiberendoscopy, and records were referred to and evaluated by two experienced otolaryngologists. Examiners analysed the records according to different evaluation methods; i.e., estimated, and measured percentage of choanal occlusion; as well as subjective and objective classificatory systems of adenoid hypertrophy. Results Data disclosed excellent intraexaminer reproducibility for both estimated and measured choanal occlusion. analysis revealed lower reproducibility rates of estimated in relation to measured choanal occlusion. Measured choanal occlusion also demonstrated less agreement among evaluations made through the right and left sides of the nasal cavity. Alternatively, intra- and interexaminers reliability analysis revealed higher agreement for subjective than objective classificatory system. Besides, subjective method demonstrated higher agreement than the objective classificatory system, when opposite sides were compared. Conclusion Our results suggest that measured is superior to estimated percentage of choanal occlusion, particularly if employed bilaterally, diminishing the lack of agreement between sides. When adenoid categorization is used instead, the authors recommend subjective rather than objective classificatory system of adenoid hypertrophy. PMID:23526477

  13. 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…

  14. The Quasicontinuum Method: Overview, applications and current directions

    NASA Astrophysics Data System (ADS)

    Miller, Ronald E.; Tadmor, E. B.

    2002-10-01

    The Quasicontinuum (QC) Method, originally conceived and developed by Tadmor, Ortiz and Phillips [1] in 1996, has since seen a great deal of development and application by a number of researchers. The idea of the method is a relatively simple one. With the goal of modeling an atomistic system without explicitly treating every atom in the problem, the QC provides a framework whereby degrees of freedom are judiciously eliminated and force/energy calculations are expedited. This is combined with adaptive model refinement to ensure that full atomistic detail is retained in regions of the problem where it is required while continuum assumptions reduce the computational demand elsewhere. This article provides a review of the method, from its original motivations and formulation to recent improvements and developments. A summary of the important mechanics of materials results that have been obtained using the QC approach is presented. Finally, several related modeling techniques from the literature are briefly discussed. As an accompaniment to this paper, a website designed to serve as a clearinghouse for information on the QC method has been established at www.qcmethod.com. The site includes information on QC research, links to researchers, downloadable QC code and documentation.

  15. Generalized Weighted Residual Method; Advancements and Current Studies

    NASA Astrophysics Data System (ADS)

    Scheffel, Jan; Lindvall, Kristoffer

    2016-10-01

    The Generalized Weighted Residual Method (GWRM) is a time-spectral method for solving initial value partial differential equations. The GWRM treats the temporal, spatial, and parameter domains by projecting the residual to a Chebyshev polynomial space, with the variational principle being that the residual is zero. This treatment provides a global semi-analytical solution. However, straightforward global solution is not economical. One remedy is the inclusion of spatial and temporal sub-domains with coupled internal boundary conditions, which decreases memory requirements and introduces sparse matrices. Only the equations pertaining to the boundary conditions need be solved globally, making the method parallelizable in time. Efficient solution of the linearized ideal MHD stability equations of screw-pinch equilibria are proved possible. The GWRM has also been used to solve strongly nonlinear ODEs such as the Lorenz equations (1984), and is capable of competing with finite time difference schemes in terms of both accuracy and efficiency. GWRM solutions of linear and nonlinear model problems of interest for stability and turbulence modelling will be presented, including detailed comparisons with time stepping methods.

  16. Protein Microarrays with Novel Microfluidic Methods: Current Advances

    PubMed Central

    Dixit, Chandra K.; Aguirre, Gerson R.

    2014-01-01

    Microfluidic-based micromosaic technology has allowed the pattering of recognition elements in restricted micrometer scale areas with high precision. This controlled patterning enabled the development of highly multiplexed arrays multiple analyte detection. This arraying technology was first introduced in the beginning of 2001 and holds tremendous potential to revolutionize microarray development and analyte detection. Later, several microfluidic methods were developed for microarray application. In this review we discuss these novel methods and approaches which leverage the property of microfluidic technologies to significantly improve various physical aspects of microarray technology, such as enhanced imprinting homogeneity, stability of the immobilized biomolecules, decreasing assay times, and reduction of the costs and of the bulky instrumentation. PMID:27600343

  17. Fraley's syndrome: case report and update on current diagnostic methods

    SciTech Connect

    Zuckier, L.S.; Patel, Y.D.; Fine, E.J.; Koenigsberg, M.

    1988-01-01

    A 38-year-old woman presented with fever, right flank pain, and a clinical diagnosis of pyelonephritis. Work-up revealed the presence of a crossing arterial branch causing obstruction of the superior infundibulum of the right kidney, which is an uncommon cause of nephralgia and urinary infection initially described by Fraley in 1966. Intravenous urography, retrograde pyelography, and angiography remain the mainstay of diagnosis, much as in the initial descriptions of this entity. (/sup 131/I)Hippuran imaging, with analysis of the upper and lower pole regions of interest, provides a simple yet powerful method of evaluating functional and excretory changes in the superior infundibulum, and has proved more efficacious than previously reported whole-kidney renograms. Renal scintigraphy represents a relatively noninvasive method of serial functional examination in this disorder. Ultrasound imaging, by monitoring upper-pole dilatation, may provide complementary morphologic information important for long-term follow-up.

  18. Imaging of intestinal fibrosis: current challenges and future methods

    PubMed Central

    Higgins, Peter DR

    2016-01-01

    Crohn’s disease (CD) activity assessments are dominated by inflammatory changes without discrete measurement of the coexisting fibrotic contribution to total bowel damage. Intestinal fibrosis impacts the development of severe structural complications and the overall natural history of CD. Measuring intestinal fibrosis is challenging and existing methods of disease assessment are unable to reliably distinguish fibrosis from inflammation. Both the immediate clinical need to measure fibrosis for therapeutic decision-making and the near-future need for tools to assess pipeline anti-fibrotic medications highlight the demand for biomarkers of fibrosis in CD. Developing non-invasive technologies exploit changes in intestinal perfusion, mechanical properties, and macromolecular content to provide quantitative markers of fibrosis. In this review of existing and experimental technologies for imaging intestinal fibrosis, we discuss the expanding capabilities of quantitative MR and ultrasound imaging, encouraging developments in non-invasive elastography, and emerging novel methods including photoacoustic imaging. PMID:27536361

  19. Current methods for inducing pluripotency in somatic cells.

    PubMed

    Tavernier, Geertrui; Mlody, Barbara; Demeester, Jo; Adjaye, James; De Smedt, Stefaan C

    2013-05-28

    The groundbreaking discovery of reprogramming fibroblasts towards pluripotency merely by introducing four transcription factors (OCT4, SOX2, KLF4 and c-MYC) by means of retroviral transduction has created a promising revolution in the field of regenerative medicine. These so-called induced pluripotent stem cells (iPSCs) can provide a cell source for disease-modelling, drug-screening platforms, and transplantation strategies to treat incurable degenerative diseases, while circumventing the ethical issues and immune rejections associated with the use of non-autologous embryonic stem cells. The risk of insertional mutagenesis, caused both by the viral and transgene nature of the technique has proven to be the major limitation for iPSCs to be used in a clinical setting. In view of this, a variety of alternative techniques have been developed to induce pluripotency in somatic cells. This review provides an overview on current reprogramming protocols, discusses their pros and cons and future challenges to provide safe and transgene-free iPSCs.

  20. Modelling abstraction licensing strategies ahead of the UK's water abstraction licensing reform

    NASA Astrophysics Data System (ADS)

    Klaar, M. J.

    2012-12-01

    current EFI method, as well as allowing alternative licensing scenarios (e.g. using alternative flow statistics, flow periods and ASB bands) to be tested. Initial analysis suggests that the model is a useful tool in visualising licensing options ahead of the licensing reform.Table 1: Percentage allowable abstraction from natural flows at different abstraction sensitivity bands (ASB), as allowed under the EFI method; Table 2: Current framework used to determine flows which support GES as part of the EU WFD;

  1. Hysterectomy—Current Methods and Alternatives for Benign Indications

    PubMed Central

    Papadopoulos, Michail S.; Tolikas, Athanasios C.; Miliaras, Dimosthenis E.

    2010-01-01

    Hysterectomy is the commonest gynecologic operation performed not only for malignant disease but also for many benign conditions such as fibroids, endometrial hyperplasia, adenomyosis, uterine prolapse, dysfunctional uterine bleeding, and cervical intraepithelial neoplasia. There are many approaches to hysterectomy for benign disease: abdominal hysterectomy, vaginal hysterectomy, laparoscopic assisted vaginal hysterectomy (LAVH) where a vaginal hysterectomy is assisted by laparoscopic procedures that do not include uterine artery ligation, total laparoscopic hysterectomy (TLH) where the laparoscopic procedures include uterine artery ligation, and subtotal laparoscopic hysterectomy (STLH) where there is no vaginal component and the uterine body is removed using a morcelator. In the last decades, many new techniques, alternative to hysterectomy with conservation of the uterus have been developed. They use modern technologies and their results are promising and in many cases comparable with hysterectomy. This paper is a review of all the existing hysterectomy techniques and the alternative methods for benign indications. PMID:20798870

  2. Automated Supernova Discovery (Abstract)

    NASA Astrophysics Data System (ADS)

    Post, R. S.

    2015-12-01

    (Abstract only) We are developing a system of robotic telescopes for automatic recognition of Supernovas as well as other transient events in collaboration with the Puckett Supernova Search Team. At the SAS2014 meeting, the discovery program, SNARE, was first described. Since then, it has been continuously improved to handle searches under a wide variety of atmospheric conditions. Currently, two telescopes are used to build a reference library while searching for PSN with a partial library. Since data is taken every night without clouds, we must deal with varying atmospheric and high background illumination from the moon. Software is configured to identify a PSN, reshoot for verification with options to change the run plan to acquire photometric or spectrographic data. The telescopes are 24-inch CDK24, with Alta U230 cameras, one in CA and one in NM. Images and run plans are sent between sites so the CA telescope can search while photometry is done in NM. Our goal is to find bright PSNs with magnitude 17.5 or less which is the limit of our planned spectroscopy. We present results from our first automated PSN discoveries and plans for PSN data acquisition.

  3. Fundamental Feature Extraction Methods for the Analysis of Eddy Current Data (Preprint)

    DTIC Science & Technology

    2006-12-01

    5d. PROJECT NUMBER 4349 5e. TASK NUMBER RG 6. AUTHOR(S) Jeremy S. Knopp (AFRL/RXLP) John C. Aldrin (Computational Tools ) 5f. WORK UNIT...NUMBER M04R1000 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Computational Tools Gurnee...1 and John C. ALDRINb a Air Force Research Laboratory, USA b Computational Tools ,USA Abstract. Features are investigated in eddy current

  4. Technical Abstracts, 1988

    SciTech Connect

    Kotowski, M.

    1989-05-01

    This document is a compilation of the abstracts from unclassified documents published by Mechanical Engineering at Lawrence Livermore National Laboratory (LLNL) during the calendar year 1988. Many abstracts summarize work completed and published in report form. These are UCRL-90,000 and 100,000 series documents, which include the full text of articles to be published in journals and of papers to be presented at meetings, and UCID reports, which are informal documents. Not all UCIDs contain abstracts: short summaries were generated when abstracts were not included. Technical Abstracts also provides brief descriptions of those documents assigned to the MISC (miscellaneous) category. These are generally viewgraphs or photographs presented at meetings. The abstracts cover the broad range of technologies within Mechanical Engineering and are grouped by the principal author's division. An eighth category is devoted to abstracts presented at the CUBE symposium sponsored jointly by LLNL, Los Alamos National Laboratory, and Sandia Laboratories. Within these areas, abstracts are listed numerically. An author index and title index are provided at the back of the book for cross referencing. The publications listed may be obtained by contacting LLNL's TID library or the National Technical Information Service, US Department of Commerce, 5285 Port Royal Road, Springfield, VA 22161. Further information may be obtained by contacting the author directly or the persons listed in the introduction of each subject area.

  5. Paper Abstract Animals

    ERIC Educational Resources Information Center

    Sutley, Jane

    2010-01-01

    Abstraction is, in effect, a simplification and reduction of shapes with an absence of detail designed to comprise the essence of the more naturalistic images being depicted. Without even intending to, young children consistently create interesting, and sometimes beautiful, abstract compositions. A child's creations, moreover, will always seem to…

  6. Leadership Abstracts, Volume 10.

    ERIC Educational Resources Information Center

    Milliron, Mark D., Ed.

    1997-01-01

    The abstracts in this series provide brief discussions of issues related to leadership, administration, professional development, technology, and education in community colleges. Volume 10 for 1997 contains the following 12 abstracts: (1) "On Community College Renewal" (Nathan L. Hodges and Mark D. Milliron); (2) "The Community College Niche in a…

  7. Is It Really Abstract?

    ERIC Educational Resources Information Center

    Kernan, Christine

    2011-01-01

    For this author, one of the most enjoyable aspects of teaching elementary art is the willingness of students to embrace the different styles of art introduced to them. In this article, she describes a project that allows upper-elementary students to learn about abstract art and the lives of some of the master abstract artists, implement the idea…

  8. Designing for Mathematical Abstraction

    ERIC Educational Resources Information Center

    Pratt, Dave; Noss, Richard

    2010-01-01

    Our focus is on the design of systems (pedagogical, technical, social) that encourage mathematical abstraction, a process we refer to as "designing for abstraction." In this paper, we draw on detailed design experiments from our research on children's understanding about chance and distribution to re-present this work as a case study in designing…

  9. Leadership Abstracts, 1996.

    ERIC Educational Resources Information Center

    Johnson, Larry, Ed.

    1996-01-01

    The abstracts in this series provide two-page discussions of issues related to leadership, administration, professional development, technology, and education in community colleges. Volume 9 for 1996 includes the following 12 abstracts: (1) "Tech-Prep + School-To-Work: Working Together To Foster Educational Reform," (Roderick F. Beaumont); (2)…

  10. Mechanical Engineering Department technical abstracts

    SciTech Connect

    Not Available

    1984-07-01

    The Mechanical Engineering Department publishes abstracts twice a year to inform readers of the broad range of technical activities in the Department, and to promote an exchange of ideas. Details of the work covered by an abstract may be obtained by contacting the author(s). General information about the current role and activities of each of the Department's seven divisions precedes the technical abstracts. Further information about a division's work may be obtained from the division leader, whose name is given at the end of each divisional summary. The Department's seven divisions are as follows: Nuclear Test Engineering Division, Nuclear Explosives Engineering Division, Weapons Engineering Division, Energy Systems Engineering Division, Engineering Sciences Division, Magnetic Fusion Engineering Division and Materials Fabrication Division.

  11. Abstract Datatypes in PVS

    NASA Technical Reports Server (NTRS)

    Owre, Sam; Shankar, Natarajan

    1997-01-01

    PVS (Prototype Verification System) is a general-purpose environment for developing specifications and proofs. This document deals primarily with the abstract datatype mechanism in PVS which generates theories containing axioms and definitions for a class of recursive datatypes. The concepts underlying the abstract datatype mechanism are illustrated using ordered binary trees as an example. Binary trees are described by a PVS abstract datatype that is parametric in its value type. The type of ordered binary trees is then presented as a subtype of binary trees where the ordering relation is also taken as a parameter. We define the operations of inserting an element into, and searching for an element in an ordered binary tree; the bulk of the report is devoted to PVS proofs of some useful properties of these operations. These proofs illustrate various approaches to proving properties of abstract datatype operations. They also describe the built-in capabilities of the PVS proof checker for simplifying abstract datatype expressions.

  12. White Paper on Multicarrier Excitation of Multipactor Breakdown: A Survey of Current Methods and Research Opportunities

    DTIC Science & Technology

    2015-06-18

    AEROSPACE REPORT NO. TOR-2015-02548 White Paper on Multicarrier Excitation of Multipactor Breakdown: A Survey of Current Methods and...SUBTITLE White Paper on Multicarrier Excitation of Multipactor Breakdown: A Survey of Current Methods and Research Opportunities 5a. CONTRACT NUMBER...verification. This white paper describes methods of assessment and possibly to mitigate multipactor for spacecraft components in multiple carrier

  13. Searching Sociological Abstracts.

    ERIC Educational Resources Information Center

    Kerbel, Sandra Sandor

    1981-01-01

    Describes the scope, content, and retrieval characteristics of Sociological Abstracts, an online database of literature in the social sciences. Sample searches are displayed, and the strengths and weaknesses of the database are summarized. (FM)

  14. Conference Abstracts: AEDS '82.

    ERIC Educational Resources Information Center

    Journal of Computers in Mathematics and Science Teaching, 1982

    1982-01-01

    Abstracts from nine selected papers presented at the 1982 Association for Educational Data Systems (AEDS) conference are provided. Copies of conference proceedings may be obtained for fifteen dollars from the Association. (MP)

  15. Abstracts of contributed papers

    SciTech Connect

    Not Available

    1994-08-01

    This volume contains 571 abstracts of contributed papers to be presented during the Twelfth US National Congress of Applied Mechanics. Abstracts are arranged in the order in which they fall in the program -- the main sessions are listed chronologically in the Table of Contents. The Author Index is in alphabetical order and lists each paper number (matching the schedule in the Final Program) with its corresponding page number in the book.

  16. ERGONOMICS ABSTRACTS 48347-48982.

    ERIC Educational Resources Information Center

    Ministry of Technology, London (England). Warren Spring Lab.

    IN THIS COLLECTION OF ERGONOMICS ABSTRACTS AND ANNOTATIONS THE FOLLOWING AREAS OF CONCERN ARE REPRESENTED--GENERAL REFERENCES, METHODS, FACILITIES, AND EQUIPMENT RELATING TO ERGONOMICS, SYSTEMS OF MAN AND MACHINES, VISUAL, AUDITORY, AND OTHER SENSORY INPUTS AND PROCESSES (INCLUDING SPEECH AND INTELLIGIBILITY), INPUT CHANNELS, BODY MEASUREMENTS,…

  17. Metacognition and abstract reasoning.

    PubMed

    Markovits, Henry; Thompson, Valerie A; Brisson, Janie

    2015-05-01

    The nature of people's meta-representations of deductive reasoning is critical to understanding how people control their own reasoning processes. We conducted two studies to examine whether people have a metacognitive representation of abstract validity and whether familiarity alone acts as a separate metacognitive cue. In Study 1, participants were asked to make a series of (1) abstract conditional inferences, (2) concrete conditional inferences with premises having many potential alternative antecedents and thus specifically conducive to the production of responses consistent with conditional logic, or (3) concrete problems with premises having relatively few potential alternative antecedents. Participants gave confidence ratings after each inference. Results show that confidence ratings were positively correlated with logical performance on abstract problems and concrete problems with many potential alternatives, but not with concrete problems with content less conducive to normative responses. Confidence ratings were higher with few alternatives than for abstract content. Study 2 used a generation of contrary-to-fact alternatives task to improve levels of abstract logical performance. The resulting increase in logical performance was mirrored by increases in mean confidence ratings. Results provide evidence for a metacognitive representation based on logical validity, and show that familiarity acts as a separate metacognitive cue.

  18. Automated Assume-Guarantee Reasoning by Abstraction Refinement

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina S.; Giannakopoulous, Dimitra; Glannakopoulou, Dimitra

    2008-01-01

    Current automated approaches for compositional model checking in the assume-guarantee style are based on learning of assumptions as deterministic automata. We propose an alternative approach based on abstraction refinement. Our new method computes the assumptions for the assume-guarantee rules as conservative and not necessarily deterministic abstractions of some of the components, and refines those abstractions using counter-examples obtained from model checking them together with the other components. Our approach also exploits the alphabets of the interfaces between components and performs iterative refinement of those alphabets as well as of the abstractions. We show experimentally that our preliminary implementation of the proposed alternative achieves similar or better performance than a previous learning-based implementation.

  19. System and method for motor fault detection using stator current noise cancellation

    DOEpatents

    Zhou, Wei; Lu, Bin; Nowak, Michael P.; Dimino, Steven A.

    2010-12-07

    A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to acquire at least on additional set of real-time operating current data from the motor during operation, redefine the noise component present in each additional set of real-time operating current data, and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

  20. Leadership Abstracts, 2001.

    ERIC Educational Resources Information Center

    Wilson, Cynthia, Ed.

    2001-01-01

    This is volume 14 of Leadership Abstracts, a newsletter published by the League for Innovation (California). Issue 1 of February 2001, "Developmental Education: A Policy Primer," discusses developmental programs in the community college. According to the article, community college trustees and presidents would serve their constituents well by…

  1. Abstract Film and Beyond.

    ERIC Educational Resources Information Center

    Le Grice, Malcolm

    A theoretical and historical account of the main preoccupations of makers of abstract films is presented in this book. The book's scope includes discussion of nonrepresentational forms as well as examination of experiments in the manipulation of time in films. The ten chapters discuss the following topics: art and cinematography, the first…

  2. Leadership Abstracts, 1993.

    ERIC Educational Resources Information Center

    Doucette, Don, Ed.

    1993-01-01

    This document includes 10 issues of Leadership Abstracts (volume 6, 1993), a newsletter published by the League for Innovation in the Community College (California). The featured articles are: (1) "Reinventing Government" by David T. Osborne; (2) "Community College Workforce Training Programs: Expanding the Mission to Meet Critical Needs" by…

  3. Leadership Abstracts, 1999.

    ERIC Educational Resources Information Center

    Leadership Abstracts, 1999

    1999-01-01

    This document contains five Leadership Abstracts publications published February-December 1999. The article, "Teaching the Teachers: Meeting the National Teacher Preparation Challenge," authored by George R. Boggs and Sadie Bragg, examines the community college role and makes recommendations and a call to action for teacher education.…

  4. Reasoning abstractly about resources

    NASA Technical Reports Server (NTRS)

    Clement, B.; Barrett, A.

    2001-01-01

    r describes a way to schedule high level activities before distributing them across multiple rovers in order to coordinate the resultant use of shared resources regardless of how each rover decides how to perform its activities. We present an algorithm for summarizing the metric resource requirements of an abstract activity based n the resource usages of its potential refinements.

  5. Conference Abstracts: AEDS '84.

    ERIC Educational Resources Information Center

    Baird, William E.

    1985-01-01

    The Association of Educational Data Systems (AEDS) conference included 102 presentations. Abstracts of seven of these presentations are provided. Topic areas considered include LOGO, teaching probability through a computer game, writing effective computer assisted instructional materials, computer literacy, research on instructional…

  6. Leadership Abstracts, 2002.

    ERIC Educational Resources Information Center

    Wilson, Cynthia, Ed.; Milliron, Mark David, Ed.

    2002-01-01

    This 2002 volume of Leadership Abstracts contains issue numbers 1-12. Articles include: (1) "Skills Certification and Workforce Development: Partnering with Industry and Ourselves," by Jeffrey A. Cantor; (2) "Starting Again: The Brookhaven Success College," by Alice W. Villadsen; (3) "From Digital Divide to Digital Democracy," by Gerardo E. de los…

  7. Abstraction and art.

    PubMed Central

    Gortais, Bernard

    2003-01-01

    In a given social context, artistic creation comprises a set of processes, which relate to the activity of the artist and the activity of the spectator. Through these processes we see and understand that the world is vaster than it is said to be. Artistic processes are mediated experiences that open up the world. A successful work of art expresses a reality beyond actual reality: it suggests an unknown world using the means and the signs of the known world. Artistic practices incorporate the means of creation developed by science and technology and change forms as they change. Artists and the public follow different processes of abstraction at different levels, in the definition of the means of creation, of representation and of perception of a work of art. This paper examines how the processes of abstraction are used within the framework of the visual arts and abstract painting, which appeared during a period of growing importance for the processes of abstraction in science and technology, at the beginning of the twentieth century. The development of digital platforms and new man-machine interfaces allow multimedia creations. This is performed under the constraint of phases of multidisciplinary conceptualization using generic representation languages, which tend to abolish traditional frontiers between the arts: visual arts, drama, dance and music. PMID:12903659

  8. Annual Conference Abstracts

    ERIC Educational Resources Information Center

    Journal of Engineering Education, 1972

    1972-01-01

    Includes abstracts of papers presented at the 80th Annual Conference of the American Society for Engineering Education. The broad areas include aerospace, affiliate and associate member council, agricultural engineering, biomedical engineering, continuing engineering studies, chemical engineering, civil engineering, computers, cooperative…

  9. Abstracts of SIG Sessions.

    ERIC Educational Resources Information Center

    Proceedings of the ASIS Annual Meeting, 1994

    1994-01-01

    Includes abstracts of 18 special interest group (SIG) sessions. Highlights include natural language processing, information science and terminology science, classification, knowledge-intensive information systems, information value and ownership issues, economics and theories of information science, information retrieval interfaces, fuzzy thinking…

  10. RESEARCH ABSTRACTS, VOLUME VI.

    ERIC Educational Resources Information Center

    COLETTE, SISTER M.

    THIS SIXTH VOLUME OF RESEARCH ABSTRACTS PRESENTS REPORTS OF 35 RESEARCH STUDIES COMPLETED BY CANDIDATES FOR THE MASTER'S DEGREE AT THE CARDINAL STRITCH COLLEGE IN 1964. TWENTY-NINE STUDIES ARE CONCERNED WITH READING, AND SIX ARE CONCERNED WITH THE EDUCATION OF THE MENTALLY HANDICAPPED. OF THE READING STUDIES, FIVE PERTAIN TO THE JUNIOR HIGH LEVEL…

  11. Learning Abstracts, 1999.

    ERIC Educational Resources Information Center

    League for Innovation in the Community Coll.

    This document contains volume two of Learning Abstracts, a bimonthly newsletter from the League for Innovation in the Community College. Articles in these seven issues include: (1) "Get on the Fast Track to Learning: An Accelerated Associate Degree Option" (Gerardo E. de los Santos and Deborah J. Cruise); (2) "The Learning College:…

  12. Annual Conference Abstracts

    ERIC Educational Resources Information Center

    Engineering Education, 1976

    1976-01-01

    Presents the abstracts of 158 papers presented at the American Society for Engineering Education's annual conference at Knoxville, Tennessee, June 14-17, 1976. Included are engineering topics covering education, aerospace, agriculture, biomedicine, chemistry, computers, electricity, acoustics, environment, mechanics, and women. (SL)

  13. Making the Abstract Concrete

    ERIC Educational Resources Information Center

    Potter, Lee Ann

    2005-01-01

    President Ronald Reagan nominated a woman to serve on the United States Supreme Court. He did so through a single-page form letter, completed in part by hand and in part by typewriter, announcing Sandra Day O'Connor as his nominee. While the document serves as evidence of a historic event, it is also a tangible illustration of abstract concepts…

  14. Abstracts of SIG Sessions.

    ERIC Educational Resources Information Center

    Proceedings of the ASIS Annual Meeting, 1995

    1995-01-01

    Presents abstracts of 15 special interest group (SIG) sessions. Topics include navigation and information utilization in the Internet, natural language processing, automatic indexing, image indexing, classification, users' models of database searching, online public access catalogs, education for information professions, information services,…

  15. Seismic Consequence Abstraction

    SciTech Connect

    M. Gross

    2004-10-25

    The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]).

  16. Abstraction through Game Play

    ERIC Educational Resources Information Center

    Avraamidou, Antri; Monaghan, John; Walker, Aisha

    2012-01-01

    This paper examines the computer game play of an 11-year-old boy. In the course of building a virtual house he developed and used, without assistance, an artefact and an accompanying strategy to ensure that his house was symmetric. We argue that the creation and use of this artefact-strategy is a mathematical abstraction. The discussion…

  17. EBS Radionuclide Transport Abstraction

    SciTech Connect

    R. Schreiner

    2001-06-27

    The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M&O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations determined by other

  18. Novel methods to optimize the effects of transcranial direct current stimulation: a systematic review of transcranial direct current stimulation patents.

    PubMed

    Malavera, Alejandra; Vasquez, Alejandra; Fregni, Felipe

    2015-01-01

    Transcranial direct current stimulation (tDCS) is a neuromodulatory technique that has been extensively studied. While there have been initial positive results in some clinical trials, there is still variability in tDCS results. The aim of this article is to review and discuss patents assessing novel methods to optimize the use of tDCS. A systematic review was performed using Google patents database with tDCS as the main technique, with patents filling date between 2010 and 2015. Twenty-two patents met our inclusion criteria. These patents attempt to address current tDCS limitations. Only a few of them have been investigated in clinical trials (i.e., high-definition tDCS), and indeed most of them have not been tested before in human trials. Further clinical testing is required to assess which patents are more likely to optimize the effects of tDCS. We discuss the potential optimization of tDCS based on these patents and the current experience with standard tDCS.

  19. Over-current carrying characteristics of rectangular-shaped YBCO thin films prepared by MOD method

    NASA Astrophysics Data System (ADS)

    Hotta, N.; Yokomizu, Y.; Iioka, D.; Matsumura, T.; Kumagai, T.; Yamasaki, H.; Shibuya, M.; Nitta, T.

    2008-02-01

    A fault current limiter (FCL) may be manufactured at competitive qualities and prices by using rectangular-shaped YBCO films which are prepared by metal-organic deposition (MOD) method, because the MOD method can produce large size elements with a low-cost and non-vacuum technique. Prior to constructing a superconducting FCL (SFCL), AC over-current carrying experiments were conducted for 120 mm long elements where YBCO thin film of about 200 nm in thickness was coated on sapphire substrate with cerium oxide (CeO2) interlayer. In the experiments, only single cycle of the ac damping current of 50 Hz was applied to the pure YBCO element without protective metal coating or parallel resistor and the magnitude of the current was increased step by step until the breakdown phenomena occurred in the element. In each experiment, current waveforms flowing through the YBCO element and voltage waveform across the element were measured to get the voltage-current characteristics. The allowable over-current and generated voltage were successfully estimated for the pure YBCO films. It can be pointed out that the lower n-value trends to bring about the higher allowable over-current and the higher withstand voltage more than tens of volts. The YBCO film having higher n-value is sensitive to the over-current. Thus, some protective methods such as a metal coating should be employed for applying to the fault current limiter.

  20. Tunneling Current of Electron in Armchair Graphene Nanoribbon Bipolar Transistor Model Using Transfer Matrix Method

    NASA Astrophysics Data System (ADS)

    Fahmi, A. K.; Hasanah, L.; Rusdiana, D.; Aminudin, A.; Suhendi, E.

    2017-03-01

    The tunneling current of n-p-n bipolar junction transistor AGNR-based is modeled with semi-numerical method. The exponential solution from Schrödinger equation is used and solved analytically. The potential profile of n-p-n BJT divided into several segments in the numerical method. Then, the solved analytical result is used in the numerical method to compute the electron transmittance. Transfer Matrix Method (TMM) is the numerical method used to compute the electron transmittance. From the calculated transmittance the tunneling current can be computed by using Landauer formula with aid of Gauss-Legendre Quadrature (GLQ). Next, the tunneling current is computed with several change of variables which are base-emitter voltage (VBE), base-collector voltage (VBC), temperature and the AGNR’s width. The computed tunneling current shows that the larger value of applied voltage for both VBE and VBC results in larger value of tunneling current. At the lower temperature, the current is larger. The computed tunneling current shows that at wider width of AGNR, the current is also larger. This is due to the decreased band-gap energy (Eg) because of the wider width of AGNR.

  1. [A rapid method of eddy current compensation in magnetic resonance imaging systems].

    PubMed

    Liu, Zheng-min; Zhou, He-qin; Wu, Hai-cheng

    2005-11-01

    Imaging objects are spatially encoded by gradient magnetic fields in magnetic resonance imaging systems. The eddy current caused by rapid switches of gradient fields will result in artifacts in the images. A method of eddy current compensation based on pre-emphasis of gradient current is presented in this thesis. The compensation parameters are acquired rapidly utilizing Faraday's induction theorem and data fitting method. The experiments prove that the method is efficient for reduction of the debugging time and for the improvement of the image quality.

  2. Current Progress in Gene Delivery Technology Based on Chemical Methods and Nano-carriers

    PubMed Central

    Jin, Lian; Zeng, Xin; Liu, Ming; Deng, Yan; He, Nongyue

    2014-01-01

    Gene transfer methods are promising in the field of gene therapy. Current methods for gene transfer include three major groups: viral, physical and chemical methods. This review mainly summarizes development of several types of chemical methods for gene transfer in vitro and in vivo by means of nano-carriers like; calcium phosphates, lipids, and cationic polymers including chitosan, polyethylenimine, polyamidoamine dendrimers, and poly(lactide-co-glycolide). This review also briefly introduces applications of these chemical methods for gene delivery. PMID:24505233

  3. Non-destructive testing of composite materials used in military applications by eddy current thermography method

    NASA Astrophysics Data System (ADS)

    Swiderski, Waldemar

    2016-10-01

    Eddy current thermography is a new NDT-technique for the detection of cracks in electro conductive materials. It combines the well-established inspection techniques of eddy current testing and thermography. The technique uses induced eddy currents to heat the sample being tested and defect detection is based on the changes of induced eddy currents flows revealed by thermal visualization captured by an infrared camera. The advantage of this method is to use the high performance of eddy current testing that eliminates the known problem of the edge effect. Especially for components of complex geometry this is an important factor which may overcome the increased expense for inspection set-up. The paper presents the possibility of applying eddy current thermography method for detecting defects in ballistic covers made of carbon fiber reinforced composites used in the construction of military vehicles.

  4. A Modified Time-Delay Addition Method to Extract Resistive Leakage Current of MOSA

    NASA Astrophysics Data System (ADS)

    Khodsuz, Masume; Mirzaie, Mohammad

    2016-12-01

    Metal oxide surge arresters are one of the most important equipment for power system protection against switching and lightning over-voltages. High-energy stresses and environmental features are the main factors which degrade surge arresters. In order to verify surge arresters good condition, their monitoring is necessary. The majority of surge arrester monitoring techniques is based on total leakage current decomposition of their capacitive and resistive components. This paper introduces a new approach based on time-delay addition method to extract the resistive current from the total leakage current without measuring voltage signal. Surge arrester model for calculating leakage current has been performed in ATP-EMTP. In addition, the signal processing has been done using MATLAB software. To show the accuracy of the proposed method, experimental tests have been performed to extract resistive leakage current by the proposed method.

  5. Nodal Analysis Optimization Based on the Use of Virtual Current Sources: A Powerful New Pedagogical Method

    ERIC Educational Resources Information Center

    Chatzarakis, G. E.

    2009-01-01

    This paper presents a new pedagogical method for nodal analysis optimization based on the use of virtual current sources, applicable to any linear electric circuit (LEC), regardless of its complexity. The proposed method leads to straightforward solutions, mostly arrived at by inspection. Furthermore, the method is easily adapted to computer…

  6. Methods, systems and apparatus for synchronous current regulation of a five-phase machine

    DOEpatents

    Gallegos-Lopez, Gabriel; Perisic, Milun

    2012-10-09

    Methods, systems and apparatus are provided for controlling operation of and regulating current provided to a five-phase machine when one or more phases has experienced a fault or has failed. In one implementation, the disclosed embodiments can be used to synchronously regulate current in a vector controlled motor drive system that includes a five-phase AC machine, a five-phase inverter module coupled to the five-phase AC machine, and a synchronous current regulator.

  7. System and method for bearing fault detection using stator current noise cancellation

    DOEpatents

    Zhou, Wei; Lu, Bin; Habetler, Thomas G.; Harley, Ronald G.; Theisen, Peter J.

    2010-08-17

    A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to repeatedly receive real-time operating current data from the operating motor and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

  8. A new method of reconstructing current paths in HTS tapes with defects

    NASA Astrophysics Data System (ADS)

    Podlivaev, Alexey; Rudnev, Igor

    2017-03-01

    We propose a new method for calculating current paths in high-temperature superconductive (HTS) tapes with various defects including cracks, non-superconducting inclusions, and superconducting inclusions with lower local critical current density. The calculation method is based on a model of critical state which takes into account the dependence of the critical current on the magnetic field. The method allows us to calculate the spatial distribution of currents flowing through the defective HTS tape for both currents induced by the external magnetic field and transport currents from an external source. For both cases, we performed simulations of the current distributions in these tapes with different types of defects and have shown that the combination of the action of the magnetic field and transport current leads to a more detailed identification of the boundaries and shape of the defects. The proposed method is adapted for calculating modern superconductors in real superconducting devices and may be more useful as compared to the conventional magnetometric diagnostic studies, when the tape is affected by the magnetic field only.

  9. Abstraction Augmented Markov Models.

    PubMed

    Caragea, Cornelia; Silvescu, Adrian; Caragea, Doina; Honavar, Vasant

    2010-12-13

    High accuracy sequence classification often requires the use of higher order Markov models (MMs). However, the number of MM parameters increases exponentially with the range of direct dependencies between sequence elements, thereby increasing the risk of overfitting when the data set is limited in size. We present abstraction augmented Markov models (AAMMs) that effectively reduce the number of numeric parameters of k(th) order MMs by successively grouping strings of length k (i.e., k-grams) into abstraction hierarchies. We evaluate AAMMs on three protein subcellular localization prediction tasks. The results of our experiments show that abstraction makes it possible to construct predictive models that use significantly smaller number of features (by one to three orders of magnitude) as compared to MMs. AAMMs are competitive with and, in some cases, significantly outperform MMs. Moreover, the results show that AAMMs often perform significantly better than variable order Markov models, such as decomposed context tree weighting, prediction by partial match, and probabilistic suffix trees.

  10. EBS Radionuclide Transport Abstraction

    SciTech Connect

    J. Prouty

    2006-07-14

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  11. Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits

    DOEpatents

    Campbell, A.N.; Anderson, R.E.; Cole, E.I. Jr.

    1995-11-07

    A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits are disclosed. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits. 17 figs.

  12. Systems and methods for commutating inductor current using a matrix converter

    DOEpatents

    Ransom, Ray M; Kajouke, Lateef A; Perisic, Milun

    2012-10-16

    Systems and methods are provided for delivering current using a matrix converter in a vehicle. An electrical system comprises an AC interface, a first conversion module coupled to the AC interface, an inductive element coupled between the AC interface and the first conversion module, and a control module coupled to the first conversion module. The control module is configured to operate the first conversion module in a bidirectional operating mode to commutate current bidirectionally. When a magnitude of the current through the inductive element is greater than a first threshold value, the control module operates the conversion module in a unidirectional operating mode, wherein current is commutated unidirectionally.

  13. Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits

    DOEpatents

    Campbell, Ann. N.; Anderson, Richard E.; Cole, Jr., Edward I.

    1995-01-01

    A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits.

  14. [Methods of brain stimulation based on weak electric current--future tool for the clinician?].

    PubMed

    Kotilainen, Tuukka; Lehto, Soili M

    2016-01-01

    Methods of brain stimulation based on a weak electric current are non-invasive neuromodulation techniques. They include transcranial direct current, alternating current and random noise stimulation. These methods modify the membrane potential of neurons without triggering the action potential, and have been successfully utilized to influence cognition and regulation of emotions in healthy experimental subjects. In clinical studies, indications of the efficacy of these techniques have been obtained in the treatment of depression, schizophrenia, memory disorders and pain as well as in stroke rehabilitation. It is hoped that these techniques will become established as part of the care and rehabilitation of psychiatric and neurologic patients in the future.

  15. Method of making a current collector for a sodium/sulfur battery

    DOEpatents

    Tischer, Ragnar P.; Winterbottom, Walter L.; Wroblowa, Halina S.

    1987-01-01

    This specification is directed to a method of making a current collector (14) for a sodium/sulfur battery (10). The current collector so-made is electronically conductive and resistant to corrosive attack by sulfur/polysulfide melts. The method includes the step of forming the current collector for the sodium/sulfur battery from a composite material (16) formed of aluminum filled with electronically conductive fibers selected from the group of fibers consisting essentially of graphite fibers having a diameter up to 10 microns and silicon carbide fibers having a diameter in a range of 500-1000 angstroms.

  16. Method of making a current collector for a sodium/sulfur battery

    DOEpatents

    Tischer, R.P.; Winterbottom, W.L.; Wroblowa, H.S.

    1987-03-10

    This specification is directed to a method of making a current collector for a sodium/sulfur battery. The current collector so-made is electronically conductive and resistant to corrosive attack by sulfur/polysulfide melts. The method includes the step of forming the current collector for the sodium/sulfur battery from a composite material formed of aluminum filled with electronically conductive fibers selected from the group of fibers consisting essentially of graphite fibers having a diameter up to 10 microns and silicon carbide fibers having a diameter in a range of 500--1,000 angstroms. 2 figs.

  17. White Paper on Multicarrier Excitation of Multipactor Breakdown: A Survey of Current Methods and Research Opportunities

    DTIC Science & Technology

    2015-06-18

    AEROSPACE REPORT NO. TOR-2015-02548 White Paper on Multicarrier Excitation of Multipactor Breakdown: A Survey of Current Methods and...simultaneously, there are a variety of methods used to address multipactor breakdown verification. This white paper describes methods of assessment...and possibly to mitigate multipactor for spacecraft components in multiple carrier systems [1]–[3]. The methods described in this paper highlight

  18. Characteristics of Current Imbalance on Superconducting Coils and Suppressionwith Iron Core Method

    NASA Astrophysics Data System (ADS)

    Ohtaki, Naohiro; Nakamura, Keiji; Yamaguchi, Sataro; Nomura, Shin-Ichi; Ninomiya, Akira; Sato, Toshikazu; Hasegawa, Yasuhiro; Hanai, Satoshi

    This paper describes characteristics of current imbalance in AC-operated superconducting coil and trial for its suppression with iron core method. Measurements of strand current in the frequency less than —1 Hz revealed that the current imbalance significantly occurred to the frequency increase, and that the critical frequency almost corresponds to a frequency where the coil leakage inductance is comparable to the coil resistive. Such a current imbalance was not seriously affected by ferromagnetic materials set in the coil. The iron core method was effective for suppression of the current imbalance, especially in the low frequency region, and inductance measurements suggested that the suppression effect was attributed to inductance compensation as well as reduction of effective electro-magnetic coupling between coil strands.

  19. Study on model current predictive control method of PV grid- connected inverters systems with voltage sag

    NASA Astrophysics Data System (ADS)

    Jin, N.; Yang, F.; Shang, S. Y.; Tao, T.; Liu, J. S.

    2016-08-01

    According to the limitations of the LVRT technology of traditional photovoltaic inverter existed, this paper proposes a low voltage ride through (LVRT) control method based on model current predictive control (MCPC). This method can effectively improve the photovoltaic inverter output characteristics and response speed. The MCPC method of photovoltaic grid-connected inverter designed, the sum of the absolute value of the predictive current and the given current error is adopted as the cost function with the model predictive control method. According to the MCPC, the optimal space voltage vector is selected. Photovoltaic inverter has achieved automatically switches of priority active or reactive power control of two control modes according to the different operating states, which effectively improve the inverter capability of LVRT. The simulation and experimental results proves that the proposed method is correct and effective.

  20. 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,…

  1. Method and apparatus for correcting eddy current signal voltage for temperature effects

    DOEpatents

    Kustra, Thomas A.; Caffarel, Alfred J.

    1990-01-01

    An apparatus and method for measuring physical characteristics of an electrically conductive material by the use of eddy-current techniques and compensating measurement errors caused by changes in temperature includes a switching arrangement connected between primary and reference coils of an eddy-current probe which allows the probe to be selectively connected between an eddy current output oscilloscope and a digital ohm-meter for measuring the resistances of the primary and reference coils substantially at the time of eddy current measurement. In this way, changes in resistance due to temperature effects can be completely taken into account in determining the true error in the eddy current measurement. The true error can consequently be converted into an equivalent eddy current measurement correction.

  2. A method for estimating tokamak poloidal field coil currents which incorporates engineering constraints

    SciTech Connect

    Stewart, W.A.

    1990-05-01

    This thesis describes the development of a design tool for the poloidal field magnet system of a tokamak. Specifically, an existing program for determining the poloidal field coil currents has been modified to: support the general case of asymmetric equilibria and coil sets, determine the coil currents subject to constraints on the maximum values of those currents, and determine the coil currents subject to limits on the forces those coils may carry. The equations representing the current limits and coil force limits are derived and an algorithm based on Newton's method is developed to determine a set of coil currents which satisfies those limits. The resulting program allows the designer to quickly determine whether or not a given coil set is capable of supporting a given equilibrium. 25 refs.

  3. Object Classification via Planar Abstraction

    NASA Astrophysics Data System (ADS)

    Oesau, Sven; Lafarge, Florent; Alliez, Pierre

    2016-06-01

    We present a supervised machine learning approach for classification of objects from sampled point data. The main idea consists in first abstracting the input object into planar parts at several scales, then discriminate between the different classes of objects solely through features derived from these planar shapes. Abstracting into planar shapes provides a means to both reduce the computational complexity and improve robustness to defects inherent to the acquisition process. Measuring statistical properties and relationships between planar shapes offers invariance to scale and orientation. A random forest is then used for solving the multiclass classification problem. We demonstrate the potential of our approach on a set of indoor objects from the Princeton shape benchmark and on objects acquired from indoor scenes and compare the performance of our method with other point-based shape descriptors.

  4. Research Abstracts of 1980.

    DTIC Science & Technology

    1980-12-01

    ABSTRACTS OF 1980. 9 - DTIC ELECTEf ii S AN3O 1981j _NAVAL DISTRIBUTION SMT:MIT DENTAL RESEARCH Approved for PUbDiC T INSTITE iii~2 YA3 It81 Naval...Medical Research apd Development Command 30 £ Bethesda, Maryland ( *- i - NTIS - GRA&I DTIC TAB - Urrannouneed NAVAL DENTAL RESEARCH INSTITUTE...r1 w American Assoctat/ion for Dental Research, 58th Annual Session, Los Angeles, California, March 20-23, 1980. 1. AV6ERSON*, D. N., LANGELAND, K

  5. Research Abstracts of 1979.

    DTIC Science & Technology

    1979-12-01

    7 AD-AO82 309 NAVAL DENTAL RESEARCH INST GREAT LAKES IL F/6 6/9 RESCH ABTAT79 991 UNCLASSIFIED NORI-PR-79-11 NL ’NDRI-PR 79-11 December 1979...RESEARCH ABSTRACTS OF 1979 OTICSELZCreD MAR 2?718 S A NAVAL DENTAL RESEARCH INSTITUTE Naval Medical Research and Development Command Bethesda, Maryland...8G 3 23 O4ൌ p.,. ... ....-- - I -- - ’.... .I l l ---,, .. . = ., , ." .;’.- I 1 IV NAVAL DENTAL RESEARCH INSTITUTE NAVAL BASE, BLDG. I-H GREAT LAKES

  6. Clinical experimentation with aerosol antibiotics: current and future methods of administration

    PubMed Central

    Zarogoulidis, Paul; Kioumis, Ioannis; Porpodis, Konstantinos; Spyratos, Dionysios; Tsakiridis, Kosmas; Huang, Haidong; Li, Qiang; Turner, J Francis; Browning, Robert; Hohenforst-Schmidt, Wolfgang; Zarogoulidis, Konstantinos

    2013-01-01

    Currently almost all antibiotics are administered by the intravenous route. Since several systems and situations require more efficient methods of administration, investigation and experimentation in drug design has produced local treatment modalities. Administration of antibiotics in aerosol form is one of the treatment methods of increasing interest. As the field of drug nanotechnology grows, new molecules have been produced and combined with aerosol production systems. In the current review, we discuss the efficiency of aerosol antibiotic studies along with aerosol production systems. The different parts of the aerosol antibiotic methodology are presented. Additionally, information regarding the drug molecules used is presented and future applications of this method are discussed. PMID:24115836

  7. EBS Radionuclide Transport Abstraction

    SciTech Connect

    J.D. Schreiber

    2005-08-25

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers

  8. Method for the formation of cylindrical current and its application to evaluate electrical resistivity

    NASA Astrophysics Data System (ADS)

    Li, T.-C.; Chang, C.-S.; Liang, W.-L.; Tsai, W.-F.; Ai, C.-F.; Lin, J.-F.

    2012-07-01

    A cylindrical current method is developed to obtain a stable and precise electrical resistivity of a specimen with or without a coating film. The electrical resistivity of a standard silicon wafer doped with boron at a concentration can be measured using the proposed method if the experimental results of electrical voltage varying with the distance from the center line of the cylindrical current are available. A comparison of the electrical resistivity obtained using the present method and the theoretical reference value indicates that the proposed method produces reliable and precise measurements. Using four test samples, the experimental results of electrical resistivity measured by the present method are shown to be reproducible and more precise than those measured by the four-terminal sensing method and the van der Pauw method. The electrical voltage and current obtained at various distances from the center line of the cylindrical current are almost independent of the distance and the direction of measurements. The effect of specimen's crystallinity appears to be the governing factor of electrical resistivity. Electrical resistivity decreases with increasing crystallinity generally.

  9. A new method for electric impedance imaging using an eddy current with a tetrapolar circuit.

    PubMed

    Ahsan-Ul-Ambia; Toda, Shogo; Takemae, Tadashi; Kosugi, Yukio; Hongo, Minoru

    2009-02-01

    A new contactless technique for electrical impedance imaging, using an eddy current managed along with the tetrapolar circuit method, is proposed. The eddy current produced by a magnetic field is superimposed on a constant current that is normally used in the tetrapolar circuit method, and thus is used to control the current distribution in the body. By changing the current distribution, a set of voltage differences is measured with a pair of electrodes. This set of voltage differences is used in the image reconstruction of the resistivity distribution. The least square error minimization method is used in the reconstruction algorithm. The principle of this method is explained theoretically. A backprojection algorithm was used to get 2-D images. Based on this principle, a measurement system was developed and model experiments were conducted with a saline-filled phantom. The estimated shape of each model in the reconstructed image was similar to that of the corresponding model. From the results of these experiments, it is confirmed that the proposed method is applicable to the realization of electrical conductivity imaging.

  10. Motor current signature analysis method for diagnosing motor-operated devices

    SciTech Connect

    Haynes, H D; Eissenberg, D M

    1986-09-30

    A motor current noise signature analysis method for remotely monitoring the operating characteristics of an electric motor-operated device such as a motor-operated valve. Frequency domain signal analysis techniques are applied to a conditioned motor current signal to distinctly identify various operating parameters of the motor driven device from the motor current signature. The signature may be recorded and compared with subsequent signatures to detect operating abnormalities and degradation of the device. This diagnostic method does not require special equipment to be installed on the motor-operated device, and the current sensing may be performed at remote control locations, e.g., where the motor-operated devices are used in inaccessible or hostile environments. 6 figs.

  11. Inrush Current Suppression Circuit and Method for Controlling When a Load May Be Fully Energized

    NASA Technical Reports Server (NTRS)

    Schwerman, Paul (Inventor)

    2017-01-01

    A circuit and method for controlling when a load may be fully energized includes directing electrical current through a current limiting resistor that has a first terminal connected to a source terminal of a field effect transistor (FET), and a second terminal connected to a drain terminal of the FET. The gate voltage magnitude on a gate terminal of the FET is varied, whereby current flow through the FET is increased while current flow through the current limiting resistor is simultaneously decreased. A determination is made as to when the gate voltage magnitude on the gate terminal is equal to or exceeds a predetermined reference voltage magnitude, and the load is enabled to be fully energized when the gate voltage magnitude is equal to or exceeds the predetermined reference voltage magnitude.

  12. Groundwater abstraction pollution risk assessment.

    PubMed

    Lytton, L; Howe, S; Sage, R; Greenaway, P

    2003-01-01

    A generic groundwater pollution risk assessment methodology has been developed to enable the evaluation and ranking of the potential risk of pollution to groundwater abstractions. The ranking can then be used to prioritise risk management or mitigation procedures in a robust and quantifiable framework and thus inform business investment decisions. The risk assessment consider the three components of the pollution transport model: source-pathway-receptor. For groundwater abstractions these correspond to land use (with associated pollutants and shallow subsurface characteristics), aquifer and the abstraction borehole. An hierarchical approach was chosen to allow the risk assessment to be successfully carried out with different quality data for different parts of the model. The 400-day groundwater protection zone defines the catchment boundary that form the spatial limit of the land use audit for each receptor. A risk score is obtained for each land use (potential pollution source) within the catchment. These scores are derived by considering the characteristics (such as load, persistence and toxicity) of all pollutants pertaining to each land use, their on-site management and the potential for the unsaturated subsurface to attenuate their effects in the event of a release. Risk scores are also applied to the aquifer characteristics (as pollutant pathway) and to the abstraction borehole (as pollutant receptor). Each risk score is accompanied by an uncertainty score which provides a guide to the confidence in the data used to compile the risk assessment. The application of the methodology has highlighted a number of problems in this type of work and results of initial case studies are being used to trial alternative scoring methods and a more simplified approach to accelerate the process of pollution risk assessment.

  13. Israel Education Abstracts: A Selected Bibliography of Current and Past Literature and Materials on the Philosophy, Policy and Practice of Education in Israel. Vol. 4, No. 3, August-November, 1969.

    ERIC Educational Resources Information Center

    Elefant, William L., Ed.

    This 122-entry, selected bibliography contains English abstracts of books and articles in Hebrew on the philosophy, policy, and practice of education in Israel. The materials were submitted between August and November 1969; for earlier bibliographies see ED 027 810 and ED 032 806. A special section on the teaching of English in Israel comprises…

  14. System and method for quench and over-current protection of superconductor

    DOEpatents

    Huang, Xianrui; Laskaris, Evangelos Trifon; Sivasubramaniam, Kiruba Haran; Bray, James William; Ryan, David Thomas; Fogarty, James Michael; Steinbach, Albert Eugene

    2005-05-31

    A system and method for protecting a superconductor. The system may comprise a current sensor operable to detect a current flowing through the superconductor. The system may comprise a coolant temperature sensor operable to detect the temperature of a cryogenic coolant used to cool the superconductor to a superconductive state. The control circuit is operable to estimate the superconductor temperature based on the current flow and the coolant temperature. The system may also be operable to compare the estimated superconductor temperature to at least one threshold temperature and to initiate a corrective action when the superconductor temperature exceeds the at least one threshold temperature.

  15. Method for determining transport critical current densities and flux penetration depth in bulk superconductors

    NASA Technical Reports Server (NTRS)

    Israelsson, Ulf E. (Inventor); Strayer, Donald M. (Inventor)

    1992-01-01

    A contact-less method for determining transport critical current density and flux penetration depth in bulk superconductor material. A compressor having a hollow interior and a plunger for selectively reducing the free space area for distribution of the magnetic flux therein are formed of superconductor material. Analytical relationships, based upon the critical state model, Maxwell's equations and geometrical relationships define transport critical current density and flux penetration depth in terms of the initial trapped magnetic flux density and the ratio between initial and final magnetic flux densities whereby data may be reliably determined by means of the simple test apparatus for evaluating the current density and flux penetration depth.

  16. Method for Determining Local Current Density in 2G HTS Tapes

    NASA Astrophysics Data System (ADS)

    Bludova, A. I.

    Practically important problem is to determine the density and direction of 2G HTS induced currents at each point on the tape in order to examine its local deviations. This problem is resolved indirectly by spatial measurement of generated magnetic field with a scanning Hall sensor at a given height above the tape surface. Current density is subsequently determined by the Biot-Savart law inversion in Fourier domain. Tikhonov regularization is used in order to increase precision. Method is verified with the model current density reconstruction. Optimal calculation parameters and resulting precision are described.

  17. Methods for shielding a flexible, PCB-made eddy current array probe against edge effects

    NASA Astrophysics Data System (ADS)

    Lepage, B.

    2012-05-01

    Probe shielding has been used in combination with eddy current and eddy current array sensors for quite some time to improve detection of defects located near component edges. Conventional methods of providing such shielding are not suitable for coils etched on printed circuit board. This paper describes an innovative shielded coil design suitable for highly flexible, printed circuit board eddy current array probes. The benefits of the new design will be demonstrated for the inspection of dovetails, where detection of defects along the edge is critical.

  18. Writing a successful research abstract.

    PubMed

    Bliss, Donna Z

    2012-01-01

    Writing and submitting a research abstract provides timely dissemination of the findings of a study and offers peer input for the subsequent development of a quality manuscript. Acceptance of abstracts is competitive. Understanding the expected content of an abstract, the abstract review process and tips for skillful writing will improve the chance of acceptance.

  19. 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.

  20. 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.

  1. An Improved Distributed Secondary Control Method for DC Microgrids With Enhanced Dynamic Current Sharing Performance

    SciTech Connect

    Wang, Panbao; Lu, Xiaonan; Yang, Xu; Wang, Wei; Xu, Dianguo

    2016-09-01

    This paper proposes an improved distributed secondary control scheme for dc microgrids (MGs), aiming at overcoming the drawbacks of conventional droop control method. The proposed secondary control scheme can remove the dc voltage deviation and improve the current sharing accuracy by using voltage-shifting and slope-adjusting approaches simultaneously. Meanwhile, the average value of droop coefficients is calculated, and then it is controlled by an additional controller included in the distributed secondary control layer to ensure that each droop coefficient converges at a reasonable value. Hence, by adjusting the droop coefficient, each participating converter has equal output impedance, and the accurate proportional load current sharing can be achieved with different line resistances. Furthermore, the current sharing performance in steady and transient states can be enhanced by using the proposed method. The effectiveness of the proposed method is verified by detailed experimental tests based on a 3 × 1 kW prototype with three interface converters.

  2. Source tracking fecal bacteria in water: a critical review of current methods.

    PubMed

    Meays, Cynthia L; Broersma, Klaas; Nordin, Rick; Mazumder, Asit

    2004-10-01

    Many molecular and biochemical methods and techniques are being developed to track sources of bacteria in water and food. Currently, there is no standard method proposed for source tracking. This manuscript is a critical evaluation of the various methods used in watersheds, and highlights some of the advantages and disadvantages of each method. Making a decision on a single or combination of methods to use under a particular situation will depend on a number of factors including: question(s) to be answered, scale of identification (broad scale versus specific species identification), available expertise, cost of analysis, turnaround time, and access to facilities. This manuscript reviews several source tracking methodologies which are in current use for source tracking fecal bacteria in the environment including: ribotyping, pulse-field gel electrophoresis, denaturing-gradient gel electrophoresis, repetitive DNA sequences (Rep-PCR), host-specific 16S rDNA genetic markers, and antibiotic resistance analysis.

  3. Approach for Wide Use of Diagnostic Method for XLPE Cables Using Harmonics in AC Loss Current

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Tomiyuki; Nakade, Masahiko; Yagi, Yukihiro; Ishii, Noboru

    Water tree is one of the degradation aspects of XLPE cables used for under-ground distribution or transmission lines. We have developed the loss current method using 3rd harmonic in AC loss current for cable diagnosis. Harmonic components in loss current arise as a result of the non-linear voltage-current characteristics of water trees. We confirmed that the 3rd harmonic in AC loss current had good correlation with water tree growth and break down strength. After that, we have applied this method to the actual 66kV XLPE cable lines. Up to now, the number of the application results is more than 130 lines. In case of cable lines terminated at gas-insulated switchgear (GIS), we have to remove the lightning arrestor (LA) and the potential transformer (PT) out of the test circuit. The reason is that we are afraid that each of LA and PT disturbs the degradation signal from cable lines. It takes extra time (1 or 2 days) and costs more to remove LA and PT in GIS out of a circuit. In order to achieve easy and reasonable diagnosis, we have developed a new method for cable lines terminated at GIS, by utilizing a technique, which enables to reduce signal of LA and PT from disturbed signal of cable lines. We confirmed the effect of the new method by experiments with actual cables.

  4. Field-induced phase transitions in chiral smectic liquid crystals studied by the constant current method

    NASA Astrophysics Data System (ADS)

    H, Dhaouadi; R, Zgueb; O, Riahi; F, Trabelsi; T, Othman

    2016-05-01

    In ferroelectric liquid crystals, phase transitions can be induced by an electric field. The current constant method allows these transition to be quickly localized and thus the (E,T) phase diagram of the studied product can be obtained. In this work, we make a slight modification to the measurement principles based on this method. This modification allows the characteristic parameters of ferroelectric liquid crystal to be quantitatively measured. The use of a current square signal highlights a phenomenon of ferroelectric hysteresis with remnant polarization at null field, which points out an effect of memory in this compound.

  5. An interior point method for state estimation with current magnitude measurements and inequality constraints

    SciTech Connect

    Handschin, E.; Langer, M.; Kliokys, E.

    1995-12-31

    The possibility of power system state estimation with non-traditional measurement configuration is investigated. It is assumed that some substations are equipped with current magnitude measurements. Unique state estimation is possible, in such a situation, if currents are combined with voltage or power measurements and inequality constraints on node power injections are taken into account. The state estimation algorithm facilitating the efficient incorporation of inequality constraints is developed using an interior point optimization method. Simulation results showing the performance of the algorithm are presented. The method can be used for state estimation in medium voltage subtransmission and distribution networks.

  6. Foundations of the Bandera Abstraction Tools

    NASA Technical Reports Server (NTRS)

    Hatcliff, John; Dwyer, Matthew B.; Pasareanu, Corina S.; Robby

    2003-01-01

    Current research is demonstrating that model-checking and other forms of automated finite-state verification can be effective for checking properties of software systems. Due to the exponential costs associated with model-checking, multiple forms of abstraction are often necessary to obtain system models that are tractable for automated checking. The Bandera Tool Set provides multiple forms of automated support for compiling concurrent Java software systems to models that can be supplied to several different model-checking tools. In this paper, we describe the foundations of Bandera's data abstraction mechanism which is used to reduce the cardinality (and the program's state-space) of data domains in software to be model-checked. From a technical standpoint, the form of data abstraction used in Bandera is simple, and it is based on classical presentations of abstract interpretation. We describe the mechanisms that Bandera provides for declaring abstractions, for attaching abstractions to programs, and for generating abstracted programs and properties. The contributions of this work are the design and implementation of various forms of tool support required for effective application of data abstraction to software components written in a programming language like Java which has a rich set of linguistic features.

  7. Linear decomposition method for approximating arbitrary magnetic field profiles by optimization of discrete electromagnet currents

    SciTech Connect

    Tejero, E. M.; Gatling, G.

    2009-03-15

    A method for approximating arbitrary axial magnetic field profiles for a given solenoidal electromagnet coil array is described. The method casts the individual contributions from each coil as a truncated orthonormal basis for the space within the array. This truncated basis allows for the linear decomposition of an arbitrary profile function, which returns the appropriate currents for each coil to best reproduce the desired profile. We present the mathematical details of the method along with a detailed example of its use. The results from the method are used in a simulation and compared with magnetic field measuremen0008.

  8. Exoplanets and Multiverses (Abstract)

    NASA Astrophysics Data System (ADS)

    Trimble, V.

    2016-12-01

    (Abstract only) To the ancients, the Earth was the Universe, of a size to be crossed by a god in a day, by boat or chariot, and by humans in a lifetime. Thus an exoplanet would have been a multiverse. The ideas gradually separated over centuries, with gradual acceptance of a sun-centered solar system, the stars as suns likely to have their own planets, other galaxies beyond the Milky Way, and so forth. And whenever the community divided between "just one' of anything versus "many," the "manies" have won. Discoveries beginning in 1991 and 1995 have gradually led to a battalion or two of planets orbiting other stars, very few like our own little family, and to moderately serious consideration of even larger numbers of other universes, again very few like our own. I'm betting, however, on habitable (though not necessarily inhabited) exoplanets to be found, and habitable (though again not necessarily inhabited) universes. Only the former will yield pretty pictures.

  9. Experience with abstract notation one

    NASA Technical Reports Server (NTRS)

    Harvey, James D.; Weaver, Alfred C.

    1990-01-01

    The development of computer science has produced a vast number of machine architectures, programming languages, and compiler technologies. The cross product of these three characteristics defines the spectrum of previous and present data representation methodologies. With regard to computer networks, the uniqueness of these methodologies presents an obstacle when disparate host environments are to be interconnected. Interoperability within a heterogeneous network relies upon the establishment of data representation commonality. The International Standards Organization (ISO) is currently developing the abstract syntax notation one standard (ASN.1) and the basic encoding rules standard (BER) that collectively address this problem. When used within the presentation layer of the open systems interconnection reference model, these two standards provide the data representation commonality required to facilitate interoperability. The details of a compiler that was built to automate the use of ASN.1 and BER are described. From this experience, insights into both standards are given and potential problems relating to this development effort are discussed.

  10. Non-contact current and voltage sensing method using a clamshell housing and a ferrite cylinder

    SciTech Connect

    Carpenter, Gary D.; El-Essawy, Wael; Ferreira, Alexandre Peixoto; Keller, Thomas Walter; Rubio, Juan C.; Schappert, Michael

    2016-04-26

    A method of measurement using a detachable current and voltage sensor provides an isolated and convenient technique for to measuring current passing through a conductor such as an AC branch circuit wire, as well as providing an indication of an electrostatic potential on the wire, which can be used to indicate the phase of the voltage on the wire, and optionally a magnitude of the voltage. The device includes a housing that contains the current and voltage sensors, which may be a ferrite cylinder with a hall effect sensor disposed in a gap along the circumference to measure current, or alternative a winding provided through the cylinder along its axis and a capacitive plate or wire disposed adjacent to, or within, the ferrite cylinder to provide the indication of the voltage.

  11. Apparatus and method for measuring critical current properties of a coated conductor

    DOEpatents

    Mueller, Fred M [Los Alamos, NM; Haenisch, Jens [Dresden, DE

    2012-07-24

    The transverse critical-current uniformity in a superconducting tape was determined using a magnetic knife apparatus. A critical current I.sub.c distribution and transverse critical current density J.sub.c distribution in YBCO coated conductors was measured nondestructively with high resolution using a magnetic knife apparatus. The method utilizes the strong depression of J.sub.c in applied magnetic fields. A narrow region of low, including zero, magnetic field in a surrounding higher field is moved transversely across a sample of coated conductor. This reveals the critical current density distribution. A Fourier series inversion process was used to determine the transverse J.sub.c distribution in the sample.

  12. The method of measuring the temperature dependence of the critical current of the HTS-2

    NASA Astrophysics Data System (ADS)

    Yashkin, D. S.; Krasnoperov, E. P.; Brazhnik, P. A.; Kruglov, V. S.

    2016-09-01

    A new method of measurement of Ic(T) dependence for the HTS-2 tape is realized. In this method, the metal substrate of the tape is used as both a heater and a thermometer. Index n(T) was calculated from the measured current-voltage characteristics (CVC). For the tape manufactured by SuperPower Inc. the data of n-index temperature dependence in the range from 77 K up to 90 K are presented.

  13. Representation of bioelectric current sources using Whitney elements in the finite element method.

    PubMed

    Tanzer, I Oğuz; Järvenpää, Seppo; Nenonen, Jukka; Somersalo, Erkki

    2005-07-07

    Bioelectric current sources of magneto- and electroencephalograms (MEG, EEG) are usually modelled with discrete delta-function type current dipoles, despite the fact that the currents in the brain are naturally continuous throughout the neuronal tissue. In this study, we represent bioelectric current sources in terms of Whitney-type elements in the finite element method (FEM) using a tetrahedral mesh. The aim is to study how well the Whitney elements can reproduce the potential and magnetic field patterns generated by a point current dipole in a homogeneous conducting sphere. The electric potential is solved for a unit sphere model with isotropic conductivity and magnetic fields are calculated for points located on a cap outside the sphere. The computed potential and magnetic field are compared with analytical solutions for a current dipole. Relative difference measures between the FEM and analytical solutions are less than 1%, suggesting that Whitney elements as bioelectric current sources are able to produce the same potential and magnetic field patterns as the point dipole sources.

  14. Representation of bioelectric current sources using Whitney elements in the finite element method

    NASA Astrophysics Data System (ADS)

    Oguz Tanzer, I.; Järvenpää, Seppo; Nenonen, Jukka; Somersalo, Erkki

    2005-07-01

    Bioelectric current sources of magneto- and electroencephalograms (MEG, EEG) are usually modelled with discrete delta-function type current dipoles, despite the fact that the currents in the brain are naturally continuous throughout the neuronal tissue. In this study, we represent bioelectric current sources in terms of Whitney-type elements in the finite element method (FEM) using a tetrahedral mesh. The aim is to study how well the Whitney elements can reproduce the potential and magnetic field patterns generated by a point current dipole in a homogeneous conducting sphere. The electric potential is solved for a unit sphere model with isotropic conductivity and magnetic fields are calculated for points located on a cap outside the sphere. The computed potential and magnetic field are compared with analytical solutions for a current dipole. Relative difference measures between the FEM and analytical solutions are less than 1%, suggesting that Whitney elements as bioelectric current sources are able to produce the same potential and magnetic field patterns as the point dipole sources.

  15. Universal 'imaginary closed circuit method' and formula for determination of direction of induced emf/current

    NASA Astrophysics Data System (ADS)

    Balaram Atram, Dattatraya

    2011-01-01

    Fleming's right-hand rule and the right-flat-hand rule are generally applied for determining the direction of flow of induced emf/current in straight conductors. The right-hand-fingers rule is applied for coils only. The right-hand-thumb rule can be applied for either straight conductors or coils. Different rules have to be applied for different situations. Also, a formula for determining the direction of induced emf/current does not exist on the basis of these rules. In this article, based on Faraday's law of electromagnetic induction and Lenz's law, an 'imaginary closed circuit method' and a formula for determination of direction of induced emf/current has been proposed. The method is universal in the sense that it is applicable for conductors of any shape, for any kind of relative motion of the conductor with respect to the magnetic flux, and moreover it is applicable for the case of varying magnetic flux.

  16. Current harmonics elimination control method for six-phase PM synchronous motor drives.

    PubMed

    Yuan, Lei; Chen, Ming-liang; Shen, Jian-qing; Xiao, Fei

    2015-11-01

    To reduce the undesired 5th and 7th stator harmonic current in the six-phase permanent magnet synchronous motor (PMSM), an improved vector control algorithm was proposed based on vector space decomposition (VSD) transformation method, which can control the fundamental and harmonic subspace separately. To improve the traditional VSD technology, a novel synchronous rotating coordinate transformation matrix was presented in this paper, and only using the traditional PI controller in d-q subspace can meet the non-static difference adjustment, the controller parameter design method is given by employing internal model principle. Moreover, the current PI controller parallel with resonant controller is employed in x-y subspace to realize the specific 5th and 7th harmonic component compensation. In addition, a new six-phase SVPWM algorithm based on VSD transformation theory is also proposed. Simulation and experimental results verify the effectiveness of current decoupling vector controller.

  17. A new method of CCD dark current correction via extracting the dark Information from scientific images

    NASA Astrophysics Data System (ADS)

    Ma, Bin; Shang, Zhaohui; Hu, Yi; Liu, Qiang; Wang, Lifan; Wei, Peng

    2014-07-01

    We have developed a new method to correct dark current at relatively high temperatures for Charge-Coupled Device (CCD) images when dark frames cannot be obtained on the telescope. For images taken with the Antarctic Survey Telescopes (AST3) in 2012, due to the low cooling efficiency, the median CCD temperature was -46°C, resulting in a high dark current level of about 3e-/pix/sec, even comparable to the sky brightness (10e-/pix/sec). If not corrected, the nonuniformity of the dark current could even overweight the photon noise of the sky background. However, dark frames could not be obtained during the observing season because the camera was operated in frame-transfer mode without a shutter, and the telescope was unattended in winter. Here we present an alternative, but simple and effective method to derive the dark current frame from the scientific images. Then we can scale this dark frame to the temperature at which the scientific images were taken, and apply the dark frame corrections to the scientific images. We have applied this method to the AST3 data, and demonstrated that it can reduce the noise to a level roughly as low as the photon noise of the sky brightness, solving the high noise problem and improving the photometric precision. This method will also be helpful for other projects that suffer from similar issues.

  18. Method and apparatus for detecting cyber attacks on an alternating current power grid

    DOEpatents

    McEachern, Alexander; Hofmann, Ronald

    2017-04-11

    A method and apparatus for detecting cyber attacks on remotely-operable elements of an alternating current distribution grid. Two state estimates of the distribution grid are prepared, one of which uses micro-synchrophasors. A difference between the two state estimates indicates a possible cyber attack.

  19. Current methods for detecting the presence of botulinum neurotoxins in food and other biological samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current methods for detecting the presence of botulinum neurotoxins in food and other biological samples Botulinum neurotoxins (BoNTs), the causative agents of botulism, are among the most lethal human bacterial toxins and the causative agent of botulism. BoNTs are also classified as Select Agents ...

  20. Method and apparatus for monitoring armature position in direct-current solenoids

    DOEpatents

    Moyers, John C.; Haynes, Howard D.

    1996-12-10

    A method for determining the position of an armature of a dc-powered solenoid. Electrical circuitry is provided to introduce a small alternating current flow through the coil. As a result, the impedance and resistance of the solenoid coil can be measured to provide information indicative of the armature's position.

  1. Autonomous Method and System for Minimizing the Magnitude of Plasma Discharge Current Oscillations in a Hall Effect Plasma Device

    NASA Technical Reports Server (NTRS)

    Hruby, Vladimir (Inventor); Demmons, Nathaniel (Inventor); Ehrbar, Eric (Inventor); Pote, Bruce (Inventor); Rosenblad, Nathan (Inventor)

    2014-01-01

    An autonomous method for minimizing the magnitude of plasma discharge current oscillations in a Hall effect plasma device includes iteratively measuring plasma discharge current oscillations of the plasma device and iteratively adjusting the magnet current delivered to the plasma device in response to measured plasma discharge current oscillations to reduce the magnitude of the plasma discharge current oscillations.

  2. (abstract) Measurement of the Deformation Field Around a Strike Slip Fault at Parkfield California from 107 Monuments using the Rapid Static Surveying Method of GPS

    NASA Technical Reports Server (NTRS)

    Hurst, Kenneth; Blewitt, Geoff

    1993-01-01

    We have surveyed 107 monuments in a 30x45 km area around Parkfield California in June 1992 and again in May 1993. We are analyzing the data from these observations and will present the details of the method and the displacements measured from 1992 to 1993.

  3. Teaching Methods and Teaching Materials in German: A Survey of the UMT Project with Report Abstracts. Pedagogisk-Dokumentation, No. 32, 1974.

    ERIC Educational Resources Information Center

    Lofgren, Horst

    The UNT project (Instructional Methods in German), begun in 1965 and ended in 1974, had as its principal aims (1) to investigate scientifically certain prerequisites for and methodological approaches to teaching German to Swedish comprehensive school pupils and (2) in the light of this investigation and with the aid of successive trails and…

  4. Geoinformatics 2006--Abstracts

    USGS Publications Warehouse

    Brady, Shailaja R.; Sinha, A. Krishna; Gundersen, Linda C.

    2006-01-01

    In order to facilitate the discovery, integration, and analysis of distributed data, geoscientists-in partnership with information technologists and computer scientists-have established the emerging science of geoinformatics. Geoinformatics 2006, an international conference that was attended by over 300 participants between May 10 and 12, 2006, represents the first nationally organized meeting whose primary goal was to provide a forum for the exchange of the most current research in geoinformatics.

  5. Abstraction of Drift Seepage

    SciTech Connect

    J.T. Birkholzer

    2004-11-01

    This model report documents the abstraction of drift seepage, conducted to provide seepage-relevant parameters and their probability distributions for use in Total System Performance Assessment for License Application (TSPA-LA). Drift seepage refers to the flow of liquid water into waste emplacement drifts. Water that seeps into drifts may contact waste packages and potentially mobilize radionuclides, and may result in advective transport of radionuclides through breached waste packages [''Risk Information to Support Prioritization of Performance Assessment Models'' (BSC 2003 [DIRS 168796], Section 3.3.2)]. The unsaturated rock layers overlying and hosting the repository form a natural barrier that reduces the amount of water entering emplacement drifts by natural subsurface processes. For example, drift seepage is limited by the capillary barrier forming at the drift crown, which decreases or even eliminates water flow from the unsaturated fractured rock into the drift. During the first few hundred years after waste emplacement, when above-boiling rock temperatures will develop as a result of heat generated by the decay of the radioactive waste, vaporization of percolation water is an additional factor limiting seepage. Estimating the effectiveness of these natural barrier capabilities and predicting the amount of seepage into drifts is an important aspect of assessing the performance of the repository. The TSPA-LA therefore includes a seepage component that calculates the amount of seepage into drifts [''Total System Performance Assessment (TSPA) Model/Analysis for the License Application'' (BSC 2004 [DIRS 168504], Section 6.3.3.1)]. The TSPA-LA calculation is performed with a probabilistic approach that accounts for the spatial and temporal variability and inherent uncertainty of seepage-relevant properties and processes. Results are used for subsequent TSPA-LA components that may handle, for example, waste package corrosion or radionuclide transport.

  6. Analytical mass spectrometry. Abstracts

    SciTech Connect

    Not Available

    1990-12-31

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  7. 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.

  8. Hierarchical abstract semantic model for image classification

    NASA Astrophysics Data System (ADS)

    Ye, Zhipeng; Liu, Peng; Zhao, Wei; Tang, Xianglong

    2015-09-01

    Semantic gap limits the performance of bag-of-visual-words. To deal with this problem, a hierarchical abstract semantics method that builds abstract semantic layers, generates semantic visual vocabularies, measures semantic gap, and constructs classifiers using the Adaboost strategy is proposed. First, abstract semantic layers are proposed to narrow the semantic gap between visual features and their interpretation. Then semantic visual words are extracted as features to train semantic classifiers. One popular form of measurement is used to quantify the semantic gap. The Adaboost training strategy is used to combine weak classifiers into strong ones to further improve performance. For a testing image, the category is estimated layer-by-layer. Corresponding abstract hierarchical structures for popular datasets, including Caltech-101 and MSRC, are proposed for evaluation. The experimental results show that the proposed method is capable of narrowing semantic gaps effectively and performs better than other categorization methods.

  9. Method for exciting inductive-resistive loads with high and controllable direct current

    DOEpatents

    Hill, Jr., Homer M.

    1976-01-01

    Apparatus and method for transmitting dc power to a load circuit by applying a dc voltage from a standard waveform synthesizer to duration modulate a bipolar rectangular wave generator. As the amplitude of the dc voltage increases, the widths of the rectangular wave generator output pulses increase, and as the amplitude of the dc voltage decreases, the widths of the rectangular wave generator output pulses decrease. Thus, the waveform synthesizer selectively changes the durations of the rectangular wave generator bipolar output pulses so as to produce a rectangular wave ac carrier that is duration modulated in accordance with and in direct proportion to the voltage amplitude from the synthesizer. Thereupon, by transferring the carrier to the load circuit through an amplifier and a rectifier, the load current also corresponds directly to the voltage amplitude from the synthesizer. To this end, the rectified wave at less than 100% duty factor, amounts to a doubled frequency direct voltage pulse train for applying a direct current to the load, while the current ripple is minimized by a high L/R in the load circuit. In one embodiment, a power transmitting power amplifier means having a dc power supply is matched to the load circuit through a transformer for current magnification without sacrificing load current duration capability, while negative voltage and current feedback are provided in order to insure good output fidelity.

  10. Method for producing silicon thin-film transistors with enhanced forward current drive

    DOEpatents

    Weiner, K.H.

    1998-06-30

    A method is disclosed for fabricating amorphous silicon thin film transistors (TFTs) with a polycrystalline silicon surface channel region for enhanced forward current drive. The method is particularly adapted for producing top-gate silicon TFTs which have the advantages of both amorphous and polycrystalline silicon TFTs, but without problem of leakage current of polycrystalline silicon TFTs. This is accomplished by selectively crystallizing a selected region of the amorphous silicon, using a pulsed excimer laser, to create a thin polycrystalline silicon layer at the silicon/gate-insulator surface. The thus created polysilicon layer has an increased mobility compared to the amorphous silicon during forward device operation so that increased drive currents are achieved. In reverse operation the polysilicon layer is relatively thin compared to the amorphous silicon, so that the transistor exhibits the low leakage currents inherent to amorphous silicon. A device made by this method can be used, for example, as a pixel switch in an active-matrix liquid crystal display to improve display refresh rates. 1 fig.

  11. Method for producing silicon thin-film transistors with enhanced forward current drive

    DOEpatents

    Weiner, Kurt H.

    1998-01-01

    A method for fabricating amorphous silicon thin film transistors (TFTs) with a polycrystalline silicon surface channel region for enhanced forward current drive. The method is particularly adapted for producing top-gate silicon TFTs which have the advantages of both amorphous and polycrystalline silicon TFTs, but without problem of leakage current of polycrystalline silicon TFTs. This is accomplished by selectively crystallizing a selected region of the amorphous silicon, using a pulsed excimer laser, to create a thin polycrystalline silicon layer at the silicon/gate-insulator surface. The thus created polysilicon layer has an increased mobility compared to the amorphous silicon during forward device operation so that increased drive currents are achieved. In reverse operation the polysilicon layer is relatively thin compared to the amorphous silicon, so that the transistor exhibits the low leakage currents inherent to amorphous silicon. A device made by this method can be used, for example, as a pixel switch in an active-matrix liquid crystal display to improve display refresh rates.

  12. Quantitatively estimating defects in graphene devices using discharge current analysis method

    PubMed Central

    Jung, Ukjin; Lee, Young Gon; Kang, Chang Goo; Lee, Sangchul; Kim, Jin Ju; Hwang, Hyeon June; Lim, Sung Kwan; Ham, Moon-Ho; Lee, Byoung Hun

    2014-01-01

    Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 1014/cm2, which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication. PMID:24811431

  13. A novel readout method for focal plane array imaging in the presence of large dark current

    NASA Astrophysics Data System (ADS)

    Qiu, Changqing

    1999-08-01

    This research was an investigation of a novel readout method for focal plane array (FPA) optical imaging, especially for very sensitive detectors with large dark current. The readout method is based on periodically blocking the optical input enabling the removal of the dark current integration from the output. The research demonstrated that it is feasible to modulate the optical input with the designed readout circuit and thus achieve longer signal integration time to enhance the signal-to- noise ratio. Study of a proposed circuit model showed that in theory the correlated readout method could increase the output voltage swing and reduce the noise level by attenuating low frequency noise, thereby effectively improving the FPA dynamic range. Circuits based on standard CMOS circuitry were designed, simulated by PSpice, fabricated using Orbit 2μm n-well technology, and tested with a PI-4000 system. In the circuit evaluation, the output noise due to the clock switching phenomena, the gate signal feedthrough and the charge relaxation, was considered to be the critical problem. The most promising design for minimizing this problem had a CMOS current steering circuit at the input of a high CMRR operational amplifier. Simulation and test results showed that a modified capacitive transimpedance amplifier (CTIA) could subtract dark current output and reduce the output signal due to any difference between the frequencies of the optical input modulation signal and the switch modulation signal. In conclusion, the correlated readout circuit was shown to be a promising approach for advancing FPA technology.

  14. Quantitatively estimating defects in graphene devices using discharge current analysis method.

    PubMed

    Jung, Ukjin; Lee, Young Gon; Kang, Chang Goo; Lee, Sangchul; Kim, Jin Ju; Hwang, Hyeon June; Lim, Sung Kwan; Ham, Moon-Ho; Lee, Byoung Hun

    2014-05-08

    Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 10(14)/cm(2), which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication.

  15. Quantitatively estimating defects in graphene devices using discharge current analysis method

    NASA Astrophysics Data System (ADS)

    Jung, Ukjin; Lee, Young Gon; Kang, Chang Goo; Lee, Sangchul; Kim, Jin Ju; Hwang, Hyeon June; Lim, Sung Kwan; Ham, Moon-Ho; Lee, Byoung Hun

    2014-05-01

    Defects of graphene are the most important concern for the successful applications of graphene since they affect device performance significantly. However, once the graphene is integrated in the device structures, the quality of graphene and surrounding environment could only be assessed using indirect information such as hysteresis, mobility and drive current. Here we develop a discharge current analysis method to measure the quality of graphene integrated in a field effect transistor structure by analyzing the discharge current and examine its validity using various device structures. The density of charging sites affecting the performance of graphene field effect transistor obtained using the discharge current analysis method was on the order of 1014/cm2, which closely correlates with the intensity ratio of the D to G bands in Raman spectroscopy. The graphene FETs fabricated on poly(ethylene naphthalate) (PEN) are found to have a lower density of charging sites than those on SiO2/Si substrate, mainly due to reduced interfacial interaction between the graphene and the PEN. This method can be an indispensable means to improve the stability of devices using a graphene as it provides an accurate and quantitative way to define the quality of graphene after the device fabrication.

  16. Beyond captions: linking figures with abstract sentences in biomedical articles.

    PubMed

    Bockhorst, Joseph P; Conroy, John M; Agarwal, Shashank; O'Leary, Dianne P; Yu, Hong

    2012-01-01

    Although figures in scientific articles have high information content and concisely communicate many key research findings, they are currently under utilized by literature search and retrieval systems. Many systems ignore figures, and those that do not typically only consider caption text. This study describes and evaluates a fully automated approach for associating figures in the body of a biomedical article with sentences in its abstract. We use supervised methods to learn probabilistic language models, hidden Markov models, and conditional random fields for predicting associations between abstract sentences and figures. Three kinds of evidence are used: text in abstract sentences and figures, relative positions of sentences and figures, and the patterns of sentence/figure associations across an article. Each information source is shown to have predictive value, and models that use all kinds of evidence are more accurate than models that do not. Our most accurate method has an F1-score of 69% on a cross-validation experiment, is competitive with the accuracy of human experts, has significantly better predictive accuracy than state-of-the-art methods and enables users to access figures associated with an abstract sentence with an average of 1.82 fewer mouse clicks. A user evaluation shows that human users find our system beneficial. The system is available at http://FigureItOut.askHERMES.org.

  17. Diffusion length and grain boundary recombination activity determination by means of induced current methods

    NASA Astrophysics Data System (ADS)

    Shabelnikova, Yana; Yakimov, Eugene

    2016-11-01

    The application of induced current methods for a quantitative description of multicrystalline silicon solar cell properties is demonstrated. For the minority carriers' diffusion length (L) and grain boundary recombination velocity (Vs) determination three types of measurements were used. They included the measurement of EBIC signal dependence on electron beam energy and of EBIC and XBIC grain boundary contrast profiles. The L and Vs values obtained by means of minimization the residual function between measured and model induced current curves are presented. The inaccuracy of obtained parameters is discussed for each of three types of measurements.

  18. Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement

    DOEpatents

    Kikta, T.J.; Mitchell, R.D.

    1992-11-24

    A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet. 4 figs.

  19. Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement

    DOEpatents

    Kikta, Thomas J.; Mitchell, Ronald D.

    1992-01-01

    A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet.

  20. Abstract Spatial Reasoning as an Autistic Strength

    PubMed Central

    Stevenson, Jennifer L.; Gernsbacher, Morton Ann

    2013-01-01

    Autistic individuals typically excel on spatial tests that measure abstract reasoning, such as the Block Design subtest on intelligence test batteries and the Raven’s Progressive Matrices nonverbal test of intelligence. Such well-replicated findings suggest that abstract spatial processing is a relative and perhaps absolute strength of autistic individuals. However, previous studies have not systematically varied reasoning level – concrete vs. abstract – and test domain – spatial vs. numerical vs. verbal, which the current study did. Autistic participants (N = 72) and non-autistic participants (N = 72) completed a battery of 12 tests that varied by reasoning level (concrete vs. abstract) and domain (spatial vs. numerical vs. verbal). Autistic participants outperformed non-autistic participants on abstract spatial tests. Non-autistic participants did not outperform autistic participants on any of the three domains (spatial, numerical, and verbal) or at either of the two reasoning levels (concrete and abstract), suggesting similarity in abilities between autistic and non-autistic individuals, with abstract spatial reasoning as an autistic strength. PMID:23533615

  1. A comparative study of new and current methods for dental micro-CT image denoising

    PubMed Central

    Lashgari, Mojtaba; Qin, Jie; Swain, Michael

    2016-01-01

    Objectives: The aim of the current study was to evaluate the application of two advanced noise-reduction algorithms for dental micro-CT images and to implement a comparative analysis of the performance of new and current denoising algorithms. Methods: Denoising was performed using gaussian and median filters as the current filtering approaches and the block-matching and three-dimensional (BM3D) method and total variation method as the proposed new filtering techniques. The performance of the denoising methods was evaluated quantitatively using contrast-to-noise ratio (CNR), edge preserving index (EPI) and blurring indexes, as well as qualitatively using the double-stimulus continuous quality scale procedure. Results: The BM3D method had the best performance with regard to preservation of fine textural features (CNREdge), non-blurring of the whole image (blurring index), the clinical visual score in images with very fine features and the overall visual score for all types of images. On the other hand, the total variation method provided the best results with regard to smoothing of images in texture-free areas (CNRTex-free) and in preserving the edges and borders of image features (EPI). Conclusions: The BM3D method is the most reliable technique for denoising dental micro-CT images with very fine textural details, such as shallow enamel lesions, in which the preservation of the texture and fine features is of the greatest importance. On the other hand, the total variation method is the technique of choice for denoising images without very fine textural details in which the clinician or researcher is interested mainly in anatomical features and structural measurements. PMID:26764583

  2. The cost of applying current helicopter external noise reduction methods while maintaining realistic vehicle performance

    NASA Technical Reports Server (NTRS)

    Bowes, M. A.

    1978-01-01

    Analytical methods were developed and/or adopted for calculating helicopter component noise, and these methods were incorporated into a unified total vehicle noise calculation model. Analytical methods were also developed for calculating the effects of noise reduction methodology on helicopter design, performance, and cost. These methods were used to calculate changes in noise, design, performance, and cost due to the incorporation of engine and main rotor noise reduction methods. All noise reduction techniques were evaluated in the context of an established mission performance criterion which included consideration of hovering ceiling, forward flight range/speed/payload, and rotor stall margin. The results indicate that small, but meaningful, reductions in helicopter noise can be obtained by treating the turbine engine exhaust duct. Furthermore, these reductions do not result in excessive life cycle cost penalties. Currently available main rotor noise reduction methodology, however, is shown to be inadequate and excessively costly.

  3. On Data Interpolation at Three Croatian Repeat Stations by Using the Spherical Elementary Currents Systems Method

    NASA Astrophysics Data System (ADS)

    Vujić, Eugen

    2016-04-01

    A general mathematical tool for expanding vector systems on a sphere into basis functions, spherical elementary current system (SECS) method, was applied for separation of the geomagnetic field variations into external and internal parts, over a limited region of central and southeastern Europe. The registered variations at three Croatian repeat stations were compared to the variations estimated by the SECS method using the variations from the different sets of observatories. The results of the SECS method were also compared to a simple assumption that the variations at repeat station are equal to those at particular observatory. The relevance of this comparison was to get an insight about the possibility of using the SECS method for estimating the geomagnetic field variations over Croatia. The guidelines for the application of the SECS method for the purpose of reducing repeat station data were also given.

  4. Thickness measuring of electroconductive pipe walls using the dual-frequency eddy-current method

    NASA Astrophysics Data System (ADS)

    Yakimov, Evgeny; Galtseva, Olga; Ustyugov, Daniil

    2017-01-01

    The paper describes a dual-frequency method for reducing the impact of changes in the gap size between the eddy-current transducer and the pipe, as well as the pipe electrical conductivity on the eddy-current thickness gauge readings. A block-diagram of the dual-frequency eddy-current thickness gauge is proposed for light-alloy drill pipes. The amplitude and signal phase dependencies on the wall thickness in the range from 6 to 17 mm and the gap in the range from 0 to 13.5 mm were studied, the results are presented. The digital signal processing algorithms based on the piecewise-linear approximation of low-frequency and high-frequency signal phase dependencies on the wall thickness are proposed. It is shown that the proposed correction algorithms can reduce the error caused by variations of electrical conductivity and the gap between the transducer and the pipe.

  5. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOEpatents

    Danby, G.T.; Jackson, J.W.

    1990-03-19

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations (dB/dt) in the particle beam.

  6. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOEpatents

    Danby, Gordon T.; Jackson, John W.

    1991-01-01

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.

  7. The value of value of information: best informing research design and prioritization using current methods.

    PubMed

    Eckermann, Simon; Karnon, Jon; Willan, Andrew R

    2010-01-01

    Value of information (VOI) methods have been proposed as a systematic approach to inform optimal research design and prioritization. Four related questions arise that VOI methods could address. (i) Is further research for a health technology assessment (HTA) potentially worthwhile? (ii) Is the cost of a given research design less than its expected value? (iii) What is the optimal research design for an HTA? (iv) How can research funding be best prioritized across alternative HTAs? Following Occam's razor, we consider the usefulness of VOI methods in informing questions 1-4 relative to their simplicity of use. Expected value of perfect information (EVPI) with current information, while simple to calculate, is shown to provide neither a necessary nor a sufficient condition to address question 1, given that what EVPI needs to exceed varies with the cost of research design, which can vary from very large down to negligible. Hence, for any given HTA, EVPI does not discriminate, as it can be large and further research not worthwhile or small and further research worthwhile. In contrast, each of questions 1-4 are shown to be fully addressed (necessary and sufficient) where VOI methods are applied to maximize expected value of sample information (EVSI) minus expected costs across designs. In comparing complexity in use of VOI methods, applying the central limit theorem (CLT) simplifies analysis to enable easy estimation of EVSI and optimal overall research design, and has been shown to outperform bootstrapping, particularly with small samples. Consequently, VOI methods applying the CLT to inform optimal overall research design satisfy Occam's razor in both improving decision making and reducing complexity. Furthermore, they enable consideration of relevant decision contexts, including option value and opportunity cost of delay, time, imperfect implementation and optimal design across jurisdictions. More complex VOI methods such as bootstrapping of the expected value of

  8. The current state-of-the-art of spinal cord imaging: Methods

    PubMed Central

    Stroman, P.W.; Wheeler-Kingshott, C.; Bacon, M.; Schwab, J.M.; Bosma, R.; Brooks, J.; Cadotte, D.; Carlstedt, T.; Ciccarelli, O.; Cohen-Adad, J.; Curt, A.; Evangelou, N.; Fehlings, M.G.; Filippi, M.; Kelley, B.J.; Kollias, S.; Mackay, A.; Porro, C.A.; Smith, S.; Strittmatter, S.M.; Summers, P.; Tracey, I.

    2015-01-01

    A first-ever spinal cord imaging meeting was sponsored by the International Spinal Research Trust and the Wings for Life Foundation with the aim of identifying the current state-of-the-art of spinal cord imaging, the current greatest challenges, and greatest needs for future development. This meeting was attended by a small group of invited experts spanning all aspects of spinal cord imaging from basic research to clinical practice. The greatest current challenges for spinal cord imaging were identified as arising from the imaging environment itself; difficult imaging environment created by the bone surrounding the spinal canal, physiological motion of the cord and adjacent tissues, and small cross-sectional dimensions of the spinal cord, exacerbated by metallic implants often present in injured patients. Challenges were also identified as a result of a lack of “critical mass” of researchers taking on the development of spinal cord imaging, affecting both the rate of progress in the field, and the demand for equipment and software to manufacturers to produce the necessary tools. Here we define the current state-of-the-art of spinal cord imaging, discuss the underlying theory and challenges, and present the evidence for the current and potential power of these methods. In two review papers (part I and part II), we propose that the challenges can be overcome with advances in methods, improving availability and effectiveness of methods, and linking existing researchers to create the necessary scientific and clinical network to advance the rate of progress and impact of the research. PMID:23685159

  9. Current methods and attitudes of women towards contraception in Europe and America

    PubMed Central

    2013-01-01

    Background The choice of available contraceptive methods has increased in recent years; however, recent data on women’s awareness of methods and reasons for their method choice, or reasons for changing methods, is limited. The aim of this study was to examine the use and awareness of contraceptive methods in the USA, UK, Germany, Italy and Spain. Methods Quantitative survey of heterosexual women aged 25–44 years (n=2544), with no known infertility. Questions related to knowledge and use of contraceptive methods, reasons for choice and for changing methods, and sources of advice. Results There was generally good awareness of most forms of contraception in all five countries. Awareness and current usage was greatest for the contraceptive pill (awareness >98%, usage varied from 35% [Spain] to 63% [Germany]); and male condom (awareness >95%, usage varied from 20% [Germany] to 47% [Spain]); awareness of other methods varied between countries. Doctors have the greatest influence on women’s choice of contraceptive method (>50% for all countries), and are most likely to suggest the contraceptive pill or male condom. Women’s contraceptive needs change; 4–36% of contraceptive pill users were likely to change their method within 12 months. For previous contraceptive pill users (n=377), most common reason for change was concern about side effects (from 26% [Italy] to 10% [UK]); however, awareness of many non-hormonal contraceptive methods was low. Conclusions Women aged 25–44 are aware of a wide variety of contraceptive methods, but knowledge and usage of the contraceptive pill and condoms predominates. Changing contraception method is frequent, occurring for a variety of reasons, including change in life circumstances and, for pill users, concerns about side effects. PMID:23384291

  10. Pediatric stroke and transcranial direct current stimulation: methods for rational individualized dose optimization

    PubMed Central

    Gillick, Bernadette T.; Kirton, Adam; Carmel, Jason B.; Minhas, Preet; Bikson, Marom

    2014-01-01

    Background: Transcranial direct current stimulation (tDCS) has been investigated mainly in adults and doses may not be appropriate in pediatric applications. In perinatal stroke where potential applications are promising, rational adaptation of dosage for children remains under investigation. Objective: Construct child-specific tDCS dosing parameters through case study within a perinatal stroke tDCS safety and feasibility trial. Methods: 10-year-old subject with a diagnosis of presumed perinatal ischemic stroke and hemiparesis was identified. T1 magnetic resonance imaging (MRI) scans used to derive computerized model for current flow and electrode positions. Workflow using modeling results and consideration of dosage in previous clinical trials was incorporated. Prior ad hoc adult montages vs. de novo optimized montages provided distinct risk benefit analysis. Approximating adult dose required consideration of changes in both peak brain current flow and distribution which further tradeoff between maximizing efficacy and adding safety factors. Electrode size, position, current intensity, compliance voltage, and duration were controlled independently in this process. Results: Brain electric fields modeled and compared to values previously predicted models (Datta et al., 2011; Minhas et al., 2012). Approximating conservative brain current flow patterns and intensities used in previous adult trials for comparable indications, the optimal current intensity established was 0.7 mA for 10 min with a tDCS C3/C4 montage. Specifically 0.7 mA produced comparable peak brain current intensity of an average adult receiving 1.0 mA. Electrode size of 5 × 7 cm2 with 1.0 mA and low-voltage tDCS was employed to maximize tolerability. Safety and feasibility confirmed with subject tolerating the session well and no serious adverse events. Conclusion: Rational approaches to dose customization, with steps informed by computational modeling, may improve guidance for pediatric stroke t

  11. Current Applications of Chromatographic Methods in the Study of Human Body Fluids for Diagnosing Disorders.

    PubMed

    Jóźwik, Jagoda; Kałużna-Czaplińska, Joanna

    2016-01-01

    Currently, analysis of various human body fluids is one of the most essential and promising approaches to enable the discovery of biomarkers or pathophysiological mechanisms for disorders and diseases. Analysis of these fluids is challenging due to their complex composition and unique characteristics. Development of new analytical methods in this field has made it possible to analyze body fluids with higher selectivity, sensitivity, and precision. The composition and concentration of analytes in body fluids are most often determined by chromatography-based techniques. There is no doubt that proper use of knowledge that comes from a better understanding of the role of body fluids requires the cooperation of scientists of diverse specializations, including analytical chemists, biologists, and physicians. This article summarizes current knowledge about the application of different chromatographic methods in analyses of a wide range of compounds in human body fluids in order to diagnose certain diseases and disorders.

  12. Magnetic, eddy-current, and electrical methods. Electromagnetic quality control of carburization of steel products

    SciTech Connect

    Gorkunov, E.S.; Kogan, L.Kh.; Baraz, E.M.; Korolev, A.L.

    1994-08-01

    We have studied the effect that the casehardening (carburizing) temperature and time, carburizer activity, and variation of the conditions of subsequent heat treatment has on the electromagnetic properties of carburized specimens of 12Kh2N4A steel. The possibilities of nondestructive testing for the main parameters that determine the quality of carburization of 12Kh2N4A steel products, using coercimetric and eddy-current methods, are considered. The optimal depth of penetration of the magnetic flux in the portion of the inspected carburized product for greater inspection reliability is determined. The joint use of coercimetric and eddy-current methods makes it possible to monitor the depth and wear resistance of the carburized case and also to estimate the amount of retained austenite in the layer and reveal the effect of the decarburized surface zone.

  13. The investigation of carbon nitride films prepared at various arc currents by vacuum cathode arc method

    NASA Astrophysics Data System (ADS)

    Zhou, Zhimin; Xia, Lifang

    2002-08-01

    The carbon nitride films have been prepared in the arc currents range of 20-60 A at the Ar/N2 atmosphere of 50/400 sccm by the vacuum cathode arc deposition method. The properties of the films were characterized by x-ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and nanoindentation. The N concentration showed a maximum of 35 at% at 20 A and decreased gradually with the arc currents. The films below 40 A consisted of linear polymeric-like component and sp2 graphitic cluster. With the increasing of the arc current from 20 to 40 A, the ID/IG rose and the photoluminescence (PL) fell gradually, which resulted from the development of the sp2 graphitic phase and the decrease of the polymeric-like phase. As a result, the CC bonds increased and sp3CN and sp2CN decreased. Above 40 A, with the increasing of arc currents, ID/IG fell and the PL increased gradually, which reflected the decreasing of sp2 graphitic phase and the modification of C and N atoms in sp2 cluster. The CC bonds and sp3CN fell and the sp2CN rose. The nanohardness of films showed increasing tendency with the arc currents. The variation of the relative ratio and the average energy of N-containing species and C-containing species at the atmosphere would be responsible for the change in the properties of films.

  14. Compilation of Thesis Abstracts

    DTIC Science & Technology

    2005-09-01

    Postgraduate School, 2002 Doctor of Philosophy in Electrical Engineering-September 2005 Advisor: Charles W. Therrien , Department of Electrical and Computer...Charles W. Therrien , Department of Electrical and Computer Engineering Signal processing methods for signals sampled at different rates are...OCEAN Joel W. Feldmeier-Lieutenant Commander, United States Navy B.S., Carnegie Mellon University, 1996 M.S., University of Idaho, 2003 Master of

  15. 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.

  16. Solution to the Eddy-Current Problem for Type-II Superconductors by Relaxation Method

    NASA Astrophysics Data System (ADS)

    Janíková, Edita; Slodička, Marián

    2008-09-01

    The fast developing industrial applications of superconductors require rigorous mathematical models of their physical behaviour and efficient numerical methods to solve them. We propose and study theoretically a new approximation scheme to solve the 3D eddy-current problem of diffusion of the electric field in type-II superconductors. The method is based on the relaxation principle, where the nonlinear time- and space-dependent partial differential equation (PDE) is split into a linear time-independent PDE coupled with a nonlinear equation involving no partial derivatives.

  17. Electrodeposition and characterization of Ni-ZrO2 nanocomposites by direct and pulse current methods.

    PubMed

    Kumar, K Arunsunai; Mohan, P; Kalaignan, G Paruthimal; Muralidharan, V S

    2012-11-01

    Direct Current (DC) and Pulse current (PC) methods were used to get nanocrystalline Ni-ZrO2 composites from tri-ammonium citrate bath. In the electrocomposite formation, the ZrO2 particles were transported to the surface by mechanical action and got entrapped in the nickel matrix. Incorporation of ZrO2 in the nickel matrix was found to increase with current densities when DC was employed. Beyond 2 A/dm2, their incorporation became saturated when PC was used. PC method offered better electrocomposites than DC method producing finer grains and uniform surface. Scanning electron micrographs (SEM) reveals that smaller grains and uniform distribution of Zirconia particles in the nickel matrix. The increased hardness of Ni-ZrO2 electrocomposite coatings is due to incorporation of ZrO2 particles in the nickel matrix and also changes in grain size. Incorporation of ZrO2 particles in Ni-matrix favoured the enhanced microhardness and corrosion resistance of the deposit.

  18. Solution of 3D inverse scattering problems by combined inverse equivalent current and finite element methods

    SciTech Connect

    Kılıç, Emre Eibert, Thomas F.

    2015-05-01

    An approach combining boundary integral and finite element methods is introduced for the solution of three-dimensional inverse electromagnetic medium scattering problems. Based on the equivalence principle, unknown equivalent electric and magnetic surface current densities on a closed surface are utilized to decompose the inverse medium problem into two parts: a linear radiation problem and a nonlinear cavity problem. The first problem is formulated by a boundary integral equation, the computational burden of which is reduced by employing the multilevel fast multipole method (MLFMM). Reconstructed Cauchy data on the surface allows the utilization of the Lorentz reciprocity and the Poynting's theorems. Exploiting these theorems, the noise level and an initial guess are estimated for the cavity problem. Moreover, it is possible to determine whether the material is lossy or not. In the second problem, the estimated surface currents form inhomogeneous boundary conditions of the cavity problem. The cavity problem is formulated by the finite element technique and solved iteratively by the Gauss–Newton method to reconstruct the properties of the object. Regularization for both the first and the second problems is achieved by a Krylov subspace method. The proposed method is tested against both synthetic and experimental data and promising reconstruction results are obtained.

  19. A comparative study: the impact of different lipid extraction methods on current microalgal lipid research

    PubMed Central

    2014-01-01

    Microalgae cells have the potential to rapidly accumulate lipids, such as triacylglycerides that contain fatty acids important for high value fatty acids (e.g., EPA and DHA) and/or biodiesel production. However, lipid extraction methods for microalgae cells are not well established, and there is currently no standard extraction method for the determination of the fatty acid content of microalgae. This has caused a few problems in microlagal biofuel research due to the bias derived from different extraction methods. Therefore, this study used several extraction methods for fatty acid analysis on marine microalga Tetraselmis sp. M8, aiming to assess the potential impact of different extractions on current microalgal lipid research. These methods included classical Bligh & Dyer lipid extraction, two other chemical extractions using different solvents and sonication, direct saponification and supercritical CO2 extraction. Soxhlet-based extraction was used to weigh out the importance of solvent polarity in the algal oil extraction. Coupled with GC/MS, a Thermogravimetric Analyser was used to improve the quantification of microalgal lipid extractions. Among these extractions, significant differences were observed in both, extract yield and fatty acid composition. The supercritical extraction technique stood out most for effective extraction of microalgal lipids, especially for long chain unsaturated fatty acids. The results highlight the necessity for comparative analyses of microalgae fatty acids and careful choice and validation of analytical methodology in microalgal lipid research. PMID:24456581

  20. A new method to measure the taper of part hole by pneumatic-to-current

    NASA Astrophysics Data System (ADS)

    Yang, Musheng; Zhang, Yu

    2008-12-01

    The manufacture quality of hole of fiddly part with fit requirements doesn't only depend on the machining accuracy, but also depend on the measuring method of dimension. Traditional detecting instruments have the drawbacks of low commonality, accuracy and efficiency. However, the high-end instruments are always marked exorbitant price for the performance. This paper presents a taper measuring method for the hole of part. According to the pneumatic-to-current theory, this method translates dimensional variables of part's hole into the electric signals, and then, through collection of A/D data, acquire the dimension of part measured. Finally, the taper of part's hole will be calculated and analyzed by the computer software system. The method has the superiority in high accuracy, good credibility, strong anti-interference, high measure efficiency and intuitionistic result recognition.

  1. Distributed point source method for the modeling of a three-dimensional eddy current NDE problem

    NASA Astrophysics Data System (ADS)

    Bore, T.; Joubert, P.-Y.; Placko, D.

    2014-03-01

    This paper deals with modeling in electromagnetism in the field of eddy current for Non Destructive Evaluation. Several techniques could be used to diagnose structural damages. In eddy current application, a magnetic field generates by an excitation coil (or primary coil), interacts with a conductive target and generates eddy current. Variations in the phase and the magnitude of these eddy currents can be monitored using a second "receiver" coil. Variations in the physical properties (electrical conductivity, magnetic permeability,..) or the presence of any flaw in the target will cause a change in eddy current and a corresponding change in the phase and amplitude of measured signal. The interpretation of the signals requires a good understanding of the interaction between eddy current and structure. Therefore, researchers need analytical or numerical techniques to obtain a clear understanding of wave propagation behaviors. However, modeling of wave scattering phenomenon by conventional numerical techniques such as finite elements requires very fine mesh and heavy computational power. To go further, an innovative implementation of a semi-analytical modeling method, called the Distributed Points Source Method (DPSM), has been developed and used. The DPSM has already shown great potentialities for the versatile and computationally efficient modeling of complex electrostatic, electromagnetic or ultrasounic problems. In this paper, we report on a new implementation of the DPSM, called differential DPSM, which shows interesting prospects for the modeling of complex eddy current problems. In parallel, an Eddy Current Imager (ECI) has been recently developed in our laboratory in the aim of imaging cracks in metallic structures. In this paper, a simplified modeling of the ECI is presented using DPSM technique, the basics of DPSM formalism being firstly developed. A comparison between experimental and computed data obtained for a millimetric surface defect is presented in

  2. Reporting quality of abstracts of trials published in top five pain journals: a protocol for a systematic survey

    PubMed Central

    Sriganesh, Kamath; Bharadwaj, Suparna; Wang, Mei; Abbade, Luciana P F; Couban, Rachel; Mbuagbaw, Lawrence; Thabane, Lehana

    2016-01-01

    Introduction Abstracts of randomised controlled trials (RCTs) are often the first and the only source read in a journal by busy healthcare providers. This necessitates good reporting of abstracts. The quality of reporting of abstracts, though gradually improving over time, is still not uniform across medical journals. Improvement in completeness of reporting of abstracts has been documented in general medical journals after the publication of the consolidated standards of reporting trials (CONSORT) extension for abstracts in 2008. Currently, this aspect has not been assessed with regards to pain journals. This study aims to compare the completeness of reporting of abstracts before and after the publication of CONSORT statement for abstracts in five pain journals. Methods and analyses The abstracts of RCTs published from 1 January 2005 to 31 December 2007 (pre-CONSORT) and from 1 January 2013 to 31 December 2015 (post-CONSORT) will be assessed for the quality of reporting. Studies without abstracts, non-English abstracts, abstracts not reporting on RCTs or on humans and conference abstracts will be excluded. A thorough search of MEDLINE will be carried out in April 2016. All identified studies will be screened for inclusion based on titles and abstracts. Data will be extracted by two sets of independent reviewers for each abstract in duplicate regarding compliance with CONSORT statement for abstracts. Full-text review will be performed to obtain additional characteristics which are likely to affect reporting quality. The unadjusted and adjusted differences in the mean number of items reported will be analysed using a two sample t-test and generalised estimation equation in SPSS. Ethics and dissemination As far as we know, this is the first study to evaluate reporting quality of abstracts of pain journals based on CONSORT extension for abstracts. The findings of this study will be disseminated by a presentation at a conference and through publication in a peer

  3. A Computer Code for 2-D Transport Calculations in x-y Geometry Using the Interface Current Method.

    SciTech Connect

    1990-12-01

    Version 00 RICANT performs 2-dimensional neutron transport calculations in x-y geometry using the interface current method. In the interface current method, the angular neutron currents crossing region surfaces are expanded in terms of the Legendre polynomials in the two half-spaces made by the region surfaces.

  4. Synthesis of Pt nanoparticles on electrochemically reduced graphene oxide by potentiostatic and alternate current methods

    SciTech Connect

    Molina, J.; Fernández, J.; Río, A.I. del; Bonastre, J.; Cases, F.

    2014-03-01

    Reduced graphene oxide (RGO) has been synthesized on Pt wires by means of a potentiodynamic method between + 0.6 V and − 1.4 V for 20 scans. Cyclic voltammetry characterization of the coatings showed the typical capacitative behavior of graphene. Pt nanoparticles were synthesized on Pt–RGO electrodes by means of potentiostatic methods and a comparison between different synthesis potentials (− 0.16, 0, + 0.2 and + 0.4 V) for the same synthesis charge (mC·cm{sup −2}) was established. The electrodes obtained were characterized in 0.5 M H{sub 2}SO{sub 4} solution to observe the characteristic oxidation and reduction processes of the Pt surface. A 0.5 M H{sub 2}SO{sub 4}/0.5 M CH{sub 3}OH solution was used to measure the catalytic properties of the deposits against methanol oxidation. The most appropriate potential to perform the synthesis was 0 V followed by − 0.16 V and + 0.2 V. The morphology of the coatings varied depending on the potential applied as observed by scanning electron microscopy. Alternate current methods were also used to synthesize Pt nanoparticles and compare the results with the traditional potentiostatic method. Different frequencies were used: 0.1, 1, 10, 100, 1000 and 10 000 Hz. Alternate current synthesis is more efficient than traditional potentiostatic methods, obtaining more electroactive coatings with less effective synthesis time. - Highlights: • Reduced graphene oxide has been obtained by electrochemical reduction on Pt wires. • Pt nanoparticles have been obtained potentiostatically at different potentials. • Pt nanoparticles have been obtained by ac methods with different frequencies. • ac synthesis is a better synthesis method than potentiostatic synthesis.

  5. Grounding Abstractness: Abstract Concepts and the Activation of the Mouth.

    PubMed

    Borghi, Anna M; Zarcone, Edoardo

    2016-01-01

    One key issue for theories of cognition is how abstract concepts, such as freedom, are represented. According to the WAT (Words As social Tools) proposal, abstract concepts activate both sensorimotor and linguistic/social information, and their acquisition modality involves the linguistic experience more than the acquisition of concrete concepts. We report an experiment in which participants were presented with abstract and concrete definitions followed by concrete and abstract target-words. When the definition and the word matched, participants were required to press a key, either with the hand or with the mouth. Response times and accuracy were recorded. As predicted, we found that abstract definitions and abstract words yielded slower responses and more errors compared to concrete definitions and concrete words. More crucially, there was an interaction between the target-words and the effector used to respond (hand, mouth). While responses with the mouth were overall slower, the advantage of the hand over the mouth responses was more marked with concrete than with abstract concepts. The results are in keeping with grounded and embodied theories of cognition and support the WAT proposal, according to which abstract concepts evoke linguistic-social information, hence activate the mouth. The mechanisms underlying the mouth activation with abstract concepts (re-enactment of acquisition experience, or re-explanation of the word meaning, possibly through inner talk) are discussed. To our knowledge this is the first behavioral study demonstrating with real words that the advantage of the hand over the mouth is more marked with concrete than with abstract concepts, likely because of the activation of linguistic information with abstract concepts.

  6. Grounding Abstractness: Abstract Concepts and the Activation of the Mouth

    PubMed Central

    Borghi, Anna M.; Zarcone, Edoardo

    2016-01-01

    One key issue for theories of cognition is how abstract concepts, such as freedom, are represented. According to the WAT (Words As social Tools) proposal, abstract concepts activate both sensorimotor and linguistic/social information, and their acquisition modality involves the linguistic experience more than the acquisition of concrete concepts. We report an experiment in which participants were presented with abstract and concrete definitions followed by concrete and abstract target-words. When the definition and the word matched, participants were required to press a key, either with the hand or with the mouth. Response times and accuracy were recorded. As predicted, we found that abstract definitions and abstract words yielded slower responses and more errors compared to concrete definitions and concrete words. More crucially, there was an interaction between the target-words and the effector used to respond (hand, mouth). While responses with the mouth were overall slower, the advantage of the hand over the mouth responses was more marked with concrete than with abstract concepts. The results are in keeping with grounded and embodied theories of cognition and support the WAT proposal, according to which abstract concepts evoke linguistic-social information, hence activate the mouth. The mechanisms underlying the mouth activation with abstract concepts (re-enactment of acquisition experience, or re-explanation of the word meaning, possibly through inner talk) are discussed. To our knowledge this is the first behavioral study demonstrating with real words that the advantage of the hand over the mouth is more marked with concrete than with abstract concepts, likely because of the activation of linguistic information with abstract concepts. PMID:27777563

  7. Tunnel-Current based Single-Molecule Detection Method of Biopolymer Identification

    NASA Astrophysics Data System (ADS)

    Ohshiro, Takahito; Tsutsui, Makusu; Yokota, Kazumichi; Taniguchi, Masateru; Bionanotechnology Team

    2015-03-01

    We have been proposed a tunneling-current based identification as a single-molecule biopolymer sequencing. This methodology is based on sequentially reading the tunneling-current across individual single-biopolymer in the sequence, resulting in a high-speed electrical discrimination of the individual nucleotides. In this study, we report on a read of nucleotide sequence by the transverse electron transport through nanogap-electrode. We measured the extent of the electron-tunneling by using nanofabricated, mechanically controllable break junction, and determined the conductance values for deoxyribo/ribo- nucleoside monophosphates. When the molecules passed between the nanoelectrodes separated by a sub-nanometer gap, the tunneling-current through the molecules was increased, relative to that in the absence of molecules. The current intensity is found to be closely related to the individual molecular energy level. We also applied this method to base-typing in oligonucleotides. Based on the electrical conductivity for single-nucleotides, we read the fragment of sample nucleotide passing through the sensing electrode. On the basis of a reconstruction of the read fragment sequences, we successfully determined a sample nucleotide sequence.

  8. Investigation of a pulsed current annealing method in reusing MOSFET dosimeters for in vivo IMRT dosimetry

    SciTech Connect

    Luo, Guang-Wen; Qi, Zhen-Yu Deng, Xiao-Wu; Rosenfeld, Anatoly

    2014-05-15

    Purpose: To explore the feasibility of pulsed current annealing in reusing metal oxide semiconductor field-effect transistor (MOSFET) dosimeters forin vivo intensity modulated radiation therapy (IMRT) dosimetry. Methods: Several MOSFETs were irradiated atd{sub max} using a 6 MV x-ray beam with 5 V on the gate and annealed with zero bias at room temperature. The percentage recovery of threshold voltage shift during multiple irradiation-annealing cycles was evaluated. Key dosimetry characteristics of the annealed MOSFET such as the dosimeter's sensitivity, reproducibility, dose linearity, and linearity of response within the dynamic range were investigated. The initial results of using the annealed MOSFETs for IMRT dosimetry practice were also presented. Results: More than 95% of threshold voltage shift can be recovered after 24-pulse current continuous annealing in 16 min. The mean sensitivity degradation was found to be 1.28%, ranging from 1.17% to 1.52%, during multiple annealing procedures. Other important characteristics of the annealed MOSFET remained nearly consistent before and after annealing. Our results showed there was no statistically significant difference between the annealed MOSFETs and their control samples in absolute dose measurements for IMRT QA (p = 0.99). The MOSFET measurements agreed with the ion chamber results on an average of 0.16% ± 0.64%. Conclusions: Pulsed current annealing provides a practical option for reusing MOSFETs to extend their operational lifetime. The current annealing circuit can be integrated into the reader, making the annealing procedure fully automatic.

  9. A new method of rapid power measurement for MW-scale high-current particle beams

    NASA Astrophysics Data System (ADS)

    Xu, Yongjian; Hu, Chundong; Xie, Yuanlai; Liu, Zhimin; Xie, Yahong; Liu, Sheng; Liang, Lizheng; Jiang, Caichao; Sheng, Peng; Yu, Ling

    2015-09-01

    MW-scale high current particle beams are widely applied for plasma heating in the magnetic confinement fusion devices, in which beam power is an important indicator for efficient heating. Generally, power measurement of MW-scale high current particle beam adopts water flow calorimetry (WFC). Limited by the principles of WFC, the beam power given by WFC is an averaged value. In this article a new method of beam power for MW-scale high-current particle beams is introduced: (1) the temperature data of thermocouples embedded in the beam stopping elements were obtained using high data acquire system, (2) the surface heat flux of the beam stopping elements are calculated using heat transfer, (3) the relationships between positions and heat flux were acquired using numerical simulation, (4) the real-time power deposited on the beam stopping elements can be calculated using surface integral. The principle of measurement was described in detail and applied to the EAST neutral beam injector for demonstration. The result is compared with that measured by WFC. Comparison of the results shows good accuracy and applicability of this measuring method.

  10. Minimum current principle and variational method in theory of space charge limited flow

    SciTech Connect

    Rokhlenko, A.

    2015-10-21

    In spirit of the principle of least action, which means that when a perturbation is applied to a physical system, its reaction is such that it modifies its state to “agree” with the perturbation by “minimal” change of its initial state. In particular, the electron field emission should produce the minimum current consistent with boundary conditions. It can be found theoretically by solving corresponding equations using different techniques. We apply here the variational method for the current calculation, which can be quite effective even when involving a short set of trial functions. The approach to a better result can be monitored by the total current that should decrease when we on the right track. Here, we present only an illustration for simple geometries of devices with the electron flow. The development of these methods can be useful when the emitter and/or anode shapes make difficult the use of standard approaches. Though direct numerical calculations including particle-in-cell technique are very effective, but theoretical calculations can provide an important insight for understanding general features of flow formation and even sometimes be realized by simpler routines.

  11. A simple and efficient solar cell parameter extraction method from a single current-voltage curve

    NASA Astrophysics Data System (ADS)

    Zhang, Chunfu; Zhang, Jincheng; Hao, Yue; Lin, Zhenhua; Zhu, Chunxiang

    2011-09-01

    In this work, a simple and efficient method for the extraction of all the parameters of a solar cell from a single current-voltage (I-V) curve under the constant illumination level is proposed. With the help of the Lambert W function, the explicit analytic expression for I is obtained. By reducing the number of the parameters, the expression for I only depends on the ideality factor n, the series resistance Rs, and the shunt resistance Rsh. This analytic expression is directly used to fit the experimental data and extract the device parameters. This simple solar cell parameter extraction method can be directly applied for all kinds of solar cells whose I-V characteristics follow the single-diode model. The parameters of various solar devices including silicon solar cells, silicon solar modules, dye-sensitized solar cells, and organic solar cells with standalone, tandem, and multi-junction structures have been successfully extracted by using our proposed method.

  12. Current status of computational methods for transonic unsteady aerodynamics and aeroelastic applications

    NASA Technical Reports Server (NTRS)

    Edwards, John W.; Malone, John B.

    1992-01-01

    The current status of computational methods for unsteady aerodynamics and aeroelasticity is reviewed. The key features of challenging aeroelastic applications are discussed in terms of the flowfield state: low-angle high speed flows and high-angle vortex-dominated flows. The critical role played by viscous effects in determining aeroelastic stability for conditions of incipient flow separation is stressed. The need for a variety of flow modeling tools, from linear formulations to implementations of the Navier-Stokes equations, is emphasized. Estimates of computer run times for flutter calculations using several computational methods are given. Applications of these methods for unsteady aerodynamic and transonic flutter calculations for airfoils, wings, and configurations are summarized. Finally, recommendations are made concerning future research directions.

  13. A review of the current state of antimicrobial susceptibility test methods for Brachyspira.

    PubMed

    Kulathunga, Dharmasiri G R S; Rubin, Joseph E

    2017-03-21

    The re-emergence of swine dysentery (Brachyspira-associated muco-haemorrhagic colitis) since the late 2000's has illuminated diagnostic challenges associated with this genus. The methods used to detect, identify and characterize Brachyspira from clinical samples have not been standardized and laboratories frequently rely heavily on in-house techniques. Particularly concerning is the lack of standardized methods for determining and interpreting the antimicrobial susceptibility of Brachyspira spp. The integration of laboratory data into a treatment plan is a critical component of prudent antimicrobial usage, the lack of standardized methods is therefore an important limitation to the evidence based use of antimicrobials. This review will focus on describing the methodological limitations and inconsistencies between current susceptibility testing schemes employed for Brachyspira, provide an overview of what we do know about the susceptibility of these organisms and suggest future directions to improve and standardize diagnostic strategies.

  14. Application of Millimeter Wave, Eddy Current and Thermographic Methods for Detection of Corrosion in Aluminum Substrate

    SciTech Connect

    Ryley, A. C.; Ghasr, M. T.; Kharkovsky, S.; Zoughi, R.; Steffes, Gary

    2007-03-21

    Aluminum structures exposed to the elements are susceptible to corrosion. Corrosion may cause various mechanical and structural deficiencies such as material thinning. It is desirable to rapidly detect and evaluate the properties of an aluminum substrate early in the corrosion process to avoid costly maintenance actions later. There are several nondestructive testing methods for this purpose. To investigate capabilities of millimeter wave, conventional eddy current, and flash thermography techniques for detection of large corrosion areas in aluminum substrates, two corroded samples were inspected with and without dielectric coating (applique). This paper presents the results of the c-scan imaging of these samples using the methods mentioned above. The attributes of these methods for detection and evaluation of large, severe and non-uniform corrosion areas with and without a dielectric coating are discussed.

  15. A practical method of analysis of the current-voltage characteristics of solar cells

    NASA Astrophysics Data System (ADS)

    Charles, J. P.; Abdelkrim, M.; Muoy, Y. H.; Mialhe, P.

    1981-09-01

    A numerical method suitable for use with a programmable calculator is developed for determining the current-voltage (I-V) equation parameters of a solar cell driven as a generator only. The exact magnitude of the photocurrent is found and the fill factor is deduced. High and low quality Si solar cells were studied under illumination from a 12 V lamp in AM1 conditions. I-V curves are plotted for varying diode quality factors and the fill factors were analytically examined. Series resistance, shunt resistance, photocurrent, series current, and diode quality factors were calculated from the experimental data of the fourth quadrant characteristic for an ideal cell and results are diagrammed with performance data from the test cells. A flow chart is provided for the operations of the program. The quality factor is found to be dominant, unless significant output losses are encountered, and then series and shunt resistances gain effect.

  16. Methods for Specific Electrode Resistance Measurement during Transcranial Direct Current Stimulation

    PubMed Central

    Khadka, Niranjan; Rahman, Asif; Sarantos, Chris; Truong, Dennis Q.; Bikson, Marom

    2014-01-01

    Background Transcranial Direct Current Stimulation (tDCS) is investigated to treat a wide range of neuropsychiatric disorders, for rehabilitation, and for enhancing cognitive performance. The monitoring of electrode resistance before and during tDCS is considered important for tolerability and safety, where an unusually high resistance is indicative of undesired electrode or poor skin contact conditions. Conventional resistance measurement methods do not isolate individual electrode resistance but rather measures overall voltage. Moreover, for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. Objective We propose a novel method for monitoring of the individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low-intensity and low-frequency sinusoids with electrode– specific frequencies) and a single sentinel electrode (not used for DC). Methods To validate this methodology, we developed lumped-parameter models of two and multi-electrode tDCS. Approaches with and without a sentinel electrode were solved and underlying assumptions identified. Assumptions were tested and parameterized in healthy participants using forearm stimulation combining tDCS (2 mA) and sinusoidal test-signals (38 μA and 76 μA peak to peak at 1 Hz, 10 Hz, and 100 Hz) and an in vitro test (where varied electrode failure modes were created). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain. Results A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. For multi-electrode resistance tracking, cross talk was aggravated with electrode proximity and current/resistance mismatches, but could be corrected using proposed approaches. Average voltage and average pain scores were not significantly different across test current intensities and frequencies (two-way repeated measures ANOVA) indicating the

  17. Application of coupled electric field method for eddy current non-destructive inspection of multilayer structures

    NASA Astrophysics Data System (ADS)

    Bouchala, T.; Abdelhadi, B.; Benoudjit, A.

    2015-04-01

    The development of fast and accurate method describing the electromagnetic phenomena intervening in eddy current non-destructive systems is very interesting, since it permits the design of reliable systems permitting the detection and the characterisation of defect in conductive materials. The coupled electric field method presented in this article can assume a large part of these objectives, because it is fast in comparison to the finite element method and easily invertible since the sensor impedance variation is an explicit function of target physical and geometrical characteristics. These advantages have motivated us to extend this method for multilayered structures, very interesting in aeronautic industry, by superposing the inductive effects in different layers. The impedance of an absolute sensor operating above three conducting layers will be calculated and compared to those obtained with finite element method. Afterwards, we shall exploit the model to study the effect of defect characteristics on the sensor impedance. Furthermore, regarding to the depth penetration effect, we shall make into evidence the necessity of accomplishing an optimal choice of the exciting field frequency during the inspection of multilayered materials. The essential importance of this method, besides of its rapidity, resides in its possibility to be extended to 2D irregular and 3D asymmetric configurations.

  18. An improved current potential method for fast computation of stellarator coil shapes

    NASA Astrophysics Data System (ADS)

    Landreman, Matt

    2017-04-01

    Several fast methods for computing stellarator coil shapes are compared, including the classical NESCOIL procedure (Merkel 1987 Nucl. Fusion 27 867), its generalization using truncated singular value decomposition, and a Tikhonov regularization approach we call REGCOIL in which the squared current density is included in the objective function. Considering W7-X and NCSX geometries, and for any desired level of regularization, we find the REGCOIL approach simultaneously achieves lower surface-averaged and maximum values of both current density (on the coil winding surface) and normal magnetic field (on the desired plasma surface). This approach therefore can simultaneously improve the free-boundary reconstruction of the target plasma shape while substantially increasing the minimum distances between coils, preventing collisions between coils while improving access for ports and maintenance. The REGCOIL method also allows finer control over the level of regularization, it preserves convexity to ensure the local optimum found is the global optimum, and it eliminates two pathologies of NESCOIL: the resulting coil shapes become independent of the arbitrary choice of angles used to parameterize the coil surface, and the resulting coil shapes converge rather than diverge as Fourier resolution is increased. We therefore contend that REGCOIL should be used instead of NESCOIL for applications in which a fast and robust method for coil calculation is needed, such as when targeting coil complexity in fixed-boundary plasma optimization, or for scoping new stellarator geometries.

  19. Differential magnetometer method applied to measurement of geomagnetically induced currents in Southern African power networks

    NASA Astrophysics Data System (ADS)

    Matandirotya, Electdom; Cilliers, Pierre. J.; Van Zyl, Robert R.; Oyedokun, David T.; Villiers, Jean

    2016-03-01

    Geomagnetically induced currents (GICs) in conductors connected to the Earth are driven by an electric field produced by a time-varying magnetic field linked to magnetospheric-ionospheric current perturbations during geomagnetic storms. The GIC measurements are traditionally done on the neutral-to-ground connections of power transformers. A method of inferring the characteristics of GIC in power lines using differential magnetic field measurements is presented. Measurements of the GIC in the power lines connected to a particular power transformer are valuable in the verification of the modeling of GIC in the power transmission network. The differential magnetometer method (DMM) is an indirect method used to estimate the GIC in a power line. With the DMM, low-frequency GIC in the power line is estimated from the difference between magnetic field recordings made directly underneath the power line and at some distance away, where the magnetic field of the GIC in the transmission line has negligible effect. Results of the first application of the DMM to two selected sites of the Southern African power transmission network are presented. The results show that good quality GIC measurements are achieved through the DMM using Commercially-Off-The-Shelf magnetometers.

  20. Method of Breast Reconstruction Determines Venous Thromboembolism Risk Better Than Current Prediction Models

    PubMed Central

    Patel, Niyant V.; Wagner, Douglas S.

    2015-01-01

    Background: Venous thromboembolism (VTE) risk models including the Davison risk score and the 2005 Caprini risk assessment model have been validated in plastic surgery patients. However, their utility and predictive value in breast reconstruction has not been well described. We sought to determine the utility of current VTE risk models in this population and the VTE rate observed in various methods of breast reconstruction. Methods: A retrospective review of breast reconstructions by a single surgeon was performed. One hundred consecutive transverse rectus abdominis myocutaneous (TRAM) patients, 100 consecutive implant patients, and 100 consecutive latissimus dorsi patients were identified over a 10-year period. Patient demographics and presence of symptomatic VTE were collected. 2005 Caprini risk scores and Davison risk scores were calculated for each patient. Results: The TRAM reconstruction group was found to have a higher VTE rate (6%) than the implant (0%) and latissimus (0%) reconstruction groups (P < 0.01). Mean Davison risk scores and 2005 Caprini scores were similar across all reconstruction groups (P > 0.1). The vast majority of patients were stratified as high risk (87.3%) by the VTE risk models. However, only TRAM reconstruction patients demonstrated significant VTE risk. Conclusions: TRAM reconstruction appears to have a significantly higher risk of VTE than both implant and latissimus reconstruction. Current risk models do not effectively stratify breast reconstruction patients at risk for VTE. The method of breast reconstruction appears to have a significant role in patients’ VTE risk. PMID:26090287

  1. The effect of space charges on conduction current in polymer by modified PEA method

    SciTech Connect

    Hwangbo, S.; Yun, D.H.; Yi, D.Y.; Han, M.K.

    1996-12-31

    Direct measurement of space charge and conduction current was carried out on low-density polyethylene degraded by ultra-violet using a pulsed electro-acoustic (PEA) method. Dominant hetero-charges were formed near both electrodes by high voltage application and was found to be deeply trapped. In this paper, the effect of temperature and electric field reversal on the detrapping and trapping of space charges was investigated and the role of space charge in electrical conduction was discussed quantitatively. The main mechanism for detrapping and trapping of space charges was Poole-Frenkel model.

  2. Method and composition for improving flux pinning and critical current in superconductors

    DOEpatents

    Morris, Donald E.

    1995-01-01

    Superconducting materials and methods of forming superconducting materials are disclosed. Highly oxidized superconductors are heated at a relatively high temperature so as to release oxygen, which migrates out of the material, and form a non-superconducting phase which does not diffuse out of grains of the material. The material is then reoxidized at a lower temperature, leaving the non-superconducting inclusions inside a superconducting phase. The non-superconducting inclusions act as pinning centers in the superconductor, increasing the critical current thereof.

  3. Method and composition for improving flux pinning and critical current in superconductors

    DOEpatents

    Morris, D.E.

    1995-07-04

    Superconducting materials and methods of forming superconducting materials are disclosed. Highly oxidized superconductors are heated at a relatively high temperature so as to release oxygen, which migrates out of the material, and form a non-superconducting phase which does not diffuse out of grains of the material. The material is then reoxidized at a lower temperature, leaving the non-superconducting inclusions inside a superconducting phase. The non-superconducting inclusions act as pinning centers in the superconductor, increasing the critical current thereof. 14 figs.

  4. System and method for magnetic current density imaging at ultra low magnetic fields

    SciTech Connect

    Espy, Michelle A.; George, John Stevens; Kraus, Robert Henry; Magnelind, Per; Matlashov, Andrei Nikolaevich; Tucker, Don; Turovets, Sergei; Volegov, Petr Lvovich

    2016-02-09

    Preferred systems can include an electrical impedance tomography apparatus electrically connectable to an object; an ultra low field magnetic resonance imaging apparatus including a plurality of field directions and disposable about the object; a controller connected to the ultra low field magnetic resonance imaging apparatus and configured to implement a sequencing of one or more ultra low magnetic fields substantially along one or more of the plurality of field directions; and a display connected to the controller, and wherein the controller is further configured to reconstruct a displayable image of an electrical current density in the object. Preferred methods, apparatuses, and computer program products are also disclosed.

  5. A method to calculate tunneling leakage currents in silicon inversion layers

    NASA Astrophysics Data System (ADS)

    Lujan, Guilherme S.; Sorée, Bart; Magnus, Wim; De Meyer, Kristin

    2006-08-01

    This paper proposes a quantum mechanical model for the calculation of tunneling leakage currents in a metal-oxide-semiconductor structure. The model incorporates both variational calculus and the transfer matrix method to compute the subband energies and the lifetimes of the inversion layer states. The use of variational calculus simplifies the subband energy calculation due to the analytical form of the wave functions, which offers an attractive perspective towards the calculation of the electron mobility in the channel. The model can be extended to high-k dielectrics with several layers. Good agreement between experimental data and simulation results is obtained for metal gate capacitors.

  6. 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

  7. Simulation for the assessment of wall thinning using eddy current method

    SciTech Connect

    Cheng, W.; Komura, I.

    2011-06-23

    A pipe with protective cladding and insulation was simplified to a four-layered structure when the diameter of a pipe is large enough, and analytical solutions for sinusoidal and pulsed wave excitation were derived. Simulation implemented by using the analytical solutions showed that sinusoidal excitation is not appropriate for the monitoring of inner thinning, while pulsed eddy current method can be used to measure wall-thickness regardless of inner or outer thinning by using the decay rate of log(Bz) as a particular parameter to evaluate wall thickness.

  8. [Current laboratory methods to evaluate the efficiency of immunization against dangerous and extremely dangerous infections].

    PubMed

    Bogacheva, N V; Darmov, I V; Elagin, G D; Kriuchkov, A V; Tikhvinskaia, O V

    2011-06-01

    By taking into account the leading role of specific cellular immunity in the development of protection against the majority of dangerous and extremely dangerous infections of bacterial, viral, and rickettsial nature, the study of the above immunity should be considered as most important on estimating the body's immunological rearrangement when vaccines against respective infections are administered. The battery of the test used to date for the analysis of specific cellular immunity is mainly restricted to skin tests that have disadvantages. This paper reviews the currently available laboratory methods for in vitro studies of a specific cellular immune response as a criterion for evaluating the efficiency of immunization.

  9. Leadership Abstracts; Volume 4, 1991.

    ERIC Educational Resources Information Center

    Doucette, Don, Ed.

    1991-01-01

    "Leadership Abstracts" is published bimonthly and distributed to the chief executive officer of every two-year college in the United States and Canada. This document consists of the 15 one-page abstracts published in 1991. Addressing a variety of topics of interest to the community college administrators, this volume includes: (1) "Delivering the…

  10. Innovation Abstracts, Volume XV, 1993.

    ERIC Educational Resources Information Center

    Roueche, Suanne D., Ed.

    1993-01-01

    This volume of 30 one- to two-page abstracts from 1993 highlights a variety of innovative approaches to teaching and learning in the community college. Topics covered in the abstracts include: (1) role-playing to encourage critical thinking; (2) team learning techniques to cultivate business skills; (3) librarian-instructor partnerships to create…

  11. Vague Language in Conference Abstracts

    ERIC Educational Resources Information Center

    Cutting, Joan

    2012-01-01

    This study examined abstracts for a British Association for Applied Linguistics conference and a Sociolinguistics Symposium, to define the genre of conference abstracts in terms of vague language, specifically universal general nouns (e.g. people) and research general nouns (e.g. results), and to discover if the language used reflected the level…

  12. Method and apparatus for controlling current in inductive loads such as large diameter coils

    DOEpatents

    Riveros, Carlos A.

    1981-01-01

    A method and apparatus for controlling electric current in loads that are essentially inductive, such that sparking and "ringing" current problems are reduced or eliminated. The circuit apparatus employs a pair of solid state switches (each of which switch may be an array of connected or parallel solid state switching devices such as transistors) and means for controlling those switches such that a power supply supplying two d.c. voltages (e.g. positive 150 volts d.c. and negative 150 volts d.c.) at low resistance may be connected across an essentially inductive load (e.g. a 6 gauge wire loop one hundred meters in diameter) alternatively and such that the first solid state switch is turned off and the second is turned on such that both are not on at the same time but the first turned on and the other on in less time than the inductive time constant (L/R) so that the load is essentially always presented with a low resistance path across its input. In this manner a steady AC current may be delivered to the load at a frequency desired. Shut-off problems are avoided by gradually shortening the period of switching to less than the time constant so that the maximum energy contained in the inductive load is reduced to approximately zero and dissipated in the inherent resistance. The invention circuit may be employed by adjusting the timing of switching to deliver a desired waveform (such as sinusoidal) to the load.

  13. Design and development of DC high current sensor using Hall-Effect method

    NASA Astrophysics Data System (ADS)

    Dewi, Sasti Dwi Tungga; Panatarani, C.; Joni, I. Made

    2016-02-01

    This paper report a newly developed high DC current sensor by using a Hall effect method and also the measurement system. The Hall effect sensor receive the magnetic field generated by a current carrying conductor wire. The SS49E (Honeywell) magnetoresistive sensor was employed to sense the magnetic field from the field concentrator. The voltage received from SS49E then converted into digital by using analog to digital converter (ADC-10 bit). The digital data then processed in the microcontroller to be displayed as the value of the electric current in the LCD display. In addition the measurement was interfaced into Personal Computer (PC) using the communication protocols of RS232 which was finally displayed in real-time graphical form on the PC display. The performance test on the range ± 40 Ampere showed that the maximum relative error is 5.26%. It is concluded that the sensors and the measurement system worked properly according to the design with acceptable accuracy.

  14. Application of projection methods of multivariate data analysis in eddy current testing of materials

    NASA Astrophysics Data System (ADS)

    Polyakov, V. V.; Egorov, A. V.; Pirogov, A. A.; Kolubaev, E. A.

    2015-10-01

    The paper considers the applicability of projection methods of multivariate data analysis to discriminate between the factors that simultaneously affect the results of multi-frequency eddy current testing of nonmagnetic metals and alloys. Measurements were carried out for copper, magnesium, aluminum alloy and bronze specimens with different electrical conductivity equal to 57, 22, 16 and 7.5 S/m, respectively. The measured probe impedance changes were used to plot hodographs within the frequency range from 100 Hz to 6.4 kHz. The gap width between an attachable parametric probe and the specimen surface was specified using dielectric spacers within the range from 0 to 1 mm. The principal component analysis applied to experimental hodographs allowed us to safely discriminate between the influence of such factors as electrical conductivity of the material and gap width. The proposed approach to discriminating between individual factors that strongly affect eddy current measurement results is an enhancement in eddy current testing of materials.

  15. Spherical Elementary Current Systems Method Applied to Geomagnetic Field Modeling for the Adriatic

    NASA Astrophysics Data System (ADS)

    Vujić, Eugen; Brkić, Mario

    2016-08-01

    The aim of this work was to derive an accurate regional model of geomagnetic components on the Adriatic. Data of north, east and vertical geomagnetic components at repeat stations and ground survey sites enclosing the Adriatic Sea were used to obtain a geomagnetic model at 2010.5 epoch. The core field was estimated by use of the global Enhanced Magnetic Model, while the crustal field by a mathematical technique for expanding vector systems on a sphere into basis functions, known as spherical elementary current systems method. The results of this method were presented and compared to the crustal field estimations by the Enhanced Magnetic Model. The maps of isolines of the regional model are also presented.

  16. Current Researches on the Methods of Diagnosing Sasang Constitution: An Overview

    PubMed Central

    Lee, Si-Woo; Jang, Eun-Su; Lee, Jeon; Kim, Jong Yeol

    2009-01-01

    Sasang constitution diagnosis has traditionally been conducted by a Sasang constitutional medicine (SCM) doctor who examines the external appearance, temperament and various symptoms of an individual and then collectively analyzes this information to determine their own constitutions. However, because this process is subjective and not quantitative, many researchers have been attempting to develop objective and reasonable methods of determining constitutions. In Korea, even though a wide range of research regarding SCM has been conducted, most of the work has not been revealed internationally. So in this review, the authors have searched the Journal of Sasang Constitutional Medicine, as well as other Korean domestic journal databases and Pubmed for research regarding modernized constitution diagnosis methods so to provide the understanding of current research state and outlook for future research. PMID:19745010

  17. HUMAN RELIABILITY ANALYSIS FOR COMPUTERIZED PROCEDURES, PART TWO: APPLICABILITY OF CURRENT METHODS

    SciTech Connect

    Ronald L. Boring; David I. Gertman

    2012-10-01

    Computerized procedures (CPs) are an emerging technology within nuclear power plant control rooms. While CPs have been implemented internationally in advanced control rooms, to date no U.S. nuclear power plant has implemented CPs in its main control room. Yet, CPs are a reality of new plant builds and are an area of considerable interest to existing plants, which see advantages in terms of easier records management by omitting the need for updating hardcopy procedures. The overall intent of this paper is to provide a characterization of human reliability analysis (HRA) issues for computerized procedures. It is beyond the scope of this document to propose a new HRA approach or to recommend specific methods or refinements to those methods. Rather, this paper serves as a review of current HRA as it may be used for the analysis and review of computerized procedures.

  18. [An updated review of methods for human retinal oximetry measurements and current applications].

    PubMed

    Ben-Zion, Itay; Harris, Alon; Weizman, Yosi; Ehrlich, Rita; Rechtman, Ehud

    2008-10-01

    The concept of retinal oximetry is based on physical properties that have been recognized since the 18th century. Attempts to non-invasively quantify the oxygen saturation of blood within the retinal vasculature date back to the 1950's. There are different techniques in existence for the measurement of retinal oxygenation, the leading ones are: photographic, digital, spectroscopy and the pulse methods. Each method has its advantages and disadvantages. Current data from studies on retinal oximetry is presented, for both the healthy retina and in diseases such as glaucoma, diabetic retinopathy and age-related macular degeneration. It is clear that a thorough understanding of retinal oxygen tension is vital to our understanding of normal retinal physiology and the pathophysiology of degenerative eye diseases.

  19. Technical abstracts: Mechanical engineering, 1990

    SciTech Connect

    Broesius, J.Y.

    1991-03-01

    This document is a compilation of the published, unclassified abstracts produced by mechanical engineers at Lawrence Livermore National Laboratory (LLNL) during the calendar year 1990. Many abstracts summarize work completed and published in report form. These are UCRL-JC series documents, which include the full text of articles to be published in journals and of papers to be presented at meetings, and UCID reports, which are informal documents. Not all UCIDs contain abstracts: short summaries were generated when abstracts were not included. Technical Abstracts also provides descriptions of those documents assigned to the UCRL-MI (miscellaneous) category. These are generally viewgraphs or photographs presented at meetings. An author index is provided at the back of this volume for cross referencing.

  20. Abstraction/Representation Theory for heterotic physical computing.

    PubMed

    Horsman, D C

    2015-07-28

    We give a rigorous framework for the interaction of physical computing devices with abstract computation. Device and program are mediated by the non-logical representation relation; we give the conditions under which representation and device theory give rise to commuting diagrams between logical and physical domains, and the conditions for computation to occur. We give the interface of this new framework with currently existing formal methods, showing in particular its close relationship to refinement theory, and the implications for questions of meaning and reference in theoretical computer science. The case of hybrid computing is considered in detail, addressing in particular the example of an Internet-mediated social machine, and the abstraction/representation framework used to provide a formal distinction between heterotic and hybrid computing. This forms the basis for future use of the framework in formal treatments of non-standard physical computers.

  1. Abstracts

    NASA Astrophysics Data System (ADS)

    2012-09-01

    Measuring cosmological parameters with GRBs: status and perspectives New interpretation of the Amati relation The SED Machine - a dedicated transient spectrograph PTF10iue - evidence for an internal engine in a unique Type Ic SN Direct evidence for the collapsar model of long gamma-ray bursts On pair instability supernovae and gamma-ray bursts Pan-STARRS1 observations of ultraluminous SNe The influence of rotation on the critical neutrino luminosity in core-collapse supernovae General relativistic magnetospheres of slowly rotating and oscillating neutron stars Host galaxies of short GRBs GRB 100418A: a bridge between GRB-associated hypernovae and SNe Two super-luminous SNe at z ~ 1.5 from the SNLS Prospects for very-high-energy gamma-ray bursts with the Cherenkov Telescope Array The dynamics and radiation of relativistic flows from massive stars The search for light echoes from the supernova explosion of 1181 AD The proto-magnetar model for gamma-ray bursts Stellar black holes at the dawn of the universe MAXI J0158-744: the discovery of a supersoft X-ray transient Wide-band spectra of magnetar burst emission Dust formation and evolution in envelope-stripped core-collapse supernovae The host galaxies of dark gamma-ray bursts Keck observations of 150 GRB host galaxies Search for properties of GRBs at large redshift The early emission from SNe Spectral properties of SN shock breakout MAXI observation of GRBs and short X-ray transients A three-dimensional view of SN 1987A using light echo spectroscopy X-ray study of the southern extension of the SNR Puppis A All-sky survey of short X-ray transients by MAXI GSC Development of the CALET gamma-ray burst monitor (CGBM)

  2. Abstracts

    ERIC Educational Resources Information Center

    Parsegian, V. L., Ed.

    1972-01-01

    Includes summaries of six articles dealing with engineering education, population management, blood sampling, international pollution control, environmental quality index, and scientific phases in political science. (CC)

  3. Investigation of steel thickness measurement by an electromagnetic method using a step exciting current

    SciTech Connect

    Naruse, Takeshi; Shimada, Michio; Yoshii, Tokuharu

    1998-05-01

    The electromagnetic measurement of steel thickness was noted as a new method for inspecting corroded surfaces of ship structures. Experiments to measure the electromagnetic response of steel and simulations using finite element methods (FEM) were carried out. Two peaks appeared in the induced voltage waveforms obtained from the sensing coil (situated on the opposite side of the steel plate from the exciting coil) as the response to a step exciting current. It was found that the peak that appeared first was the response of the magnetic flux that came around the steel plate, while the second peak was the response of the magnetic flux that penetrated the steel plate. Three values, amplitude, delay time, and half value breadth (HVB) were defined in both peaks. All the values from the second peak were correlated to the thickness of steel. Delay time was expected to be the most useful value, which was most stable for the effect of exciting and sensing coil lift-off and amplitude of the step exciting current. The permeability of steel had great effect on the values, but the slits in the specimens had only a minimal effect.

  4. An Elimination Method of Temperature-Induced Linear Birefringence in a Stray Current Sensor

    PubMed Central

    Xu, Shaoyi; Li, Wei; Xing, Fangfang; Wang, Yuqiao; Wang, Ruilin; Wang, Xianghui

    2017-01-01

    In this work, an elimination method of the temperature-induced linear birefringence (TILB) in a stray current sensor is proposed using the cylindrical spiral fiber (CSF), which produces a large amount of circular birefringence to eliminate the TILB based on geometric rotation effect. First, the differential equations that indicate the polarization evolution of the CSF element are derived, and the output error model is built based on the Jones matrix calculus. Then, an accurate search method is proposed to obtain the key parameters of the CSF, including the length of the cylindrical silica rod and the number of the curve spirals. The optimized results are 302 mm and 11, respectively. Moreover, an effective factor is proposed to analyze the elimination of the TILB, which should be greater than 7.42 to achieve the output error requirement that is not greater than 0.5%. Finally, temperature experiments are conducted to verify the feasibility of the elimination method. The results indicate that the output error caused by the TILB can be controlled less than 0.43% based on this elimination method within the range from −20 °C to 40 °C. PMID:28282953

  5. Cerebral blood flow and autoregulation: current measurement techniques and prospects for noninvasive optical methods.

    PubMed

    Fantini, Sergio; Sassaroli, Angelo; Tgavalekos, Kristen T; Kornbluth, Joshua

    2016-07-01

    Cerebral blood flow (CBF) and cerebral autoregulation (CA) are critically important to maintain proper brain perfusion and supply the brain with the necessary oxygen and energy substrates. Adequate brain perfusion is required to support normal brain function, to achieve successful aging, and to navigate acute and chronic medical conditions. We review the general principles of CBF measurements and the current techniques to measure CBF based on direct intravascular measurements, nuclear medicine, X-ray imaging, magnetic resonance imaging, ultrasound techniques, thermal diffusion, and optical methods. We also review techniques for arterial blood pressure measurements as well as theoretical and experimental methods for the assessment of CA, including recent approaches based on optical techniques. The assessment of cerebral perfusion in the clinical practice is also presented. The comprehensive description of principles, methods, and clinical requirements of CBF and CA measurements highlights the potentially important role that noninvasive optical methods can play in the assessment of neurovascular health. In fact, optical techniques have the ability to provide a noninvasive, quantitative, and continuous monitor of CBF and autoregulation.

  6. Critical review of current and emerging quantification methods for the development of influenza vaccine candidates.

    PubMed

    Manceur, Aziza P; Kamen, Amine A

    2015-11-04

    Significant improvements in production and purification have been achieved since the first approved influenza vaccines were administered 75 years ago. Global surveillance and fast response have limited the impact of the last pandemic in 2009. In case of another pandemic, vaccines can be generated within three weeks with certain platforms. However, our Achilles heel is at the quantification level. Production of reagents for the quantification of new vaccines using the SRID, the main method formally approved by regulatory bodies, requires two to three months. The impact of such delays can be tragic for vulnerable populations. Therefore, efforts have been directed toward developing alternative quantification methods, which are sensitive, accurate, easy to implement and independent of the availability of specific reagents. The use of newly-developed antibodies against a conserved region of hemagglutinin (HA), a surface protein of influenza, holds great promises as they are able to recognize multiple subtypes of influenza; these new antibodies could be used in immunoassays such as ELISA and slot-blot analysis. HA concentration can also be determined using reversed-phase high performance liquid chromatography (RP-HPLC), which obviates the need for antibodies but still requires a reference standard. The number of viral particles can be evaluated using ion-exchange HPLC and techniques based on flow cytometry principles, but non-viral vesicles have to be taken into account with cellular production platforms. As new production systems are optimized, new quantification methods that are adapted to the type of vaccine produced are required. The nature of these new-generation vaccines might dictate which quantification method to use. In all cases, an alternative method will have to be validated against the current SRID assay. A consensus among the scientific community would have to be reached so that the adoption of new quantification methods would be harmonized between

  7. Automata Learning with Automated Alphabet Abstraction Refinement

    NASA Astrophysics Data System (ADS)

    Howar, Falk; Steffen, Bernhard; Merten, Maik

    on is the key when learning behavioral models of realistic systems, but also the cause of a major problem: the introduction of non-determinism. In this paper, we introduce a method for refining a given abstraction to automatically regain a deterministic behavior on-the-fly during the learning process. Thus the control over abstraction becomes part of the learning process, with the effect that detected non-determinism does not lead to failure, but to a dynamic alphabet abstraction refinement. Like automata learning itself, this method in general is neither sound nor complete, but it also enjoys similar convergence properties even for infinite systems as long as the concrete system itself behaves deterministically, as illustrated along a concrete example.

  8. Numerical methods in vehicle system dynamics: state of the art and current developments

    NASA Astrophysics Data System (ADS)

    Arnold, M.; Burgermeister, B.; Führer, C.; Hippmann, G.; Rill, G.

    2011-07-01

    introduced and illustrated by a well-known benchmark problem from rail vehicle simulation. Over the last few decades, the complexity of high-end applications in vehicle system dynamics has frequently given a fresh impetus for substantial improvements of numerical methods and for the development of novel methods for new problem classes. In the present paper, we address three of these challenging problems of current interest that are today still beyond the mainstream of numerical mathematics: (i) modelling and simulation of contact problems in multibody dynamics, (ii) real-time capable numerical simulation techniques in vehicle system dynamics and (iii) modelling and time integration of multidisciplinary problems in system dynamics including co-simulation techniques.

  9. Newborn infants perceive abstract numbers.

    PubMed

    Izard, Véronique; Sann, Coralie; Spelke, Elizabeth S; Streri, Arlette

    2009-06-23

    Although infants and animals respond to the approximate number of elements in visual, auditory, and tactile arrays, only human children and adults have been shown to possess abstract numerical representations that apply to entities of all kinds (e.g., 7 samurai, seas, or sins). Do abstract numerical concepts depend on language or culture, or do they form a part of humans' innate, core knowledge? Here we show that newborn infants spontaneously associate stationary, visual-spatial arrays of 4-18 objects with auditory sequences of events on the basis of number. Their performance provides evidence for abstract numerical representations at the start of postnatal experience.

  10. Abstraction and addition kinetics of C2H radicals with CH4, C2H6, C3H8, C2H4, and C3H6: CVT/SCT/ISPE and hybrid meta-DFT methods.

    PubMed

    Dash, Manas Ranjan; Rajakumar, B

    2015-02-07

    Rate coefficients for the reactions of C2H radicals with methane (k1), ethane (k2), propane (k3), ethylene (k4), and propylene (k5) were computed using canonical variational transition state theory (CVT) coupled with hybrid-meta density functional theory (DFT) over a wide range of temperatures from 150 to 5000 K. The quantum chemical tunneling effect was corrected by the small curvature tunneling (SCT) method. The dynamic calculations are performed using the variational transition state theory (VTST) with the interpolated single-point energies (ISPE) method at the CCSD(T)/cc-pVTZ//M06-2X/6-31+G(d,p) level of theory. Intrinsic reaction coordinate (IRC) calculations were performed to verify that the transition states are connected to the reactants and products. The rate coefficients obtained over the studied temperature range yield the following Arrhenius expressions (cm(3) molecule(-1) s(-1)): k1 = 4.69 × 10(-19)T(2.44) exp[331/T], k2 = 4.29 × 10(-17)T(2.11) exp[432/T], k3 = 4.81 × 10(-17)T(1.98) exp[697/T], k4 = 7.54 × 10(-21)T(2.96) exp[1942/T], and k5 = 8.04 × 10(-23)T(3.44) exp[3011/T] cm(3) molecule(-1) s(-1). Branching ratio calculation for the reactions of C2H radicals with ethylene and propylene shows that the abstraction reactions are not important at lower temperatures. However, as the temperature increases, abstraction reactions become more important.

  11. [Nutritional status of adults with cystic fibrosis - current methods of assessment].

    PubMed

    Szabla, Anna; Skorupa, Wojciech; Milewska, Magdalena; Weker, Halina

    2015-11-01

    Cystic fibrosis (CF) is one of the most frequent monogenic disease in the Caucasian population, inherited in an autosomal recessive pattern. This is a multiple organ disease and its main manifestations include pulmonary and gastrointestinal dysfunction. The exocrine pancreatic deficiency results in impaired digestion and absorption what may lead to malnutrition and vitamins and minerals deficiencies. The life expectancy of cystic fibrosis patients has been increasing over the past years, so there is a need to verify usefulness of existing or create new methods of nutritional status assessment. The aim of this paper was presentation current data on the methods of assessment and monitoring of nutritional status. Particular attention has been paid to appropriate nutritional support in prevention and treatment of malnutrition patients with cystic fibrosis. On the basis of recent literature we can conclude that the advanced nutritional status assessment is recommended in patient with CF by using anthropometrical methods, body composition analysis and biochemical data. Good nutritional status is connected with pulmonary functions, quality and life length.

  12. Current and potential providers of blood pressure self-screening: a mixed methods study in Oxfordshire

    PubMed Central

    Tompson, A C; Heneghan, C J; Greenfield, S M; Hobbs, F D R; Ward, A M

    2017-01-01

    Objectives To (1) establish the extent of opportunities for members of the public to check their own blood pressure (BP) outside of healthcare consultations (BP self-screening), (2) investigate the reasons for and against hosting such a service and (3) ascertain how BP self-screening data are used in primary care. Design A mixed methods, cross-sectional study. Setting Primary care and community locations in Oxfordshire, UK. Participants 325 sites were surveyed to identify where and in what form BP self-screening services were available. 23 semistructured interviews were then completed with current and potential hosts of BP self-screening services. Results 18/82 (22%) general practices offered BP self-screening and 68/110 (62%) pharmacies offered professional-led BP screening. There was no evidence of permanent BP self-screening activities in other community settings. Healthcare professionals, managers, community workers and leaders were interviewed. Those in primary care generally felt that practice-based BP self-screening was a beneficial activity that increased the attainment of performance targets although there was variation in its perceived usefulness for patient care. The pharmacists interviewed provided BP checking as a service to the community but were unable to develop self-screening services without a clear business plan. Among potential hosts, barriers to providing a BP self-screening service included a perceived lack of healthcare commissioner and public demand, and a weak—if any—link to their core objectives as an organisation. Conclusions BP self-screening currently occurs in a minority of general practices. Any future development of community BP self-screening programmes will require (1) public promotion and (2) careful consideration of how best to support—and reward—the community hosts who currently perceive little if any benefit. PMID:28336742

  13. Localization Versus Abstraction: A Comparison of Two Search Reduction Techniques

    NASA Technical Reports Server (NTRS)

    Lansky, Amy L.

    1992-01-01

    There has been much recent work on the use of abstraction to improve planning behavior and cost. Another technique for dealing with the inherently explosive cost of planning is localization. This paper compares the relative strengths of localization and abstraction in reducing planning search cost. In particular, localization is shown to subsume abstraction. Localization techniques can model the various methods of abstraction that have been used, but also provide a much more flexible framework, with a broader range of benefits.

  14. Digital pulse deconvolution method for current tails of NaI(Tl) detectors

    NASA Astrophysics Data System (ADS)

    Zeng, Guo-Qiang; Yang, Jian; Yu, Ming-Fu; Zhang, Kai-Qi; Ge, Qing; Ge, Liang-Quan

    2017-01-01

    To overcome the problem of pulse pile-up at high count rates, a digital deconvolution algorithm is used to remove the exponential current tails of NaI(Tl) detectors, so as to obtain a current unit impulse. Then a narrow pulse can be obtained through pulse shaping. The pulse deconvolution technique can thoroughly eliminate the influences of ballistic deficit and improve traditional pulse shaping systems in both pulse throughput and energy resolution. To demonstrate this method, the energy spectrum of a 137Cs radioactive source was measured. When the shaping time constant is 1.5 μs, traditional pulse shaping systems yielded a 6.99% energy resolution and 68 kcps count rate, while the new pulse deconvolution technique, used to improve traditional pulse shaping systems, yielded a 6.37% energy resolution and 102 kcps count rate. Supported by National Natural Science Foundation of China (41474159), Sichuan Youth Science & Technology Foundation (2015JQ0035) and Key Laboratory of Applied Nuclear Techniques in Geosciences Sichuan (gnzds2014006)

  15. A new method to calculate the beam charge for an integrating current transformer

    SciTech Connect

    Wu Yuchi; Han Dan; Zhu Bin; Dong Kegong; Tan Fang; Gu Yuqiu

    2012-09-15

    The integrating current transformer (ICT) is a magnetic sensor widely used to precisely measure the charge of an ultra-short-pulse charged particle beam generated by traditional accelerators and new laser-plasma particle accelerators. In this paper, we present a new method to calculate the beam charge in an ICT based on circuit analysis. The output transfer function shows an invariable signal profile for an ultra-short electron bunch, so the function can be used to evaluate the signal quality and calculate the beam charge through signal fitting. We obtain a set of parameters in the output function from a standard signal generated by an ultra-short electron bunch (about 1 ps in duration) at a radio frequency linear electron accelerator at Tsinghua University. These parameters can be used to obtain the beam charge by signal fitting with excellent accuracy.

  16. Use of Biosensors as Alternatives to Current Regulatory Methods for Marine Biotoxins

    PubMed Central

    Vilariño, Natalia; Fonfría, Eva S.; Louzao, M. Carmen; Botana, Luis M.

    2009-01-01

    Marine toxins are currently monitored by means of a bioassay that requires the use of many mice, which poses a technical and ethical problem in many countries. With the exception of domoic acid, there is a legal requirement for the presence of other toxins (yessotoxin, saxitoxin and analogs, okadaic acid and analogs, pectenotoxins and azaspiracids) in seafood to be controlled by bioassay, but other toxins, such as palytoxin, cyclic imines, ciguatera and tetrodotoxin are potentially present in European food and there are no legal requirements or technical approaches available to identify their presence. The need for alternative methods to the bioassay is clearly important, and biosensors have become in recent years a feasible alternative to animal sacrifice. This review will discuss the advantages and disadvantages of using biosensors as alternatives to animal assays for marine toxins, with particular focus on surface plasmon resonance (SPR) technology. PMID:22291571

  17. Logarithmic current measurement circuit with improved accuracy and temperature stability and associated method

    DOEpatents

    Ericson, M. Nance; Rochelle, James M.

    1994-01-01

    A logarithmic current measurement circuit for operating upon an input electric signal utilizes a quad, dielectrically isolated, well-matched, monolithic bipolar transistor array. One group of circuit components within the circuit cooperate with two transistors of the array to convert the input signal logarithmically to provide a first output signal which is temperature-dependant, and another group of circuit components cooperate with the other two transistors of the array to provide a second output signal which is temperature-dependant. A divider ratios the first and second output signals to provide a resultant output signal which is independent of temperature. The method of the invention includes the operating steps performed by the measurement circuit.

  18. Ethics, Methods, and Measures in Intimate Partner Violence Research: The Current State of the Field.

    PubMed

    Bender, Annah K

    2016-08-04

    Although intimate partner violence (IPV) is a well-studied topic, surprisingly little consensus among researchers has been reached with regard to the definition and measurement of its major typologies and constructs. The rigorous development and testing of prevention and intervention strategies on a large scale are hampered by many of these methodological difficulties as well as ethical considerations that make conducting IPV research difficult. The author presents a review of the current state of IPV research in these three areas (ethics, methods, and measurement) with suggestions for innovative research possibilities building from this status quo. Moving the field of IPV research forward is necessary to establish a broader evidence base for the prevention and treatment of abuse and to improve outcomes for survivors of IPV.

  19. Measuring microchannel electroosmotic mobility and zeta potential by the current monitoring method.

    PubMed

    Shao, Chenren; Devoe, Don L

    2013-01-01

    Electroosmotic flow (EOF) is an electrokinetic flow control technique widely used in microfluidic systems for applications including direct electrokinetic pumping, hydrodynamic pressure generation, and counterflow for microfluidic separations. During EOF, an electric field is applied along the length of a microchannel containing an electrolyte, with mobile ions near the charged microchannel walls experiencing a Coulomb force due to electrostatic interactions with the applied electric field that leads to bulk solution movement. The goal of this laboratory is to experimentally determine the fixed channel surface charge (zeta potential) and electroosmotic mobility associated with a given microchannel substrate material and buffer solution, using a simple current monitoring method to measure the average flow velocity within the microchannel. It is a straightforward experiment designed to help students understand EOF physics while gaining hands-on experience with basic world-to-chip interfacing. It is well suited to a 90-min laboratory session for up to 12 students with minimal infrastructure requirements.

  20. Apparatus and method for phase fronts based on superluminal polarization current

    DOEpatents

    Singleton, John [Los Alamos, NM; Ardavan, Houshang [Cambridge, GB; Ardavan, Arzhang [Cambridge, GB

    2012-02-28

    An apparatus and method for a radiation source involving phase fronts emanating from an accelerated, oscillating polarization current whose distribution pattern moves superluminally (that is, faster than light in vacuo). Theoretical predictions and experimental measurements using an existing prototype superluminal source show that the phase fronts from such a source can be made to be very complex. Consequently, it will be very difficult for an aircraft imaged by such a radiation to detect where this radiation has come from. Moreover, the complexity of the phase fronts makes it almost impossible for electronics on an aircraft to synthesize a rogue reflection. A simple directional antenna and timing system should, on the other hand, be sufficient for the radar operators to locate the aircraft, given knowledge of their own source's speed and modulation pattern.

  1. Engineering Ethics Education : Its Necessity, Objectives, Methods, Current State, and Challenges

    NASA Astrophysics Data System (ADS)

    Fudano, Jun

    The importance of engineering ethics education has become widely recognized in the industrialized countries including Japan. This paper examines the background against which engineering ethics education is required, and reviews its objectives, methods, and challenges, as well as its current state. In pointing out important issues associated with the apparent acceptance and quantitative development of ethics education, especially after the establishment of the Japan Accreditation Board for Engineering Education in 1999, the author stresses that the most serious problem is the lack of common understanding on the objectives of engineering ethics education. As a strategy to improve the situation, the so-called “Ethics-across-the-Curriculum” approach is introduced. The author also claims that business/organization ethics which is consistent with engineering ethics should be promoted in Japan.

  2. A method for removing copper from charcoal of waste wood using an electrical current.

    PubMed

    Goto, S; Xiong, J F; Nakajima, D; Inaba, K; Ohata, M; Yoshizawa, S; Yajima, H; Sakai, S

    2007-08-01

    The reclamation of resources from wastes, through such activities as recycling various kinds of wastes and finding more ways to use them, is an important part of changing to a sustainable society. It is also important to ensure the safety of products by, for example, removing hazardous substances from recycled items. Wood is a type of demolition waste. The reuse and recycling of wood from demolition have not progressed much. To increase the number of ways of using wood wastes we have examined methods of making carbonized materials from them and using these carbonized materials to control indoor air pollution (Shibano et al., 2002). Research currently underway on ensuring the safety of recycled items includes investigating the behavior and other characteristics of hazardous substances that are, or may very well be, found in recycled items. It is known that the smoke arising from the process of carbonizing wood wastes is mutagenic. However, such mutagenic components become smoke and separate from carbonized materials, and, especially at temperatures of 800 degrees C and higher, they hardly remain in carbonized materials at all (Nakajima et al., 2003, 2004). In the carbonization of wood wastes containing hazardous metals such as CCA (Cr, Cu, As)-treated wood, substances that readily vaporize separate from the carbonized materials. One cannot expect, however, the same removal effect on metals that vaporize with difficulty, such as Cu, making it likely that they remain in the carbonized material (Takahashi et al., 2004). To examine methods of removing hazardous metals which may well remain in carbonized wood wastes, we investigated the removal and recovery of copper from charcoal with a high copper content by applying electricity (direct current) to it.

  3. Animal Disease Import Risk Analysis--a Review of Current Methods and Practice.

    PubMed

    Peeler, E J; Reese, R A; Thrush, M A

    2015-10-01

    The application of risk analysis to the spread of disease with international trade in animals and their products, that is, import risk analysis (IRA), has been largely driven by the Sanitary and Phytosanitary (SPS) agreement of the World Trade Organization (WTO). The degree to which the IRA standard established by the World Organization for Animal Health (OIE), and associated guidance, meets the needs of the SPS agreement is discussed. The use of scenario trees is the core modelling approach used to represent the steps necessary for the hazard to occur. There is scope to elaborate scenario trees for commodity IRA so that the quantity of hazard at each step is assessed, which is crucial to the likelihood of establishment. The dependence between exposure and establishment suggests that they should fall within the same subcomponent. IRA undertaken for trade reasons must include an assessment of consequences to meet SPS criteria, but guidance is sparse. The integration of epidemiological and economic modelling may open a path for better methods. Matrices have been used in qualitative IRA to combine estimates of entry and exposure, and consequences with likelihood, but this approach has flaws and better methods are needed. OIE IRA standards and guidance indicate that the volume of trade should be taken into account, but offer no detail. Some published qualitative IRAs have assumed current levels and patterns of trade without specifying the volume of trade, which constrains the use of IRA to determine mitigation measures (to reduce risk to an acceptable level) and whether the principle of equivalence, fundamental to the SPS agreement, has been observed. It is questionable whether qualitative IRA can meet all the criteria set out in the SPS agreement. Nevertheless, scope exists to elaborate the current standards and guidance, so they better serve the principle of science-based decision-making.

  4. Hydrogen energy. A bibliography with abstracts

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Hydrogen Energy is a continuing bibliographic summary with abstracts of research and projections on the subject of hydrogen as a secondary fuel and as an energy carrier. This update to Hydrogen Energy cites additional references identified during the fourth quarter of 1978. It is the fourth in a 1978 quarterly series intended to provide current awareness to those interested in hydrogen energy. A series of cross indexes are included which track directly with those of the cumulative volume.

  5. Deficiencies in structured medical abstracts.

    PubMed

    Froom, P; Froom, J

    1993-07-01

    This study was carried out to determine if the content of structured abstracts conforms with recommendations of the Ad Hoc Working Group for the critical appraisal of the medical literature as adopted by the Annals of Internal Medicine. The study design was a survey. All articles published in Annals of Internal Medicine in 1991, excluding editorials, case-reports, literature reviews, decision analysis, studies in medical education, descriptive studies of clinical and basic phenomena, and papers lacking a structured abstract, were studied. Of a total of 150 articles, 20 were excluded. The abstract and text of each article were assessed for the presence of the following items; patient selection criteria, statements concerning extrapolation of findings, need for further study, and whether or not the information should be used now. Number of refusers, drop outs and reason(s) for drop outs were assessed for intervention and prospective cohort studies only. Deficiencies of assessed items were noted in both abstracts and texts. For abstracts, patient selection criteria, numbers of refusers, number of drop outs and reason(s) for drop outs were reported in 44.6% (58/130), 3.1% (4/130), 16.9% (14/83) and 2.4% (2/83) respectively. These items were reported more frequently in the texts 87.7% (114/130), 9.2% (12/130), 60.2% (50/83) and 37.3% (31/83) respectively (p < 0.05). Statements concerning extrapolation of findings, need for further study and use of information now were also more frequent in texts than abstracts (p < 0.0001). A large number of structured abstracts published in the Annals of Internal Medicine in 1991, lack information recommended by the Ad Hoc Working Group. Our findings should not be extrapolated to other journals requiring structured abstracts.

  6. Alternative (non-animal) methods for cosmetics testing: current status and future prospects-2010.

    PubMed

    Adler, Sarah; Basketter, David; Creton, Stuart; Pelkonen, Olavi; van Benthem, Jan; Zuang, Valérie; Andersen, Klaus Ejner; Angers-Loustau, Alexandre; Aptula, Aynur; Bal-Price, Anna; Benfenati, Emilio; Bernauer, Ulrike; Bessems, Jos; Bois, Frederic Y; Boobis, Alan; Brandon, Esther; Bremer, Susanne; Broschard, Thomas; Casati, Silvia; Coecke, Sandra; Corvi, Raffaella; Cronin, Mark; Daston, George; Dekant, Wolfgang; Felter, Susan; Grignard, Elise; Gundert-Remy, Ursula; Heinonen, Tuula; Kimber, Ian; Kleinjans, Jos; Komulainen, Hannu; Kreiling, Reinhard; Kreysa, Joachim; Leite, Sofia Batista; Loizou, George; Maxwell, Gavin; Mazzatorta, Paolo; Munn, Sharon; Pfuhler, Stefan; Phrakonkham, Pascal; Piersma, Aldert; Poth, Albrecht; Prieto, Pilar; Repetto, Guillermo; Rogiers, Vera; Schoeters, Greet; Schwarz, Michael; Serafimova, Rositsa; Tähti, Hanna; Testai, Emanuela; van Delft, Joost; van Loveren, Henk; Vinken, Mathieu; Worth, Andrew; Zaldivar, José-Manuel

    2011-05-01

    The 7th amendment to the EU Cosmetics Directive prohibits to put animal-tested cosmetics on the market in Europe after 2013. In that context, the European Commission invited stakeholder bodies (industry, non-governmental organisations, EU Member States, and the Commission's Scientific Committee on Consumer Safety) to identify scientific experts in five toxicological areas, i.e. toxicokinetics, repeated dose toxicity, carcinogenicity, skin sensitisation, and reproductive toxicity for which the Directive foresees that the 2013 deadline could be further extended in case alternative and validated methods would not be available in time. The selected experts were asked to analyse the status and prospects of alternative methods and to provide a scientifically sound estimate of the time necessary to achieve full replacement of animal testing. In summary, the experts confirmed that it will take at least another 7-9 years for the replacement of the current in vivo animal tests used for the safety assessment of cosmetic ingredients for skin sensitisation. However, the experts were also of the opinion that alternative methods may be able to give hazard information, i.e. to differentiate between sensitisers and non-sensitisers, ahead of 2017. This would, however, not provide the complete picture of what is a safe exposure because the relative potency of a sensitiser would not be known. For toxicokinetics, the timeframe was 5-7 years to develop the models still lacking to predict lung absorption and renal/biliary excretion, and even longer to integrate the methods to fully replace the animal toxicokinetic models. For the systemic toxicological endpoints of repeated dose toxicity, carcinogenicity and reproductive toxicity, the time horizon for full replacement could not be estimated.

  7. A Method to Simultaneously Detect the Current Sensor Fault and Estimate the State of Energy for Batteries in Electric Vehicles.

    PubMed

    Xu, Jun; Wang, Jing; Li, Shiying; Cao, Binggang

    2016-08-19

    Recently, State of energy (SOE) has become one of the most fundamental parameters for battery management systems in electric vehicles. However, current information is critical in SOE estimation and current sensor is usually utilized to obtain the latest current information. However, if the current sensor fails, the SOE estimation may be confronted with large error. Therefore, this paper attempts to make the following contributions: Current sensor fault detection and SOE estimation method is realized simultaneously. Through using the proportional integral observer (PIO) based method, the current sensor fault could be accurately estimated. By taking advantage of the accurate estimated current sensor fault, the influence caused by the current sensor fault can be eliminated and compensated. As a result, the results of the SOE estimation will be influenced little by the fault. In addition, the simulation and experimental workbench is established to verify the proposed method. The results indicate that the current sensor fault can be estimated accurately. Simultaneously, the SOE can also be estimated accurately and the estimation error is influenced little by the fault. The maximum SOE estimation error is less than 2%, even though the large current error caused by the current sensor fault still exists.

  8. A Method to Simultaneously Detect the Current Sensor Fault and Estimate the State of Energy for Batteries in Electric Vehicles

    PubMed Central

    Xu, Jun; Wang, Jing; Li, Shiying; Cao, Binggang

    2016-01-01

    Recently, State of energy (SOE) has become one of the most fundamental parameters for battery management systems in electric vehicles. However, current information is critical in SOE estimation and current sensor is usually utilized to obtain the latest current information. However, if the current sensor fails, the SOE estimation may be confronted with large error. Therefore, this paper attempts to make the following contributions: Current sensor fault detection and SOE estimation method is realized simultaneously. Through using the proportional integral observer (PIO) based method, the current sensor fault could be accurately estimated. By taking advantage of the accurate estimated current sensor fault, the influence caused by the current sensor fault can be eliminated and compensated. As a result, the results of the SOE estimation will be influenced little by the fault. In addition, the simulation and experimental workbench is established to verify the proposed method. The results indicate that the current sensor fault can be estimated accurately. Simultaneously, the SOE can also be estimated accurately and the estimation error is influenced little by the fault. The maximum SOE estimation error is less than 2%, even though the large current error caused by the current sensor fault still exists. PMID:27548183

  9. Phase Segregation of Polyether-Polyamide Copolymer PEBAX by Thermally Stimulated Current Method

    NASA Astrophysics Data System (ADS)

    Faruque, H. S.; Lacabanne, C.

    1986-03-01

    The glass transition β of polyamide 12 (PA12, \\bar{M}n{=}830) and polytetramethylene glycol (PTMG, \\bar{M}n{=}2000) has been observed at 43°C and -74°C respectively by thermally stimulated current (TSC) method. The copolymer poly(ether block amide), PEBAX having hard segment PA12 (\\bar{M}n{=}898) and soft segment PTMG (\\bar{M}n{=}2032) has been studied by TSC. The respective peaks of PTMG and PA12 are located at -69.5°C and 13.5°C for a raw material sample and -70°C and 9°C when the sample is recrystallised after melting showing the presence of two defined phases in this system. The effect of slow cooling after polarisation on the hard segment has been observed. The influence of viscosity on the phases polytetramethylene glycol βPTMG and polyamide 12 βPA has been investigated. Activation energy and relaxation times have been calculated for βPTMG and βPA relaxations by the fractional polarisation method. Two phases are also identified.

  10. Evaluating the osseointegration of nanostructured titanium implants in animal models: Current experimental methods and perspectives (Review).

    PubMed

    Babuska, Vaclav; Moztarzadeh, Omid; Kubikova, Tereza; Moztarzadeh, Amin; Hrusak, Daniel; Tonar, Zbynek

    2016-09-15

    The aim of this paper is to review the experimental methods currently being used to evaluate the osseointegration of nanostructured titanium implants using animal models. The material modifications are linked to the biocompatibility of various types of oral implants, such as laser-treated, acid-etched, plasma-coated, and sand-blasted surface modifications. The types of implants are reviewed according to their implantation site (endoosseous, subperiosteal, and transosseous implants). The animal species and target bones used in experimental implantology are carefully compared in terms of the ratio of compact to spongy bone. The surgical technique in animal experiments is briefly described, and all phases of the histological evaluation of osseointegration are described in detail, including harvesting tissue samples, processing undemineralized ground sections, and qualitative and quantitative histological assessment of the bone-implant interface. The results of histological staining methods used in implantology are illustrated and compared. A standardized and reproducible technique for stereological quantification of bone-implant contact is proposed and demonstrated. In conclusion, histological evaluation of the experimental osseointegration of dental implants requires careful selection of the experimental animals, bones, and implantation sites. It is also advisable to use larger animal models and older animals with a slower growth rate rather than small or growing experimental animals. Bones with a similar ratio of compact to spongy bone, such as the human maxilla and mandible, are preferred. A number of practical recommendations for the experimental procedures, harvesting of samples, tissue processing, and quantitative histological evaluations are provided.

  11. Eddy current probe with foil sensor mounted on flexible probe tip and method of use

    DOEpatents

    Viertl, John R. M.; Lee, Martin K.

    2001-01-01

    A pair of copper coils are embedded in the foil strip. A first coil of the pair generates an electromagnetic field that induces eddy currents on the surface, and the second coil carries a current influenced by the eddy currents on the surface. The currents in the second coil are analyzed to obtain information on the surface eddy currents. An eddy current probe has a metal housing having a tip that is covered by a flexible conductive foil strip. The foil strip is mounted on a deformable nose at the probe tip so that the strip and coils will conform to the surface to which they are applied.

  12. Method for reducing peak phase current and decreasing staring time for an internal combustion engine having an induction machine

    DOEpatents

    Amey, David L.; Degner, Michael W.

    2002-01-01

    A method for reducing the starting time and reducing the peak phase currents for an internal combustion engine that is started using an induction machine starter/alternator. The starting time is reduced by pre-fluxing the induction machine and the peak phase currents are reduced by reducing the flux current command after a predetermined period of time has elapsed and concurrent to the application of the torque current command. The method of the present invention also provides a strategy for anticipating the start command for an internal combustion engine and determines a start strategy based on the start command and the operating state of the internal combustion engine.

  13. Automatic identification of abstract online groups

    DOEpatents

    Engel, David W; Gregory, Michelle L; Bell, Eric B; Cowell, Andrew J; Piatt, Andrew W

    2014-04-15

    Online abstract groups, in which members aren't explicitly connected, can be automatically identified by computer-implemented methods. The methods involve harvesting records from social media and extracting content-based and structure-based features from each record. Each record includes a social-media posting and is associated with one or more entities. Each feature is stored on a data storage device and includes a computer-readable representation of an attribute of one or more records. The methods further involve grouping records into record groups according to the features of each record. Further still the methods involve calculating an n-dimensional surface representing each record group and defining an outlier as a record having feature-based distances measured from every n-dimensional surface that exceed a threshold value. Each of the n-dimensional surfaces is described by a footprint that characterizes the respective record group as an online abstract group.

  14. Introducing structured abstracts for A&A articles

    NASA Astrophysics Data System (ADS)

    Bertout, Claude; Schneider, Peter

    2005-10-01

    Context: Due to their wide availability, abstracts have become the most important part of any astrophysical paper. Aims: Having noticed that abstracts published in astronomical journals are not always optimal, we introduce the concept of structured abstracts for A&A articles. Methods: We explain what structured abstracts are and where they come from, provide examples showing how to structure an abstract, and discuss the advantages and drawbacks of this novel concept. In an on-line appendix, we show what some published abstracts look like once they are structured. Results: We demonstrate the improvements in information content, readability, and style that can be made when writing structured abstracts instead of traditional ones. Conclusions: A new version 6.0 of the A&A LaTeX macro is now available for structuring the abstracts of articles, and A&A authors are kindly invited to use it for their new submissions.

  15. Meeting Abstracts - Annual Meeting 2016.

    PubMed

    2016-04-01

    The AMCP Abstracts program provides a forum through which authors can share their insights and outcomes of advanced managed care practice through publication in AMCP's Journal of Managed Care & Specialty Pharmacy (JMCP). Most of the reviewed and unreviewed abstracts are presented as posters so that interested AMCP meeting attendees can review findings and query authors. The Student/Resident/ Fellow poster presentation (unreviewed) is Wednesday, April 20, 2016, and the Professional poster presentation (reviewed) is Thursday, April 21. The Professional posters will also be displayed on Friday, April 22. The reviewed abstracts are published in the JMCP Meeting Abstracts supplement. The AMCP Managed Care & Specialty Pharmacy Annual Meeting 2016 in San Francisco, California, is expected to attract more than 3,500 managed care pharmacists and other health care professionals who manage and evaluate drug therapies, develop and manage networks, and work with medical managers and information specialists to improve the care of all individuals enrolled in managed care programs. Abstracts were submitted in the following categories: Research Report: describe completed original research on managed care pharmacy services or health care interventions. Examples include (but are not limited to) observational studies using administrative claims, reports of the impact of unique benefit design strategies, and analyses of the effects of innovative administrative or clinical programs. Economic Model: describe models that predict the effect of various benefit design or clinical decisions on a population. For example, an economic model could be used to predict the budget impact of a new pharmaceutical product on a health care system. Solving Problems in Managed Care: describe the specific steps taken to introduce a needed change, develop and implement a new system or program, plan and organize an administrative function, or solve other types of problems in managed care settings. These

  16. Simulation of the distribution of current density in the brain of slaughter pigs with the finite element method.

    PubMed

    Eike, H; Koch, R; Feldhusen, F; Seifert, H

    2005-04-01

    The current density in the brain of a slaughter pig during electric stunning was calculated and visualised with an finite element method computer model. The anatomic model of the pig's head was constructed with the computer programme Ansys. Ansys offers the possibility of calculating the current density between electrodes in any position using the mathematical "finite element method" model. After calculation the current density distribution can be visualised in planes in any direction through the pig's head. Our simulation confirmed the common practice of positioning the electrodes for electric stunning either eye to eye or eye to ear, because the highest current density through the brain was calculated for these positions. Setting the electrodes further caudally reduced the current density remarkably and, stunning is therefore not guaranteed. Additionally, this model showed for the first time that, due to their lower resistance, the nervus opticus and blood vessels conduct the current like wires into the brain.

  17. Abstraction and natural language semantics.

    PubMed Central

    Kayser, Daniel

    2003-01-01

    According to the traditional view, a word prototypically denotes a class of objects sharing similar features, i.e. it results from an abstraction based on the detection of common properties in perceived entities. I explore here another idea: words result from abstraction of common premises in the rules governing our actions. I first argue that taking 'inference', instead of 'reference', as the basic issue in semantics does matter. I then discuss two phenomena that are, in my opinion, particularly difficult to analyse within the scope of traditional semantic theories: systematic polysemy and plurals. I conclude by a discussion of my approach, and by a summary of its main features. PMID:12903662

  18. Tense Use and Move Analysis in Journal Article Abstracts

    ERIC Educational Resources Information Center

    Wang, Shih-ping; Tu, Pin-ning

    2014-01-01

    There has long been a growing interest in journal article (JA) abstract writing, and this pervading interest has boosted the exigency for further research. This current study therefore aims to investigate both the various applications of verb tense and the rhetorical structure within JA abstracts. A corpus of 1,000 JAs was collected from four…

  19. Methods, systems and apparatus for optimization of third harmonic current injection in a multi-phase machine

    DOEpatents

    Gallegos-Lopez, Gabriel

    2012-10-02

    Methods, system and apparatus are provided for increasing voltage utilization in a five-phase vector controlled machine drive system that employs third harmonic current injection to increase torque and power output by a five-phase machine. To do so, a fundamental current angle of a fundamental current vector is optimized for each particular torque-speed of operating point of the five-phase machine.

  20. Medical Temporal-Knowledge Discovery via Temporal Abstraction

    PubMed Central

    Moskovitch, Robert; Shahar, Yuval

    2009-01-01

    Medical knowledge includes frequently occurring temporal patterns in longitudinal patient records. These patterns are not easily detectable by human clinicians. Current knowledge could be extended by automated temporal data mining. However, multivariate time-oriented data are often present at various levels of abstraction and at multiple temporal granularities, requiring a transformation into a more abstract, yet uniform dimension suitable for mining. Temporal abstraction (of both the time and value dimensions) can transform multiple types of point-based data into a meaningful, time-interval-based data representation, in which significant, interval-based temporal patterns can be discovered. We introduce a modular, fast time-interval mining method, KarmaLego, which exploits the transitivity inherent in temporal relations. We demonstrate the usefulness of KarmaLego in finding meaningful temporal patterns within a set of records of diabetic patients; several patterns seem to have a different frequency depending on gender. We also suggest additional uses of the discovered patterns for temporal clustering of the mined population and for classifying multivariate time series. PMID:20351898

  1. Is transcranial direct current stimulation a potential method for improving response inhibition?

    PubMed

    Kwon, Yong Hyun; Kwon, Jung Won

    2013-04-15

    Inhibitory control of movement in motor learning requires the ability to suppress an inappropriate action, a skill needed to stop a planned or ongoing motor response in response to changes in a variety of environments. This study used a stop-signal task to determine whether transcranial direct-current stimulation over the pre-supplementary motor area alters the reaction time in motor inhibition. Forty healthy subjects were recruited for this study and were randomly assigned to either the transcranial direct-current stimulation condition or a sham-transcranial direct-current stimulation condition. All subjects consecutively performed the stop-signal task before, during, and after the delivery of anodal transcranial direct-current stimulation over the pre-supplementary motor area (pre-transcranial direct-current stimulation phase, transcranial direct-current stimulation phase, and post-transcranial direct-current stimulation phase). Compared to the sham condition, there were significant reductions in the stop-signal processing times during and after transcranial direct-current stimulation, and change times were significantly greater in the transcranial direct-current stimulation condition. There was no significant change in go processing-times during or after transcranial direct-current stimulation in either condition. Anodal transcranial direct-current stimulation was feasibly coupled to an interactive improvement in inhibitory control. This coupling led to a decrease in the stop-signal process time required for the appropriate responses between motor execution and inhibition. However, there was no transcranial direct-current stimulation effect on the no-signal reaction time during the stop-signal task. Transcranial direct-current stimulation can adjust certain behaviors, and it could be a useful clinical intervention for patients who have difficulties with response inhibition.

  2. Abstract models for the synthesis of optimization algorithms.

    NASA Technical Reports Server (NTRS)

    Meyer, G. G. L.; Polak, E.

    1971-01-01

    Systematic approach to the problem of synthesis of optimization algorithms. Abstract models for algorithms are developed which guide the inventive process toward ?conceptual' algorithms which may consist of operations that are inadmissible in a practical method. Once the abstract models are established a set of methods for converting ?conceptual' algorithms falling into the class defined by the abstract models into ?implementable' iterative procedures is presented.

  3. Metaphoric Images from Abstract Concepts.

    ERIC Educational Resources Information Center

    Vizmuller-Zocco, Jana

    1992-01-01

    Discusses children's use of metaphors to create meaning, using as an example the pragmatic and "scientific" ways in which preschool children explain thunder and lightning to themselves. Argues that children are being shortchanged by modern scientific notions of abstractness and that they should be encouraged to create their own explanations of…

  4. Carry Groups: Abstract Algebra Projects

    ERIC Educational Resources Information Center

    Miller, Cheryl Chute; Madore, Blair F.

    2004-01-01

    Carry Groups are a wonderful collection of groups to introduce in an undergraduate Abstract Algebra course. These groups are straightforward to define but have interesting structures for students to discover. We describe these groups and give examples of in-class group projects that were developed and used by Miller.

  5. Typographic Settings for Structured Abstracts.

    ERIC Educational Resources Information Center

    Hartley, James

    2000-01-01

    Lists some of the major typographic variables involved in structured abstracts (containing sub-headings). Illustrates how typography can affect clarity by presenting seven examples that illustrate the effects of these typographic variables in practice. Concludes with a final example of an effective approach. (SR)

  6. Handedness Shapes Children's Abstract Concepts

    ERIC Educational Resources Information Center

    Casasanto, Daniel; Henetz, Tania

    2012-01-01

    Can children's handedness influence how they represent abstract concepts like "kindness" and "intelligence"? Here we show that from an early age, right-handers associate rightward space more strongly with positive ideas and leftward space with negative ideas, but the opposite is true for left-handers. In one experiment, children indicated where on…

  7. Innovation Abstracts, Volume XVII, 1995.

    ERIC Educational Resources Information Center

    Roueche, Suanne D., Ed.

    1995-01-01

    The abstracts in this volume describe innovative approaches to teaching and learning in the community college. Topics covered include: (1) the use of message mapping for speaking and writing instruction; (2) group projects and portfolios as evaluation tools; (3) helping students become strategic learners; (4) using writing assignments to ensure…

  8. Chemical Abstracts' Document Delivery Service.

    ERIC Educational Resources Information Center

    Rollins, Stephen

    1984-01-01

    The Document Delivery Service offered by Chemical Abstracts is described in terms of the DIALORDER option on the Dialog information retrieval system, mail requests, and requests transmitted through OCLC's Interlibrary Loan system. Transmission costs, success rates, delivery rates, and other considerations in utilizing the service are included.…

  9. Probing electrical tuning of hair cells with a Zap current method in the intact amphibian papilla of bullfrogs.

    PubMed

    Frolov, Daniil; Li, Geng-Lin

    2017-02-01

    Most, if not all, modern vertebrate species have evolved exquisite inner ears to discriminate acoustic signals of different frequencies, through a process called frequency tuning. For non-mammalian species, at least part of frequency tuning has been attributed to intrinsic electrical properties of hair cells, i.e. electrical tuning. Since it was first discovered, the traditional method to assess electrical tuning has been to inject step current into hair cells and examine dampened membrane voltage oscillation. However, this method is not applicable for hair cells that do not oscillate. In this study, we developed a Zap current method that can be unbiasedly applied to all hair cells regardless of their oscillating behavior. Similar to a chirp sound in acoustic stimulation, a Zap current is a sinusoidal current with the frequency increased linearly with time. We first validated this new method with the traditional step current method on hair cells with dampened membrane voltage oscillation, and then applied it to all hair cells in the intact amphibian papilla of bullfrogs. We found that while hair cells with dampened membrane voltage oscillation are sharply tuned, non-oscillating hair cells are broadly tuned. In addition, we found a third type of hair cells, which oscillate continuously and are extremely sharply tuned, with multiple peaks that are reminiscent of harmonics in the mammalian cochlea. In conclusion, the new Zap current method provides an unbiased way to assess electrical tuning, and it reveals an underappreciated heterogeneity of electrical tuning in the bullfrog amphibian papilla.

  10. Simple and effective method to lock buoy position to ocean currents

    NASA Technical Reports Server (NTRS)

    Vachon, W. A.; Dahlen, J. M.

    1975-01-01

    Window-shade drogue, used with drifting buoys to keep them moving with current at speed as close to that of current as possible, has drag coefficient of 1.93 compared to maximum of 1.52 for previous drogues. It is remarkably simple to construct, use, and store.

  11. Development of Harmonic-Noise Reduction Technology in Diagnostic Method using AC Loss Current for Water Treed XLPE Cable

    NASA Astrophysics Data System (ADS)

    Tsujimoto, Tomiyuki; Nakade, Masahiko; Yagi, Yukihiro; Ishii, Noboru

    Water tree is one of the degradation aspects of XLPE cables used for under-ground distribution or transmission lines. We have developed the loss current method using 3rd harmonic in AC loss current for cable diagnosis. Harmonic components in loss current arise as a result of the non-linear voltage-current characteristics of water trees. We confirmed that the 3rd harmonic in AC loss current had good correlation with water tree growth and break down strength. After that, we have applied this method to the actual 66kV XLPE cable lines. Up to now, the number of the application results is more than 120 lines. In this method, it is sometimes said that the degradation signal (3rd harmonic in loss current) is affected by the 3rd harmonic in the test voltage. To indicate and solve this problem, we investigated the extent of influence by 3rd harmonic in the test voltage, and found the rule of the influence. As a result, we developed a new technique of harmonic-noise reduction in loss current method that enabled a more highly accurate diagnosis and confirmed the effectiveness of this new technique by simulations and experiments with actual cables.

  12. Odors and Air Pollution: A Bibliography with Abstracts.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Research Triangle Park, NC. Office of Air Programs.

    The annotated bibliography presents a compilation of abstracts which deal with odors as they relate to air pollution. The abstracts are arranged within the following categories: Emission sources; Control methods; Measurement methods; Air quality measurements; Atmospheric interaction; Basic science and technology; Effects-human health;…

  13. Adopting Abstract Images for Semantic Scene Understanding.

    PubMed

    Zitnick, C Lawrence; Vedantam, Ramakrishna; Parikh, Devi

    2016-04-01

    Relating visual information to its linguistic semantic meaning remains an open and challenging area of research. The semantic meaning of images depends on the presence of objects, their attributes and their relations to other objects. But precisely characterizing this dependence requires extracting complex visual information from an image, which is in general a difficult and yet unsolved problem. In this paper, we propose studying semantic information in abstract images created from collections of clip art. Abstract images provide several advantages over real images. They allow for the direct study of how to infer high-level semantic information, since they remove the reliance on noisy low-level object, attribute and relation detectors, or the tedious hand-labeling of real images. Importantly, abstract images also allow the ability to generate sets of semantically similar scenes. Finding analogous sets of real images that are semantically similar would be nearly impossible. We create 1,002 sets of 10 semantically similar abstract images with corresponding written descriptions. We thoroughly analyze this dataset to discover semantically important features, the relations of words to visual features and methods for measuring semantic similarity. Finally, we study the relation between the saliency and memorability of objects and their semantic importance.

  14. An evaluation of 'Inpharma', a drug literature abstracting service.

    PubMed

    Milne, A

    1981-09-01

    This study aimed to provide data on the characteristics of the drug literature abstracting service 'Inpharma'. Journal coverage, article yield and timeliness for a 3-year period were examined; the reliability and information content of 100 abstracts were also assessed. It was found that although 'Inpharma' is claimed to monitor a very large number of journals, over 98% of the abstracts were from 'core' journals of which there are approximately 350. Over 80% of the abstracts appeared within 4 months of publications of the original and abstracts from some of the American journals were available in the United Kingdom before the relevant primary journal. Sixteen errors were detected in 100 abstracts; five of these were typographical errors and nine deviations in accuracy. The publication is a good 'current awareness tool' but it should not be used where a comprehensive coverage of the literature is required. It is also important that the primary journal is consulted when detailed information is required.

  15. Methods and apparatus for controlling respective load currents of multiple series-connected loads

    DOEpatents

    Datta, Michael; Lys, Ihor

    2014-05-27

    A lighting apparatus (100) includes one or more first LEDs (202) for generating a first spectrum of radiation (503), and one or more second LEDs (204) for generating a second different spectrum radiation (505). The first and second LEDs are electrically connected in series between a first node (516A) and a second node (516B), between which a series current (550) flows with the application of an operating voltage (516) across the nodes. A controllable current path (518) is connected in parallel with one or both of the first and second LEDs so as to at least partially divert the series current, such that a first current (552) through the first LED(s) and a second current (554) through the second LED(s) are different. Such current diversion techniques may be employed to compensate for shifts in color or color temperature of generated light during thermal transients, due to different temperature-dependent current-to-flux relationships for different types of LEDs.

  16. An Abstract Plan Preparation Language

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Munoz, Cesar A.

    2006-01-01

    This paper presents a new planning language that is more abstract than most existing planning languages such as the Planning Domain Definition Language (PDDL) or the New Domain Description Language (NDDL). The goal of this language is to simplify the formal analysis and specification of planning problems that are intended for safety-critical applications such as power management or automated rendezvous in future manned spacecraft. The new language has been named the Abstract Plan Preparation Language (APPL). A translator from APPL to NDDL has been developed in support of the Spacecraft Autonomy for Vehicles and Habitats Project (SAVH) sponsored by the Explorations Technology Development Program, which is seeking to mature autonomy technology for application to the new Crew Exploration Vehicle (CEV) that will replace the Space Shuttle.

  17. Abstraction Techniques for Parameterized Verification

    DTIC Science & Technology

    2006-11-01

    difference, consider an example frequently discussed in the history of science, namely the Ptolemaic system in which the planet earth is surrounded by...tend to imagine systems with the human observer in the center. While a Ptolemaic viewpoint is known to be wrong (or, more precisely, infeasible) in...physics, it naturally appears in the systems we construct. Consequently, the Ptolemaic viewpoint yields a natural abstraction principle for computer

  18. Cryogenic foam insulation: Abstracted publications

    NASA Technical Reports Server (NTRS)

    Williamson, F. R.

    1977-01-01

    A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied natural gas storage tanks and pipelines.

  19. New Current Control Method of DC Power Supply for Magnetic Perturbation Coils on J-TEXT

    NASA Astrophysics Data System (ADS)

    Zeng, Wubing; Ding, Yonghua; Yi, Bin; Xu, Hangyu; Rao, Bo; Zhang, Ming; Liu, Minghai

    2014-11-01

    In order to advance the research on suppressing tearing modes and driving plasma rotation, a DC power supply (PS) system has been developed for dynamic resonant magnetic perturbation (DRMP) coils and applied in the J-TEXT experiment. To enrich experimental phenomena in the J-TEXT tokamak, applying the circulating current four-quadrant operation mode in the DRMP DC PS system is proposed. By using the circulating current four-quadrant operation, DRMP coils can be smoothly controlled without the dead-time when the current polarity reverses. Essential circuit analysis, control optimization and simulation of desired scenarios have been performed for normal current. Relevant simulation and test results are also presented.

  20. Methods, systems and apparatus for controlling operation of two alternating current (AC) machines

    DOEpatents

    Gallegos-Lopez, Gabriel [Torrance, CA; Nagashima, James M [Cerritos, CA; Perisic, Milun [Torrance, CA; Hiti, Silva [Redondo Beach, CA

    2012-06-05

    A system is provided for controlling two alternating current (AC) machines via a five-phase PWM inverter module. The system comprises a first control loop, a second control loop, and a current command adjustment module. The current command adjustment module operates in conjunction with the first control loop and the second control loop to continuously adjust current command signals that control the first AC machine and the second AC machine such that they share the input voltage available to them without compromising the target mechanical output power of either machine. This way, even when the phase voltage available to either one of the machines decreases, that machine outputs its target mechanical output power.

  1. A Current Source Method For t(sub q) Measurement of Fast Switching Thyristors

    NASA Technical Reports Server (NTRS)

    Niedra, Janis M.

    2006-01-01

    A current source driven circuit has been constructed to measure the turn-off time (t(sub q)) of fast-switching SiC thyristors. This circuit operates from a single power supply and a dual channel pulse generator to provide adjustment of forward current, magnitude and duration of reverse applied voltage, and rate of rise of reapplied forward voltage. Values of t(sub q) down to 100 ns can be resolved.

  2. Method for removal of random noise in eddy-current testing system

    DOEpatents

    Levy, Arthur J.

    1995-01-01

    Eddy-current response voltages, generated during inspection of metallic structures for anomalies, are often replete with noise. Therefore, analysis of the inspection data and results is difficult or near impossible, resulting in inconsistent or unreliable evaluation of the structure. This invention processes the eddy-current response voltage, removing the effect of random noise, to allow proper identification of anomalies within and associated with the structure.

  3. Geostrophic current estimation using altimetric cross-track method in northwest Pacific

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Wang, Longfei; Zheng, Quan'an; Li, Ziwei

    2014-03-01

    Geostrophic current contributes a large part of ocean current, which plays an important role in global climate change. Based on classic oceanography, geostrophic current can be derived from pressure gradient. Assuming water density to be constant, we can estimate geostrophic current from Absolute Dynamic Topography (ADT). In this paper, we use ADT data obtained from multi-satellite altimeter to extract sea surface tilt along track at ground track crossover points. The calculated tilt along these two tracks can be converted into orthogonal directions and are used to estimate geostrophic current. In northwest Pacific, geostrophic current velocities computed above are evaluated using Argos data, a global Langrangian drifter program. 771 precisely temporal and spatial coherent Argos data with estimated geostrophic velocity data are used for evaluating. Effect of different threshold length of the low pass filter applied to ADT is discussed. A threshold length of 75 km is most suitable for the study area. The estimated geostrophic velocity and the Argos measurement agree well with each other, with correlation coefficient R equals 0.867 for zonal component, and 0.734 for meridional component. A relationship between the estimated geostrophic velocity and Argos measurement is drawn.

  4. Development of an in situ calibration method for current-to-voltage converters for high-accuracy SI-traceable low dc current measurements

    NASA Astrophysics Data System (ADS)

    Eppeldauer, George P.; Yoon, Howard W.; Jarrett, Dean G.; Larason, Thomas C.

    2013-10-01

    For photocurrent measurements with low uncertainties, wide dynamic range reference current-to-voltage converters and a new converter calibration method have been developed at the National Institute of Standards and Technology (NIST). The high-feedback resistors of a reference converter were in situ calibrated on a high-resistivity, printed circuit board placed in an electrically shielded box electrically isolated from the operational amplifier using jumpers. The feedback resistors, prior to their installation, were characterized, selected and heat treated. The circuit board was cleaned with solvents, and the in situ resistors were calibrated using measurement systems for 10 kΩ to 10 GΩ standard resistors. We demonstrate that dc currents from 1 nA to 100 µA can be measured with uncertainties of 55 × 10-6 (k = 2) or lower, which are lower in uncertainties than any commercial device by factors of 10 to 30 at the same current setting. The internal (NIST) validations of the reference converter are described.

  5. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality by Eddy Current Method

    SciTech Connect

    B.Mi; X. Zhao; R. Bayles

    2006-05-26

    Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with different surface preparation conditions before applying the coating, e.g., grit-blasted surface, wire-brush cleaned surface, and a dirty surface. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that the three surface preparation conditions can be successfully differentiated by looking into the impedance difference observed from the eddy current probe. The measurement is fairly robust and consistent. More specimens are also prepared with variations of process parameters, such as spray angle, stand-off distance, and application of corrosion protective sealant, etc. They are blindly tested to evaluate the reliability of the eddy current system. Quantitative relations between the coating bond strength and the eddy current response are also established with the support of destructive testing. This non-contact, non-destructive, easy to use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

  6. Model development and validation of geometrically complex eddy current coils using finite element methods

    NASA Astrophysics Data System (ADS)

    Brown, Alexander; Eviston, Connor

    2017-02-01

    Multiple FEM models of complex eddy current coil geometries were created and validated to calculate the change of impedance due to the presence of a notch. Capable realistic simulations of eddy current inspections are required for model assisted probability of detection (MAPOD) studies, inversion algorithms, experimental verification, and tailored probe design for NDE applications. An FEM solver was chosen to model complex real world situations including varying probe dimensions and orientations along with complex probe geometries. This will also enable creation of a probe model library database with variable parameters. Verification and validation was performed using other commercially available eddy current modeling software as well as experimentally collected benchmark data. Data analysis and comparison showed that the created models were able to correctly model the probe and conductor interactions and accurately calculate the change in impedance of several experimental scenarios with acceptable error. The promising results of the models enabled the start of an eddy current probe model library to give experimenters easy access to powerful parameter based eddy current models for alternate project applications.

  7. System and method for generating current by selective minority species heating

    DOEpatents

    Fisch, Nathaniel J.

    1983-01-01

    A system for the generation of toroidal current in a plasma which is prepared in a toroidal magnetic field. The system utilizes the injection of low-frequency waves into the plasma by means of phased antenna arrays or phased waveguide arrays. The plasma is prepared with a minority ion species of different charge state and different gyrofrequency from the majority ion species. The wave frequency and wave phasing are chosen such that the wave energy is absorbed preferentially by minority species ions traveling in one toroidal direction. The absorption of energy in this manner produces a toroidal electric current even when the injected waves themselves do not have substantial toroidal momentum. This current can be continuously maintained at modest cost in power and may be used to confine the plasma. The system can operate efficiently on fusion grade tokamak plasmas.

  8. Non-Destructive Evaluation of Thermal Spray Coating Interface Quality By Eddy Current Method

    SciTech Connect

    B. Mi; G. Zhao; R. Bayles

    2006-08-10

    Thermal spray coating is usually applied through directing molten or softened particles at very high velocities onto a substrate. An eddy current non-destructive inspection technique is presented here for thermal spray coating interface quality characterization. Several high-velocity-oxy-fuel (HVOF) coated steel plates were produced with various surface preparation conditions or spray process parameters. A quad-frequency eddy current probe was used to manually scan over the coating surface to evaluate the bonding quality. Experimental results show that different surface preparation conditions and varied process parameters can be successfully differentiated by the impedance value observed from the eddy current probe. The measurement is fairly robust and consistent. This non-contact, nondestructive, easy-to-use technique has the potential for evaluating the coating quality immediately after its application so that any defects can be corrected immediately.

  9. 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.

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

    SciTech Connect

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

    2015-05-07

    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.

  11. Debating Curricular Strategies for Teaching Statistics and Research Methods: What Does the Current Evidence Suggest?

    ERIC Educational Resources Information Center

    Barron, Kenneth E.; Apple, Kevin J.

    2014-01-01

    Coursework in statistics and research methods is a core requirement in most undergraduate psychology programs. However, is there an optimal way to structure and sequence methodology courses to facilitate student learning? For example, should statistics be required before research methods, should research methods be required before statistics, or…

  12. SOME CURRENT TRENDS IN NUMERICAL METHODS FOR TRANSIENT ACOUSTIC AND ELASTIC WAVES IN MULTIDIMENSIONAL INHOMOGENEOUS MEDIA. (R825225)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. Subwog 12-D tritium technology meeting. Abstracts

    SciTech Connect

    Parker, M.J.; Addis, R.P.

    1991-12-31

    The first Subwog 12-D Tritium Technology Meeting was held at the Westinghouse Savannah River Site during the week of May 21, 1990. Subwog 12-D was created as a subwog of JOWOG 12 to address the need to understand tritium applications throughout the entire weapons complex. This includes weapons related concerns, but is primarily intended to cover tritium production and handling, environmental, safety and health issues, compatibility with materials in general; and facility design, commissioning and decommissioning activities. Tritium technology issues discussed included the physical and chemical properties, kinetics, storage, reservoir loading techniques, isotope exchange, radiolysis/aging, process and handling technology, compatibility, purification and filtering, analysis, monitoring methods, function testing, packaging and shipping, environmental and operational safety, facility design and safety, glovebox atmosphere clean-up systems, glovebox/facility decommissioning, tritium production target materials, and tritium recovery. This document provides a collection of most of the unclassified extended abstracts and abstracts presented at Subwog 12-D.

  14. Estimation of critical current density and grain connectivity in superconducting MgB 2 bulk using Campbell’s method

    NASA Astrophysics Data System (ADS)

    Ni, B.; Morita, Y.; Liu, Z.; Liu, C.; Himeki, K.; Otabe, E. S.; Kiuchi, M.; Matsushita, T.

    2008-09-01

    Many recent reports on the critical current density ( Jc) in superconducting MgB 2 bulks indicated that improving the grain connectivity is important, since the obtained Jc values were generally much lower than those in other metallic superconductors and it was ascribed to the poor connectivity between grains in polycrystalline MgB 2. In this study, we focused on the estimation of the global critical current density, super-current path, grain connectivity and their relationships with the faults volume fraction in the MgB 2 bulks prepared by a modified PIT (powder in tube) method. Campbell’s method was applied for the purpose of obtaining the penetrating AC flux profile and the characteristic of AC magnetic field vs. penetration depth from the sample’s surface. A computer simulation on the penetrating AC flux profile in MgB 2 bulks with randomly distributed voids, oxidized grains and other faults was also carried out. Jc obtained by Campbell’s method turned out to be smaller than that obtained from the SQUID measurement, implying that the global super-current was reduced by the existence of various faults and the lack of the electrical connectivity. It was verified that the relationship between the global critical current characteristics and the faults contained in MgB 2 samples can be quantitatively clarified by comparing the simulated critical current densities and other factors with the experimental results.

  15. Operating System Abstraction Layer (OSAL)

    NASA Technical Reports Server (NTRS)

    Yanchik, Nicholas J.

    2007-01-01

    This viewgraph presentation reviews the concept of the Operating System Abstraction Layer (OSAL) and its benefits. The OSAL is A small layer of software that allows programs to run on many different operating systems and hardware platforms It runs independent of the underlying OS & hardware and it is self-contained. The benefits of OSAL are that it removes dependencies from any one operating system, promotes portable, reusable flight software. It allows for Core Flight software (FSW) to be built for multiple processors and operating systems. The presentation discusses the functionality, the various OSAL releases, and describes the specifications.

  16. Universal "Imaginary Closed Circuit Method" and Formula for Determination of Direction of Induced EMF/Current

    ERIC Educational Resources Information Center

    Atram, Dattatraya Balaram

    2011-01-01

    Fleming's right-hand rule and the right-flat-hand rule are generally applied for determining the direction of flow of induced emf/current in straight conductors. The right-hand-fingers rule is applied for coils only. The right-hand-thumb rule can be applied for either straight conductors or coils. Different rules have to be applied for different…

  17. Assessing Food Preferences in Dogs and Cats: A Review of the Current Methods

    PubMed Central

    Tobie, Christelle; Péron, Franck; Larose, Claire

    2015-01-01

    Simple Summary The objective of this review is to present the different approaches and techniques used to assess petfood palatability, either with expert panels or naïve individuals (in-home panels). Abstract Food is a major aspect of pet care; therefore, ensuring that pet foods are not only healthful but attractive to companion animals and their owners is essential. The petfood market remains active and requires ongoing evaluation of the adaptation and efficiency of the new products. Palatability—foods’ characteristics enticing animals and leading them to consumption—is therefore a key element to look at. Based on the type of information needed, different pet populations (expert or naïve) can be tested to access their preference and acceptance for different food products. Classical techniques are the one-bowl and two-bowl tests, but complementary (i.e., operant conditioning) and novel (i.e., exploratory behavior) approaches are available to gather more information on the evaluation of petfood palatability. PMID:26479142

  18. An efficient 3-D eddy-current solver using an independent impedance method for transcranial magnetic stimulation.

    PubMed

    De Geeter, Nele; Crevecoeur, Guillaume; Dupre, Luc

    2011-02-01

    In many important bioelectromagnetic problem settings, eddy-current simulations are required. Examples are the reduction of eddy-current artifacts in magnetic resonance imaging and techniques, whereby the eddy currents interact with the biological system, like the alteration of the neurophysiology due to transcranial magnetic stimulation (TMS). TMS has become an important tool for the diagnosis and treatment of neurological diseases and psychiatric disorders. A widely applied method for simulating the eddy currents is the impedance method (IM). However, this method has to contend with an ill conditioned problem and consequently a long convergence time. When dealing with optimal design problems and sensitivity control, the convergence rate becomes even more crucial since the eddy-current solver needs to be evaluated in an iterative loop. Therefore, we introduce an independent IM (IIM), which improves the conditionality and speeds up the numerical convergence. This paper shows how IIM is based on IM and what are the advantages. Moreover, the method is applied to the efficient simulation of TMS. The proposed IIM achieves superior convergence properties with high time efficiency, compared to the traditional IM and is therefore a useful tool for accurate and fast TMS simulations.

  19. Abstraction of Seepage into Drifts

    SciTech Connect

    M.L. Wilson; C.K. Ho

    2000-09-26

    A total-system performance assessment (TSPA) for a potential nuclear-waste repository requires an estimate of the amount of water that might contact waste. This paper describes the model used for part of that estimation in a recent TSPA for the Yucca Mountain site. The discussion is limited to estimation of how much water might enter emplacement drifts; additional considerations related to flow within the drifts, and how much water might actually contact waste, are not addressed here. The unsaturated zone at Yucca Mountain is being considered for the potential repository, and a drift opening in unsaturated rock tends to act as a capillary barrier and divert much of the percolating water around it. For TSPA, the important questions regarding seepage are how many waste packages might be subjected to water flow and how much flow those packages might see. Because of heterogeneity of the rock and uncertainty about the future (how the climate will evolve, etc.), it is not possible to predict seepage amounts or locations with certainty. Thus, seepage is treated as a stochastic quantity in TSPA simulations, with the magnitude and spatial distribution of seepage sampled from uncertainty distributions. The distillation of the essential components of process modeling into a form suitable for use in TSPA simulations is referred to as abstraction. In the following sections, seepage process models and abstractions will be summarized and then some illustrative results are presented.

  20. Abstract art by shape classification.

    PubMed

    Song, Yi-Zhe; Pickup, David; Li, Chuan; Rosin, Paul; Hall, Peter

    2013-08-01

    This paper shows that classifying shapes is a tool useful in nonphotorealistic rendering (NPR) from photographs. Our classifier inputs regions from an image segmentation hierarchy and outputs the "best" fitting simple shape such as a circle, square, or triangle. Other approaches to NPR have recognized the benefits of segmentation, but none have classified the shape of segments. By doing so, we can create artwork of a more abstract nature, emulating the style of modern artists such as Matisse and other artists who favored shape simplification in their artwork. The classifier chooses the shape that "best" represents the region. Since the classifier is trained by a user, the "best shape" has a subjective quality that can over-ride measurements such as minimum error and more importantly captures user preferences. Once trained, the system is fully automatic, although simple user interaction is also possible to allow for differences in individual tastes. A gallery of results shows how this classifier contributes to NPR from images by producing abstract artwork.

  1. Current Physical and SDS Extraction Methods Do Not Efficiently Remove Exosporium Proteins from Bacillus anthracis spores

    PubMed Central

    Thompson, Brian M.; Binkley, Jana M.; Stewart, George C.

    2011-01-01

    Biochemical studies of the outermost spore layers of the Bacillus cereus family are hindered by difficulties in efficient dispersal of the external spore layers and difficulties in dissociating protein complexes that comprise the exosporium layer. Detergent and physical methods have been utilized to disrupt the exosporium layer. Herein we compare commonly used SDS extraction buffers used to extract spore proteins and demonstrate the incomplete extractability of the exosporium layer by these methods. Sonication and bead beating methods for exosporium layer removal were also examined. A combination of genetic and physical methods is the most effective for isolating proteins found in the spore exosporium. PMID:21338631

  2. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    PubMed Central

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

  3. New methods for high current fast ion beam production by laser-driven acceleration.

    PubMed

    Margarone, D; Krasa, J; Prokupek, J; Velyhan, A; Torrisi, L; Picciotto, A; Giuffrida, L; Gammino, S; Cirrone, P; Cutroneo, M; Romano, F; Serra, E; Mangione, A; Rosinski, M; Parys, P; Ryc, L; Limpouch, J; Laska, L; Jungwirth, K; Ullschmied, J; Mocek, T; Korn, G; Rus, B

    2012-02-01

    An overview of the last experimental campaigns on laser-driven ion acceleration performed at the PALS facility in Prague is given. Both the 2 TW, sub-nanosecond iodine laser system and the 20 TW, femtosecond Ti:sapphire laser, recently installed at PALS, are used along our experiments performed in the intensity range 10(16)-10(19) W∕cm(2). The main goal of our studies was to generate high energy, high current ion streams at relatively low laser intensities. The discussed experimental investigations show promising results in terms of maximum ion energy and current density, which make the laser-accelerated ion beams a candidate for new-generation ion sources to be employed in medicine, nuclear physics, matter physics, and industry.

  4. Method and apparatus for Delta Kappa synthetic aperture radar measurement of ocean current

    NASA Technical Reports Server (NTRS)

    Jain, A. (Inventor)

    1985-01-01

    A synthetic aperture radar (SAR) employed for delta k measurement of ocean current from a spacecraft without the need for a narrow beam and long observation times. The SAR signal is compressed to provide image data for different sections of the chirp band width, equivalent to frequencies and a common area for the separate image fields is selected. The image for the selected area at each frequency is deconvolved to obtain the image signals for the different frequencies and the same area. A product of pairs of signals is formed, Fourier transformed and squared. The spectrum thus obtained from different areas for the same pair of frequencies are added to provide an improved signal to noise ratio. The shift of the peak from the center of the spectrum is measured and compared to the expected shift due to the phase velocity of the Bragg scattering wave. Any difference is a measure of current velocity v sub o (delta k).

  5. Validation of the geostrophic method for estimating zonal currents at the equator from Geosat altimeter data

    NASA Technical Reports Server (NTRS)

    Picaut, Joel; Camusat, Bruno; Busalacchi, Antonio J.; Mcphaden, Michael J.

    1990-01-01

    The applicability of satellite altimeter data for estimating zonal current variability at the equator is assessed using the meriodionally differenced form of the geostrophic balance. Estimates of geostrophic zonal flow anomalies in the equatorial Pacific have been deduced from 17-day collinear altimeter data during the first year of the Geosat Exact Repeat Mission. Altimeter-derived geostrophic estimates agree well with in situ zonal current variability. Comparison of flow-frequency near-surface zonal current observed from equatorial moorings at 165 deg E, 140 deg W, and 110 deg W yield correlations of 0.83, 0.85, and 0.51, respectively, with a mean rms difference of 23 cm/sec. The inclusion of up to 11 ascending and descending Geosat tracks within the 9-deg band for every 17-day repeat effectively reduced the temporal sampling interval to 1.5 days at 165 deg E and 140 deg W. The 6.8-km along track spacing of the altimeter measurements provides sufficient resolution for the effective filtering of small-scale meridional noise, both instrumental and oceanic.

  6. Flux-focusing eddy current probe and rotating probe method for flaw detection

    NASA Astrophysics Data System (ADS)

    Wincheski, Buzz A.; Fulton, James P.; Nath, Shridhar C.; Simpson, John W.; Namkung, Min

    1994-11-01

    A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks about circular fasteners and other circular inhomogeneities in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil. The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. By rotating the probe in a path around a circular fastener such as a rivet while maintaining a constant distance between the probe and the center of a rivet, the signal due to current flow about the rivet can be held constant. Any further changes in the current distribution, such as due to a fatigue crack at the rivet joint, can be detected as an increase in the output voltage above that due to the flow about the rivet head.

  7. An overview of recent developments and current status of gluten ELISA methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ELISA methods for detecting and quantitating allergens have been around for some time and they are continuously improved. In this context, the development of gluten methods is no exception. Around the turn of the millennium, doubts were raised whether the existing “Skerritt-ELISA” would meet the 20 ...

  8. 75 FR 49930 - Stakeholder Meeting Regarding Re-Evaluation of Currently Approved Total Coliform Analytical Methods

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ... Protection Agency (EPA or Agency) is hosting three public Web conferences during which the Agency will have a... use in evaluation of method performance, setting method performance acceptance criteria, and/or... Register on July 14, 2010. DATES: The first public Web conference will be held on Wednesday, September...

  9. Obtaining source current density related to irregularly structured electromagnetic target field inside human body using hybrid inverse/FDTD method.

    PubMed

    Han, Jijun; Yang, Deqiang; Sun, Houjun; Xin, Sherman Xuegang

    2017-01-01

    Inverse method is inherently suitable for calculating the distribution of source current density related with an irregularly structured electromagnetic target field. However, the present form of inverse method cannot calculate complex field-tissue interactions. A novel hybrid inverse/finite-difference time domain (FDTD) method that can calculate the complex field-tissue interactions for the inverse design of source current density related with an irregularly structured electromagnetic target field is proposed. A Huygens' equivalent surface is established as a bridge to combine the inverse and FDTD method. Distribution of the radiofrequency (RF) magnetic field on the Huygens' equivalent surface is obtained using the FDTD method by considering the complex field-tissue interactions within the human body model. The obtained magnetic field distributed on the Huygens' equivalent surface is regarded as the next target. The current density on the designated source surface is derived using the inverse method. The homogeneity of target magnetic field and specific energy absorption rate are calculated to verify the proposed method.

  10. Method of estimating mechanical stress on Si body of MOSFET using drain-body junction current

    NASA Astrophysics Data System (ADS)

    Seo, Ji-Hoon; Kim, Gang-Jun; Son, Donghee; Lee, Nam-Hyun; Kang, Bongkoo

    2017-01-01

    A simple and accurate method of estimating the mechanical stress σ on the Si body of a MOSFET is proposed. This method measures the doping concentration of the body, N d, and the onset voltage V hl for the high-level injection of the drain-body junction, uses N d, the ideality factor η, and the Fermi potential ϕf ≈ V hl/2η to calculate the intrinsic carrier concentration n i of the Si body, and then uses the calculated n i to obtain the bandgap energy E g of the Si body. σ is estimated from E g using the deformation potential theory. The estimates of σ agree well with those obtained using previous methods. The proposed method requires one MOSFET, whereas the others require at least two MOSFETs, so the proposed method can give an absolute measurement of σ on the Si body of a MOSFET.

  11. Knowledge Base Refinement by Monitoring Abstract Control Knowledge.

    ERIC Educational Resources Information Center

    Wilkins, D. C.; And Others

    Arguing that an explicit representation of the problem-solving method of an expert system shell as abstract control knowledge provides a powerful foundation for learning, this paper describes the abstract control knowledge of the Heracles expert system shell for heuristic classification problems, and describes how the Odysseus apprenticeship…

  12. 2013 SYR Accepted Poster Abstracts.

    PubMed

    2013-01-01

    SYR 2013 Accepted Poster abstracts: 1. Benefits of Yoga as a Wellness Practice in a Veterans Affairs (VA) Health Care Setting: If You Build It, Will They Come? 2. Yoga-based Psychotherapy Group With Urban Youth Exposed to Trauma. 3. Embodied Health: The Effects of a Mind�Body Course for Medical Students. 4. Interoceptive Awareness and Vegetable Intake After a Yoga and Stress Management Intervention. 5. Yoga Reduces Performance Anxiety in Adolescent Musicians. 6. Designing and Implementing a Therapeutic Yoga Program for Older Women With Knee Osteoarthritis. 7. Yoga and Life Skills Eating Disorder Prevention Among 5th Grade Females: A Controlled Trial. 8. A Randomized, Controlled Trial Comparing the Impact of Yoga and Physical Education on the Emotional and Behavioral Functioning of Middle School Children. 9. Feasibility of a Multisite, Community based Randomized Study of Yoga and Wellness Education for Women With Breast Cancer Undergoing Chemotherapy. 10. A Delphi Study for the Development of Protocol Guidelines for Yoga Interventions in Mental Health. 11. Impact Investigation of Breathwalk Daily Practice: Canada�India Collaborative Study. 12. Yoga Improves Distress, Fatigue, and Insomnia in Older Veteran Cancer Survivors: Results of a Pilot Study. 13. Assessment of Kundalini Mantra and Meditation as an Adjunctive Treatment With Mental Health Consumers. 14. Kundalini Yoga Therapy Versus Cognitive Behavior Therapy for Generalized Anxiety Disorder and Co-Occurring Mood Disorder. 15. Baseline Differences in Women Versus Men Initiating Yoga Programs to Aid Smoking Cessation: Quitting in Balance Versus QuitStrong. 16. Pranayam Practice: Impact on Focus and Everyday Life of Work and Relationships. 17. Participation in a Tailored Yoga Program is Associated With Improved Physical Health in Persons With Arthritis. 18. Effects of Yoga on Blood Pressure: Systematic Review and Meta-analysis. 19. A Quasi-experimental Trial of a Yoga based Intervention to Reduce Stress and

  13. Voltage—clamp analysis of the early current in frog skeletal muscle fibre using the double sucrose-gap method

    PubMed Central

    Ildefonse, Michèle; Rougier, Oger

    1972-01-01

    1. The early membrane currents in skeletal muscle fibres have been studied with the double sucrose-gap method, according to the experimental procedure used for the study of the giant axon of the squid. 2. The earliest observable current is a capacitative transient. An equivalent circuit with two capacity-resistance systems can account for such a current. The components of the electrical circuit are estimated from the records. 3. The capacitative transient current is followed by an initial current, the time and voltage dependence of which are analogous to those of nerve fibres. During this phase of current, the membrane behaves like a sodium electrode for modifications of the external sodium concentration. 4. Using tetrodotoxin, a specific inhibitor of the sodium permeability, it is possible to separate two current components, (i) a transient component, suppressed by tetrodotoxin, which reflects the modifications, with time and voltage, of the membrane permeability towards sodium ions; the larger the depolarization, the shorter the time to reach peak current. This current is inward for depolarizations (V) of about +30 mV to about +130 mV (VNa). There was some variation in these values between individual fibres. Beyond VNa, the current is outward. This current shows a small rectification — inward going — for high depolarizations which is comparable to the behaviour of the Ranvier node membrane. (ii) A quasi-instantaneous outward component, only voltage dependent. The current—voltage relation of this current shows an outward going rectification for high depolarizations. This current can be considered as a `leak' current, in which chloride ions could play an important role. 5. A sodium tail current is observed when the imposed potential fall occurs during the time course of the initial current. It corresponds to the deactivation of the sodium current previously activated. Because of the large contemporary capacitative currents, it is difficult to measure

  14. Inflight Microbial Monitoring - An Alternative Method to Culture Based Detection Currently Used on the International Space Station

    NASA Technical Reports Server (NTRS)

    Khodadad, Christina L.; Birmele, Michele N.; Hummerick, Mary E.; Roman, Monsi; Smith, David J.

    2015-01-01

    Microorganisms including potential human pathogens have been detected on the International Space Station (ISS). The potential to introduce new microorganisms occurs with every exchange of crew or addition of equipment or supplies. Current microbial monitoring methods require enrichment of microorganisms and a 48-hour incubation time resulting in an increase in microbial load, detecting a limited number of unidentified microorganisms. An expedient, low-cost, in-flight method of microbial detection, identification, and enumeration is warranted.

  15. mHealth Research: Current Methods, Alternative Approaches, and Issues for Discussion | Smokefree.gov

    Cancer.gov

    On December 3, 2015, the National Cancer Institute convened a group of 18 behavioral scientists for a day-long meeting to discuss scientific methods for evaluating technology-mediated behavior change interventions, with an emphasis on mobile smoking cessation interventions. This post contains excerpts from a document provided to participants in advance of the December 3 meeting. The document was used to set context for discussion by providing a high-level overview of the methods most commonly used in published

  16. Thermal Control Method for High-Current Wire Bundles by Injecting a Thermally Conductive Filler

    NASA Technical Reports Server (NTRS)

    Rodriguez-Ruiz, Juan; Rowles, Russell; Greer, Greg

    2011-01-01

    A procedure was developed to inject thermal filler material (a paste-like substance) inside the power wire bundle coming from solar arrays. This substance fills in voids between wires, which enhances the heat path and reduces wire temperature. This leads to a reduced amount of heat generated. This technique is especially helpful for current and future generation high-power spacecraft (1 kW or more), because the heat generated by the power wires is significant enough to cause unacceptable overheating to critical components that are in close contact with the bundle.

  17. Non-Destructive Inspection and Volume Fraction Determination of CFRP Using an Eddy Current Method

    DTIC Science & Technology

    1976-06-01

    thickness 9 4.3 Edge effect 11 4.4 Response to volume fraction 12 5 RESULTS FROM DIRECTIONAL PROBE 13 6 DISCUSSION 14 7 CONCLUSIONS 15 Acknowledgment...use of one unique probe. 4.3 Edge effect It has been demonstrated in section 4.1 that the important part of the eddy current path covers an area 7.5mm...in diameter on cross ply and 15 x 7.5mm on unidirectional CFRP. As might be expected, this results in an edge effect which arises when part of the

  18. Method of preparing electrodes with porous current collector structures and solid reactants for secondary electrochemical cells

    DOEpatents

    Gay, Eddie C.; Martino, Fredric J.

    1976-01-01

    Particulate electrode reactants, for instance transition metal sulfides for the positive electrodes and lithium alloys for the negative electrodes, are vibratorily compacted into porous, electrically conductive structures. Structures of high porosity support sufficient reactant material to provide high cell capacity per unit weight while serving as an electrical current collector to improve the utilization of reactant materials. Pore sizes of the structure and particle sizes of the reactant material are selected to permit uniform vibratory loading of the substrate without settling of the reactant material during cycling.

  19. [Means and methods of acoustic protection in aviation: current status and outlook for development].

    PubMed

    Soldatov, S K; Bogomolov, A V; Zinkin, V N; Aver'ianov, A A; Rossel's, A V; Patskin, G A; Sokolov, B A

    2011-01-01

    Analysis of the current status of acoustic protection in aviation shows that despite the material progress in the field, risk of professional pathologies in flying and technical personnel is still high. The situation is dramatized by the lack of effective personal and crew acoustic protectors. The authors speculate on applicability of innovative materials and technologies, ingenious designs of earphones and modular prefabricated demountable structures. Tests of proposed personal protectors demonstrated their competitiveness with foreign analogs. Prospective lines of development, e.g. incorporation of active sound absorption systems in existing passive protectors are discussed.

  20. Current methods of the analysis of immunosuppressive agents in clinical materials: A review.

    PubMed

    Mika, Adriana; Stepnowski, Piotr

    2016-08-05

    More than 100000 solid organ transplantations are performed every year worldwide. Calcineurin (cyclosporine A, tacrolimus), serine/threonine kinase (sirolimus, everolimus) and inosine monophosphate dehydrogenase inhibitor (mycophenolate mofetil), are the most common drugs used as immunosuppressive agents after solid organ transplantation. Immunosuppressive therapy, although necessary after transplantation, is associated with many adverse consequences, including the formation of secondary metabolites of drugs and the induction of their side effects. Calcineurin inhibitors are associated with nephrotoxicity, cardiotoxicity and neurotoxicity; moreover, they increase the risk of many diseases after transplantation. The review presents a study of the movement of drugs in the body, including the processes of absorption, distribution, localisation in tissues, biotransformation and excretion, and also their accompanying side effects. Therefore, there is a necessity to monitor immunosuppressants, especially because these drugs are characterised by narrow therapeutic ranges. Their incorrect concentrations in a patient's blood could result in transplant rejection or in the accumulation of toxic effects. Immunosuppressive pharmaceuticals are macrolide lactones, peptides, and high molecular weight molecules that can be metabolised to several metabolites. Therefore the two main analytical methods used for their determination are high performance liquid chromatography with various detection methods and immunoassay methods. Despite the rapid development of new analytical methods of analysing immunosuppressive agents, the application of the latest generation of detectors and increasing sensitivity of such methods, there is still a great demand for the development of highly selective, sensitive, specific, rapid and relatively simple methods of immunosuppressive drugs analysis.

  1. Detection of cold cracks in the cast-steels by the methods of ultrasonic and eddy-current infrared thermography

    NASA Astrophysics Data System (ADS)

    Cheprasov, A. I.; Knyazev, S. V.; Usoltsev, A. A.; Dolgopolov, A. E.; Mamedov, R. O.

    2016-09-01

    The aim of this study was to investigate the possibility of detection of cold cracks in the massive steel products using ultrasonic and eddy-current excitation, as well as the thermal imaging method of temperature recording, that in the perspective should be completed by the development of requirements for the monitoring equipment.

  2. Teaching Intercultural Communication in a Basic Technical Writing Course: A Survey of Our Current Practices and Methods

    ERIC Educational Resources Information Center

    Matveeva, Natalia

    2008-01-01

    This research article reports the results of an online survey distributed among technical writing instructors in 2006. The survey aimed to examine how we teach intercultural communication in basic technical writing courses: our current practices and methods. The article discusses three major challenges that instructors may face when teaching about…

  3. A review of current methods using bacteriophages in live animals, food and animal products intended for human consumption.

    PubMed

    Cooper, Ian R

    2016-11-01

    Bacteriophages are utilised in the food industry as biocontrol agents to reduce the load of bacteria, and thus reduce potential for human infection. This review focuses on current methods using bacteriophages within the food chain. Limitations of research will be discussed, and the potential for future food-based bacteriophage research.

  4. Nondestructive Testing Eddy Current Equipment, Methods and Applications RQA/M1-5330.12 (V-II).

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    As one in the series of programmed instruction handbooks, prepared by the U. S. space program, home study material is presented in this volume concerning familiarization and orientation on eddy current testing. The subject is presented under the following headings: Test Coils, Methods and Indications, and Applications. High product quality and…

  5. Model-based probe state estimation and crack inverse methods addressing eddy current probe variability

    NASA Astrophysics Data System (ADS)

    Aldrin, John C.; Oneida, Erin K.; Shell, Eric B.; Sabbagh, Harold A.; Sabbagh, Elias; Murphy, R. Kim; Mazdiyasni, Siamack; Lindgren, Eric A.; Mooers, Ryan D.

    2017-02-01

    A model-based calibration process is introduced that estimates the state of the eddy current probe. First, a carefully designed surrogate model was built using VIC-3D® simulations covering the critical range of probe rotation angles, tilt in two directions, and probe offset (liftoff) for both transverse and longitudinal flaw orientations. Some approximations and numerical compromises in the model were made to represent tilt in two directions and reduce simulation time; however, this surrogate model was found to represent the key trends in the eddy current response for each of the four probe properties in experimental verification studies well. Next, this model was incorporated into an iterative inversion scheme during the calibration process, to estimate the probe state while also addressing the amplitude/phase fit and centering the calibration notch indication. Results are presented showing several examples of the blind estimation of tilt and rotation angle for known experimental cases with reasonable agreement. Once the probe state is estimated, the final step is to transform the base crack inversion surrogate model and apply it for crack characterization. Using this process, results are presented demonstrating improved crack inversion performance for extreme probe states.

  6. System and method for generating steady state confining current for a toroidal plasma fusion reactor

    DOEpatents

    Bers, Abraham

    1981-01-01

    A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave RF energy is injected into said plasma to estalish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected RF energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected RF energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range .DELTA.. The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width .DELTA. in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated inthe plasma.

  7. System and method for generating steady state confining current for a toroidal plasma fusion reactor

    DOEpatents

    Fisch, Nathaniel J.

    1981-01-01

    A system for generating steady state confining current for a toroidal plasma fusion reactor providing steady-state generation of the thermonuclear power. A dense, hot toroidal plasma is initially prepared with a confining magnetic field with toroidal and poloidal components. Continuous wave RF energy is injected into said plasma to establish a spectrum of traveling waves in the plasma, where the traveling waves have momentum components substantially either all parallel, or all anti-parallel to the confining magnetic field. The injected RF energy is phased to couple to said traveling waves with both a phase velocity component and a wave momentum component in the direction of the plasma traveling wave components. The injected RF energy has a predetermined spectrum selected so that said traveling waves couple to plasma electrons having velocities in a predetermined range .DELTA.. The velocities in the range are substantially greater than the thermal electron velocity of the plasma. In addition, the range is sufficiently broad to produce a raised plateau having width .DELTA. in the plasma electron velocity distribution so that the plateau electrons provide steady-state current to generate a poloidal magnetic field component sufficient for confining the plasma. In steady state operation of the fusion reactor, the fusion power density in the plasma exceeds the power dissipated in the plasma.

  8. Determination of vitamin C in foods: current state of method validation.

    PubMed

    Spínola, Vítor; Llorent-Martínez, Eulogio J; Castilho, Paula C

    2014-11-21

    Vitamin C is one of the most important vitamins, so reliable information about its content in foodstuffs is a concern to both consumers and quality control agencies. However, the heterogeneity of food matrixes and the potential degradation of this vitamin during its analysis create enormous challenges. This review addresses the development and validation of high-performance liquid chromatography methods for vitamin C analysis in food commodities, during the period 2000-2014. The main characteristics of vitamin C are mentioned, along with the strategies adopted by most authors during sample preparation (freezing and acidification) to avoid vitamin oxidation. After that, the advantages and handicaps of different analytical methods are discussed. Finally, the main aspects concerning method validation for vitamin C analysis are critically discussed. Parameters such as selectivity, linearity, limit of quantification, and accuracy were studied by most authors. Recovery experiments during accuracy evaluation were in general satisfactory, with usual values between 81 and 109%. However, few methods considered vitamin C stability during the analytical process, and the study of the precision was not always clear or complete. Potential future improvements regarding proper method validation are indicated to conclude this review.

  9. Gene and genetic diagnostic method patent claims: a comparison under current European and US patent law.

    PubMed

    Huys, Isabelle; Van Overwalle, Geertrui; Matthijs, Gert

    2011-10-01

    The paper focuses on the fundamental debate that is going on in Europe and the United States about whether genes and genetic diagnostic methods are to be regarded as inventions or subject matter eligible for patent protection, or whether they are discoveries or principles of nature and thus excluded from patentability. The study further explores some possible scenarios of American influences on European patent applications with respect to genetic diagnostic methods. Our analysis points out that patent eligibility for genes and genetic diagnostic methods, as discussed in the United States in the Association of Molecular Pathology versus US Patent and Trademark Office decision, is based on a different reasoning compared with the European Patent Convention.

  10. [Current cooling methods for induction of mild hypothermia in cardiac arrest survivors].

    PubMed

    Skulec, R; Truhlár, A; Ostádal, P; Telekes, P; Knor, J; Tichácek, M; Cerný, V; Seblová, J

    2009-11-01

    Induction of mild therapeutic hypothermia early after return of spontaneous circulation improves prognosis of cardiac arrest survivors. Rapid cooling of the patients and correct maintainance of the target therapeutic temperature followed by controlled slow rewarming can be achieved by several noninvasive and invasive methods of various efficacy. Elementary and the most frequently used methods are surface cooling via ice-packs and rapid intravenous administration of cold crystaloids. Mattress cooling systems and facilities for endovascular cathether-cooling are more sophisticated, manageable and ensure more precise titration of therapeutic temperature. Cooling caps and helmets leading to selective head cooling can be used as the complementary techniques. Several other methods are too instrumentation-intensive, too invasive or investigated in animal experiments only. Anyway, near future may bring a rapid development of new effective and safe cooling systems.

  11. A Suitable Coordinate Transformation Method for Correcting Voltage Vector in Motor Current Detection Using a Single Shunt Resistor

    NASA Astrophysics Data System (ADS)

    Tomigashi, Yoshio; Hida, Hajime; Ueyama, Kenji

    To reduce costs of inverters, a current detection method using a single shunt resistor is required for motor drive systems in home electrical appliances. In this paper, a method is proposed to correct a voltage reference vector by converting coordinates from a rotating reference frame into a fixed reference frame. Also proposed is a new coordinate transformation method that is appropriate for the correction. Authors focused on the undetectable area that exists every 60 degrees in α-β coordinates. When the α-β coordinates in an nπ/3 rotation are defined as αn-βn, the αn-axis can be defined as the central axis in an undetectable area. We propose a coordinate transformation method that converts the voltage vector in the d-q coordinates into uvw phase voltages through αn-βn coordinates then correct it. This method corrects the voltage vector by a very simple algorithm that limits the αn-βn elements. The effectiveness of the proposed method is confirmed by simulation and experiment. Currents were clearly detected by using the proposed method. This shows that the proposed method is suitable for position sensor-less drives in permanent magnet synchronous motors.

  12. Concrete Model Checking with Abstract Matching and Refinement

    NASA Technical Reports Server (NTRS)

    Pasareanu Corina S.; Peianek Radek; Visser, Willem

    2005-01-01

    We propose an abstraction-based model checking method which relies on refinement of an under-approximation of the feasible behaviors of the system under analysis. The method preserves errors to safety properties, since all analyzed behaviors are feasible by definition. The method does not require an abstract transition relation to he generated, but instead executes the concrete transitions while storing abstract versions of the concrete states, as specified by a set of abstraction predicates. For each explored transition. the method checks, with the help of a theorem prover, whether there is any loss of precision introduced by abstraction. The results of these checks are used to decide termination or to refine the abstraction, by generating new abstraction predicates. If the (possibly infinite) concrete system under analysis has a finite bisimulation quotient, then the method is guaranteed to eventually explore an equivalent finite bisimilar structure. We illustrate the application of the approach for checking concurrent programs. We also show how a lightweight variant can be used for efficient software testing.

  13. Left ventricular function assessment in cirrhosis: Current methods and future directions.

    PubMed

    Sampaio, Francisco; Pimenta, Joana

    2016-01-07

    Cirrhotic cardiomyopathy has been defined as a chronic cardiac dysfunction in patients with cirrhosis characterized by impaired contractile responsiveness to stress and/or altered diastolic relaxation with electrophysiological abnormalities in the absence of other known cardiac disease. Non-invasive cardiovascular imaging modalities play a major role in unmasking systolic and diastolic dysfunction in patients with cirrhosis. Echocardiography has been the most commonly used modality for assessing myocardial function in these patients. Conventional echocardiographic indices rely on several assumptions that may limit their applicability in patients with a hyperdynamic circulation. Newer imaging modalities may contribute to a more accurate diagnosis of cardiovascular abnormalities in cirrhotic patients, thereby influencing clinical management. We aimed to review the different non-invasive imaging technologies currently used for assessing left ventricular systolic and diastolic function in cirrhosis, as well as to describe new imaging modalities with potential clinical applicability in the near future.

  14. Frontal transcranial direct current stimulation (tDCS) abolishes list-method directed forgetting.

    PubMed

    Silas, Jonathan; Brandt, Karen R

    2016-03-11

    It is a point of controversy as to whether directed forgetting effects are a result of active inhibition or a change of context initiated by the instruction to forget. In this study we test the causal role of active inhibition in directed forgetting. By applying cathodal transcranial direct current stimulation (tDCS) over the right prefrontal cortex we suppressed cortical activity commonly associated with inhibitory control. Participants who underwent real brain stimulation before completing the directed forgetting paradigm showed no directed forgetting effects. Conversely, those who underwent sham brain stimulation demonstrated classical directed forgetting effects. We argue that these findings suggest that inhibition is the primary mechanism that results in directed forgetting costs and benefits.

  15. [Evaluation of disease management programs--current deficits, demands and methods].

    PubMed

    Gerlach, Ferdinand M; Beyer, Martin; Szecsenyi, Joachim; Raspe, Heiner

    2003-10-01

    The evaluation of disease management programmes is necessary and has been made obligatory in Germany by the Fifth Book of Social Code. So far there has been extensive ambiguity as regards the precise definition of suitable strategies for the evaluation. Considering the scientific evaluation of the diabetes contract in North-Rhine current deficits of the evaluation of already existing programmes for chronically ill patients are exemplarily described. On the basis of international experience reasonable demands are discussed that ought to be accomplished when evaluating the effectiveness and benefit of the programmes. Taking the British Medical Research Council as an example, a four-step model will be suggested as a loophole in the methodological dilemma of varying suitable study designs, which allows for the adequate evaluation of even complex interventions.

  16. Electrochemical sensor having suspended element counter electrode and deflection method for current sensing

    DOEpatents

    Thundat, Thomas G.; Brown, Gilbert M.

    2010-05-18

    An electrochemical suspended element-based sensor system includes a solution cell for holding an electrolyte comprising solution including at least one electrochemically reducible or oxidizable species. A working electrode (WE), reference electrode (RE) and a counter electrode (CE) are disposed in the solution. The CE includes an asymmetric suspended element, wherein one side of the suspended element includes a metal or a highly doped semiconductor surface. The suspended element bends when current associated with reduction or oxidation of the electrochemically reducible or oxidizable species at the WE passes through the suspended element. At least one measurement system measures the bending of the suspended element or a parameter which is a function of the bending.

  17. Method for transferring thermal energy and electrical current in thin-film electrochemical cells

    DOEpatents

    Rouillard, Roger; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Ranger, Michel; Sudano, Anthony; Trice, Jennifer L.; Turgeon, Thomas A.

    2003-05-27

    An improved electrochemical generator is disclosed. The electrochemical generator includes a thin-film electrochemical cell which is maintained in a state of compression through use of an internal or an external pressure apparatus. A thermal conductor, which is connected to at least one of the positive or negative contacts of the cell, conducts current into and out of the cell and also conducts thermal energy between the cell and thermally conductive, electrically resistive material disposed on a vessel wall adjacent the conductor. The thermally conductive, electrically resistive material may include an anodized coating or a thin sheet of a plastic, mineral-based material or conductive polymer material. The thermal conductor is fabricated to include a resilient portion which expands and contracts to maintain mechanical contact between the cell and the thermally conductive material in the presence of relative movement between the cell and the wall structure. The electrochemical generator may be disposed in a hermetically sealed housing.

  18. Gelatin Controversies in Food, Pharmaceuticals and Personal Care Products: Authentication Methods, Current Status and Future Challenges.

    PubMed

    Ali, Md Eaqub; Sultana, Sharmin; Hamid, Sharifah Bee Abd; Hossain, M A Motalib; Yehya, Wageeh A; Kader, Md Abdul; Bhargava, Suresh K

    2016-12-29

    Gelatin is a highly purified animal protein of pig, cow and fish origins and is extensively used in food, pharmaceuticals and personal care products. However, the acceptability of gelatin products greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid- and protein-based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review article has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication.

  19. Improving Low Order, Linear, Positive Spatial Quadratures for the Partial Current Neutron Transport Method

    DTIC Science & Technology

    2010-03-01

    an integro - differential equation that is not directly solvable except in the simplest cases; therefore it requires a numerical approximation...AFIT researchers have developed a new approach to solving Discrete Ordinates equations , which approximate the linear Boltzmann Transport Equation ...linear equation . Positive, linear methods are available, but are only first-order accurate. The latter can achieve needed accuracy by using optically

  20. VET Program Completion Rates: An Evaluation of the Current Method. Occasional Paper

    ERIC Educational Resources Information Center

    National Centre for Vocational Education Research (NCVER), 2016

    2016-01-01

    This work asks one simple question: "how reliable is the method used by the National Centre for Vocational Education Research (NCVER) to estimate projected rates of VET program completion?" In other words, how well do early projections align with actual completion rates some years later? Completion rates are simple to calculate with a…

  1. Intestinal Carriage of Carbapenemase-Producing Organisms: Current Status of Surveillance Methods.

    PubMed

    Viau, Roberto; Frank, Karen M; Jacobs, Michael R; Wilson, Brigid; Kaye, Keith; Donskey, Curtis J; Perez, Federico; Endimiani, Andrea; Bonomo, Robert A

    2016-01-01

    Carbapenemases have become a significant mechanism for broad-spectrum β-lactam resistance in Enterobacteriaceae and other Gram-negative bacteria such as Pseudomonas and Acinetobacter spp. Intestinal carriage of carbapenemase-producing organisms (CPOs) is an important source of transmission. Isolation of carriers is one strategy that can be used to limit the spread of these bacteria. In this review, we critically examine the clinical performance, advantages, and disadvantages of methods available for the detection of intestinal carriage of CPOs. Culture-based methods (Centers for Disease Control and Prevention [CDC] protocols, chromogenic media, specialized agars, and double-disk synergy tests) for detecting carriage of CPOs are convenient due to their ready availability and low cost, but their limited sensitivity and long turnaround time may not always be optimal for infection control practices. Contemporary nucleic acid amplification techniques (NAATs) such as real-time PCR, hybridization assays, loop-mediated isothermal amplification (LAMP), or a combined culture and NAAT approach may provide fast results and/or added sensitivity and specificity compared with culture-based methods. Infection control practitioners and clinical microbiologists should be aware of the strengths and limitations of available methods to determine the most suitable approach for their medical facility to fit their infection control needs.

  2. Intestinal Carriage of Carbapenemase-Producing Organisms: Current Status of Surveillance Methods

    PubMed Central

    Jacobs, Michael R.; Wilson, Brigid; Kaye, Keith; Donskey, Curtis J.; Perez, Federico

    2015-01-01

    SUMMARY Carbapenemases have become a significant mechanism for broad-spectrum β-lactam resistance in Enterobacteriaceae and other Gram-negative bacteria such as Pseudomonas and Acinetobacter spp. Intestinal carriage of carbapenemase-producing organisms (CPOs) is an important source of transmission. Isolation of carriers is one strategy that can be used to limit the spread of these bacteria. In this review, we critically examine the clinical performance, advantages, and disadvantages of methods available for the detection of intestinal carriage of CPOs. Culture-based methods (Centers for Disease Control and Prevention [CDC] protocols, chromogenic media, specialized agars, and double-disk synergy tests) for detecting carriage of CPOs are convenient due to their ready availability and low cost, but their limited sensitivity and long turnaround time may not always be optimal for infection control practices. Contemporary nucleic acid amplification techniques (NAATs) such as real-time PCR, hybridization assays, loop-mediated isothermal amplification (LAMP), or a combined culture and NAAT approach may provide fast results and/or added sensitivity and specificity compared with culture-based methods. Infection control practitioners and clinical microbiologists should be aware of the strengths and limitations of available methods to determine the most suitable approach for their medical facility to fit their infection control needs. PMID:26511484

  3. Electrochemical Method of Making Porous Particles Using a Constant Current Density

    NASA Technical Reports Server (NTRS)

    Ferrari, Mauro (Inventor); Liu, Xuewu (Inventor); Cheng, Ming-Cheng (Inventor)

    2014-01-01

    Provided is a particle that includes a first porous region and a second porous region that differs from the first porous region. Also provided is a particle that has a wet etched porous region and that does have a nucleation layer associated with wet etching. Methods of making porous particles are also provided.

  4. Cryopreservation of Human Mesenchymal Stem Cells for Clinical Applications: Current Methods and Challenges.

    PubMed

    Yong, Kar Wey; Wan Safwani, Wan Kamarul Zaman; Xu, Feng; Wan Abas, Wan Abu Bakar; Choi, Jane Ru; Pingguan-Murphy, Belinda

    2015-08-01

    Mesenchymal stem cells (MSCs) hold many advantages over embryonic stem cells (ESCs) and other somatic cells in clinical applications. MSCs are multipotent cells with strong immunosuppressive properties. They can be harvested from various locations in the human body (e.g., bone marrow and adipose tissues). Cryopreservation represents an efficient method for the preservation and pooling of MSCs, to obtain the cell counts required for clinical applications, such as cell-based therapies and regenerative medicine. Upon cryopreservation, it is important to preserve MSCs functional properties including immunomodulatory properties and multilineage differentiation ability. Further, a biosafety evaluation of cryopreserved MSCs is essential prior to their clinical applications. However, the existing cryopreservation methods for MSCs are associated with notable limitations, leading to a need for new or improved methods to be established for a more efficient application of cryopreserved MSCs in stem cell-based therapies. We review the important parameters for cryopreservation of MSCs and the existing cryopreservation methods for MSCs. Further, we also discuss the challenges to be addressed in order to preserve MSCs effectively for clinical applications.

  5. Current distribution in a three-dimensional IC analyzed by a perturbation method. Part 1: A simple steady state theory

    NASA Technical Reports Server (NTRS)

    Edmonds, Larry D.

    1987-01-01

    The steady state current distribution in a three dimensional integrated circuit is presented. A device physics approach, based on a perturbation method rather than an equivalent lumped circuit approach, is used. The perturbation method allows the various currents to be expressed in terms of elementary solutions which are solutions to very simple boundary value problems. A Simple Steady State Theory is the subtitle because the most obvious limitation of the present version of the analysis is that all depletion region boundary surfaces are treated as equipotential surfaces. This may be an adequate approximation in some applications but it is an obvious weakness in the theory when applied to latched states. Examples that illustrate the use of these analytical methods are not given because they will be presented in detail in the future.

  6. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    NASA Astrophysics Data System (ADS)

    Li, Yuting; Gan, Fangji; Wan, Zhengjun; Liao, Junbi; Li, Wenqiang

    2015-10-01

    Potential drop techniques are of two types: the direct current potential drop (DCPD) technique and alternating current potential drop (ACPD) technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

  7. Evaluation and comparison of current biopsy needle localization and tracking methods using 3D ultrasound.

    PubMed

    Zhao, Yue; Shen, Yi; Bernard, Adeline; Cachard, Christian; Liebgott, Hervé

    2017-01-01

    This article compares four different biopsy needle localization algorithms in both 3D and 4D situations to evaluate their accuracy and execution time. The localization algorithms were: Principle component analysis (PCA), random Hough transform (RHT), parallel integral projection (PIP) and ROI-RK (ROI based RANSAC and Kalman filter). To enhance the contrast of the biopsy needle and background tissue, a line filtering pre-processing step was implemented. To make the PCA, RHT and PIP algorithms comparable with the ROI-RK method, a region of interest (ROI) strategy was added. Simulated and ex-vivo data were used to evaluate the performance of the different biopsy needle localization algorithms. The resolutions of the sectorial and cylindrical volumes were 0.3mm×0.4mm×0.6mmand0.1mm×0.1mm×0.2mm (axial×lateral×azimuthal) respectively. In so far as the simulation and experimental results show, the ROI-RK method successfully located and tracked the biopsy needle in both 3D and 4D situations. The tip localization error was within 1.5mm and the axis accuracy was within 1.6mm. To the best of our knowledge, considering both localization accuracy and execution time, the ROI-RK was the most stable and time-saving method. Normally, accuracy comes at the expense of time. However, the ROI-RK method was able to locate the biopsy needle with high accuracy in real time, which makes it a promising method for clinical applications.

  8. Channel Current Analysis for Pore-forming Properties of an Antimicrobial Peptide, Magainin 1, Using the Droplet Contact Method.

    PubMed

    Watanabe, Hirokazu; Kawano, Ryuji

    2016-01-01

    This study describes the pore-forming properties of magainin 1 in planar lipid bilayers. These bilayers were prepared by the droplet contact method, which was executed on a microfabricated device for a high-throughput study. We arrayed four droplet chambers parallelly in the single device, and the current measurements were carried out simultaneously. Using this system, we measured the channel current conductance of magainin 1. We determined the pore size and the number of assembling monomers in magainin pores in mammalian and bacterial model membranes. This system is a powerful tool for analyzing transmembrane peptides and their antimicrobial activities.

  9. 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.

  10. A simple method to increase the current range of the TERA chip in charged particle therapy applications

    NASA Astrophysics Data System (ADS)

    Cirio, R.; Fausti, F.; Fanola Guarachi, L.; Giordanengo, S.; Marchetto, F.; Mazza, G.; Monaco, V.; Sacchi, R.; Talpacci, E.; Varasteh Anvar, M.; Vignati, A.

    2015-10-01

    The development of the next generation of accelerators for charged particle radiotherapy aims to reduce dimensions and operational complexity of the machines by engineering pulsed beams accelerators. The drawback is the increased difficulty to monitor the beam delivery. Within each pulse, instantaneous currents larger by two to three orders of magnitude than present applications are expected, which would saturate the readout of the monitor chambers. In this paper, we report of a simple method to increase by almost two orders of magnitude the current range of an Application Specific Integrated Circuit chip previously developed by our group to read out monitor ionization chambers.

  11. Methods for Quantification of Soil-Transmitted Helminths in Environmental Media: Current Techniques and Recent Advances.

    PubMed

    Collender, Philip A; Kirby, Amy E; Addiss, David G; Freeman, Matthew C; Remais, Justin V

    2015-12-01

    Limiting the environmental transmission of soil-transmitted helminths (STHs), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost-effective methods to detect and quantify STHs in the environment. We review the state-of-the-art of STH quantification in soil, biosolids, water, produce, and vegetation with regard to four major methodological issues: environmental sampling; recovery of STHs from environmental matrices; quantification of recovered STHs; and viability assessment of STH ova. We conclude that methods for sampling and recovering STHs require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment.

  12. A new method for infrared imaging of air currents in and around critical hazard fume hoods

    SciTech Connect

    Mulac, W.A.; McCreary, J.R. ); Schmalz, H. Thermal Surveys, Inc., Rockford, IL )

    1992-01-01

    A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated.

  13. A new method for infrared imaging of air currents in and around critical hazard fume hoods

    SciTech Connect

    Mulac, W.A.; McCreary, J.R.; Schmalz, H. |

    1992-11-01

    A real time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods is being developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a non-toxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principle advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principle limitation is the necessity of high tracer gas concentration to obtain strong visualizations. We hope that this technique can be found to be an effective and safe method to test hoods in locations that were built before present regulations were promulgated.

  14. Chemical vs. biotechnological synthesis of C13-apocarotenoids: current methods, applications and perspectives.

    PubMed

    Cataldo, Vicente F; López, Javiera; Cárcamo, Martín; Agosin, Eduardo

    2016-07-01

    Apocarotenoids are natural compounds derived from the oxidative cleavage of carotenoids. Particularly, C13-apocarotenoids are volatile compounds that contribute to the aromas of different flowers and fruits and are highly valued by the Flavor and Fragrance industry. So far, the chemical synthesis of these terpenoids has dominated the industry. Nonetheless, the increasing consumer demand for more natural and sustainable processes raises an interesting opportunity for bio-production alternatives. In this regard, enzymatic biocatalysis and metabolically engineered microorganisms emerge as attractive biotechnological options. The present review summarizes promising bioengineering approaches with regard to chemical production methods for the synthesis of two families of C13-apocarotenoids: ionones/dihydroionones and damascones/damascenone. We discuss each method and its applicability, with a thorough comparative analysis for ionones, focusing on the production process, regulatory aspects, and sustainability.

  15. Methods for quantification of soil-transmitted helminths in environmental media: current techniques and recent advances

    PubMed Central

    Collender, Philip A.; Kirby, Amy E.; Addiss, David G.; Freeman, Matthew C.; Remais, Justin V.

    2015-01-01

    Limiting the environmental transmission of soil-transmitted helminths (STH), which infect 1.5 billion people worldwide, will require sensitive, reliable, and cost effective methods to detect and quantify STH in the environment. We review the state of the art of STH quantification in soil, biosolids, water, produce, and vegetation with respect to four major methodological issues: environmental sampling; recovery of STH from environmental matrices; quantification of recovered STH; and viability assessment of STH ova. We conclude that methods for sampling and recovering STH require substantial advances to provide reliable measurements for STH control. Recent innovations in the use of automated image identification and developments in molecular genetic assays offer considerable promise for improving quantification and viability assessment. PMID:26440788

  16. [The current status and outlook for molecular genetic methods in solving the tasks of medical microbiology].

    PubMed

    Gintsburg, A L; Zigangirova, N A; Romanova, Iu M

    1999-01-01

    The article deals with modern methods, viz. PCR, molecular display and genotherapy, which permit the new approach to the solution of problems connected with the identification of infective agents, the study of the mechanisms of the pathogenesis of infectious diseases and their treatment. In this article concrete examples, clearly demonstrating how each of the above-mentioned technologies makes it possible to broaden the circle of problems solved in infectious pathology of man, are presented.

  17. Extracting accurate strain measurements in bone mechanics: A critical review of current methods.

    PubMed

    Grassi, Lorenzo; Isaksson, Hanna

    2015-10-01

    Osteoporosis related fractures are a social burden that advocates for more accurate fracture prediction methods. Mechanistic methods, e.g. finite element models, have been proposed as a tool to better predict bone mechanical behaviour and strength. However, there is little consensus about the optimal constitutive law to describe bone as a material. Extracting reliable and relevant strain data from experimental tests is of fundamental importance to better understand bone mechanical properties, and to validate numerical models. Several techniques have been used to measure strain in experimental mechanics, with substantial differences in terms of accuracy, precision, time- and length-scale. Each technique presents upsides and downsides that must be carefully evaluated when designing the experiment. Moreover, additional complexities are often encountered when applying such strain measurement techniques to bone, due to its complex composite structure. This review of literature examined the four most commonly adopted methods for strain measurements (strain gauges, fibre Bragg grating sensors, digital image correlation, and digital volume correlation), with a focus on studies with bone as a substrate material, at the organ and tissue level. For each of them the working principles, a summary of the main applications to bone mechanics at the organ- and tissue-level, and a list of pros and cons are provided.

  18. A review of current anti-islanding methods for photovoltaic power system

    SciTech Connect

    Yu, Byunggyu; Yu, Gwonjong; Matsui, Mikihiko

    2010-05-15

    Islanding phenomenon is undesirable because it leads to a safety hazard to utility service personnel and may cause damage to power generation and power supply facilities as a result of unsynchronized re-closure. Until now, various anti-islanding methods (AIMs) for detecting and preventing islanding of photovoltaic and other distributed generations (DGs) have been proposed. This paper presents an overview of recent anti-islanding method developments for grid-connected photovoltaic (PV) power generation, focusing on the concept and operating principle, mainly based on single phase system. For the performance comparison, the experimental results of the various AIMs with 3 kW PV inverter are provided based on the islanding detection capability and power quality. As a result, the active AIMs have better islanding detection capability rather than the passive one. However, the active AIMs have power quality degradation on harmonic distortion or displacement power factor based on the injected active signal type. In addition to the evaluation and comparison of the main anti-islanding methods, this paper also summarizes the related anti-islanding standards to evaluate anti-islanding capability for PV system. This paper can be used as a useful anti-islanding reference for future work in DG like PV, and wind turbine. (author)

  19. Stacking Cans: Abstracting from Computation

    ERIC Educational Resources Information Center

    Roy, George J.; Safi, Farshid; Graul, LuAnn

    2015-01-01

    As current mathematics standards, such as the Common Core, are being implemented throughout the United States, it has become evident that teachers need support to enact the tenets of those standards. To help in this endeavor, this article was published as a guideline to emphasize to mathematics education stakeholders that "effective teaching…

  20. 1986 annual information meeting. Abstracts

    SciTech Connect

    Not Available

    1986-01-01

    Abstracts are presented for the following papers: Geohydrological Research at the Y-12 Plant (C.S. Haase); Ecological Impacts of Waste Disposal Operations in Bear Creek Valley Near the Y-12 Plant (J.M. Loar); Finite Element Simulation of Subsurface Contaminant Transport: Logistic Difficulties in Handling Large Field Problems (G.T. Yeh); Dynamic Compaction of a Radioactive Waste Burial Trench (B.P. Spalding); Comparative Evaluation of Potential Sites for a High-Level Radioactive Waste Repository (E.D. Smith); Changing Priorities in Environmental Assessment and Environmental Compliance (R.M. Reed); Ecology, Ecotoxicology, and Ecological Risk Assessment (L.W. Barnthouse); Theory and Practice in Uncertainty Analysis from Ten Years of Practice (R.H. Gardner); Modeling Landscape Effects of Forest Decline (V.H. Dale); Soil Nitrogen and the Global Carbon Cycle (W.M. Post); Maximizing Wood Energy Production in Short-Rotation Plantations: Effect of Initial Spacing and Rotation Length (L.L. Wright); and Ecological Communities and Processes in Woodland Streams Exhibit Both Direct and Indirect Effects of Acidification (J.W. Elwood).

  1. Ozone Conference II: Abstract Proceedings

    SciTech Connect

    1999-11-01

    Ozone Conference II: Pre- and Post-Harvest Applications Two Years After Gras, was held September 27-28, 1999 in Tulare, California. This conference, sponsored by EPRI's Agricultural Technology Alliance and Southern California Edison's AgTAC facility, was coordinated and organized by the on-site ATA-AgTAC Regional Center. Approximately 175 people attended the day-and-a-half conference at AgTAC. During the Conference twenty-two presentations were given on ozone food processing and agricultural applications. Included in the presentations were topics on: (1) Ozone fumigation; (2) Ozone generation techniques; (3) System and design applications; (4) Prewater treatment requirements; (5) Poultry water reuse; (6) Soil treatments with ozone gas; and (7) Post-harvest aqueous and gaseous ozone research results. A live videoconference between Tulare and Washington, D.C. was held to discuss the regulators' view from inside the beltway. Attendees participated in two Roundtable Question and Answer sessions and visited fifteen exhibits and demonstrations. The attendees included university and governmental researchers, regulators, consultants and industry experts, technology developers and providers, and corporate and individual end-users. This report is comprised of the Abstracts of each presentation, biographical sketches for each speaker and a registration/attendees list.

  2. SLAS Library Telescope Program (Abstract)

    NASA Astrophysics Data System (ADS)

    Small, J. S.

    2016-12-01

    (Abstract only) In the fall of 2014, I submitted to the members of the St. Louis Astronomical Society to take the $1,000 profit we had from a convention we had hosted and use it to purchase three telescopes to modify for a Library Telescope program that was invented by Mark Stowbridge and promoted by the New Hampshire Astronomical Society. I had met Mark at NEAF in 2012 when he was walking the floor demonstrating the telescope. We held meetings with three libraries, the St. Louis County Library system, the St. Louis Public Library system and an independent library in Kirkwood, Missouri. The response was overwhelming! SLCL responded with a request for ten telescopes and SLPL asked for five. We did our first build in October, 2014 and placed a total of eighteen telescopes. Since that time, SLAS has placed a total of eighty-eight telescopes in library systems around the St. Louis Metro area, expanding into neighboring counties and across the river in Illinois. In this talk, I will discuss how to approach this project and put it in place in your libraries!

  3. An abstract approach to music.

    SciTech Connect

    Kaper, H. G.; Tipei, S.

    1999-04-19

    In this article we have outlined a formal framework for an abstract approach to music and music composition. The model is formulated in terms of objects that have attributes, obey relationships, and are subject to certain well-defined operations. The motivation for this approach uses traditional terms and concepts of music theory, but the approach itself is formal and uses the language of mathematics. The universal object is an audio wave; partials, sounds, and compositions are special objects, which are placed in a hierarchical order based on time scales. The objects have both static and dynamic attributes. When we realize a composition, we assign values to each of its attributes: a (scalar) value to a static attribute, an envelope and a size to a dynamic attribute. A composition is then a trajectory in the space of aural events, and the complex audio wave is its formal representation. Sounds are fibers in the space of aural events, from which the composer weaves the trajectory of a composition. Each sound object in turn is made up of partials, which are the elementary building blocks of any music composition. The partials evolve on the fastest time scale in the hierarchy of partials, sounds, and compositions. The ideas outlined in this article are being implemented in a digital instrument for additive sound synthesis and in software for music composition. A demonstration of some preliminary results has been submitted by the authors for presentation at the conference.

  4. Handedness shapes children's abstract concepts.

    PubMed

    Casasanto, Daniel; Henetz, Tania

    2012-03-01

    Can children's handedness influence how they represent abstract concepts like kindness and intelligence? Here we show that from an early age, right-handers associate rightward space more strongly with positive ideas and leftward space with negative ideas, but the opposite is true for left-handers. In one experiment, children indicated where on a diagram a preferred toy and a dispreferred toy should go. Right-handers tended to assign the preferred toy to a box on the right and the dispreferred toy to a box on the left. Left-handers showed the opposite pattern. In a second experiment, children judged which of two cartoon animals looked smarter (or dumber) or nicer (or meaner). Right-handers attributed more positive qualities to animals on the right, but left-handers to animals on the left. These contrasting associations between space and valence cannot be explained by exposure to language or cultural conventions, which consistently link right with good. Rather, right- and left-handers implicitly associated positive valence more strongly with the side of space on which they can act more fluently with their dominant hands. Results support the body-specificity hypothesis (Casasanto, 2009), showing that children with different kinds of bodies think differently in corresponding ways.

  5. Attracting Girls into Physics (abstract)

    NASA Astrophysics Data System (ADS)

    Gadalla, Afaf

    2009-04-01

    A recent international study of women in physics showed that enrollment in physics and science is declining for both males and females and that women are severely underrepresented in careers requiring a strong physics background. The gender gap begins early in the pipeline, from the first grade. Girls are treated differently than boys at home and in society in ways that often hinder their chances for success. They have fewer freedoms, are discouraged from accessing resources or being adventurous, have far less exposure to problem solving, and are not encouraged to choose their lives. In order to motivate more girl students to study physics in the Assiut governorate of Egypt, the Assiut Alliance for the Women and Assiut Education District collaborated in renovating the education of physics in middle and secondary school classrooms. A program that helps in increasing the number of girls in science and physics has been designed in which informal groupings are organized at middle and secondary schools to involve girls in the training and experiences needed to attract and encourage girls to learn physics. During implementation of the program at some schools, girls, because they had not been trained in problem-solving as boys, appeared not to be as facile in abstracting the ideas of physics, and that was the primary reason for girls dropping out of science and physics. This could be overcome by holding a topical physics and technology summer school under the supervision of the Assiut Alliance for the Women.

  6. Behavioural methods used in rodent models of autism spectrum disorders: current standards and new developments.

    PubMed

    Wöhr, Markus; Scattoni, Maria Luisa

    2013-08-15

    Autism is a behaviourally defined disorder including attenuated or abnormal social interaction and communication, as well as aberrant repetitive behaviour, with symptoms emerging early in childhood. Although the cause of autism has not been discovered, several data strongly support the role of genetic factors in autism aetiology. For this reason, preclinical research is now focusing on generating transgenic and knockout mice, and more recently also rats, with mutations in genes identified in autistic children, with the main aim of understanding the role of those genes in autism aetiology, discovering the biological mechanisms underlying autistic behaviours detected in these mutant lines and evaluating potential treatments. Over the last years, a huge number of behavioural phenotyping assays for rodent models of autism and related disorders have been designed. In the first part of our review, we focus on current standards, i.e. state-of-the-art behavioural phenotyping tasks to assess autism core symptoms in rodent models. The second part is devoted to some few, in our view, very promising examples of new developments, namely an autism severity score, scent marking behaviour as an additional, ethologically valid measure for communication, plus a number of new developments in the behavioural domains of social facilitation, observational learning, and empathy. Finally, we will highlight the huge potential impact of newly generated rat knockout models of autism.

  7. Current LC-MS methods and procedures applied to the identification of new steroid metabolites.

    PubMed

    Marcos, Josep; Pozo, Oscar J

    2016-09-01

    The study of the metabolism of steroids has a long history; from the first characterizations of the major metabolites of steroidal hormones in the pre-chromatographic era, to the latest discoveries of new forms of excretions. The introduction of mass spectrometers coupled to gas chromatography at the end of the 1960's represented a major breakthrough for the elucidation of new metabolites. In the last two decades, this technique is being complemented by the use of liquid chromatography-mass spectrometry (LC-MS). In addition of becoming fundamental in clinical steroid determinations due to its excellent specificity, throughput and sensitivity, LC-MS has emerged as an exceptional tool for the discovery of new steroid metabolites. The aim of the present review is to provide an overview of the current LC-MS procedures used in the quest of novel metabolic products of steroidal hormones and exogenous steroids. Several aspects regarding LC separations are first outlined, followed by a description of the key processes that take place in the mass spectrometric analysis, i.e. the ionization of the steroids in the source and the fragmentation of the selected precursor ions in the collision cell. The different analyzers and approaches employed together with representative examples of each of them are described. Special emphasis is placed on triple quadrupole analyzers (LC-MS/MS), since they are the most commonly employed. Examples on the use of precursor ion scan, neutral loss scan and theoretical selected reaction monitoring strategies are also explained.

  8. Incorporating cumulative effects into environmental assessments of mariculture: Limitations and failures of current siting methods

    SciTech Connect

    King, Sarah C. Pushchak, Ronald

    2008-11-15

    Assessing and evaluating the cumulative impacts of multiple marine aquaculture facilities has proved difficult in environmental assessment. A retrospective review of 23 existing mariculture farms in southwestern New Brunswick was conducted to determine whether cumulative interactions would have justified site approvals. Based on current scientific evidence of cumulative effects, six new criteria were added to a set of far-field impacts and other existing criteria were expanded to include regional and cumulative environmental impacts in Hargrave's [Hargrave BT. A traffic light decision system for marine finfish aquaculture siting. Ocean Coast Manag 2002; 45:215-35.] Traffic Light Decision Support System (DSS) presently used in Canadian aquaculture environmental assessments. Before mitigation, 19 of the 23 sites failed the amended set of criteria and after considering mitigation, 8 sites failed. Site and ecosystem indices yielded varying site acceptability scores; however, many sites would not have been approved if siting decisions had been made within a regional management framework and cumulative impact criteria were considered in the site evaluation process.

  9. Structural Characterization of Phase Separation in Fe-Cr: A Current Comparison of Experimental Methods

    NASA Astrophysics Data System (ADS)

    Xu, Xin; Odqvist, Joakim; Colliander, Magnus Hörnqvist; Thuvander, Mattias; Steuwer, Axel; Westraadt, Johan E.; King, Stephen; Hedström, Peter

    2016-12-01

    Self-assembly due to phase separation within a miscibility gap is important in numerous material systems and applications. A system of particular interest is the binary alloy system Fe-Cr, since it is both a suitable model material and the base system for the stainless steel alloy category, suffering from low-temperature embrittlement due to phase separation. Structural characterization of the minute nano-scale concentration fluctuations during early phase separation has for a long time been considered a major challenge within material characterization. However, recent developments present new opportunities in this field. Here, we present an overview of the current capabilities and limitations of different techniques. A set of Fe-Cr alloys were investigated using small-angle neutron scattering (SANS), atom probe tomography, and analytical transmission electron microscopy. The complementarity of the characterization techniques is clear, and combinatorial studies can provide complete quantitative structure information during phase separation in Fe-Cr alloys. Furthermore, we argue that SANS provides a unique in-situ access to the nanostructure, and that direct comparisons between SANS and phase-field modeling, solving the non-linear Cahn Hilliard equation with proper physical input, should be pursued.

  10. Current advance methods for the identification of blast resistance genes in rice.

    PubMed

    Tanweer, Fatah A; Rafii, Mohd Y; Sijam, Kamaruzaman; Rahim, Harun A; Ahmed, Fahim; Latif, Mohammad A

    2015-05-01

    Rice blast caused by Magnaporthe oryzae is one of the most devastating diseases of rice around the world and crop losses due to blast are considerably high. Many blast resistant rice varieties have been developed by classical plant breeding and adopted by farmers in various rice-growing countries. However, the variability in the pathogenicity of the blast fungus according to environment made blast disease a major concern for farmers, which remains a threat to the rice industry. With the utilization of molecular techniques, plant breeders have improved rice production systems and minimized yield losses. In this article, we have summarized the current advanced molecular techniques used for controlling blast disease. With the advent of new technologies like marker-assisted selection, molecular mapping, map-based cloning, marker-assisted backcrossing and allele mining, breeders have identified more than 100 Pi loci and 350 QTL in rice genome responsible for blast disease. These Pi genes and QTLs can be introgressed into a blast-susceptible cultivar through marker-assisted backcross breeding. These molecular techniques provide timesaving, environment friendly and labour-cost-saving ways to control blast disease. The knowledge of host-plant interactions in the frame of blast disease will lead to develop resistant varieties in the future.

  11. A review on bioadhesive buccal drug delivery systems: current status of formulation and evaluation methods

    PubMed Central

    Chinna Reddy, P; Chaitanya, K.S.C.; Madhusudan Rao, Y.

    2011-01-01

    Owing to the ease of the administration, the oral cavity is an attractive site for the delivery of drugs. Through this route it is possible to realize mucosal (local effect) and transmucosal (systemic effect) drug administration. In the first case, the aim is to achieve a site-specific release of the drug on the mucosa, whereas the second case involves drug absorption through the mucosal barrier to reach the systemic circulation. The main obstacles that drugs meet when administered via the buccal route derive from the limited absorption area and the barrier properties of the mucosa. The effective physiological removal mechanisms of the oral cavity that take the formulation away from the absorption site are the other obstacles that have to be considered. The strategies studied to overcome such obstacles include the employment of new materials that, possibly, combine mucoadhesive, enzyme inhibitory and penetration enhancer properties and the design of innovative drug delivery systems which, besides improving patient compliance, favor a more intimate contact of the drug with the absorption mucosa. This presents a brief description of advantages and limitations of buccal drug delivery and the anatomical structure of oral mucosa, mechanisms of drug permeation followed by current formulation design in line with developments in buccal delivery systems and methodology in evaluating buccal formulations. PMID:23008684

  12. Annual Quality Assurance Conference Abstracts by Barbara Marshik

    EPA Pesticide Factsheets

    25th Annual Quality Assurance Conference. Abstracts: Material and Process Conditions for Successful Use of Extractive Sampling Techniques and Certification Methods Errors in the Analysis of NMHC and VOCs in CNG-Based Engine Emissions by Barbara Marshik

  13. Effectiveness of female controlled barrier methods in preventing sexually transmitted infections and HIV: current evidence and future research directions

    PubMed Central

    Minnis, A; Padian, N

    2005-01-01

    Objectives: To evaluate evidence for the effectiveness of female controlled physical and chemical barrier methods in preventing STI/HIV transmission, to examine recent reviews on microbicide development, and to highlight promising research directions. To discuss challenges in conducting effectiveness research and in translating results to public health intervention. Methods: Systematic review of articles that examined the disease prevention effectiveness of at least one female controlled barrier method. Review of conference abstracts that presented clinical and preclinical microbicide data. Results: Randomised controlled trials provide evidence that female condoms confer as much protection from STIs as male condoms. Observational studies suggest that the diaphragm protects against STI pathogens. Several microbicide effectiveness studies are under way and new directions, such as adaptation of therapeutic agents as preventive products, are being examined. Substantial attention is now given to product formulation and novel delivery strategies. Combining microbicide products with different mechanisms of action as well as combining chemical and physical barriers will be necessary to maximise prevention effectiveness. Conclusions: Increased investment in the development and identification of female controlled barrier methods offers promise that additional products will be available in the years ahead. Generalising trial results to a community setting, promoting products that may be less effective than male condoms, and bringing an effective product to scale introduce public health challenges that warrant attention. The need for female controlled barrier methods that provide women with the opportunity to take an active role in reducing their STI/HIV risk are urgently needed and constitute an essential tool to prevent continued spread of these infections. PMID:15923284

  14. [Pharmacological vigilance and pharmacological epidemiology: principles, definition, methods and current trends in neurology].

    PubMed

    Montastruc, J L; Bagheri, H; Lapeyre-Mestre, M; Senard, J M

    1999-04-01

    It is now well established that only clinical trials performed before drug approval are not sufficient for a full modern pharmacological evaluation of drugs and treatments. The need of both pharmacovigilance and pharmacoepidemiology is underlined in order to evaluate drugs under real conditions. After a summary of methods used in pharmacoepidemiological trials (spontaneous reports, imputability assessment, cohorts, case control studies etc.), recent pharmacoepidemiological data useful for the neurologist are summarized: side effects of tacrine and vaccines, serotoninergic syndrome and side effects of new antiepileptic drugs.

  15. Non-destructive Testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method

    NASA Technical Reports Server (NTRS)

    Lu, D. F.; Fan, Chang-Xin; Ruan, J. Z.; Han, S. G.; Wong, K. W.; Sun, G. F.

    1995-01-01

    A SQUID is the most sensitive device to detect change in magnetic field. A nondestructive testing (NDT) device using high temperature SQUID's and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUID's. In this paper, we present our study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDT device will have a significant impact on metal corrosion or crack detection technology.

  16. Non-destructive Testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method

    SciTech Connect

    Lu, D.F.; Fan, C.; Ruan, J.Z.; Han, S.G.; Wong, K.W.; Sun, G.F.

    1995-04-01

    A SQUID is the most sensitive device to detect change in magnetic field. A nondestructive testing (NDT) device using high temperature SQUID`s and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUID`s. In this paper, the authors present their study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDT device will have a significant impact on metal corrosion or crack detection technology.

  17. Non-destructive testing (NDT) of metal cracks using a high Tc rf-SQUID and eddy current method

    SciTech Connect

    Lu, D.F.; Fan, C.; Ruan, J.Z.

    1994-12-31

    A SQUID is the most sensitive device to detect change in magnetic field. A non-destructive testing (NDT) device using high temperature SQUIDs and eddy current method will be much more sensitive than those currently used eddy current systems, yet much cheaper than one with low temperature SQUIDs. In this paper, we present our study of such a NDT device using a high temperature superconducting rf-SQUID as a gradiometer sensor. The result clearly demonstrates the expected sensitivity of the system, and indicates the feasibility of building a portable HTS SQUID NDT device with the help from cryocooler industry. Such a NDT device will have a significant impact on metal corrosion or crack detection technology.

  18. Development of blood transfusion product pathogen reduction treatments: a review of methods, current applications and demands.

    PubMed

    Salunkhe, Vishal; van der Meer, Pieter F; de Korte, Dirk; Seghatchian, Jerard; Gutiérrez, Laura

    2015-02-01

    Transfusion-transmitted infections (TTI) have been greatly reduced in numbers due to the strict donor selection and screening procedures, i.e. the availability of technologies to test donors for endemic infections, and routine vigilance of regulatory authorities in every step of the blood supply chain (collection, processing and storage). However, safety improvement is still a matter of concern because infection zero-risk in transfusion medicine is non-existent. Alternatives are required to assure the safety of the transfusion product and to provide a substitution to systematic blood screening tests, especially in less-developed countries or at the war-field. Furthermore, the increasing mobility of the population due to traveling poses a new challenge in the endemic screening tests routinely used, because non-endemic pathogens might emerge in a specific population. Pathogen reduction treatments sum a plethora of active approaches to eliminate or reduce potential threatening pathogen load from blood transfusion products. Despite the success of pathogen reduction treatments applied to plasma products, there is still a long way to develop and deploy pathogen reduction treatments to cellular transfusion products (such as platelets, RBCs or even to whole blood) and there is divergence on its acceptance worldwide. While the use of pathogen reduction treatments in platelets is performed routinely in a fair number of European blood banks, most of these treatments are not (or just) licensed in the USA or elsewhere in the world. The development of pathogen reduction treatments for RBC and whole blood is still in its infancy and under clinical trials. In this review, we discuss the available and emerging pathogen reduction treatments and their advantages and disadvantages. Furthermore, we highlight the importance of characterizing standard transfusion products with current and emerging approaches (OMICS) and clinical outcome, and integrating this information on a database

  19. Current Status of Surgical Planning for Orthognathic Surgery: Traditional Methods versus 3D Surgical Planning

    PubMed Central

    Hammoudeh, Jeffrey A.; Howell, Lori K.; Boutros, Shadi; Scott, Michelle A.

    2015-01-01

    Background: Orthognathic surgery has traditionally been performed using stone model surgery. This involves translating desired clinical movements of the maxilla and mandible into stone models that are then cut and repositioned into class I occlusion from which a splint is generated. Model surgery is an accurate and reproducible method of surgical correction of the dentofacial skeleton in cleft and noncleft patients, albeit considerably time-consuming. With the advent of computed tomography scanning, 3D imaging and virtual surgical planning (VSP) have gained a foothold in orthognathic surgery with VSP rapidly replacing traditional model surgery in many parts of the country and the world. What has yet to be determined is whether the application and feasibility of virtual model surgery is at a point where it will eliminate the need for traditional model surgery in both the private and academic setting. Methods: Traditional model surgery was compared with VSP splint fabrication to determine the feasibility of use and accuracy of application in orthognathic surgery within our institution. Results: VSP was found to generate acrylic splints of equal quality to model surgery splints in a fraction of the time. Drawbacks of VSP splint fabrication are the increased cost of production and certain limitations as it relates to complex craniofacial patients. Conclusions: It is our opinion that virtual model surgery will displace and replace traditional model surgery as it will become cost and time effective in both the private and academic setting for practitioners providing orthognathic surgical care in cleft and noncleft patients. PMID:25750846

  20. A Review of Current Machine Learning Methods Used for Cancer Recurrence Modeling and Prediction

    SciTech Connect

    Hemphill, Geralyn M.

    2016-09-27

    Cancer has been characterized as a heterogeneous disease consisting of many different subtypes. The early diagnosis and prognosis of a cancer type has become a necessity in cancer research. A major challenge in cancer management is the classification of patients into appropriate risk groups for better treatment and follow-up. Such risk assessment is critically important in order to optimize the patient’s health and the use of medical resources, as well as to avoid cancer recurrence. This paper focuses on the application of machine learning methods for predicting the likelihood of a recurrence of cancer. It is not meant to be an extensive review of the literature on the subject of machine learning techniques for cancer recurrence modeling. Other recent papers have performed such a review, and I will rely heavily on the results and outcomes from these papers. The electronic databases that were used for this review include PubMed, Google, and Google Scholar. Query terms used include “cancer recurrence modeling”, “cancer recurrence and machine learning”, “cancer recurrence modeling and machine learning”, and “machine learning for cancer recurrence and prediction”. The most recent and most applicable papers to the topic of this review have been included in the references. It also includes a list of modeling and classification methods to predict cancer recurrence.

  1. Method of active charge and current neutralization of intense ion beams for ICF

    SciTech Connect

    Guiragossian, Z.G.T.; Orthel, J.L.; Lemons, D.S.; Thode, L.E.

    1981-01-01

    Methods of generating the beam neutralization electrons with required properties are given in the context of a Light Ion Fusion Experiment (LIFE) designed accelerator. Recently derived envelope equations for neutralized and ballistically focused intense ion beams are applied to the LIFE geometry in which 10 MeV He/sup +/ multiple beamlets coalesce and undergo 45:1 radial compression while beam pulses experience a 20:1 axial compression in the propagation range of 10 m. Both active and auto-neutralization methods are examined and found to produce initial electron temperatures consistent with the requirement of the envelope equation for both radial and axial adiabatic beam pulse compressions. The stability of neutralized beam propagation is also examined concerning the Pierce type electrostatic instability and for the case of LIFE beams it is found to have insignificant effect. A scaled experimental setup is presented which can serve to perform near term tests on the ballistically focused propagation of neutralized light ion beams.

  2. Annotating user-defined abstractions for optimization

    SciTech Connect

    Quinlan, D; Schordan, M; Vuduc, R; Yi, Q

    2005-12-05

    This paper discusses the features of an annotation language that we believe to be essential for optimizing user-defined abstractions. These features should capture semantics of function, data, and object-oriented abstractions, express abstraction equivalence (e.g., a class represents an array abstraction), and permit extension of traditional compiler optimizations to user-defined abstractions. Our future work will include developing a comprehensive annotation language for describing the semantics of general object-oriented abstractions, as well as automatically verifying and inferring the annotated semantics.

  3. Core foundations of abstract geometry.

    PubMed

    Dillon, Moira R; Huang, Yi; Spelke, Elizabeth S

    2013-08-27

    Human adults from diverse cultures share intuitions about the points, lines, and figures of Euclidean geometry. Do children develop these intuitions by drawing on phylogenetically ancient and developmentally precocious geometric representations that guide their navigation and their analysis of object shape? In what way might these early-arising representations support later-developing Euclidean intuitions? To approach these questions, we investigated the relations among young children's use of geometry in tasks assessing: navigation; visual form analysis; and the interpretation of symbolic, purely geometric maps. Children's navigation depended on the distance and directional relations of the surface layout and predicted their use of a symbolic map with targets designated by surface distances. In contrast, children's analysis of visual forms depended on the size-invariant shape relations of objects and predicted their use of the same map but with targets designated by corner angles. Even though the two map tasks used identical instructions and map displays, children's performance on these tasks showed no evidence of integrated representations of distance and angle. Instead, young children flexibly recruited geometric representations of either navigable layouts or objects to interpret the same spatial symbols. These findings reveal a link between the early-arising geometric representations that humans share with diverse animals and the flexible geometric intuitions that give rise to human knowledge at its highest reaches. Although young children do not appear to integrate core geometric representations, children's use of the abstract geometry in spatial symbols such as maps may provide the earliest clues to the later construction of Euclidean geometry.

  4. Direct estimation of diffuse gaseous emissions from coal fires: current methods and future directions

    USGS Publications Warehouse

    Engle, Mark A.; Olea, Ricardo A.; O'Keefe, Jennifer M. K.; Hower, James C.; Geboy, Nicholas J.

    2013-01-01

    Coal fires occur in nature spontaneously, contribute to increases in greenhouse gases, and emit atmospheric toxicants. Increasing interest in quantifying coal fire emissions has resulted in the adaptation and development of specialized approaches and adoption of numerical modeling techniques. Overview of these methods for direct estimation of diffuse gas emissions from coal fires is presented in this paper. Here we take advantage of stochastic Gaussian simulation to interpolate CO2 fluxes measured using a dynamic closed chamber at the Ruth Mullins coal fire in Perry County, Kentucky. This approach allows for preparing a map of diffuse gas emissions, one of the two primary ways that gases emanate from coal fires, and establishing the reliability of the study both locally and for the entire fire. Future research directions include continuous and automated sampling to improve quantification of gaseous coal fire emissions.

  5. Coke oven doors: Historical methods of emission control and evaluation of current designs

    SciTech Connect

    Pettrey, J.O.; Greene, D.E. )

    1993-01-01

    The containment of oven door leakage has presented challenges to coke producers for many years as the requirements of environmental regulatory agencies have become increasingly stringent. A description and evaluation of past door modifications, leakage control methodologies and luting practices on Armco Steel Company, L.P.'s Ashland No. 4 Battery is detailed to provide a background for recent work, and to expand the industry's technology base. The strict door leakage standards of the 1990 amendments to the USA Clean Air Act has prompted additional technical studies. Both a joint Armco committee's evaluation of successful systems world wide and test door installations at Ashland were incorporated to determine compliance strategy. The eventual installation of Ikio Model II coke oven doors, along with modifications to ancillary equipment, has resulted in door leakage rates approaching zero. Associated methods, problems, results and evaluations are discussed.

  6. Current methods for evaluating the bioavailability of chemicals from contaminated soils using soil invertebrates

    SciTech Connect

    Lanno, R.P.

    1995-12-31

    Contaminated soils are an extremely complex, variable matrix where many modifying factors of toxicity (e.g., particle size, organic matter content) alter the availability of chemicals to biota. Although many methods have been standardized for assessing the toxicity of contaminated soils to invertebrates and plants, few studies have actually addressed the issue of contaminant bioavailability from soils. Since bioavailability is a measure of uptake of contaminants from the soil by living organisms, one approach to determining bioavailability is to measure residues of contaminants in biota. Body residues related to a specific lethal or sublethal toxicity endpoint offer the unique opportunity to relate bioavailability to biological response. This paper will present an overview of the use of body residues in assessing the bioavailability of soil contaminants by earthworms and soil arthropods. The applications of body residues in the development of soil quality guidelines will also be discussed.

  7. INSTRUMENTS AND METHODS OF INVESTIGATION: Solid-solid thermal contact problems: current understanding

    NASA Astrophysics Data System (ADS)

    Mesnyankin, Sergei Yu; Vikulov, Aleksei G.; Vikulov, Dmitrii G.

    2009-09-01

    The past 40 years of theoretical and experimental research on contact heat transfer are reviewed. Thermophysical and mechanical processes involved in heat flow propagation through various kinds of solid-solid joints are considered. Analytical and semiempirical expressions are presented, which simulate these processes both under vacuum conditions and in the presence of a heat-conducting medium in gaps. Reasons for the experimentally examined heat flux rectification are explained. Studies on thermal contact under a nonstationary regime are covered, as is the possibility of applying classical heat conduction theory to describing the contact thermal properties. A thermodynamic interpretation of the thermal contact resistance is suggested and basic approaches to the study of contact phenomena are described. The heat conduction in nanosystems is briefly reviewed. Theoretical problems yet to be solved are pointed out and possible solution methods suggested.

  8. A new method for infrared imaging of air currents in and around critical hazard fume hoods

    SciTech Connect

    Mulac, W.A.; McCreary, J.R.; Schmalz, H.

    1994-03-01

    Active, safe real-time method of measuring and recording the efficacy of vapor containment in and around critical hazard fume hoods has been developed. An infrared camera whose response is restricted to a spectral range that overlaps a strong absorption band in a nontoxic gas is used to render real-time video images of the presence and flow of the gas. The gas, nitrous oxide, is ejected in a continuous stream in and around fume hoods that are to be certified capable of containing hazardous fumes. The principal advantage is that various scenarios of air flow displacement in and outside the hood can be easily investigated; the principal limitation is the necessity of high tracer gas concentration to obtain strong visualizations.

  9. Current Proteomic Methods to Investigate the Dynamics of Histone Turnover in the Central Nervous System

    PubMed Central

    Farrelly, L.A.; Dill, B.D.; Molina, H.; Birtwistle, M.R.; Maze, I.

    2016-01-01

    Characterizing the dynamic behavior of nucleosomes in the central nervous system is vital to our understanding of brain-specific chromatin-templated processes and their roles in transcriptional plasticity. Histone turnover—the complete loss of old, and replacement by new, nucleosomal histones—is one such phenomenon that has recently been shown to be critical for cell-type-specific transcription in brain, synaptic plasticity, and cognition. Such revelations that histones, long believed to static proteins in postmitotic cells, are highly dynamic in neurons were only possible owing to significant advances in analytical chemistry-based techniques, which now provide a platform for investigations of histone dynamics in both healthy and diseased tissues. Here, we discuss both past and present proteomic methods (eg, mass spectrometry, human “bomb pulse labeling”) for investigating histone turnover in brain with the hope that such information may stimulate future investigations of both adaptive and aberrant forms of “neuroepigenetic” plasticity. PMID:27423867

  10. Current Proteomic Methods to Investigate the Dynamics of Histone Turnover in the Central Nervous System.

    PubMed

    Farrelly, L A; Dill, B D; Molina, H; Birtwistle, M R; Maze, I

    2016-01-01

    Characterizing the dynamic behavior of nucleosomes in the central nervous system is vital to our understanding of brain-specific chromatin-templated processes and their roles in transcriptional plasticity. Histone turnover-the complete loss of old, and replacement by new, nucleosomal histones-is one such phenomenon that has recently been shown to be critical for cell-type-specific transcription in brain, synaptic plasticity, and cognition. Such revelations that histones, long believed to static proteins in postmitotic cells, are highly dynamic in neurons were only possible owing to significant advances in analytical chemistry-based techniques, which now provide a platform for investigations of histone dynamics in both healthy and diseased tissues. Here, we discuss both past and present proteomic methods (eg, mass spectrometry, human "bomb pulse labeling") for investigating histone turnover in brain with the hope that such information may stimulate future investigations of both adaptive and aberrant forms of "neuroepigenetic" plasticity.

  11. SURVEY AND SUMMARY: Current methods of gene prediction, their strengths and weaknesses

    PubMed Central

    Mathé, Catherine; Sagot, Marie-France; Schiex, Thomas; Rouzé, Pierre

    2002-01-01

    While the genomes of many organisms have been sequenced over the last few years, transforming such raw sequence data into knowledge remains a hard task. A great number of prediction programs have been developed that try to address one part of this problem, which consists of locating the genes along a genome. This paper reviews the existing approaches to predicting genes in eukaryotic genomes and underlines their intrinsic advantages and limitations. The main mathematical models and computational algorithms adopted are also briefly described and the resulting software classified according to both the method and the type of evidence used. Finally, the several difficulties and pitfalls encountered by the programs are detailed, showing that improvements are needed and that new directions must be considered. PMID:12364589

  12. Current sheets in the Discontinuous Galerkin Time-Domain method: an application to graphene

    NASA Astrophysics Data System (ADS)

    Werra, Julia F. M.; Wolff, Christian; Matyssek, Christian; Busch, Kurt

    2015-05-01

    We describe the treatment of thin conductive sheets within the Discontinuous Galerkin Time-Domain (DGTD) method for solving the Maxwell equations and apply this approach to the efficient computation of the optical properties of graphene-based systems. In particular, we show that a thin conductive sheet can be handled by incorporating the associated jump conditions of the electromagnetic field into the numerical flux of the DGTD approach. This results in a flexible and efficient numerical scheme that can be applied to a number of systems. Specifically, we show how to treat individual graphene sheets on substrates as well as finite stacks of alternating graphene and dielectric layers by modeling the dispersive and dissipative properties of graphene via a two-term critical-point model for its electrostatically doped conductivity.

  13. Current Tools and Methods in Molecular Dynamics (MD) Simulations for Drug Design.

    PubMed

    Hernández-Rodríguez, Maricarmen; Rosales-Hernández, Martha C; Mendieta-Wejebe, Jessica E; Martínez-Archundia, Marlet; Basurto, José Correa

    2016-01-01

    Molecular Dynamics (MD) simulations is a computational method that employs Newton's laws to evaluate the motions of water, ions, small molecules, and macromolecules or more complex systems, for example, whole viruses, to reproduce the behavior of the biological environment, including water molecules and lipid membranes. Specifically, structural motions, such as those that are dependent of the temperature and solute/ solvent are very important to study the recognition pattern of ligandprotein or protein-protein complexes, in that sense, MD simulations are very useful because these motions can be modeled using this methodology. Furthermore, MD simulations for drug design provide insights into the structural cavities required to design novel structures with higher affinity to the target. Also, the employment of MD simulations to drug design can help to refine the three-dimensional (3D) structure of targets in order to obtain a better sampling of the binding poses and more reliable affinity values with better structural advantages, because they incorporate some biological conditions that include structural motions compared to traditional docking procedures. This work analyzes the concepts and applicability of MD simulations for drug design because molecular structural motions are considered, and these help to identify hot spots, decipher structural details in the reported protein sites, as well as to eliminate sites that could be structural artifacts which could be originated from the structural characterization conditions from MD. Moreover, better free energy values for protein ligand recognition can also be obtained, and these can be validated under experimental procedures due to the robustness of the MD simulation methods.

  14. Human Milk Warming Temperatures Using a Simulation of Currently Available Storage and Warming Methods.

    PubMed

    Bransburg-Zabary, Sharron; Virozub, Alexander; Mimouni, Francis B

    2015-01-01

    Human milk handling guidelines are very demanding, based upon solid scientific evidence that handling methods can make a real difference in infant health and nutrition. Indeed, properly stored milk maintains many of its unique qualities and continues to be the second and third best infant feeding alternatives, much superior to artificial feeding. Container type and shape, mode of steering, amount of air exposure and storage temperature may adversely affect milk stability and composition. Heating above physiological temperatures significantly impacts nutritional and immunological properties of milk. In spite of this knowledge, there are no strict guidelines regarding milk warming. Human milk is often heated in electrical-based bottle warmers that can exceed 80°C, a temperature at which many beneficial human milk properties disappear. High temperatures can also induce fat profile variations as compared with fresh human milk. In this manuscript we estimate the amount of damage due to overheating during warming using a heat flow simulation of a regular water based bottle warmer. To do so, we carried out a series of warming simulations which provided us with dynamic temperature fields within bottled milk. We simulated the use of a hot water-bath at 80°C to heat bottled refrigerated milk (60 ml and 178 ml) to demonstrate that large milk portions are overheated (above 40°C). It seems that the contemporary storage method (upright feeding tool, i.e. bottle) and bottle warming device, are not optimize to preserve the unique properties of human milk. Health workers and parents should be aware of this problem especially when it relates to sick neonates and preemies that cannot be directly fed at the breast.

  15. A Comprehensive Benchmark Study of Multiple Sequence Alignment Methods: Current Challenges and Future Perspectives

    PubMed Central

    Thompson, Julie D.; Linard, Benjamin; Lecompte, Odile; Poch, Olivier

    2011-01-01

    Multiple comparison or alignmentof protein sequences has become a fundamental tool in many different domains in modern molecular biology, from evolutionary studies to prediction of 2D/3D structure, molecular function and inter-molecular interactions etc. By placing the sequence in the framework of the overall family, multiple alignments can be used to identify conserved features and to highlight differences or specificities. In this paper, we describe a comprehensive evaluation of many of the most popular methods for multiple sequence alignment (MSA), based on a new benchmark test set. The benchmark is designed to represent typical problems encountered when aligning the large protein sequence sets that result from today's high throughput biotechnologies. We show that alignmentmethods have significantly progressed and can now identify most of the shared sequence features that determine the broad molecular function(s) of a protein family, even for divergent sequences. However,we have identified a number of important challenges. First, the locally conserved regions, that reflect functional specificities or that modulate a protein's function in a given cellular context,are less well aligned. Second, motifs in natively disordered regions are often misaligned. Third, the badly predicted or fragmentary protein sequences, which make up a large proportion of today's databases, lead to a significant number of alignment errors. Based on this study, we demonstrate that the existing MSA methods can be exploited in combination to improve alignment accuracy, although novel approaches will still be needed to fully explore the most difficult regions. We then propose knowledge-enabled, dynamic solutions that will hopefully pave the way to enhanced alignment construction and exploitation in future evolutionary systems biology studies. PMID:21483869

  16. A new method of accurate broken rotor bar diagnosis based on modulation signal bispectrum analysis of motor current signals

    NASA Astrophysics Data System (ADS)

    Gu, F.; Wang, T.; Alwodai, A.; Tian, X.; Shao, Y.; Ball, A. D.

    2015-01-01

    Motor current signature analysis (MCSA) has been an effective way of monitoring electrical machines for many years. However, inadequate accuracy in diagnosing incipient broken rotor bars (BRB) has motivated many studies into improving this method. In this paper a modulation signal bispectrum (MSB) analysis is applied to motor currents from different broken bar cases and a new MSB based sideband estimator (MSB-SE) and sideband amplitude estimator are introduced for obtaining the amplitude at (1 ± 2 s)fs (s is the rotor slip and fs is the fundamental supply frequency) with high accuracy. As the MSB-SE has a good performance of noise suppression, the new estimator produces more accurate results in predicting the number of BRB, compared with conventional power spectrum analysis. Moreover, the paper has also developed an improved model for motor current signals under rotor fault conditions and an effective method to decouple the BRB current which interferes with that of speed oscillations associated with BRB. These provide theoretical supports for the new estimators and clarify the issues in using conventional bispectrum analysis.

  17. Capabilities and limitations of a current FORTAN implementation of the T-matrix method for randomly oriented, rotationally symmetric scatterers.

    NASA Astrophysics Data System (ADS)

    Mishchenko, M.; Travis, L. D.

    1998-09-01

    The authors describe in detail a software implementation of a current version of the T-matrix method for computing light scattering by polydisperse, randomly oriented, rotationally symmetric particles. The authors give all necessary formulas, describe input and output parameters, discuss numerical aspects of T-matrix computations, demonstrate the capabilities and limitations of the codes, and discuss the performance of the codes in comparison with other available numerical approaches.

  18. Evaluating mediation and moderation effects in school psychology: a presentation of methods and review of current practice.

    PubMed

    Fairchild, Amanda J; McQuillin, Samuel D

    2010-02-01

    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 and current use of the analyses in applied school psychology research is reviewed and evaluated. Proper statistical methods to test the effects are presented, and different effect size measures for the models are provided. Extensions of the basic moderator and mediator models are also described.

  19. Current Methods for Modeling and Simulating Icing Effects on Aircraft Performance, Stability and Control

    NASA Technical Reports Server (NTRS)

    Ralvasky, Thomas P.; Barnhart, Billy P.; Lee, Sam

    2008-01-01

    Icing alters the shape and surface characteristics of aircraft components, which results in altered aerodynamic forces and moments caused by air flow over those iced components. The typical effects of icing are increased drag, reduced stall angle of attack, and reduced maximum lift. In addition to the performance changes, icing can also affect control surface effectiveness, hinge moments, and damping. These effects result in altered aircraft stability and control and flying qualities. Over the past 80 years, methods have been developed to understand how icing affects performance, stability and control. Emphasis has been on wind tunnel testing of two-dimensional subscale airfoils with various ice shapes to understand their effect on the flow field and ultimately the aerodynamics. This research has led to wind tunnel testing of subscale complete aircraft models to identify the integrated effects of icing on the aircraft system in terms of performance, stability, and control. Data sets of this nature enable pilot in the loop simulations to be performed for pilot training, or engineering evaluation of system failure impacts or control system design.

  20. Exploring the Ligand-Protein Networks in Traditional Chinese Medicine: Current Databases, Methods, and Applications

    PubMed Central

    Zhao, Mingzhu; Wei, Dong-Qing

    2013-01-01

    The traditional Chinese medicine (TCM), which has thousands of years of clinical application among China and other Asian countries, is the pioneer of the “multicomponent-multitarget” and network pharmacology. Although there is no doubt of the efficacy, it is difficult to elucidate convincing underlying mechanism of TCM due to its complex composition and unclear pharmacology. The use of ligand-protein networks has been gaining significant value in the history of drug discovery while its application in TCM is still in its early stage. This paper firstly surveys TCM databases for virtual screening that have been greatly expanded in size and data diversity in recent years. On that basis, different screening methods and strategies for identifying active ingredients and targets of TCM are outlined based on the amount of network information available, both on sides of ligand bioactivity and the protein structures. Furthermore, applications of successful in silico target identification attempts are discussed in detail along with experiments in exploring the ligand-protein networks of TCM. Finally, it will be concluded that the prospective application of ligand-protein networks can be used not only to predict protein targets of a small molecule, but also to explore the mode of action of TCM. PMID:23818932